Electrophoresis - Seperation and purification of DNA fragments

Electrophoresis refers to carrying something by applying electricity. It is an analytical device commonly used for separation and purification of DNA fragments. A gel is used in electrophoresis which is either polyacrylamide or agarose. The former is preferred for smaller DNA fragments and the latter for larger ones. Agarose is a purified powder isolated from agar, a gelatinous material of sea weeds. Agarose powder when dissolved in water and boiled results into gel form. The gel prepared in a mixture of salt and water becomes a good conductor of electricity. The gel forms small pores the size of which varies depending on its amount in a given water. These pores act as molecular sieve. These allow the larger molecules to move slowly than the smaller molecules.

The electrophoresis box consists of a positive and a negative electrode, a shelf designed to held the gel, a comb used to form the wells within the gel, and a power supply. The DNA to be electrophoresed is digested with restriction enzymes which yields DNA fragments of unequal length. The fragments are mixed with sucrose and a dye (ethidium bromide or methylene blue) which altogether is known as loading dye. Sucrose increases the density of DNA preparation and dye increases the visibility of the preparation.

The preparation is loaded into wells at one end of the gel. At least one well is filled with reference DNA (i.e. DNA fragments of known length) for comparison with those of unknown length. Electric current is applied at opposite ends of electrophoresis chamber. A current is generated between a negative electrode at the top of loading end of the gel and a positive electrode at the bottom of the end of gel resulting in movement of fragments through pores of the gel. DNA molecules have a negative electric charges due to PO4(4-) which alternate with sugar molecules. Opposite electric charges tend to attract one another. The small DNA molecules move at faster speed as compared to larger ones. All DNA molecules of a given length migrate nearly the same distance into the gel and form bands. Each band represents many copies of DNA fragments having about the same length. After completion of electrophoresis gel is removed from the chamber and stained to make bands easily seen either with ethidium bromide (EB) or methylene blue. When gel is illuminated with UV light, fluorescent orange bands appear due to EB; methylene blue results in blue bands under normal room temperature.

Celera Genomics & HGP

In 1998, an identical, privately funded quest was launched by the American researcher Craig Venter and his firm Celera Genomics. The $300 million Celera effort was intended to proceed at a faster pace and at a fraction of the cost of the roughly $3 billion publicly-funded project.Celera Genomics was established in May 1998 by the Perkin-Elmer Corporation (and was later purchased by Applera Corporation), with Dr. J. Craig Venter from The Institute for Genomic Research (TIGR) as its first president. While at TIGR, Venter and Hamilton Smith led the first successful effort to sequence an entire organism's genome, that of the Haemophilus influenzae bacterium. Celera was formed for the purpose of generating and commercializing genomic information to accelerate the understanding of biological processes.

The rise and fall of Celera as an ambitious competitor of the Human Genome Project is the main subject of the book The Genome War by James Shreeve, who takes a strong pro-Venter point of view. (He followed Venter around for two years in the process of writing the book.) A view from the public effort's side is that of Nobel laureate Sir John Sulston in his book The Common Thread: A Story of Science, Politics, Ethics and the Human Genome.Celera used a newer, riskier technique called whole genome shotgun sequencing, which had been used to sequence bacterial genomes up to 6 million base pairs in length, but not for anything nearly as large as the 3 billion base pair human genome.Celera initially announced that it would seek patent protection on "only 200-300" genes, but later amended this to seeking "intellectual property protection" on "fully-characterized important structures" amounting to 100-300 targets. Contrary to its public promises, the firm eventually filed patent applications on 6,500 whole or partial genes.Although the working draft was announced in June 2000, it was not until February 2001 that Celera and the HGP scientists published details of their drafts. Special issues of Nature (which published the publicly-funded project's scientific paper) and Science (which published Celera's paper) described the methods used to produce the draft sequence and offered analysis of the sequence. These drafts covered about 90% of the genome, with much of the remaining 10% filled in later. In February 2001, at the time of the joint publications, press releases announced that the project had been completed by both groups. Improved drafts were announced in 2003 and again in 2005, filling in roughly 8% of the remaining sequence.

HGP is the most well known of many international genome projects aimed at sequencing the DNA of a specific organism. While the human DNA sequence offers the most tangible benefits, important developments in biology and medicine are predicted as a result of the sequencing of model organisms, including mice, fruit flies, zebrafish, yeast, nematodes, plants, and many microbial organisms and parasites.In 2005, researchers from the International Human Genome Sequencing Consortium (IHGSC) of the HGP announced a new estimate of 20,000 to 25,000 genes in the human genome. Previously 30,000 to 40,000 had been predicted, while estimates at the start of the project reached up to as high as 2,000,000. The number continues to fluctuate and it is now expected that it will take many years to agree on a precise value for the number of genes in the human genome.

Goals of the original Human Genome Project (HGP)

• identify all the approximately 20,000-25,000 genes in human DNA,
• determine the sequences of the 3 billion chemical base pairs that make up human DNA,
• store this information in databases,
• improve tools for data analysis,
• transfer related technologies to the private sector, and
• address the ethical, legal, and social issues (ELSI) that may arise from the project.
  

The goals of the original HGP were not only to determine all 3 billion base pairs in the human genome with a minimal error rate, but also to identify all the genes in this vast amount of data. This part of the project is still ongoing although a preliminary count indicates about 30,000 genes in the human genome, which is far fewer than predicted by most scientists.Another goal of the HGP was to develop faster, more efficient methods for DNA sequencing and sequence analysis and the transfer of these technologies to industry.The sequence of the human DNA is stored in databases available to anyone on the Internet. The U.S. National Center for Biotechnology Information (and sister organizations in Europe and Japan) house the gene sequence in a database known as Genbank, along with sequences of known and hypothetical genes and proteins. Other organizations such as the University of California, Santa Cruz, and ENSEMBL present additional data and annotation and powerful tools for visualizing and searching it. Computer programs have been developed to analyze the data, because the data themselves are difficult to interpret without them.The process of identifying the boundaries between genes and other features in raw DNA sequence is called genome annotation and is the domain of bioinformatics. While expert biologists make the best annotators, their work proceeds slowly, and computer programs are increasingly used to meet the high-throughput demands of genome sequencing projects. The best current technologies for annotation make use of statistical models that take advantage of parallels between DNA sequences and human language, using concepts from computer science such as formal grammars.Another, often overlooked, goal of the HGP is the study of its ethical, legal, and social implications. It is important to research these issues and find the most appropriate solutions before they become large dilemmas whose effect will manifest in the form of major political concerns.All humans have unique gene sequences, therefore the data published by the HGP does not represent the exact sequence of each and every individual's genome. It is the combined genome of a small number of anonymous donors. The HGP genome is a scaffold for future work in identifying differences among individuals. Most of the current effort in identifying differences among individuals involves single nucleotide polymorphisms and the HapMap.

How it was accomplished

The publicly funded groups NIH, the Sanger Institute in Great Britain, and numerous groups from around the world broke the genome into larger pieces; approximately 150,000 base pairs in length. These pieces are called "bacterial artificial chromosomes", or BACs, because they can be inserted into bacteria where they are copied by the bacterial replication machinery. Each of these pieces was then sequenced separately as a small "shotgun" project and then assembled. The larger, 150,000 base pair chunks were then stitched together to create chromosomes. This is known as the "hierarchical shotgun" approach, because the genome is first broken into relatively large chunks, which are then mapped to chromosomes before being selected for sequencing. The whole-genome shotgun (WGS) method is faster and cheaper, and by 2003 - thanks to the availability of clever assembly algorithms - it had become the standard approach to sequencing most mammalian genomes.

Whose genome was sequenced?

In the international public-sector Human Genome Project (HGP), researchers collected blood (female) or sperm (male) samples from a large number of donors. Only a few of many collected samples were processed as DNA resources. Thus the donor identities were protected so neither donors nor scientists could know whose DNA was sequenced. DNA clones from many different libraries were used in the overall project, with most of those libraries being created by Dr. Pieter J. de Jong. It has been informally reported, and is well known in the genomics community, that much of the DNA for the public HGP came from a single anonymous male donor from the state of New York.Technically, it is much easier to prepare DNA cleanly from sperm than from other cell types because of the much higher ratio of DNA to protein in sperm and the much smaller volume in which purifications can be done. Using sperm does provide all chromosomes for study, including equal numbers of sperm with the X (female) or Y (male) sex chromosomes. HGP scientists also used white cells from the blood of female donors so as to include female-originated samples. One minor technical issue is that sperm samples contain only half as much DNA from the X and Y chromosomes as from the other 22 chromosomes (the autosomes); this happens because each sperm cell contains only one X or one Y chromosome, but not both. Thus in 100 sperm cells, on average there will be 50 X and 50 Y chromosomes, as compared to 100 copies of each of the other chromosomes.Although the main sequencing phase of the HGP has been completed, studies of DNA variation continue in the International HapMap Project, whose goal is to identify patterns of SNP groups (called haplotypes, or “haps”).

The DNA samples for the HapMap came from a total of 270 individuals: Yoruba people in Ibadan, Nigeria; Japanese in Tokyo; Han Chinese in Beijing; and the French Centre d’Etude du Polymorphisme Humain (CEPH) resource, which consisted of residents of the United States having ancestry from Western and Northern Europe.In the Celera Genomics private-sector project, DNAs from five different individuals were used for sequencing. The lead scientist of Celera Genomics at that time, Craig Venter, later acknowledged (in a public letter to the journal Science) that his DNA was one of those in the pool.

The Human Genome Projects - Benefits

The work on interpretation of genome data is still in its initial stages. It is anticipated that detailed knowledge of the human genome will provide new avenues for advances in medicine and biotechnology. Clear practical results of the project emerged even before the work was finished. For example, a number of companies, such as Myriad Genetics started offering easy ways to administer genetic tests that can show predisposition to a variety of illnesses, including breast cancer, disorders of hemostasis, cystic fibrosis, liver diseases and many others. Also, the etiologies for cancers, Alzheimer's disease and other areas of clinical interest are considered likely to benefit from genome information and possibly may lead in the long term to significant advances in their management.

There are also many tangible benefits for biological scientists. For example, a researcher investigating a certain form of cancer may have narrowed down his search to a particular gene. By visiting the human genome database on the worldwide web, this researcher can examine what other scientists have written about this gene, including (potentially) the three-dimensional structure of its product, its function(s), its evolutionary relationships to other human genes, or to genes in mice or yeast or fruit flies, possible detrimental mutations, interactions with other genes, body tissues in which this gene is activated, diseases associated with this gene or other datatypes.Further, deeper understanding of the disease processes at the level of molecular biology may determine new therapeutic procedures. Given the established importance of DNA in molecular biology and its central role in determining the fundamental operation of cellular processes, it is likely that expanded knowledge in this area will facilitate medical advances in numerous areas of clinical interest that may not have been possible without them.The analysis of similarities between DNA sequences from different organisms is also opening new avenues in the study of the theory of evolution. In many cases, evolutionary questions can now be framed in terms of molecular biology; indeed, many major evolutionary milestones (the emergence of the ribosome and organelles, the development of embryos with body plans, the vertebrate immune system) can be related to the molecular level. Many questions about the similarities and differences between humans and our closest relatives (the primates, and indeed the other mammals) are expected to be illuminated by the data from this project.

The Human Genome Diversity Project, spin-off research aimed at mapping the DNA that varies between human ethnic groups, which was rumored to have been halted, actually did continue and to date has yielded new conclusions. In the future, HGDP could possibly expose new data in disease surveillance, human development and anthropology. HGDP could unlock secrets behind and create new strategies for managing the vulnerability of ethnic groups to certain diseases (see race in biomedicine). It could also show how human populations have adapted to these vulnerabilities.

What's Turning Genomics Vision Into Reality

In "A Vision for the Future of Genomics Research," published in the April 24, 2003 issue of the journal Nature, the National Human Genome Research Institute (NHGRI) details a myriad of research opportunities in the genome era. This backgrounder describes a few of the more visible, large-scale opportunities.

The International HapMap Project

Launched in October 2002 by NHGRI and its partners, the International HapMap Project has enlisted a worldwide consortium of scientists with the goal of producing the "next-generation" map of the human genome to speed the discovery of genes related to common illnesses such as asthma, cancer, diabetes and heart disease.Expected to take three years to complete, the "HapMap" will chart genetic variation within the human genome at an unprecedented level of precision. By comparing genetic differences among individuals and identifying those specifically associated with a condition, consortium members believe they can create a tool to help researchers detect the genetic contributions to many diseases. Whereas the Human Genome Project provided the foundation on which researchers are making dramatic genetic discoveries, the HapMap will begin building the framework to make the results of genomic research applicable to individuals.

ENCyclopedia Of DNA Elements (ENCODE)

This NHGRI-led project is designed to develop efficient ways of identifying and precisely locating all of the protein-coding genes, non-protein-coding genes and other sequence-based, functional elements contained in the human DNA sequence. Creating this monumental reference work will help scientists mine and fully utilize the human sequence, gain a deeper understanding of human biology, predict potential disease risk, and develop new strategies for the prevention and treatment of disease.The ENCODE project will begin as a pilot, in which participating research teams will work cooperatively to develop efficient, high-throughput methods for rigorously and fully analyzing a defined set of target regions comprising approximately 1 percent of the human genome. Analysis of this first 30 megabases (Mb) of human genome sequence will allow the project participants to test and compare a variety of existing and new technologies to find the functional elements in human DNA.

Chemical Genomics

NHGRI is exploring the acquisition and/or creation of publicly available libraries of organic chemical compounds, also referred to as small molecules, for use by basic scientists in their efforts to chart biological pathways. Such compounds have a number of attractive features for genome analysis, including their wide structural diversity, which mirrors the diversity of the genome; their ability in many cases to enter cells readily; and the fact that they can often serve as starting points for drug development. The use of these chemical compounds to probe gene function will complement more conventional nucleic acid approaches.This initiative offers enormous potential. However, it is a fundamentally new approach to genomics, and largely new to basic biomedical research as a whole. As a result, substantial investments in physical and human capital will be needed. NHGRI is currently planning for these needs, which will include large libraries of chemical compounds (500,000 - 1,000,000 total); capacity for robotic-enabled, high-throughput screening; and medicinal chemistry to convert compounds identified through such screening into useful biological tools.

Genomes to Life

The Department of Energy's "Genomes to Life" program focuses on single-cell organisms, or microbes. The fundamental goal is to understand the intricate details of the life processes of microbes so well that computational models can be developed to accurately describe and predict their responses to changes in their environment."Genomes to Life" aims to understand the activities of single-cell organisms on three levels: the proteins and multi-molecular machines that perform most of the cell's work; the gene regulatory networks that control these processes; and microbial associations or communities in which groups of different microbes carry out fundamental functions in nature. Once researchers understand how life functions at the microbial level, they hope to use the capabilities of these organisms to help meet many of our national challenges in energy and the environment.

Structural Genomics Consortium

Structural genomics is the systematic, high-throughput generation of the three-dimensional structure of proteins. The ultimate goal for studying the structural genomics of any organism is the complete structural description of all proteins encoded by the genome of that organism. Such three-dimensional structures will be crucial for rational drug design, for diagnosis and treatment of disease, and for advancing our understanding of basic biology. A broad collection of structures will provide valuable biological information beyond that which can be obtained from individual structures.

Dell TM Optiplex TM 360

Designed with growing business and organizations with less complex IT infrastructure in mind, the OptiPlex 360 delivers reliable, cost –effective business productivity with intelR CoreTM2 Duo processors, high-speed memory options, and integrated video support. Customizable to meet your business needs, High-speed memory options, and integrated video support. Customizable to meet your business needs, the OptiPlex 360 offers technology that provides basic manageability, security and energy efficiency. All backed by a choice of smart, desktop-focused services that provide your IT professionals that tools they need throughout the technology lifecycle, from acquisition to asset retirement. Essential business value of the PptiPlex 360 is just one of the today. Exceptional value for reliable business-class computing, featuring Intel Core 2 Duo, Pentium® dual Core, and Celeron ® processors planning support with up to a 12-month lifecycle, stable images, managed transitions, and Dell Image Watch TM to provide early notification of upcoming technology changes customizable global service and support through Dell ProSupport service options dell client manager allows easy system manageability. The right fit for basic user productivity with choice of two form factors. Time-saving tool-less design and dell exclusive Direct Detect TM troubleshooting LEDs help result in reduced maintenance and service costs. System and BIOS passwords to help prevent unauthorized access. Chassis loop lock provides physical system protection. Proactive Dell Support services help reduce risk and protect your sensitive data with hard drive data recovery and certified data destruction. Dell is committed to being the greenest PC company on the planet. And the OptiPlex 360 delivers smart energy choices so that you can:· Archive outstanding performance with less energy through Dell’s Energy Smart power management· Help reduce power consumption- and with Dell’s power supply, which is upto to 88% efficient (available after 11/77/2008 on selected models)· Recycle your current desktops free of charge with the purchase of new Dell OptiPlex.

Gigabyte GA-G31MX-S2/S3L Motherboards

GA-G3IMX-S2 supports Intel latest high performance CPU delivers the most energy-efficient performances available today. Based on Intel’s Micro Architecture, the land multi-core processor with 4 cores and two shared L2 caches provide the best capability-per-watt solutions and are an ideal choice for muti-media enthusiasts and intensive multi-tasking environments. This cutting-edge processor offers significant performance boosts and provides an overall more energy efficient platform.Intel Core2 multi-core and upcoming 45nm processors GA-G31-S3L SUPPORTS INTEL LATEST HIGH PERFORMANCE CPU delivers that most energy efficient performances available today. Based on Intel’s Micro Architecture, the Intel multi-core-watt solutions and are in ideal choice for multi-media enthusiasts and intensive multi-tasking environments. This cutting-edge processors offers significant performance boosts and provides an overall more energy efficient platform.Solid Capacitor for CPU VRMStable system operation depends upon the quality of CUP VRM (voltage regular module). GIGA BYTE adopts conductive polymer aluminum solid capacitors for CUP VRM to ensure a longer lifespan for systems in daily operation and boosts system stability under extreme conditions. CPU VRM with solid capacitors featuring better electronic conductivity, excellent heat resistance enhances system durability even operating in high temperature environment. PCI Express interface Revolutionary PCI express interface provides scalable bandwidth for multi-purpose usage. PCI-Ex16 interface delivers the utmost graphics experience; PCI-E x1interface delivers twice the bandwidth of PCI interface up to 250MB/s for new generation I/O peripheral devices.Dual Channel DDR2 1066 nu 0.CC get a jump in memory performance with the advanced technology of DDR2 1066 memory performances with the advanced technology of DDR2 1066 memory architecture by overclocking, which delivers superior performance for the most demanding applications.Intel GMA 3100Intel graphics Media Accelerator 3100 support Microsoft DirectX 9.0 AND Window vista Aero experience. The 3D enhancement of GMA 3100 highly improves the realism and graphics performance. SATA 3Gb/s storage interface the SATA specification doubles bus bandwidth from 1.5Gb/s to 3Gb/ s. Native command Queuing is a new specification that enables our of –order execution of commands for efficient retrieval of data for efficient retrieval of data. Hot Plug support allows users to insert and remove hard disk drives without shutting off power to the system. Gigabit LAN connectivity The Gigabit network interface delivers a high speed LAN connection with data transfers rate up to 1000Mb/s, providing new generation connectivity for the broadband era. Gigabit LAN is ideally for seamless internet connection such as streaming audio and video contents Speed the speed complaint motherboards of GIGABYTE proprietary innovative software such as download center, @BIOS, Q-flash, Xpress install, boor menu, and smart fun. BIOS and driver management now becomes much easier and user friendly through GAGABYTE S-series motherboards with the following elements. Excellent hardware design reinforced BIOS protection through GIGABYTE Virtual dual BIOS technology and gigabyte BIOS setting recovery technology. Unique system software such as Xpress Recovery 2, PC health monitor, HDD S.M.A.R.T. and C.O.M further strengthen the stability and reliability of your PC! RoHS complaint as a member of the global community to llok after the environment, Gigabyte complies with the European Union’s Restriction of use of certain Hazardous substances (RoHS complaint As a member of the global complies with the European Union’s Restriction of use of certain hazardous substances (RoHS) directive which limits the use of lead, mercury, cadmium and other hazardous substances in electronic products. From components and material selection to production processors, make up of accessories, packaging/color boxes etc; GIGABYTE will continue to develop RoHS compliant PC components and commit valuable resources to promoting and advancing RoHS directive goals and objectives.

Intel To Launch mobile Quad-Core Processors

Keeping in mind the advent of desktop based quad-core processors in the mainstream, it was just a matter of time before they showed up in a mobile version too. This was confirmed by Digitimes, which goes onto say that Intel will be-planning to launch its first quad-core-CPU for notebooks, the Core2 Extreme QX9300, in the third quarter this year. This new processor will be manufactured at 45nm and have a core frequency of 2.53GHz. The CPU will support FSB speeds up to 1066MHz, INCULDE 12MB L2 cash and have a maximum TDP of 45 W.While this announcement is good in terms of consumer choice, it raises a number of intresting questions. Despite the low heat dissipation of these processors, they will be a lot more power hungry as compared to standard dual-core-processor and this will directly affect battery life. Secondly with such powerful chips, the GPU laptops, which is abysmal to say the least at its very best.

Nvidia Launches Tegra Family of Processor

Nvidia has introduced the Tegra family of processors, a tiny computer-on-a- chip, smaller than a US dime (10-cent piece), designed from the ground up to enable the “visual PC experience” on a new generation of mobile computing devices.“creating Tegra was a massive challenge. Our vision was to create a platform that will enable the second personal computer revolution which will be mobile centric, with devices that last days on a single charge, and yet has theweb, high definition media, and computing experience we’ve come to expect from our PC.” Said Jen-Hsun Haung, president and CEO at Nvidia. “ Shrinking down a 50 watt Pc architecture will not create the discontinuity this industry needs. The culminatin of nearly 1,000 man years of engineering, Tegra is a completely ground-up computer-on-a-chip architecture that consumes 100 times less power. Mobile internet and computing devices built with Tegra are going to be magical. “The Tegra 650 processor is thesecond product in the Tegraline, the first being the Nvidia Tegra APX 2500 processors, enabling thenext generation of windows mobile smartphones. With thelunch of thisnew processor, the Nvidia Tegra products will reach consumers towards the end of the year. “with the growing market demand for mobile internt access, Nvidia launched the APX 2500 computer-0n-a-chip targeted at smartphones and handset earlier this year. Recognizing that mobile internet access usages will occur not just on smartphones and handsets but on computer devices as well, Nvidia announced today the Tegra architecture. Representing the first products to be targeted at the MID and portable device space, it is anticipated to bring integrated capabilities similar to the APX 2500 with Navidia’s graphic expertise, an ARM core, HD video, and advanced power management.” Said Ian Lao. Senior analyst at In-stat.Nvidia Tegra is heterogeneous processor architecture with multiple processors, each architected for a specific class of tasks- an 800 MHz ARM CPU, a HD video processor, an imaging processor, each architected for a specific class of task- an 800 MHz ARM CUP, HD video processor, and an ultra-low power of GeForce GPU. With this heterogeneous ultra-low-power efficienty of exiting products in battery-opearated computer systems running compelling visual computing applications. Tegra 650 also features all-day media processing for 130 hours audio, 30 hours HD video playback; HD image processing for advanced digital still camera and HD camcorder functions; optimized hardware supporter for web 2.0 applications for a true desktop-class internet experience; display support for 108Phdmi, WSXGA+LCD and CRT, and NTSC/PAL TV-out, direct support of WIFI, disk drives, keyboard, mouse, and other peripherals and complete board support package (BSP) to enable fast time to market for windows mobile-based designs. “With Nvidia’s Tegra processor line, we will contine to see impressive mobile innovations in windows mobile products.” Said Todd warren, corporate vice president of Microsoft’s mobile communication business. “Microsoft is dedicated to providing people best -in-class people can carry a single device for work and play.”

AMD Ships Tri-Core Processors

AMD has announced the availability of its triple-core processor, a first for the PC market. The company also updated the qud-core phenom lineup by resolving the famous “errta bug” that plagued it earlier this year and has confirmed that the quad-core opteron chips for servers will be available later in the second quarter. The AMD Phenom X3 processors delivers significant enhancements in gaming and high-definition experiences for mainstream PC customers. It provides a full HD experience with support for the latest and most demanding formats, including VC-1, MPEG-2, and H.264 on a mainstream PC. With the AMD Unified Video Decoder ( UVD), The solution can process HD playback on the better-suited GPU rather than the CPU so consumers may enjoy a smooth HD viewing experience- less lag, stailing and dropped scenes – in the latest Blu-ray titles.“In 2007, AMD committed to delivering AMD Phenom triple core processor in Q1 2008 and today the company makes good on that promise,” said Bob brewer, corporate vice president, strategic marketing. AMD, “AMD understands the today’s PC applications are best accelerated with a rang of muti-core to dual core processors, and that’s why we now deliver the broadest muti-core desktop linup in the industry.

CREATIVE X-Figo

Over the last few years the market for soundcards has all but flatlined. This once-vibrant segment was dominated by creative for so long that other solutions gradually disappeared. However, creative itself was ultimately undone. Motherboards started sporting onboard solutions that offered virtually all the functionally normal PC users needed, making external sound cards redundant.Despite this, creative continued to thrive with its X-Fi series brand, offering great functionally and a good set of feature that could be scarcely found on onboard solutions. With the recent advent of netbooks and mobility computing becoming common, creative released its X-Fig go USB solution that offers a lot of the features found in its PCI- based solutions. How does it fare? Let’s find out. In terms of design, the X-Fi does not look like anything more than a normal flash drive. The unit comes in a basic black design and offers 1GB of flash memory. This makes the unit useful as the drivers for the sound functionality come stored on the unit itself. In terms of its bundle, the X-Fi does not offer much beyond a USB extender and a well designed pair of headphone/mic. Software-wise the X-FI is pretty strong. The unit supporters creative’s X-Fi headphone surround, EAX 4.0, the much maligned crative alchemy software package that promises to restore surround sound for older games under windows vista, and creative’s wave studio software that allows causal users to tinker with audio features sucha as cleaning up hissy tracks, add special FX to music, tec.Transcend Introduces a XeRam DD3-1066Transcend information has released its retiail-packaged DDR3-1066 and DDR3-1333 240-pin DIMMs. DDR3 is the successor to DDR2 memory, and will soon become the industry standard for Pc memory modules. Compared to DDR2, it offers faster transfer speeds and better bandwidth with an 8 bit as opposed to 4-bit prefect buffer, and is a perfect match for modern systems using dual or quad-core process. Moreover, the operating voltage of DDR3 memory modules has been decreased from 1.8V to 1.5v, thus reducing actual memory power consumption by 20-30% compared to systems with DDR2 memory. Transcends DDR3-1066 and DDR3-1333DIMMs are currently available in 1GB and 2GB capacities respectively.Austain Huang, Regional Head – sales, SAARC and APAC, Trancend, said “we are extremely delighted to introduce our DD3 memory resulting in enhanced performance for Desktop PC users.Transcend’S aXeRam memory.Will deliver amazing overocking performances while maintaining rock-solid systems stability.Transcend’s DDR3-1066 and DDR3-1333 DIMMs are made of high quality 128Mx8 DDR3 DRAM chips and use robust PCBs that meet JEDEC (the joint electron device Engineering Council) standards. Each chip is selected with strictest quality and performance standards and is manufactured using small Fine-Pitch Ball Gried Array (FBGA) packages with extra contacts to assure better thermal dissipation, electrical efficiency and reliable computing quality at high clock frequencies. In addition, DDR3 memory modules incorporate all new “fly-by” architecture that provides more efficient direct communication between the controller and each DRAM chip, includes dynamic on-DIMM Termination to minimize signal reflections at higher speeds.

Windows Mobile?

While Windows Mobile 6.0 is still only a teenager in terms of its not too recent lunch, it would be rather obvious to guess that Win Mob 7.0 is being worked on even according to rumors someone out there, with the fantastic contacts that they have in Microsoft, was actually able to get their hands on rather detailed information on what we can expect from the next version of Windows Mobile. The information is so detailed with diagrams and screenshots that it boggles the mind considering that the expected release for the OX would be somewhere in 2009. But he guy who got a hold of this information has revealed that the next-gen windows mobile device is probably going to rock the iPhone’s world. This future Windows Mobile OS is apparently going to use similar motion gestures for navigating menus and other options quite like the iPhone. The word is that the devices incorporating this OS will even use the camera to detect gestures to make navigation easier and it would also be able to judge what position the phone would be in as well as where. For example if it were idle on the table or in your pocket or even handbag. It will incorporate gyroscopes and accelerometers for various purposes making the device easy to manipulate. They even state that the media playback and player will take on a new look and feel. It would sound somewhere in the league of the iPhone or some of the more recent Symbian mobiles. The new OS would also probably do completely away with a stylus and make the device. Fully funcationalble with just the fingers as far as to have just a singular button as well. Drawing, scrolling and even writing could also be totally finger controlledSCAN DISK LAUNCHES NEW DAP FOR SLOTMUSI CARDSScandisk has just unveiled a new DAP – the sansa slotmusic player. The plug and play, portable music player was specially designed for use with their slot music cards that were launched in the US. N addition to the Sansa-branded player, scandisk heas created personalized, branded slot muci players for popular artists such as Robin Thicks and ABBA. It weighs in at a little over two ounces and has dimensions of 2.75 W X 1.4375 H x 1.4375 D inches. “ With no need for computers or cords, the Sansa slot Music player gives consumers more time to play, and less time to worry abut managing or downloading their music.” Said Daniel Screeiber, senior vice president and general manager for SanDisk. “SanDisk is all abut building products that are easy for consumers to enjoy. Just insert your favorite artist’s slot music card into the Sana slot Music Player and press play.”The player doesn’t require a PC or the internet for managing music. Consumers can choose their slot Music-filled microSD cards and can pop into the device. In addition to slotMusic cards, this convenient MP3 AND MWA DRM-free only files. SanDisk has also developed a special line of Sansa slotMusic player accessories, including a Sansa card wallet, an armband, and additional slotMusic player “shells” for customizing a player to one’s own tastes. The Sansa-Branded player ship with a customizable blak shell, earphones and battery. The new Sansa slot music player, both sansabranded without cards and artistbranded including cards with additional content that may include liner notes, album art and other one of a kind content personally chosen by the artist, is expected to be available from retailers in Europe and other regions of the world in 2009 for an MSRP of about dollar 19.99 and 34.99dollar respectively.

Internet Overtakes Newspapers As a News Source In 2008

The internet has surpassed all other media, except television, as a main source for national and international news.

According to Pew Research, 40% say they get most of their news about national and international issues from the internet, up from just 24% in September 2007. Television continues to be cited most frequently as a main source for national and international news, at 70%.

The future looks dim for television and newspapers.

For young people, though, the internet now rivals television as a main source of national and international news. Nearly six-in-ten Americans younger than 30 (59%) say they get most of their national and international news online; an identical percentage cites television.

The percentage of people younger than 30 citing television as a main news source has declined from 68% in September 2007 to 59% currently. This mirrors a trend seen earlier this year in campaign news consumption. (See “Internet Now Major Source of Campaign News,” News Interest Index, Oct. 31, 2008.)

The survey by the Pew Research Center for the People & the Press, conducted Dec. 3-7 among 1,489 adults, finds there has been little change in the individual TV news outlets that people rely on for national and international news. Nearly a quarter of the public (23%) says they get most of their news from CNN, while 17% cite Fox News; smaller shares mention other cable and broadcast outlets.

In an interview with a British newspaper The Daily Telegraph, Andy Burnham, the UK Culture Secretary, said that the Internet could be given cinema-style age ratings as part of an international crackdown on offensive and harmful online activity.

Calling the Internet "quite a dangerous place," the Cabinet minister also said, "... I think we are having to revisit that stuff seriously now. It's true across the board in terms of content, harmful content, and copyright. Libel is [also] an emerging issue.... There is content that should just not be available to be viewed. That is my view. Absolutely categorical. This is not a campaign against free speech, far from it; it is simply there is a wider public interest at stake when it involves harm to other people. We have got to get better at defining where the public interest lies and being clear about it."

International cooperation is viewed as essential by the UK Culture Secretary, and the new Obama administration offers new opportunities. "The change of administration is a big moment. We have got a real opportunity to make common cause," he says. "The more we seek international solutions to this stuff - the UK and the US working together - the more that an international norm will set an industry norm."

My view is that, despite the very negative reaction by those commenting on the article, several of the proposals mentioned by the Culture Secretary will be coming soon - probably in 2009. This interview offers a glimpse into what the current thinking is regarding Internet decency. As with other aspects of the Internet, the international challenges are immense, but UK experts are obviously working closely with their US counterparts on specific next steps.

Web ratings would be a significant, and very controversial, development for the public sector and for society as a whole. All online content would need to be classified (similar to movies but in real-time at sites like YouTube). Opponents argue that any rating systems will be biased and flawed.

No doubt, the new technology and processes required by the masses would be overwhelming. There are great arguments against government intervention. Current laws around Internet piracy can't even be enforced. What new enforcement police will be put in place? What happens to rating violators? Who decides what's what? What about sites that cross into mutiple categories (like newspapers). Is this approach "big brother" from government? How can we monitor real-time blogs, health sites, or other content that falls into various shades of gray?

I agree that the obstacles are huge, and yet I (reluctantly) support aspects of Andy Burnham's position. The negative attacks are unfair and don't offer workable solutions. We can't keep doing the same things and expect different results online. We must provide mechanisms for families to surf their values and not let a minority of "bad guys" control the Internet. While it would be best if the technology tools existed now to maintain one's integrity online without government involvement, our problems are getting worse - not better. A few weeks back, I wrote about ISAlliance's newly proposed cyber security social contract, which would also help if implemented.

What we need is easy-to-use technology to help move pragmatic proposals forward. No doubt, the big Internet players like Microsoft and Google are also involved in planning efforts. Perhaps proposals should start off with voluntary standards and extensive new training by ISPs? However, I agree with opponents that technology and legislation alone will not solve our Internet decency problems. We need to win the hearts and minds of the majority online. And yet, we also need to police the bad actors online. Setting appropriate standards (like speed limits on highways) is an important step.

How Xbox Works

The game consoles that are available today are never enough for video gamers; their attention is always focused on what the next great thing will be. In 2000, it was the PlayStation 2. The game console wars heated up as Nintendo unveiled its latest console, called GameCube. But the big news was that the computer software giant Microsoft entered the multi-billion dollar game console market with the Xbox. The console is a black box with a large "X" imprinted into the top. Microsoft Chairman Bill Gates has said that the Xbox has more power than any console currently on the market. Sony is currently the undisputed leader of the game console industry, but it has to be looking over its shoulder at Microsoft. With $500 million in its marketing arsenal, the software giant is pitting its Xbox against the PS2 in a head-to-head battle for supremacy in the $20 billion game console industry. Microsoft says that its marketing for the Xbox has been the largest effort ever for one of its products. In fact, the Xbox's marketing budget is the largest for any game console in history, easily surpassing Sega's $100 million campaign in 1998. But will money alone be enough to push Xbox ahead of the PlayStation 2? On paper, the Xbox has more brute power and speed than any game console on the market.Now, we'll take a look at this machine and see how it compares to the competition.

Inside the X

In March 2000, rumors that Microsoft was developing a game console were confirmed when Gates took the wraps off the Xbox demo unit. In January 2001, the demo model, a big chrome "X" with a green-glowing light in the middle, was replaced by a more traditional black box. As analysts predicted, the only part of the demo model to make it into the final design is the glowing green light on top of the box. The sidewinder controller pad used with the demo unit was also altered for the final Xbox design. A lot has been made of the Xbox's design, but it takes more than a cool look to sell gamers on a product. Just like a book, it's what's inside the cover that really matters. One advantage that Microsoft has enjoyed is that it has been able to sit back and watch what other game console manufacturers have done. In doing so, Microsoft's designers have examined what has worked and what has failed in recent game consoles. On the inside, the Xbox is fairly similar to a PC. But Microsoft maintains that it is not a PC for your living room. There's no mouse or keyboard to go with it. The Xbox does boast:

• A modified 733-megahertz (MHz) Intel Pentium III processor with a maximum bus transfer rate of 6.4 gigabytes per second (GBps) The Xbox possesses the fastest processing speeds for a game console to date. For comparison, the PlayStation 2 has a 300-MHz processor and a maximum bus transfer rate of 3.2 GBps. The Nintendo GameCube has a 485-MHz processor and a 2.6-GB maximum bus transfer rate. See this page for a comparison of the Xbox, GameCube and PS2.

• A custom 250-MHz 3-D graphics processor from Nvidia that can process more than 1 trillion operations per second and produce up to 125 million polygons per second Polygons are the building blocks of 3-D graphic images. Increasing the number polygons results in sharper, more detailed images. The graphics processor also supports high resolutions of up to 1920x1080 pixels. For comparison, the PlayStation 2 has a 150-MHz graphics processor and produces 70 million polygons per second. The GameCube has a 162-MHz graphics processor and produces 12 million polygons per second. It should be pointed out that the PlayStation 2 and Xbox figures are theoretical top speeds -- it's unlikely that your system will reach that limit. Nintendo's figure is considered a more realistic number for its console.

• A custom 3-D audio processor that supports 256 audio channels and Dolby AC3 encoding

• An 8-GB built-in hard drive (Having a built-in hard drive allows games to start up faster.)

• 64 MB of unified memory, which game developers can allocate to the central processing unit and graphics processing unit as needed (This arguably makes the Xbox more flexible for game designers.)

• A media communications processor (MCP), also from Nvidia, that enables broadband connectivity, and a 10/100-Mbps (megabits per second) built-in Ethernet that allows you to use your cable modem or DSL to play games online A 56K modem will be an optional addition later. Microsoft has also teamed with NTT DoCoMo, the Japanese telecommunications giant, to create net access for Japanese gamers.

• Other Xbox features include: 5X DVD drive with movie playback (functional with addition of movie playback kit) 8-MB removable memory card Four custom game controller ports (one controller sold with the unit) HDTV support Expansion port

The Games

Game superiority ultimately decides who wins the battle in the video game console industry. You could design a machine with 10 times more power and speed than the Xbox, but, if the games stink, you can forget about selling it. Having better games is what vaulted Sony over Nintendo in the late 1990s. Like the PS2, the Xbox uses proprietary 4.7-GB DVD games. Microsoft has signed deals with more than 150 video game makers who have committed themselves to developing games for Microsoft's Xbox game console. These game developers include id Software, maker of the popular Quake series, and Eidos Interactive, which makes the Tomb Raider games featuring Lara Croft. Other Xbox game manufacturers include Bandai, Capcom, Hudson, Soft, Konami, Midway Home Entertainment, Namco, Sierra Studios, THQ and Ubi Soft. Microsoft, itself a PC game publisher, is producing about 30 percent of Xbox's games. One of the most impressive qualities of the Xbox is its realistic environments. For example, characters cast shadows on each other, making for some pretty realistic scenes. The momentum of the PS2 might be too much for the Xbox to overcome -- but then again, in 1995, no one thought that Sony would surpass Nintendo in popularity.

How 3DO Creates Video Games

Video games are enormously popular all over the world. In fact, the video game industry is a multibillion dollar a year machine -- A successful video game, just like a popular music CD, can sell hundreds of thousands or even millions of copies! You have probably wondered what goes into making a good video game. You may even want to get into the business yourself. Here are some of the questions that you may be wondering about:

• Where do game ideas come from?

• How many people are involved in making a game and what do they do?

• How is a game developed?

• How does a game get to my local store? To understand the entire process of video game development, we went to the folks at 3DO. 3DO is a major publisher of video games, with several popular titles for the Nintendo 64 and other game consoles, as well as PC and Mac computer systems. Now,h we will follow the development of Portal Runner TM, a new game from 3DO. You will learn about the game's technology, how the idea was developed and how the game will be distributed. Where the Game Comes From All games start with an idea. But where that idea originates can be traced to one of several sources:

• An original concept presented by an employee

• An original concept pitched to the company by an outsider

• A sequel to an existing game

• A spinoff based on a character from an existing game

• A game based on an existing character or story (such as movie, TV or comic characters)

• A simulation of another game medium (such as board games and card games)

• A game targeted to a specific demographic

• A simulation of a real world event

• A game designed to take advantage of a specific game platform (such as the Internet or an advanced interactive game system). Once the idea is accepted by the company as a viable game, then a preproduction team is assembled to begin developing the idea into a fully realized game. How the game develops depends greatly on what type of game it is. The story line and design of a game based on an existing movie or comic character are going to be much more restricted than those for a completely original game concept. Likewise, a simulation based on a real world event, such as a baseball game, has definite boundaries in what can be done. Video games can be extremely different from one another. And while there is a huge variety of games available, most fall into certain broad categories:

• 3D Action/Adventure (Portal Runner, Army Men, Tomb Raider)

• Simulation (Army Men: Air Combat, Aero Fighters' Assault, Maestro Music)

• Sports (Sammy Sosa High Heat Baseball, Tony Hawk Pro Skater)

• Strategy/Role-playing/Adventure (Heroes of Might and Magic, Zelda, Final Fantasy)

• Fighting (Mortal Kombat, SoulFighter)

• Puzzle (Tetris, Pokemon Puzzle League)

• Shooter (Defender, Silpheed)

• Platform (Sonic, Super Mario Brothers)

• Racing (Mario Kart, Tokyo Xtreme Racer)

• Conversion (American Arcade Pinball, Who Wants to Be a Millionaire?) Of course, a lot of games include aspects from more than one of these categories, and a few games are in a category all their own. In the case of Portal Runner, 3DO took a character from one of its most popular franchises and gave her a spinoff title of her own that falls into the 3D Action/Adventure category. The character, Vikki Grimm, has figured prominently in the Army Men TM universe. Portal Runner is not considered a sequel because 3DO is taking one character and building an entirely new game universe around her. As you learn about the development of Portal Runner, remember that many of the steps in the process could change significantly for a different title based on the nature of the game being developed. Planning the GameThe preproduction team normally includes one each of the following people:

• Director

• Designer

• Software Engineer/Programmer

• Artist

• Writer Sometimes a team will not have every one of these people and other times it will have more than one person in a particular category. Another person assigned to the game from the outset is the producer. While the director provides the overall vision and direction for the game and is in charge of managing all the team members, the producer is in charge of the business side. For example, the producer maintains the production and advertising budgets and makes sure that the game stays within budget. The first thing that the preproduction team does is develop the story line for the game. Think of this like writing the outline for a novel. The story line identifies the theme of the game, the main characters and the overall plot. Also, areas in the game where a full motion video (FMV) sequence would help the story along are established. An important part of developing the story line is knowing the nature of the game. This means that the game designer is typically involved from the very beginning; he/she is responsible for things like:

• identifying traits and features of the game

• the type of gameplay and user interaction that is developed

• how the game will use the technology available on a particular platform (video game system or computer). Portal Runner is a linear game. This means that you follow a predetermined path and accomplish specific goals to complete the game. The pattern of the game is: FMV1, Play1, FMV2, Play2, FMV3, Play3 and so on until the end. Each play portion has a different look, theme and goal, all of which combine to form the game world. Linear play makes the story line much easier to create than it would be for a game that branches or has multiple endings. Branching games can contain a series of paths that all lead to the same ending. Even more difficult are branching games that can result in one of several different endings, depending on the path taken. Of course, the type of game largely determines what the story line and style can be. A puzzle or sports game would not require as detailed a story line as a 3D action or role-playing game. Once the story line is developed, the team creates a set of storyboards. A storyboard is a collection of still drawings, words and technical instructions that describe each scene of the game. These include storyboards for the FMV sequences that introduce the story and continue it between the periods of actual gameplay. Here are several examples: In addition to storyboarding the game, the designers will map out the different worlds, or levels of play, within the game during the preproduction phase. The attributes of each world and the elements contained within it are pulled directly from the story line.

Developing the Game

Once the storyboards and overall game level designs are complete, the game enters the production phase. The preproduction team expands as needed to include additional artists, programmers and designers. 3DO's artists begin developing the 3D models that will make up the worlds of Portal Runner using a software application called 3D Studio Max. Richly detailed texture maps are created for each object. While the game developers at 3DO create the actual game environment using these models and textures, another division of the company, PlayWorks, will use the same models to develop the animated FMV sequences for the game. Meanwhile, the programmers are writing custom code in C programming language that will provide the framework for the game objects. A lot of code is pulled from the company's library, which is a bank of already-developed code that can be repurposed for different games. Some of the code is the 3D engine, an application that generates all the polygons, shadows and textures that you see. Another piece of code is the artificial intelligence component. This is the logic of the game. It establishes the physics of the game, detects interaction and collisions of objects and controls movement of the characters. Development of the game code is done using a special development version of the particular game system that has increased memory, a SVGA monitor connection, a network connection and a hard drive. All the bits and pieces -- objects, textures and code -- are fed into a special utility called a tool chain that combines the pieces into one big piece of code. The tool chain makes code that is executable on a specific platform, which basically means that the game code will actually run on the game system that it was designed for. To test the game, Portal Runner director John Salera uses another specialized game console built for debugging games.

Prey of the Carnivore

The FBI plans to use Carnivore for specific reasons. Particularly, the agency will request a court order to use Carnivore when a person is suspected of:
• Terrorism
• Child pornography/exploitation
• Espionage
• Information warfare
• Fraud There are some key issues that are causing a great deal of concern from various sources: • Privacy - Many folks think that Carnivore is a severe violation of privacy. While the potential for abuse is certainly there, the Electronic Communications Privacy Act (ECPA) provides legal protection of privacy for all types of electronic communication. Any type of electronics surveillance requires a court order and must show probable cause that the suspect is engaged in criminal activities. Therefore, use of Carnivore in any way that does not adhere to ECPA is illegal and can be considered unconstitutional.
• Regulation - There is a widespread belief that Carnivore is a huge system that can allow the U.S. government to seize control of the Internet and regulate its use. To do this would require an amazing infrastructure -- the FBI would need to place Carnivore systems at every ISP, including private, commercial and educational. While it is theoretically possible to do so for all of the ISPs operating in the United States, there is still no way to regulate those operating outside of U.S. jurisdiction. Any such move would also face serious opposition from every direction.
• Free speech - Some people think that Carnivore monitors all of the content flowing through an ISP, looking for certain keywords such as "bomb" or "assassination." Any packet sniffer can be set to look for certain patterns of characters or data. Without probable cause, though, the FBI has no justification to monitor your online activity and would be in severe violation of ECPA and your constitutional right to free speech if it did so.
• Echelon - This is a secret network rumored to be under development by the National Security Agency (NSA), supposedly designed to detect and capture packets crossing international borders that contain certain keywords, such as "bomb" or "assassination." There is no solid evidence to support the existence of Echelon. Many people have confused this rumored system with the very real Carnivore system. All of these concerns have made implementation of Carnivore an uphill battle for the FBI. The FBI has refused to disclose the source code and certain other pieces of technical information about Carnivore, which has only added to people's concerns. But, as long as it is used within the constraints and guidelines of ECPA, Carnivore has the potential to be a useful weapon in the war on crime.

The Process

Now that you know a bit about what Carnivore is, let's take a look at how it works:
1. The FBI has a reasonable suspicion that someone is engaged in criminal activities and requests a court order to view the suspect's online activity.
2. A court grants the request for a full content-wiretap of e-mail traffic only and issues an order. A term used in telephone surveillance, "content-wiretap" means that everything in the packet can be captured and used. The other type of wiretap is a trap-and-trace, which means that the FBI can only capture the destination information, such as the e-mail account of a message being sent out or the Web-site address that the suspect is visiting. A reverse form of trap-and-trace, called pen-register, tracks where e-mail to the suspect is coming from or where visits to a suspect's Web site originate.
3. The FBI contacts the suspect's ISP and requests a copy of the back-up files of the suspect's activity.
4. The ISP does not maintain customer-activity data as part of its back-up.
5. The FBI sets up a Carnivore computer at the ISP to monitor the suspect's activity. The computer consists of: A Pentium III Windows NT/2000 system with 128 megabytes (MB) of RAM A commercial communications software application A custom C++ application that works in conjunction with the commercial program above to provide the packet sniffing and filtering A type of physical lockout system that requires a special passcode to access the computer (This keeps anyone but the FBI from physically accessing the Carnivore system.) A network isolation device that makes the Carnivore system invisible to anything else on the network (This prevents anyone from hacking into the system from another computer.) A 2-gigabyte (GB) Iomega Jaz drive for storing the captured data (The Jaz drive uses 2-GB removable cartridges that can be swapped out as easily as a floppy disk.) 6. The FBI configures the Carnivore software with the IP address of the suspect so that Carnivore will only capture packets from this particular location. It ignores all other packets.
7. Carnivore copies all of the packets from the suspect's system without impeding the flow of the network traffic.
8. Once the copies are made, they go through a filter that only keeps the e-mail packets. The program determines what the packets contain based on the protocol of the packet. For example, all e-mail packets use the Simple Mail Transfer Protocol (SMTP).
9. The e-mail packets are saved to the Jaz cartridge. 10. Once every day or two, an FBI agent visits the ISP and swaps out the Jaz cartridge. The agent takes the retrieved cartridge and puts it in a container that is dated and sealed. If the seal is broken, the person breaking it must sign, date and reseal it -- otherwise, the cartridge can be considered "compromised."
11. The surveillance cannot continue for more than a month without an extension from the court. Once complete, the FBI removes the system from the ISP.
12. The captured data is processed using Packeteer and Coolminer.
13. If the results provide enough evidence, the FBI can use them as part of a case against the suspect. The example above shows how the system identifies which packets to store. Prey of the Carnivore The FBI plans to use Carnivore for specific reasons. Particularly, the agency will request a court order to use Carnivore when a person is suspected of:
• Terrorism
• Child pornography/exploitation
• Espionage
• Information warfare
• Fraud There are some key issues that are causing a great deal of concern from various sources:
• Privacy - Many folks think that Carnivore is a severe violation of privacy. While the potential for abuse is certainly there, the Electronic Communications Privacy Act (ECPA) provides legal protection of privacy for all types of electronic communication. Any type of electronics surveillance requires a court order and must show probable cause that the suspect is engaged in criminal activities. Therefore, use of Carnivore in any way that does not adhere to ECPA is illegal and can be considered unconstitutional.
• Regulation - There is a widespread belief that Carnivore is a huge system that can allow the U.S. government to seize control of the Internet and regulate its use. To do this would require an amazing infrastructure -- the FBI would need to place Carnivore systems at every ISP, including private, commercial and educational. While it is theoretically possible to do so for all of the ISPs operating in the United States, there is still no way to regulate those operating outside of U.S. jurisdiction. Any such move would also face serious opposition from every direction.
• Free speech - Some people think that Carnivore monitors all of the content flowing through an ISP, looking for certain keywords such as "bomb" or "assassination." Any packet sniffer can be set to look for certain patterns of characters or data. Without probable cause, though, the FBI has no justification to monitor your online activity and would be in severe violation of ECPA and your constitutional right to free speech if it did so.
• Echelon - This is a secret network rumored to be under development by the National Security Agency (NSA), supposedly designed to detect and capture packets crossing international borders that contain certain keywords, such as "bomb" or "assassination." There is no solid evidence to support the existence of Echelon. Many people have confused this rumored system with the very real Carnivore system. All of these concerns have made implementation of Carnivore an uphill battle for the FBI. The FBI has refused to disclose the source code and certain other pieces of technical information about Carnivore, which has only added to people's concerns. But, as long as it is used within the constraints and guidelines of ECPA, Carnivore has the potential to be a useful weapon in the war on crime.

Carnivorous Evolution

Carnivore is apparently the third generation of online-detection software used by the FBI. While information about the first version has never been disclosed, many believe that it was actually a readily available commercial program called Etherpeek. In 1997, the FBI deployed the second generation program, Omnivore. According to information released by the FBI, Omnivore was designed to look through e-mail traffic travelling over a specific Internet service provider (ISP) and capture the e-mail from a targeted source, saving it to a tape-backup drive or printing it in real-time. Omnivore was retired in late 1999 in favor of a more comprehensive system, the DragonWare Suite, which allows the FBI to reconstruct e-mail messages, downloaded files or even Web pages. DragonWare contains three parts:
• Carnivore - A Windows NT/2000-based system that captures the information
• Packeteer - No official information released, but presumably an application for reassembling packets into cohesive messages or Web pages
• Coolminer - No official information released, but presumably an application for extrapolating and analyzing data found in the messages As you can see, officials have not released much information about the DragonWare Suite, nothing about Packeteer and Coolminer and very little detailed information about Carnivore. But we do know that Carnivore is basically a packet sniffer, a technology that is quite common and has been around for a while.

How Carnivore Work

You may have heard about Carnivore, a controversial program developed by the U.S. Federal Bureau of Investigation (FBI) to give the agency access to the online/e-mail activities of suspected criminals. For many, it is eerily reminiscent of George Orwell's book "1984." What exactly is Carnivore? Where did it come from? How does it work? What is its purpose?Now, you will learn the answers to these questions and more!

I've heard that data travels in packets on a computer network. What is a packet, and why do networks use them?

It turns out that everything you do on the Internet involves packets. For example, every Web page that you receive comes as a series of packets, and every e-mail you send leaves as a series of packets. Networks that ship data around in small packets are called packet switched networks. On the Internet, the network breaks an e-mail message into parts of a certain size in bytes. These are the packets. Each packet carries the information that will help it get to its destination -- the sender's IP address, the intended receiver's IP address, something that tells the network how many packets this e-mail message has been broken into and the number of this particular packet. The packets carry the data in the protocols that the Internet uses: Transmission Control Protocol/Internet Protocol (TCP/IP). Each packet contains part of the body of your message. A typical packet contains perhaps 1,000 or 1,500 bytes. Each packet is then sent off to its destination by the best available route -- a route that might be taken by all the other packets in the message or by none of the other packets in the message. This makes the network more efficient. First, the network can balance the load across various pieces of equipment on a millisecond-by-millisecond basis. Second, if there is a problem with one piece of equipment in the network while a message is being transferred, packets can be routed around the problem, ensuring the delivery of the entire message. Depending on the type of network, packets may be referred to by another name:
• frame
• block
• cell
• segment Most packets are split into three parts:
• header - The header contains instructions about the data carried by the packet. These instructions may include: o Length of packet (some networks have fixed-length packets, while others rely on the header to contain this information) o Synchronization (a few bits that help the packet match up to the network) o Packet number (which packet this is in a sequence of packets) o Protocol (on networks that carry multiple types of information, the protocol defines what type of packet is being transmitted: e-mail, Web page, streaming video) o Destination address (where the packet is going) o Originating address (where the packet came from)
• payload - Also called the body or data of a packet. This is the actual data that the packet is delivering to the destination. If a packet is fixed-length, then the payload may be padded with blank information to make it the right size.
• trailer - The trailer, sometimes called the footer, typically contains a couple of bits that tell the receiving device that it has reached the end of the packet. It may also have some type of error checking. The most common error checking used in packets is Cyclic Redundancy Check (CRC). CRC is pretty neat. Here is how it works in certain computer networks: It takes the sum of all the 1s in the payload and adds them together. The result is stored as a hexadecimal value in the trailer. The receiving device adds up the 1s in the payload and compares the result to the value stored in the trailer. If the values match, the packet is good. But if the values do not match, the receiving device sends a request to the originating device to resend the packet. As an example, let's look at how an e-mail message might get broken into packets. Let's say that you send an e-mail to a friend. The e-mail is about 3,500 bits (3.5 kilobits) in size. The network you send it over uses fixed-length packets of 1,024 bits (1 kilobit). The header of each packet is 96 bits long and the trailer is 32 bits long, leaving 896 bits for the payload. To break the 3,500 bits of message into packets, you will need four packets (divide 3,500 by 896). Three packets will contain 896 bits of payload and the fourth will have 812 bits. Here is what one of the four packets would contain:Each packet's header will contain the proper protocols, the originating address (the IP address of your computer), the destination address (the IP address of the computer where you are sending the e-mail) and the packet number (1, 2, 3 or 4 since there are 4 packets). Routers in the network will look at the destination address in the header and compare it to their lookup table to find out where to send the packet. Once the packet arrives at its destination, your friend's computer will strip the header and trailer off each packet and reassemble the e-mail based on the numbered sequence of the packets.

Definition of a packet

A packet is the unit of data that is routed between an origin and a destination on the Internet or any other packet-switched network. When any file (e-mail message, HTML file, Graphics Interchange Format file, Uniform Resource Locator request, and so forth) is sent from one place to another on the Internet, the Transmission Control Protocol (TCP) layer of TCP/IP divides the file into "chunks" of an efficient size for routing. Each of these packets is separately numbered and includes the Internet address of the destination. The individual packets for a given file may travel different routes through the Internet. When they have all arrived, they are reassembled into the original file (by the TCP layer at the receiving end). A packet-switching scheme is an efficient way to handle transmissions on a connectionless network such as the Internet. An alternative scheme, circuit-switched, is used for networks allocated for voice connections. In circuit-switching, lines in the network are shared among many users as with packet-switching, but each connection requires the dedication of a particular path for the duration of the connection.

Types of networks

Broadcast network A broadcast network avoids the complex routing procedures of a switched network by ensuring that each node's transmissions are received by all other nodes in the network. Therefore, a broadcast network has only a single communications channel. A wired local area network (LAN), for example, may be set up as a broadcast network, with one user connected to each node and the nodes typically arranged in a bus, ring, or star topology, as shown in the figure. Nodes connected together in a wireless LAN may broadcast via radio or optical links. On a larger scale, many satellite radio systems are broadcast networks, since each Earth station within the system can typically hear all messages relayed by a satellite.

Telecommunications network

Data transferOpen systems interconnection > Data transfer The network layer breaks data into packets and determines how the packets are routed within the network, which nodes (if any) will check packets for errors along the route, and whether congestion control is needed in a heavily loaded network. The data-link layer transforms a raw communications channel into a line that appears essentially free of transmission errors to the network layer. This is done by breaking data up into data frames, transmitting them sequentially, and processing acknowledgment frames sent back to the source by the destination. This layer also establishes frame boundaries and implements recovery procedures from lost, damaged, or duplicated frames. The physical layer is the transmission medium itself, along with various electric and mechanical specifications.

Data recognition and useOpen systems interconnection > Data recognition and use The application layer is difficult to generalize, since its content is specific to each user. For example, distributed databases used in the banking and airline industries require several access and security issues to be solved at this level. Network transparency (making the physical distribution of resources irrelevant to the human user) also is handled at this level. The presentation layer, on the other hand, performs functions that are requested sufficiently often that a general solution is warranted. These functions are often placed in a software library that is accessible by several users running different applications. Examples are text conversion, data compression, and data encryption. User interface with the network is performed by the session layer, which handles the process of connecting to another computer, verifying user authenticity, and establishing a reliable communication process. This layer also ensures that files which can be altered by several network users are kept in order. Data from the session layer are accepted by the transport layer, which separates the data stream into smaller units, if necessary, and ensures that all arrive correctly at the destination. If fast throughput is needed, the transport layer may establish several simultaneous paths in the network and send different parts of the data over each path. Conversely, if low cost is a requirement, then the layer may time-multiplex several users' data over one path through the network. Flow control is also regulated at this level, ensuring that data from a fast source will not overrun a slow destination.

Open systems interconnectionDifferent communication requirements necessitate different network solutions, and these different network protocols can create significant problems of compatibility when networks are interconnected with one another. In order to overcome some of these interconnection problems, the open systems interconnection (OSI) was approved in 1983 as an international standard for communications architecture by the International Organization for Standardization (ISO) and the International Telegraph and Telephone Consultative Committee (CCITT). The OSI model, as shown in the figure, consists of seven layers, each of which is selected to perform a well-defined function at a different level of abstraction. The bottom three layers provide for the timely and correct transfer of data, and the top four ensure that arriving data are recognizable and useful. While all seven layers are usually necessary at each user location, only the bottom three are normally employed at a network node, since nodes are concerned only with timely and correct data transfer from point to point.

Spread-spectrum multiple access Network access > Random access > Spread-spectrum multiple access Since collisions are so detrimental to network performance, methods have been developed to allow multiple transmissions on a broadcast network without necessarily causing mutual packet destruction. One of the most successful is called spread-spectrum multiple access (SSMA). In SSMA simultaneous transmissions will cause only a slight increase in bit error probability for each user if the channel is not too heavily loaded. Error-free packets can be obtained by using an appropriate control code. Disadvantages of SSMA include wider signal bandwidth and greater equipment cost and complexity compared with conventional CSMA.

Network access Scheduled access In a scheduling method known as time-division multiple access (TDMA), a time slot is assigned in turn to each node, which uses the slot if it has something to transmit. If some nodes are much busier than others, then TDMA can be inefficient, since no data are passed during time slots allocated to silent nodes. In this case a reservation system may be implemented, in which there are fewer time slots than nodes and a node reserves a slot only when it is needed for transmission.

Since all nodes can hear each transmission in a broadcast network, a procedure must be established for allocating a communications channel to the node or nodes that have packets to transmit and at the same time preventing destructive interference from collisions (simultaneous transmissions). This type of communication, called multiple access, can be established either by scheduling (a technique in which nodes take turns transmitting in an orderly fashion) or by random access to the channel.

Using E-Smells

This digital scent technology will be able to do more than allow you to attach e-smells to your e-mails. Imagine watching The Patriot on your DVD player with a DigiScents device plugged into it -- as the Colonial army's cannons blast, you can actually smell the gunpowder. Or, as the British army marches across the battlefield, you can smell the grass beneath them. The scent of the ocean could be emitted during scenes in which Benjamin Martin's (Mel Gibson) family seeks sanctuary in a freed slave village on the South Carolina coast. The whole idea here is to increase the realism and enhance the viewing of your favorite movies.The same type of effect could be created for your favorite video games. While consoles like PlayStation 2 are designed to enhance the realism of video game graphics, a digital scent synthesizer could take games to a whole new level. Imagine smelling the bad guy who is approaching before you actually see him. Developers of racing games could embed the smell of burnt rubber or gasoline to make their games more realistic.Before being attached to movies and games, Internet odors will likely permeate through Internet advertising. Just as advertisers used scratch and sniff technology a couple of decades ago, they will likely use the novelty of digital scents to peddle their products now. Coca-Cola could embed their cola smell into banner ads, which could be triggered by a user scrolling over the ad. Suddenly, you're thirsty for a Coke. Sounds like pretty effective advertising.Consumers may also benefit from this aromatic technology. With online spending on the rise, shoppers will now be able to sample some of the goods that they buy, including flowers, candy, coffee and other food products. Soon, you'll be able to stop and smell the roses without leaving your workstation.

Creating a Virtual Stink

Can you imagine a world with no smells? Think of some of the smells that you would never be able to enjoy, like homemade cookies, flowers or that scent that follows a summer rain. Smell adds so much to our experiences. Of course, without smell there is also no taste, since our sense of taste is almost completely dependent on our sense of smell. This world without smell exists on the Internet -- but that is about to change. You will soon have your choice of two computer peripheral devices that will make your nose as involved in your Web experience as your eyes and ears. Let's take a look at these devices.Smell Personal Scent SynthesizerIn Oakland, Calif., DigiScents, Inc. is developing a digital scent device, called the iSmell. They are fully aware of how people will respond to the device's tongue-in-cheek name. Mentioning the iSmell to a friend is likely to provoke instant laughter. The company hopes the device's name will grab consumers' attention and help to sell this gadget designed to transmit digitized smells through your computer.A prototype of the iSmell Personal Scent Synthesizer is shaped like a shark's fin, and it will be connected to your PC through a serial or universal serial bus (USB) port. It can be plugged into any ordinary electrical outlet. Here's how it works:• DigiScents has indexed thousands of smells based on their chemical structure and their place on the scent spectrum.• Each scent is then coded and digitized into a small file.• The digital file is embedded in Web content or e-mail.• A user requests or triggers the file by clicking a mouse or opening an e-mail.• A small amount of the aroma is emitted by the device in the direct vicinity of the user.The iSmell can create thousands of everyday scents with a small cartridge that contains 128 primary odors. These primary odors are mixed together to generate other smells that closely replicate common natural and manmade odors. The scent cartridge, like a printer's toner cartridge, will have to be replaced periodically to maintain the scent accuracy.DigiScents has formed partnerships with several Web, interactive media and gaming companies to bring scents to your computer. Real Networks plans to make DigiScents' ScentStream software available to its more than 115 million RealPlayer users. DigiScents has not announced when the iSmell will be available or how much it will cost.SENX Scent DeviceTriSenx is planning to take you one step further, by allowing users to not only download scents, but to print out flavors that can be tasted. The Savannah, Ga., based company has developed a patented technology that allows users to print smells onto thick fiber paper sheets and taste specific flavors by licking the paper coated with the smell.The SENX machine is a printer-like desktop device that will produce smells based on data programmed into a Web page. SENX stands for Sensory Enhanced Net eXperience. Like the iSmell, the SENX machine will be activated by user actions. The fragrances and aromas are stored in a disposable cartridge within the SENX. This cartridge has 20 chambers, each holding a distinct scent. Thousands of smells can be created with a 20-chamber cartridge and a 40-palette rendition, which composes two separate cartridges.The SENX is 5.5 inches wide, 8 inches long and 2.5 inches tall (14 x 20 x 6.4 cm). Users will plug the device into an open external COM port on their computers, and it will be powered by a DC 6-volt rechargeable battery. TriSenx is already taking orders for their SENX machine, which will cost $269 and include the SenxWare Scent Design Studio Software.

How Internet Odors Will Work

Many of us spend just as much time in cyberspace touring the electronic landscapes of the Internet as we spend offline. But for all of the time we spend in front of our computer monitors, this virtual world lacks many of the real world's most precious attributes. One of the biggest drawbacks of the cyber world is its lack of realism. Most of us are born with five senses, allowing us to see, hear, touch, smell and taste; yet the Internet takes advantage of less than half of these.When you log onto your computer, what senses are you using? Sight is probably the most obvious of the senses we use to collect information. The Internet is almost completely vision-based. While audio technology, like MP3 music files, have made a lot of noise recently, the Internet is made up mostly of words and pictures. You can also throw in touch as a third sense used in computer interaction, but that is mostly in terms of interfacing by way of keyboard and mouse. Since the beginning of the Internet, software developers have chosen to ignore our senses of smell and taste. However, there are at least two American companies who are planning to awaken all of your senses by bringing digital odors to the Internet.We have the ability to recognize thousands of odors; and some scientists believe that smell has the power to unlock memories. In the section of How Dewsoft Stuff Will Work, you will learn how smells will be transmitted to your desktop and what other possible applications this technology could present.

Information and Communication Technology

Today the Information and Communication Technology becoming more broaden & advanced, and provides all the users with a broad perspective on the nature of technology, how to use and apply a variety of technologies, and the impact of information and communication technologies on themselves and on society. Adopting the facility that has been given by the technology is not intended to stand alone, but rather to be adopting and extending all over the world on the public level should be far better. What technology is using people from different part of the world is different on their understanding because of their level of difference in country development and technology implementation. VoIP (Voice over IP) is the top most popular and burning communication technology for the upcoming decades. So, let’s talk about it.

VoIP Gateways:

An Overview
Gateways have become a central, yet complex, component in most state-of-the-art VoIP systems. Although they’ve been around for years, VoIP gateways remain something of a mystery. What, exactly, are these devices gateways to? Do they lead the way into a data network, a voice network, telephones, network management or outright confusion? In a way, they actually open the door to all of these areas. That's because VoIP gateways have become a central, yet complex, component in most state-of-the-art VoIP systems.VoIP gateways act as VoIP network translators and mediators. Perhaps most importantly, they translate calls placed through the public switched telephone network (PSTN) - the "regular" telephone system - into digital data packets that are compatible with an enterprise's VoIP system. VoIP gateways can also help direct VoIP calls to specific users with the assistance of built-in routing tables. Additionally, the units can translate between different VoIP protocols, such as H.323 and SIP, enabling compatibility between various VoIP systems and devices.Given all of these benefits, it's easy to see why VoIP gateways are highly recommended for virtually any VoIP implementation. Yet this hasn't always been the case. In VoIP's early days, system designers often "VoIP-enabled" switches and routers to handle key gateway tasks. But as VoIP networks grew larger and more sophisticated, and as end users began demanding higher quality and more reliable service, most designers began specifying standalone VoIP gateways for their systems.

Various Vendors

With VoIP technology steadily gaining momentum, VoIP gateway shoppers have an array of products to choose from. Leading VoIP gateway vendors include Cisco Systems, Mediatrix Telecom, Quintum Technologies, Stratus, Welltech Computer and Nortel Networks. VoIP gateways can be either hardware- or software-based. Hardware-based VoIP gateways - by far the most widely used approach - are available as standalone boxes, chassis cards or modules. Hardware VoIP gateways, while generally most expensive than their software counterparts, are usually preferred because they are viewed as more reliable, provide built-in interfaces and don't consume computer processing power.In the enterprise market, VoIP gateways come in many different configurations. Buyers can select from products that offer numerous phone, fax machine, PBX and PSTN support capabilities. Additionally, for large enterprises with offices and branch operations spread around the country or world, VoIP gateways provide an effective way to extend and distribute voice communications systems.At the market's low-end, it's possible to find a basic VoIP gateway, featuring a phone jack, Ethernet router and firewall, for under $200. A device at this price level would likely offer a minimum of three ports: a standard RJ-11 telephone jack and two RJ-45 ports - one for a broadband modem/router and one for a computer or network sharing device. Such a system would be capable of handling the voice needs of a home or small office.A mid-level VoIP gateway, costing anywhere from $400 to $2,000, offers additional interfaces supporting a wide range of phone system and network devices. These products also include various quality of service (QoS) features, network-thrifty voice compression and built-in security capabilities, such as encryption. The primary selection criteria of these VoIP gateways is the maximum packet throughput and the number of simultaneous phone calls supported. A VoIP gateway buyer needs to know just how much capacity his or her VoIP system needs, and these figures can only be arrived at by a thorough professional analysis.At the market's high end are Carrier Class VoIP gateways, costing several thousand dollars. Widely used by both telephone carriers and large enterprises, these devices support hundreds or even thousands of channels for advanced voice services, such as interactive voice response (IVR), a technology that allows callers to select an option from a voice menu. Other advanced functions supported by carrier-class VoIP gateways include voice recording, distributed voice announcements and conference calls.

Getting Smarter

Building new VoIP gateway features and functions, such as faster translations and support for emerging VoIP standards, represents a major challenge for vendors. Fortunately, many enhancements are software based, and can be delivered to customers fairly quickly and inexpensively in the form of a simple software upgrade.Perhaps the biggest trend in VoIP gateway technology is the rapid shift toward "smarter" products. Most major vendors are developing products that work with a wider mix of VoIP products and technologies, paving the road to enhanced multi-vendor interoperability. This trend promises to allow businesses to cut costs by enabling them to purchase products from any company that offers the best features at the best rather than from a single vendor.In the months and years ahead, VoIP gateway customers can expect more products, enhanced features and increased interoperability. These trends promise to help enterprises more easily build, maintain and upgrade VoIP networks that support both inexpensive and high-quality calls.

Building VoIP Gateways

One San Francisco hotel's experience installing a gateway-based VoIP system. White Star is a large hotel located in US’s West Coast serving guests coming from Asia, Europe, Latin America and US. With a majority of its customers being business persons, there is a large volume of long-distance and international phone calls made from the hotel which are routed in the traditional telephone network (PSTN).A feasibility study on VoIP was carried out and concluded with the following two main points:
• The VoIP voice quality is indistinguishable from the traditional phone calls.
• Rates for VoIP calls charged by Savytel represent a large saving, compared to the rates charged by the traditional telephone service providers

Gateway VoIP Implementation

One San Francisco hotel's experience installing a gateway-based VoIP system. White Star is a large hotel located in US’s West Coast serving guests coming from Asia, Europe, Latin America and US. With a majority of its customers being business persons, there is a large volume of long-distance and international phone calls made from the hotel which are routed in the traditional telephone network (PSTN).A feasibility study on VoIP was carried out and concluded with the following two main points:
• The VoIP voice quality is indistinguishable from the traditional phone calls.
• Rates for VoIP calls charged by Savytel represent a large saving, compared to the rates charged by the traditional telephone service providers.

Factors affecting VoIP quality

There are several factors that profoundly impact the quality of voice over the Internet. These factors can be described in terms of their general affect on VoIP quality: Negative or Positive.Negative FactorsOf the three negative factors for VoIP performance, the first one is delay, which results in echo and talker overlap. The second one is jitter, which is essentially the variation in delay. The third problem is packet loss. These factors are explained in much more detail below.DelayDelay results in echo and talker overlap. Echo becomes a problem when the round-trip delay becomes high. Talker overlap (the problem of one caller stepping over the other talker’s speech) becomes significant if the one-way delay becomes greater than 250 milliseconds.JitterJitter is essentially the variation in delay. This is primarily introduced because of the variation in inter-packet arrival time.

Packet Loss

Packet LossPacket loss is a constant problem in packet-based networks. In a circuit-switched network, all speech in a given conversation follows the same path and is received in the order in which it is transmitted. If something is lost, the cause is a fault rather than an inherent characteristic of the system.Apart from these factors there could be impairments caused by codecs. These impairments are due to the distortion introduced by the codec and due to the interaction of network effects with codec operation. Speech coding and compression Both speech coding and compression have been used in the traditional telephony for over two decades. With the exception of the local loop, almost all voice is carried over the PSTN in digital format. The received analog voice undergoes an analog-digital conversion at 8000 samples per second with 8 bits per sample, producing a 64 kbps digital data stream. A codec is the device that performs the conversion from analog voice into a digital format and vice-versa. The standard method used in traditional telephony is PCM (pulse code modulation) implemented by using a codec that conforms to ITU-T standard G.711. Most humans can hear sound up to about 20 KHz, but the traditional telephony uses low-pass filtering to remove everything but approximately the lower 4 KHz of the speech signal. In addition to this, voice over packet networks commonly use low bit rate codecs for compressing the received noise. These low bit rate codecs preserve the parts of the speech that are of important to the human listener taking out those parts that are not of any importance such as silence, redundantly long words. This is generally known as perceptual coding and is used in a number of other areas too, such as MPEG-2 video compression, JPEG image compression and MP3 audio. Standardized codecs have been tested with multiple speakers and multiple languages. The results can be tabulated as below.Here MOS is the measurement for voice clarity. This is explained in detail later in this chapter.Positive FactorsOf the two positive factors for VoIP performance, the first one is bandwidth, which is absolutely necessary for adequate performance. The second factor is prioritization. Prioritization becomes increasingly important as the network gets congested.

Bandwidth

One of the greatest challenges of VoIP is voice quality, and one of the keys to improving voice quality to an acceptable level is bandwidth. Therefore, additional bandwidth is certainly needed, if only to support additional traffic as demand for VoIP continues to grow. While additional bandwidth is a necessity for a network that is required to support voice in addition to the data traffic that is might have carried all along, additional bandwidth is not, by itself, a complete solution for the QoS issue.PrioritizationOnce sufficient bandwidth is available to enable high-quality voice transfer, we need to control and prioritize access to the available bandwidth. As this regulation is not exerted over the Internet presently and because the IP is designed completely for the transfer of the data from its outset, depending upon the usage of the bandwidth, voice quality over the Internet might vary from acceptable to atrocious.

Voice Quality & Quality of Service (QoS)

QoS is a collective measure of the level of service delivered to a user. QoS can be considered as the level of assurance for a particular application that the network can meet its service requirements. From a technical perspective, QoS can be characterized by several performance criteria, such as uptime, throughput, connection setup time, percentage of successful transmissions, speed of fault detection and correction, etc. In an IP network, QoS can be measured in terms of bandwidth, packet loss, delay, and jitter. In order to provide a high QoS, the IP network needs to provide assurances that for a given session or set of sessions, the measurement of these characteristics will fall within certain bounds. High quality over IP networks requires the use of managed networks, QoS solutions, and service-level agreements between the providers. Given the stringent delay requirement voice imposes, one should look at the avenues to achieve quality, reliability and scalability of traditional telephone networks, if they want to make VoIP a fierce competitor to the traditional telephony.For organizations that are interested in deploying VoIP technology on their corporation Intranets or on their other networks, the success of these technologies will depend on the performance of the network elements that carry and route the voice packets। The users of VoIP are concerned about the possible voice quality degradation when voice is carried over these packet networks, as the existing Internet protocols do not support real time traffic. Voice quality is the crucial factor in making VoIP acceptable to users, and it is important to understand the factors that affect the quality of the voice over the packet transmission networks, as well as to obtain the tools and optimize them. Although speech quality is often cited as one of the greatest challenges facing the development and market acceptance of voice over packet networks, people may in fact accept ‘sub-toll quality’ voice in exchange for some other benefits such as mobility, reduced cost and other advanced services VoIP can offer.

Approach

VIPERTo investigate the quality matters of Voice over IP a project named ‘Voice over Internet Protocol Environment for Research (VIPER)’ has been undertaken which could enable network-integrated, controllable, and statistically valid end-to-end measurements of VoIP quality. This system also enables specifications for vendors about ideal network configurations to obtain better voice quality over the Internet. Following sections discuss the specific motivations and architecture of the VIPER system. Results from VIPER testing are presented in subsequent chapters.

General architecture

VIPER includes network facilities for testing, a speech data repository that contains voice files, facilities for capturing subjective data, and scripts for the analysis of this gathered subjective data. Before the data can be collected and analyzed from VIPER, certain parameters are specified such as the architectural issues that could affect end-to-end subjective performance, such as bandwidth allocation, prioritization schemes, etc. The network facilities along with certain configuration parameters combine to create a test scenario. Untrained listeners had participated in these test scenarios.The repeated exercise of the VIPER realization with multiple listeners can produce statistically meaningful insights into VoIP QoS. Thus, a significant benefit of the globally organized and integrated VIPER environment is, test-specific QoS parameters can be applied to the network elements. These parameters in effect transport, prioritize, and differentiate the service between the test data and/or noise traffic through the network.

Motivation

In performing this work, we would like to be able to determine the impact of design and environmental changes (e.g. network conditions, such as packet loss) on voice quality. The ability to quantify voice quality is important for a number of reasons. First, we would like to compare the quality of voice over packet networks to the PSTN, as the PSTN has become the de facto standard for what constitutes acceptable voice quality. We would also be able to test the effectiveness of various network protocols and policies that are known to support real time traffic. Lastly, from a business perspective, measurements of voice quality allow a vendor to offer better features than those of its competitors, as well as to provide the basis for voice quality service level agreements (SLA).Voice quality could be measured using a procedure called Mean Opinion Scores (MOS). The MOS uses the Absolute Category Rating (ACR) procedure to determine the general acceptability or quality of voice communication systems or products. A MOS measurement is made by having a group of listeners rank a speech sample on a scale of 1-5, where 1 is very bad, 5 is excellent and 4 is normally considered ‘toll-quality’ (what one hears on the Public Switched Telecommunications Network (PSTN)). Obviously MOS is highly subjective and not highly reproducible. It is difficult to assemble a group of people, creation of ideal test facilities, selection of proper sound files, assembling audio devices and it is not suitable for long-term measurementTo address the shortcomings of this subjective testing a number of methods have been developed to create an objective and reproducible measurement of perceived voice quality. There are two clarity measurements currently used, the first one is PSQM (Perceptual Speech Quality Measurement) developed by KPN Research and the second one is PAMS (Perceptual Analysis/Measurement System) developed by British Telecom. Both these techniques use natural speech or speech-like samples as their inputs. The speech samples are played over the network that is setup for different configurations and the received speech sample is compared with the original speech sample using clarity algorithms.

General architecture

VIPER includes network facilities for testing, a speech data repository that contains voice files, facilities for capturing subjective data, and scripts for the analysis of this gathered subjective data. Before the data can be collected and analyzed from VIPER, certain parameters are specified such as the architectural issues that could affect end-to-end subjective performance, such as bandwidth allocation, prioritization schemes, etc. The network facilities along with certain configuration parameters combine to create a test scenario. Untrained listeners had participated in these test scenarios.The repeated exercise of the VIPER realization with multiple listeners can produce statistically meaningful insights into VoIP QoS. Thus, a significant benefit of the globally organized and integrated VIPER environment is, test-specific QoS parameters can be applied to the network elements. These parameters in effect transport, prioritize, and differentiate the service between the test data and/or noise traffic through the network.

User Interface

To enable the VIPER testing, a web-based user-interface was created, which includes the following features:Network SetupThe network will be configured for different configurations using a tool called Expect, which can automate interactive applications such as telnet, ftp, rlogin, etc. The different network configurations used in VIPER realization are explained in the next chapter. After the quality is measured for a particular configuration, the network will be reconfigured into a default state.Generation of NoiseData enough to congest the network in the form of noise is injected into the network. This noise is generated using a tool called Iperf.Playing of voice filesVgetty is the tool used to generate the calls and to pump the voice files into the network. Vgetty is controlled through the web-based interface using the vgetty::modem, which is perl module and allows the control of voice modem through a perl script.Voice quality ratingThe test takers rate the quality of voice on a scale of 1 to 5 for the entire possible network configuration that were been designed. These results will be stored into a database for further analysis.

Technologies used in the creation of User Interface

Database (MySQL)MySQL is one of the most popular SQL servers right now. SQL is programming language developed by IBM in 1970s and after which popularized as industry-standard language for creating, updating and querying the relational database management systems (RDBMS). MySQL is very fast, multi-threaded and multi-user SQL server. Using MySQL a database is created which contains a table to place the MOS values that are gathered from various end-users.

Gmail added a new To-do list feature

How often you tend to forget to do your important tasks on time? Do you want any help? Google, the giant is right now testing a new feature for Gmail which will help users to keep a better track of their tasks on daily basis.

Google' official blog mentioned that they have designed a new feature known as Tasks which is specifically designed to help the Gmail users to create a list of their day to day activities. The Tasks will be visible in the same kind of windows just like chat window and it will remain visible throughout the user activity which means it will be visible even while users are reading their email or even using the Search feature to search or some other tasks as well.

This feature has already been designed by the Google labs and is right now into the Testing phase.

Once this feature gets integrated, we have to enable it. For that, go to your Settings, click on the Labs tab. then select "Enable" which is next to "Tasks" and finally click on the "Save Changes" link at the bottom of the page. It may take a while to display this feature, but once it is done you will see Tasks" link just under the "Contacts" link on the left. Click on "Tasks" to get started.

Now lets see how to create a new task. Just click inside the empty part of your list and type anything. You wont find any buttons to save as it is saved automatically. Hit the return key on your keyboard and gosh..... you are done with your first task.

Google Chrome: Out of Beta

Recently Google announced that its Chrome browser which it launched few months before is now out of beta stage which seems quite unusual considering the fact that another Google product: Gmail still has a beta tag even after more than 4 years since its launch.

Google also announced that the Chrome browser has more than 10 million active users through out the world. Thats a great number considering the fact that it has a market share of around 3%.

Apart from removing this beta tag, there are so many new features introduced the Chrome along with some bug fixes since few weeks. Some of these features are : Bookmark Manager. Regarding bugs, I suppose it has fixed the problems playing the audio as well as video files as previously sometimes they played and sometimes they do not. As you all must be aware of the fact that the biggest weakness of Google Chrome browser is its inability to support the extensions. Google is still working on the same.

I also use Chrome sometimes as its very fast giving it an edge over its competitors. With Chrome, I can manage my day to day email tasks like reading and replying emails, reading feeds, searching Google, downloading some files. Though I have to switch back and forth to my second favorite browser ie Firefox since Chrome has problems playing Audio and Video along with lack of extensions support. But still, I can manage.

Now as it is out of the Beta stage, I believe Google Inc would like to follow some tactics which made the Microsoft Internet Explorer the world's most popular Internet browser like bundling it out with some other software programs or even Windows. But I am forced to think whether people would be addicted to it or not?

Yahoo! layoffs hit Flickr

Flickr has been acquired by Yahoo! in 2005 for around 40$ Million and has been considered as the golden child of the organization. According to Yahoo, Flickr was such a cool web application they invested in and thought it was so good that they even dumped thier own Yahoo photos which was quite popular in favour of it. The Yahoo Layoff has not only affected the employees working for it, even the Flickr has been affected.

George Oates, female and a high-profile member of the Flickr team and one of the site's early employees, was told that she was being given the chop too. What a sad end to her contributions!! I have the news that even some other members of the Flickr team has been laid off as well including- Jeannie Yang, David Sharma and few others. Just to mention, Oates was the person responcible for designign Flickr's interface.

Clearly, Flickr is no longer untouchable. Recently I got the news that Yahoo! is even thinking of selling Flickr to Microsoft.

H2go Hybrid Hydrogen RC car

No carbon, no batteries.......Loads of fun!!

A new toy car known as H2go Hyrbid Hydrogen RC car for the kids has been launched. It took more than 5 years of dedicated research and development to develop this next generation energy management, energy technology and aerospace propulsion system. The most astonishing part of this car is that it doesnt need any batteries and even with its remote control.

This battery free toy car is a real working version of the laboratory vehicles running on renewable and zero emission hydrogen fuel. Now lets see how this car gets power. This car gets its energy from the water and sun and moreover combines fuel cells for cruise power along with fast charge super-capacitors for speed. And you get a fast propelling fueld cell car which doesnt even require any batteries.

The complete product includes: solar power plant, hydrogen station, remote control, hybrid electric hydrogen car, and a user instruction manual. Moreover, it is recommended for only ages 8 and above.

You can purchase this car for around 150$.

South African Markets - Factors to watch on

JOHANNESBURG, The following company announcements, scheduled economic indicators, debt and currency market moves and political events may affect South African markets on Thursday. GLOBAL MARKETS Asian shares fell on Thursday as concerns over the global economy once again took centre stage, while renewed uncertainty about the U.S. auto bailout plan sparked a subtle shift towards assets seen safer such as the yen. Regional bonds held firm, reflecting the aversion to risk, while oil prices edged up after rallying a day earlier on signs Saudi Arabia had slashed supplies to customers. South Korea's central bank on Thursday cut interest rates by 1 percentage point, becoming the latest central bank to respond aggressively to a sharply slowing economy and falling inflation. For a story, double click on. ZIMBABWE The death toll from Zimbabwe's cholera outbreak soared to nearly 800 on Wednesday and a court ordered police to find a missing rights activist, piling more pressure on President Robert Mugabe's government. The spreading cholera, coupled with chronic food shortages, has highlighted the economic collapse of the southern African nation and prompted calls for Mugabe's resignation from Western leaders and some within Africa. For a story, double click on. SOUTH AFRICAN MARKETS South Africa's stocks climbed to a five week high on Wednesday bouyed by firmer mining shares and government bonds rallied as retail sales data re-inforced the chance of an interest rate cut. The central bank's Monetary Policy Committee (MPC) started its meeting on Wednesday and it is widely expected to cut the repo rate by 50 basis points to 11.5 percent on Thursday. The rand firmed in late Johannesburg trade against the dollar after the greenback slipped to a two-week low against the euro as news broke that U.S. lawmakers had reached a tentative aggreement for a bailout plan of the auto industry. For Wednesday's South African financial markets closing report, double click on. BHP BILLITON Standard & Poor's revised its outlook on Billiton to stable, from negative after it scrapped an all-share takeover offer for rival Rio Tinto. S&P affirmed its 'A+' long-term and 'A-1' short-term corporate credit ratings on the company. For Standard & Poor's statement double click on STEFSTOCKS, GROUP FIVE, BASIL READ , WBHO Utility Eskom said a contract it awarded to a South African construction consortium was worth 2.9 billion rand ($283.7 million). South Africa's Stefanutti Stocks said earlier this week it would lead a joint venture to build civil works at Eskom's Kusile Power Station. The consortium also includes Group Five, Basil Read and WBHO Construction. For story double click on NEOTEL, TELKOM South Africa's No. 2 fixed-line phone operator Neotel has secured a total of 7.5 billion rand ($733.7 million) in funding to help it expand its network and better compete with former monopoly Telkom. Neotel, in which India's Tata group holds a stake, said it reached the 7.5 billion total in equity and debt after raising an extra 4.4 billion rand in project finance. For story double click on GOLD Gold edged down to around $800 on Thursday to track weaker equities, a day after posting its biggest daily rise in almost three weeks, but cuts in oil output could spur safe-haven buying. Profit-taking also erased some of gold's gains but analysts said investors' appetite for risky assets was somewhat restored after bullion rallied to a high of $813.10 on Wednesday, its strongest since Dec. 1, on firm U.S. equities and oil. Gold was trading at $803.05 an ounce, down $6.85 from New York's notional close on Wednesday, when it rose more than 4 percent, its biggest daily percentage gain since Nov. 21. Gold was 18 percent above a 13-month low around $680 hit in October. For the latest precious metals report, double click on . WALL STREET U.S. stocks rose in a choppy session on Wednesday as a rebound in oil prices and other commodities lifted energy, mining and materials shares, offsetting nervousness over whether Washington will agree on a bailout for ailing car makers. The Dow Jones industrial average rose 70.09 points, or 0.81 percent, to 8,761.42. The Standard & Poor's 500 Index gained 10.57 points, or 1.19 percent, to 899.24. The Nasdaq Composite Index was up 18.14 points, or 1.17 percent, at 1,565.48. For the New York stock market report, double click on. EMERGING MARKETS For the top emerging markets news, double click on . - - - - Some of the main stories out of the South African press: BUSINESS DAY - Retail in full retreat as sales take deep plunge - JSE recovers ground lost since October - Higher JSE bid wins Bond Exchange nod - Nedbank Capital opens its purse for Neotel - Sappi cuts output to avoid stock surplus BUSINESS REPORT - IDC gives Sheraton Textiles a lifeline - Sapia blinks at Transnet's 74 pct hike plan THE STAR - Falsely accused father wins long custody battle - No need for arms inquiry - Motlanthe

WRAPUP 2-Bleak Japan factory output points to long recession

TOKYO, (Reuters) - Japanese industrial production dropped sharply in October and manufacturers warned of record falls in coming months, prompting warnings that growing global gloom means Japan's recession will be even deeper and longer. The bleak news on Japanese factory output may point to a longer and deeper global recession, with the euro zone and U.S. economies also contracting and growth slowing in China. With household spending also sliding, Japan is now firmly caught up in the financial crisis, with its big exporters such as Toyota and other car makers facing tumbling orders from key customers in Western markets -- and increasingly across Asia. Falling oil prices point to the risk of a return to deflation, although economists are divided on this and whether the Bank of Japan will return to a zero-interes-rate policy. Finance Minister Shoichi Nakagawa called for more action by the BOJ to deal with the worsening economy. Exporters have been the main engine of growth for Japan's economy but manufacturers forecast their biggest ever quarterly fall in output in the fourth quarter. "Production is falling much faster than we expected. Companies are adjusting their production very quickly," said Takumi Tsunoda, a senior economist at Shinkin Central Bank Research. "Auto makers are the worst hit, but their turmoil is starting to spill over into other sectors, such as steel makers." Industrial output fell 3.1 percent in October, more than a median market forecast for a 2.5 percent drop, and the outlook is for a record 8.6 percent fourth-quarter contraction. For a graphic tracking monthly industrial output, Industrial output has already been falling for three quarters this year and, with household spending also in decline, economists warn of a longer and deeper recession. "The figures reconfirm that conditions are worsening very badly," said Yoshikiyo Shimamine, chief economist at Dai-Ichi Life Research Institute, warning that U.S. data and problems elsewhere meant there would be no quick turnaround. "It is now the Christmas shopping season in America, and sales of popular items like toys, clothing, high-tech gadgets and digital appliances will likely be really slow. "Chinese firms may be hit by slow sales of toys and clothing, but sluggish sales of high-tech items will impact companies in Japan and Taiwan." Some economists say Japan's recession could run for two more quarters until early next year -- a full year of contraction that would be the country's longest on record. Not helping matters is a rise in the yen to 13-year highs against the dollar last month. It is still around 95 yen per dollar, further curbing profits exporters earn in other currencies. Share prices briefly dipped after the data and Japanese bond prices edged up, but ironically the yen held firm on fears of a longer and deeper global recession, with the low-yielding currency seen by investors as a refuge from the economic storm. DEFLATION RISK Japanese core annual inflation slowed in October for a second straight month, underscoring a view that falling energy costs may heighten the risk of a return to deflation later next year. Excluding volatile prices of fresh fruit, vegetables and seafood but including oil products that are diving in price, core consumer prices rose 1.9 percent in October from a year earlier, slipping from a 2.3 percent increase in September. For a graphic on Japanese inflation, click: Annual inflation excluding oil products dipped to 1.2 percent while partial figures for November, covering Tokyo, pointed to further falls in inflation. "The pace of rises in consumer prices will keep slowing towards the July-September quarter next year and we expect core consumer prices to start falling after July-September next year," said Kyohei Morita, chief economist at Barclays Capital. Japan's jobless rate unexpectedly dropped to 3.7 percent but even that was not good news -- with officials saying it was due to discouraged workers leaving the work force, with vacancies showing the outlook for jobs at a four-year low. The OECD has singled out Japan as facing the biggest threat of deflation among industrialised nations next year, warning on Tuesday that the global financial crisis could further damage the economy. BOJ OUTLOOK SPLIT Analysts are split over whether the threat of deflation will prompt the Bank of Japan to cut rates again in the future after it trimmed them to 0.3 percent last month. Masamichi Adachi, a senior economist at JPMorgan Securities Japan, is among those expecting a return to zero interest rates, warning inflation will slide much faster than some realise. "Japan is getting closer to deflation and the nation's economy will further deteriorate without doubt," Adachi said. But other analysts say it is too early to be talking about persistent deflation, and see limited scope for a BOJ rate cut. Derivative markets are not pricing in a serious chance of a rate cut in the coming months after Friday's data. Bank of Japan Governor Masaaki Shirakawa said this month he was awake to the risk but the central bank does not forecast a return to deflation, which afflicted the nation for about a decade from the 1990s. Japan slipped into recession in the third quarter for the first time in seven years as exports crumbled, joining the euro zone in meeting the commonly used definition of two straight quarters of contraction. The United States is widely expected to follow in the fourth quarter and growth is also slowing in China, another key market for Japan.

China yuan central parity rate set at 6.8349 to dollar vs 6.8292

BEIJING (XFN-ASIA) - The central bank has set the yuan central parity rate at 6.8349 to the dollar, according to the China Foreign Exchange Trading System.The rate, published on the official Chinamoney website (www.chinamoney.com.cn), compares with the midpoint of 6.8292 set the previous trading day. The People's Bank of China (PBoC) started setting a daily central parity rate on Jan 4, 2006. On July 21, 2005, China freed the yuan from its long-standing peg to the dollar in favor of a trade-weighted basket of currencies, and allowed the local unit to appreciate by 2.1 pct. The PBoC allows a trading band of 0.5 pct on either side of the central parity rate.

US Nov foreclosure dip is false promise-RealtyTrac

U.S. foreclosure activity dipped 7 percent in November from October, but jumped 28 percent compared with the same month a year ago and will spike without a broad permanent fix for troubled loans in this recession, RealtyTrac said on Thursday. State laws that extend the foreclosure process, loan modification programs and a temporary halt through early January on foreclosures of loans bought by Fannie Mae and Freddie Mac pulled November's filings to the lowest level since June. "I'm afraid we're looking at a bit of a false promise," Rick Sharga, senior price president at RealtyTrac, said in an interview before the figures were released. "It's basically a stay of execution," he added. "I am fearful that we're going to see a pretty significant spike come January." One in every 488 U.S. households got a foreclosure filing last month, according to the Irvine, California-based research firm. Filings include notice of default, auction sale or bank repossession. More borrowers are being forced to delay mortgage payments longer, especially with unemployment leaping and the economy mired in what many economists call a deep recession. Late loan payments rose to a record high in the third quarter, the Mortgage Bankers Association reported last week. Efforts to modify loans tempered the rate that delinquent mortgages tipped into the foreclosure process. But increasing job loss and falling home prices make it likely that foreclosures will swell, the trade group said. Even when mortgage terms have been altered, many borrowers re-default, John Dugan, head of the U.S. Office of the Comptroller of the Currency, said this week. More than half of borrowers whose loans were restructured in the first quarter re-defaulted after six months, he said. The FDIC and Federal Reserve estimate that banks will foreclose on about 2.25 million U.S. homes this year, more than double the 1 million annual rate before the housing crisis. "The frustrating part has been that all the the government programs to date have gone into the system rather than directly to the homeowner," Sharga said. "Most economists are of the opinion that until you stabilize housing, the rest of the economy is not going to get better," Sharga said. "For all the hundreds of billions of dollars that have been injected into the financial system, we still see the foreclosure rates go up." USUAL SUSPECTS A handful of U.S. states stayed at the top of the foreclosure charts in November. These are typically states which had soared the highest during the five-year housing boom earlier this decade and had furthest to fall or have been most severely challenged economically. California, Florida and Michigan posted the highest foreclosure totals while Nevada, Florida and Arizona had the highest rates of foreclosure. Foreclosure activity in Nevada, for example, dropped about 4 percent in November, but held the country's highest foreclosure rate. One in every 76 Nevada housing units got a foreclosure filing last month, more than six times the national average. Cities in California and Florida accounted for nine of the top 10 metro foreclosure rates, RealtyTrac said. Las Vegas was the lone city not in those states. Cape Coral-Fort Myers, Florida had the highest metro foreclosure rate among 230 areas tracked, with one in every 59 housing units receiving a foreclosure filing in November. Keywords: USA HOUSING/FORECLOSURES REALTYTRAC

US NOV EX-AUTO SALES POST BIGGEST MONTHLY DROP IN SPENDINGPULSE REPORT HISTORY GOING BACK TO 2003

NEW YORK, - U.S. retail sales excluding autos posted their biggest monthly drop in five years November, as consumers, spooked by a deepening recession, pared spending for a third straight month, a private report released on Thursday showed.The decline accelerated in November despite a sales spurt over the crucial "Black Friday" weekend -- the three days after the Thanksgiving holiday in late November -- according to SpendingPulse, the retail data service of MasterCard Advisors, a subsidiary of MasterCard Inc.Consumer spending excluding autos fell 3.8 percent last month on a seasonally adjusted basis, steeper than the 1.5 percent decline in October, SpendingPulse said.The November figure was the largest one-month drop in SpendingPulse history, which began in 2003, surpassing the prior record fall of 2.4 percent set two months ago.The report was the latest evidence that U.S. retailers are facing one of the worst holiday retail seasons in recent memory. The year-end shopping period accounts for the bulk of the annual business of many retailers."We are talking about a consumer who is wary of spending," said Kamalesh Rao, SpendingPulse's director of economic research.Consumers, who account for more than two-thirds of the U.S. economy, have been battered by worsening job conditions, dwindling 401(k) retirement funds and a persistent credit crunch.The spending decline was again led by a drop in gasoline sales, as pump prices have fallen well below $2 a gallon since rising above $4 in July, according to Rao.Retail sales excluding cars and gasoline fell 1.3 percent in November compared with a 0.9 percent drop in October.Once red-hot categories like electronics, furniture and luxury goods have turned cold, registering double-digit sales drops from year ago, Rao said."People are a lot more price sensitive. When they buy, they buy less expensive things," Rao said.SpendingPulse's "core" measure on consumer spending, which strips out cars, gasoline and building materials, declined 1.3 percent compared with a 1.6 percent fall in October.While it is too early to predict when spending will pick up, the worst of the downturn may have occurred, Rao said."Spending may have bottomed out in October. We are not seeing more a pullback," he said.The SpendingPulse data is derived from the aggregate sales in the MasterCard U.S. payment network, coupled with estimates on all other payment methods including cash and check.

WRAPUP 2-South Korea cuts rates by record margin, more seen

SEOUL, -South Korea's central bank slashed interest rates by a record 1 percentage point to an all-time low on Thursday and warned that Asia's fourth largest economy was on the verge of an emergency that may require more drastic action. The Bank of Korea cut the base rate to 3.0 percent, marking the fourth reduction since early October when the rate was 5.25 percent. It now stands at the lowest since the rate-setting system was adopted in 1999. "We are on the verge of an emergency situation that may need more drastic policy," Bank of Korea Governor Lee Seong-tae told reporters, saying future policy would focus on lifting the economy and easing a credit crunch. Some economists believe the South Korean economy is heading into recession and analysts said the much bigger-than-expected rate cut and the central bank's comments all raised chances it would cut rates further. "It is not a good policy to keep waiting longer and take steps in a gradual manner," governor Lee said of the central bank's biggest ever rate cut. Nine of 10 analysts in a Reuters poll had forecast a cut by 50 basis points in the base rate, with the remaining analyst predicting a 25 basis-point dip. For a graphic on the South Korean base rate, double-click: https://customers.reuters.com/d/graphics/KR_RTS1208.jpg "This drastic move suggests Korea's economic growth is in real danger of a big slowdown and the Bank of Korea is ready to take further aggressive measures, as it has been attacked for not doing much to stabilise the financial market and economy," said Park So-yeon, an economist at Korea Investment and Securities. South Korea, saddled with high foreign debt, a weakening currency, capital outflows and doubts about the health of its banking sector is seen among the region's most vulnerable economies to the global financial crisis that has already pushed the United States, Japan and Western Europe into recession. Seoul has responded with a slew of emergency measures, including $130 billion in foreign debt guarantees and nearly $10 billion in fiscal stimulus, on top of aggressive central bank easing. MORE CUTS AHEAD Economist Park Sang-hyun at HI Investment & Securities said he was downgrading his rate outlook: "I had expected the rate to be lowered to as low as 2.75 percent, but the rate may go below 2 percent." The Bank of Korea also said it would add 12 brokerage houses to those eligible for its repurchase agreement operations, a move that will help non-banking institutions secure funds more easily. December treasury bond futures soared as much as 114 ticks to 110.80 as investors priced in higher chances for additional, aggressive rate cuts. Seoul stock market's benchmark KOSPI rallied immediately after the decision but has soon given back some of the gain as investors turned their attention back to the stark prospects for South Korea's economy and corporate earnings. Won was up 2.2 percent against the dollar by 0252 GMT, also retreating from its rise of nearly 4 percent immediately on profit-taking and on the gloomy economic prospects. The drop in benchmark rate of 2.25 percentage points, if followed by an equivalent drop in bank lending rates, should save South Korean companies and consumers some $30 billion in annual interest payments on their debt, Reuters calculation shows. The latest move comes amid media reports in the region that Japan and China were close to agreeing on expanding currency swap arrangements with South Korea to help their smaller neighbour restore confidence among international investors. The Bank of Korea is due to release its first official forecasts for 2009 economic growth on Friday with mounting fears the economy could register its first annual decline in 11 years in 2009. South Korea's economy expanded 5 percent in 2007 but the growth is seen slowing to around 4.5 percent this year and more than halving to around 2 percent next year, with some global investment banks even predicting an outright contraction in 2009.

Korea T-bond futures end off highs after rate cut

SEOUL, (Reuters) - South Korean treasury bond futures ended up but halved earlier hefty gains, with investors quickly shifting towards non-government debt after the central bank's record rate cut. The December futures contract ended up 51 ticks at 110.17, rewinding more than half of a 114-tick surge seen after the larger-than-expected policy easing. The Bank of Korea slashed the base rate by one full percentage point to a record low of 3.00 percent on Thursday in a bid to fend off an economic recession.

The Game World

Portal Runner uses an over-the-shoulder perspective. You, as the game player, seem to be hovering in the air slightly behind the character you are controlling. As your character moves around, you see the world of the game stretch out into the distance. But what you are really seeing is a very clever illusion reminiscent of the backlots of Hollywood!The world that Vikki can actually interact with in Portal Runner is a very defined area. If you could pull the camera view up in the air, you would see that the play area is completely self-contained. Other parts of the world that you can see in the distance are actually two-dimensional images mapped onto a flat surface that surrounds the play area like a barrel. The sky is created in the same way, by mapping the sky image onto a large dome or cylinder that fits over everything else. Look at the example below to get a better idea of how this works.The production team constantly looks for ways to add cool effects without degrading the performance of the game. A good example of this is the reflections of objects on shiny surfaces, like the chess board in the medieval world of Portal Runner. The chess pieces and characters moving around on the chess board appear to have detailed reflections on the polished surface of the chess board. What is actually happening is that a second version of each object is positioned upside-down just below the semi-transparent surface of the chess board! The upside-down version moves in concert with the "real" version of the object, providing an illusion of reflection.

Polygons, Shading and Skeletons

The vast majority of 3-D objects created for computer games are made up of polygons. A polygon is an area defined by lines. To have a polygon, you must have at least three lines. The lines connect a series of coordinates in the three-dimensional "space" the computer creates. The point where the lines connect is known as a vertex. Each vertex has X, Y and Z coordinates.
• X determines the position relative to right or left in the virtual space
• Y determines the position relative to top or bottom in the virtual space
• Z determines the position relative to front or back in the virtual space Once each polygon has a set of vertices to define its shape, it needs information that tells it what to look like. There are four common ways to do this:
• Flat shading
• Gouraud shading
• Phong shading
• Texture mapping Flat shading simply assigns a single color to a polygon. It is very simple and fast, but makes the object look artificial. Gouraud shading is more involved. Colors are assigned to each vertex and then are blended across the face of the polygon. Since each vertex is typically associated with at least three distinct polygons, this makes the object look natural instead of faceted. Look at this example: You will notice that the ball with Gouraud shading appears much smoother than the flat shaded one. But look closely at the outlines of the two balls. That is where you can tell that both balls have the exact same number of polygons! A more complex version of shading, Phong, is rarely used in games. Whereas Gouraud shading interpolates colors by averaging between the vertices, Phong shading averages each pixel based on the colors of the pixels adjacent to it. Another common technique for determining the appearance of a polygon is to use texture mapping. Think of texture mapping as wrapping a present. Each side of the box you are wrapping is a blank polygon. You could paint the box, but it would be very difficult to make it match all the designs on the wrapping paper. However, if you take the wrapping paper and tightly cover the box with it, you have completely transformed the box with just a little effort. Texture mapping works the same way. Mapping requires the use of another image. Essentially, this other image is stretched over the object like a skin. Most video game consoles and computer graphics adapters contain a special chip and dedicated memory that store the special images used for texture mapping and apply them to each polygon on the fly. This allows games such as Portal Runner to have incredibly detailed 3-D environments that you can interact with in real time. The characters in a game have skeletons. Similar to our own skeleton, this is a hidden series of objects that connect with and move in relation to each other. Using a technique called parenting, a target object (the child) is assigned to another object (the parent). Every time the parent object moves, the child object will follow according to the attributes assigned to it. A complete hierarchy can be created with objects that have children and parents. Here's an example for a human character: Once the skeleton is created and all of the parenting controls put in place, the character is animated. Probably the most popular method of character animation relies on inverse kinematics. This technique moves the child object to where the animator wants it, causing the parent object and all other attached objects to follow. Another method that is popular for games is motion capture, which uses a suit of sensors on a real person to transmit a series of coordinates to a computer system. The coordinates are mapped to the skeleton of a game character and translated into fluid, realistic motion. Each character's range of motion is programmed into the game. Here's a typical sequence of events:
• You press a button on the controller to make the character move forward.
• The button completes a circuit, and the controller sends the resulting data to the console.
• The controller chip in the console processes the data and forwards it to the game application logic.
• The game logic determines what the appropriate action at that point in the game is (move the character forward).
• The game logic analyzes all factors involved in making the movement (shadows, collision models, change of viewing angle).
• The game logic sends the new coordinates for the character's skeleton, and all other changes, to the rendering engine.
• The rendering engine renders the scene with new polygons for each affected object, redrawing the scene about sixty times each second.
• You see the character move forward.

Finishing Touches

After the basics are in place, the production team begins to refine the game. Part of this refinement involves optimizing the game code, polygon count and logic, including adjusting the clipping planes and culling. The polygon count (number of polygons on screen at the same time) is a major factor in the smooth rendering and quick response of a game. Portal Runner often has more than 50,000 polygons on screen! Clipping planes determine whether or not polygons in the field of view will be rendered. This depends on how close to the camera the polygons are. Typically, the near clipping plane will not render polygons that are close enough to intersect the plane of the camera. This keeps your viewpoint in the game from intersecting another object and thus blanking out. And the far clipping plane is normally set at the point where the screen resolution causes the details to become impossible to see. There is no need to render objects that you cannot see. This leads to another area of optimization. While the far clipping plane does not render entire objects that are too far away, culling means that the video game system does not render the parts of objects that are outside your viewing area. For example, when you look at a building, you normally only see one or two sides of the building. In a game, you can increase performance by not rendering the other sides of the building until you move around to the point that you can see them. And as you move, the game can stop rendering the things you can no longer see. One of the refinements that John Salera said 3DO wanted to make to Portal Runner was to determine where they could eliminate polygons through culling in order to increase the polygon count for Vikki, from 1,500 polygons to 3,000. They want to do this without increasing the overall number of polygons onscreen. By increasing the polygon count of a specific object (like Vikki), the object can be made to look smoother and more realistic. Periodically during the development of the game, 3DO sends builds (partially complete versions) of the game to the game console maker. This is done to keep the console maker informed about how the game is developing and to ensure that there are no surprises that the manufacturer might take issue with. As the game nears completion, it enters the post-production phase. This phase has several parts:
• Game versions
• Product testing
• ESRB review
• Marketing and advertising
• Distribution Once the game is done, an alpha version is sent to designated game testers. This preliminary version is a first pass meant to find any major flaws in the game. The problems are identified and the game is released again in beta form. The beta version is tested exhaustively to find any bugs and discover ways to further optimize the game. After the items found in the beta version are fixed, the final candidate is released. Sometime during this period, the game is sent to the Entertainment Software Rating Board (ESRB) to be given a rating. If the game is released before a final rating is set, it will have an RP (Rating Pending) in the rating box. During post-production, the marketing engine begins to ramp up. The game is advertised in print, on the Web and oftentimes on TV. Quite often, a game that is a hit or has a very memorable character provides the company with opportunities for merchandising and licensing. Comic books, cartoons, movies and amusement park rides have all spun out of the popularity of certain video game characters. Products such as clothing, toys and board games often display characters from the game. A popular video game character can be a real marketing gold mine for the parent company.

Distributing the Game

A major difference in creating a video game for a console versus a normal PC is the approval and distribution process. Console manufacturers normally require strict licensing agreements between themselves and companies that wish to develop games for their system. We will outline the process that 3DO goes through with the game console makers they work with. Every company that develops games for a video game system manufacturer is considered a third party licensee. Here's how it breaks down:
• 3DO Develops the game idea Creates the game Tests the game Markets the game Distributes the game
• Console maker Approves the game idea Tests the game Reviews and approves the game Manufactures the game When 3DO submits the game to the console maker, the testing and review process can be very rigorous. The game may be sent back to 3DO with requests to change certain parts before resubmitting it. Once the game is approved, 3DO places an initial order with the console maker that must be paid up front. The console maker sends a master copy of the game to one of its manufacturing plants. The first run of a typical 3DO game is between 150,000 and 300,000 units. It normally takes a few weeks from the time an order is placed until the games are delivered to 3DO's warehouse distribution center in Atlanta, Ga. The games come packed at between 500 and 2,000 games per pallet. A tractor-trailer can carry about 40 pallets of 2,000 games each (about 80,000 games). That means it could take four trucks to deliver 320,000 copies of a single title! During this process, 3DO has been taking orders for the game from resellers. The resellers send their own trucks to the 3DO warehouse in Atlanta to pick up their copies of the game. Quite often, the games are pulled directly off the trucks bringing them in from the manufacturer, split up and reboxed, then put right back on the trucks for the resellers! Specialty retailers like Babbages and Electronics Boutique try to get the games from the distribution center to their store shelves as quickly as possible. Big box retailers like Wal-Mart, Kmart and Target are not as rushed, and typically ship the games to their stores along with other items. Many people mistakenly assume that the cost per game to the parent company is minimal and the profit huge. This is seldom the case. While the actual material costs for the CD duplication, box and manuals may only be a few dollars per unit, there are a lot of other costs incurred:
• Console licensing royalties (about $3 to $10 per unit for the console maker)
• Game development costs (typically several millions of dollars)
• Advertising (anywhere from $1 million to $4 million for most games)
• Salaries for the production team (a typical game might employ 40 people for a year or more)
• Other licensing fees (particularly in sports titles, where the professional sports organization and any featured athletes tend to receive royalties for each unit sold)
• Operational costs (the costs of running the company must be split between the various games sold) Game companies also have to take into account the short lifespan that most games enjoy. Since the technology that video games thrive on is continually improving, the games that are cutting edge today will seem slow and clunky in just a year or two. It's amazing that companies like 3DO continue to provide us with such incredible entertainment year after year!

Honda Unicorn Grand Prix GP Edition

Honda has launched a new limited edition variant of its 150cc product Unicorn. The new Unicorn Grand Prix edition comes in a racing blue, white and green livery highlighting its racing DNA. According to Honda “the limited edition Unicorn Grand Prix Edition is derived from Honda’s racing DNA and the new sporty graphics reflect true racing attitude.” Honda last year rolled out repsol GP edition of Unicorn and sold 2000 units of the bike within few months of its launch. Honda Unicorn limited Grand Prix (GP) edition will be sold in a limited number of 3500 units and retails for Rs 59,290.

Yamaha YZF R15 150cc

Yamaha YZF R15 is a india specific bike hosting an 150cc engine which was designed for just one thing - Performance! A bike which can be said as the fastest in Indian Bikes. Although the engine details are secret YZF R15 have several first-in-Indian-bike features.

The new YZF-R15 makes full use of the MotoGP race experience and YZF-R series supersport bike development technology and know-how acquired by Yamaha Motor over the years to create a 150cc supersport bike that offers users to truly “Enjoy riding” in a full range of situations, from around-town riding to touring on winding roads and even aggressive riding on the circuit.

Yamaha YZF R 15 is the first model for the Indian market designed in the true supersport image and featuring a high-level balance of enjoyable running performance on winding roads, enjoyable performance and riding comfort with a tandem passenger and agile handling through crowded city traffic. The body has been designed to show at a glance that this is a “R series bike” and to give visual expression to technology feedback from the 10 years of YZF-R series development since the series debut in 1998. In this way, it is a direct expression of Yamaha’s motorcycle development ideal of “Exciting Performance & Stylish Design” in the 150cc class.

It is based on totally race technology with which MotoGP bikes runs, technology with which R1 is built. It is India’s first 150cc 4 valve engine. It is India’s first Bike with forged pistons. It is India’s first Bike with a Diasil Cylinder. It is India’s first Bike with the Deltabox frame, again based on the R1. And it is India’s first Bike with a 6speed gear box.

It is Fuel Injected and will hit the market in June 2008 .The rear tyres though are only a mere 100, MRF uses imported Soft compound to give it better grip than similar sized tyres.

Main Features:
(1) A newly developed 150cc liquid-cooled, 4-stroke, SOHC, single-cylinder fuel-injected engine(2) An all-aluminum “DiASil Cylinder” produced by an exclusive Yamaha casting technology
(3) Eco-friendly performance that clears the next-phase Bharat 4 emissions standard
(4) The “Deltabox frame” known for excellent rigidity balance
(5) Impressive “2-eye” multi-reflector headlight design in the YZF-R series image

Specs as shown in Yamaha Site -
1)Tyre Front: 80/90 - 17 inch tubeless
2)Tyre Rear: 100/80 - 17 inch tubeless
3)Brakes: Front- Disc, Rear- Disc
4)Fuel Tank: 12 Litres
5)Wheelbase: 1290 mm
6)Min Ground Clearance: 160 mm

SCSI Basics

SCSI is based on an older, proprietary bus interface called Shugart Associates System Interface (SASI). SASI was originally developed in 1981 by Shugart Associates in conjunction with NCR Corporation. In 1986, a modified version of SASI that provided a beefier, open system was ratified by the American National Standards Institute (ANSI) as SCSI. There are several benefits of SCSI:
• It's fast -- up to 160 megabytes per second (MBps).
• It's reliable.
• It allows you to put multiple devices on one bus.
• It works on most computer systems. There are also some potential problems when using SCSI: • It must be configured for a specific computer.
• It has limited system BIOS support.
• Its variations (speeds, connectors) can be bewildering.
• There is no common software interface. People are often confused by the different types of SCSI. You'll hear terms such as "Ultra," "Fast" and "Wide" used a lot, and sometimes in combinations. In the next section, you'll find out about the SCSI variations.

How SCSI Works

Most home and small-office PCs use an IDE hard drive and have a PCI bus for adding components to the computer. But a lot of computers, particularly high-end workstations and older Apple Macintoshes, use the Small Computer System Interface (SCSI) bus to connect components, which may include:
• Hard drives
• Scanners
• CD-ROM/RW drives
• Printers
• Tape drives Basically, SCSI (pronounced "scuzzy") is a fast communications bus that allows you to connect multiple devices to your computer.Now, you'll learn about the structure of SCSI and the various specifications and types, as well as SCSI IDs and termination.

SCSI Types

There are really only three basic specifications of SCSI:
•SCSI-1: The original specification developed in 1986
• SCSI-2: An update that became an official standard in 1994, a key component of SCSI-2 was the inclusion of the Common Command Set (CCS) -- the 18 commands considered an absolute necessity for support of any SCSI device. You also had the option to double the clock speed from 5 MHz (million cycles per second) to 10 MHz (Fast SCSI), double the bus width from 8 bits to 16 bits and increase the number of devices to 15 (Wide SCSI), or do both (Fast/Wide SCSI). Finally, SCSI-2 added command queuing, which means that an SCSI-2 device can store a series of commands from the host computer and determine which ones should be given priority.
• SCSI-3: Quickly on the heels of SCSI-2 came SCSI-3, debuting in 1995. The interesting thing about SCSI-3 is that a series of smaller standards have been built within its overall scope. Because of this continually evolving series, SCSI-3 is not considered to be a completely approved standard. Instead, some of the specifications developed within it have been officially adopted. These standards are based on variations of the SCSI Parallel Interface (SPI), which is the way that SCSI devices communicate with each other. Most SCSI-3 specifications begin with the term "Ultra" (Ultra for SPI variations, Ultra2 for SPI-2 variations and Ultra3 for SPI-3 variations). The Fast and Wide designations work just like their SCSI-2 counterparts, with the Fast designation meaning that the clock speed is double that of the base version, and the Wide designation meaning that the bus width is double that of the base. The chart below shows a comparison of the many SCSI variations: Name Specification # of Devices Bus Width Bus Speed MBpsAsynchronousSCSI SCSI-1 8 8 bits 5 MHz 4 MBpsSynchronousSCSI SCSI-1 8 8 bits 5 MHz 5 MBpsWideSCSI SCSI-2 16 16 bits 5 MHz 10 MBpsFastSCSI SCSI-2 8 8 bits 10 MHz 10 MBpsFast/WideSCSI SCSI-2 16 16 bits 10 MHz 20 MBpsUltraSCSI SCSI-3SPI 8 8 bits 20 MHz 20 MBpsUltra/WideSCSI SCSI-3SPI 8 16 bits 20 MHz 40 MBpsUltra2SCSI SCSI-3SPI-2 8 8 bits 40 MHz 40 MBpsUltra2/WideSCSI SCSI-3SPI-2 16 16 bits 40 MHz 80 MBpsUltra3SCSI SCSI-3SPI-3 16 16 bits 40 MHz 160 MBps

dentifiers

There are three components in any SCSI system: • Controller • Device • Cable The controller is the heart of SCSI. It serves as the interface between all of the other devices on the SCSI bus and the computer. Also called a host adapter, the controller can be a card that you plug into an available slot or it can be built right into the motherboard. On the controller is the SCSI BIOS. This is a small ROM or Flash memory chip that contains the software needed to access and control the devices on the SCSI bus. Usually, each device on the SCSI bus has a built-in SCSI adapter that allows it to interface and communicate with the SCSI bus. For example, an SCSI hard drive will have a small circuit board that combines a controller for the drive mechanism and an adapter for the SCSI bus. Devices with an adapter built in are called embedded SCSI devices. Each SCSI device must have a unique identifier (ID). As you saw in the previous section, an SCSI bus can support eight or 16 devices, depending on the specification. For an eight-device bus, the IDs range from zero to 7, and for a 16-device bus, they range from zero to 15. One of the IDs, typically the highest one, has to be used by the SCSI controller, which leaves you capable of adding seven or 15 other devices. With most SCSI devices, there is a hardware setting to configure the device ID. Some devices allow you to set the ID through software, while most Plug and Play SCSI cards will auto-select an ID based on what's available. This auto-selection is called SCSI Configured Automatically (SCAM). It is very important that each device on an SCSI bus have a unique ID, or you will have problems. All of the variations in the SCSI specifications have added another wrinkle: There are at least seven different SCSI connectors, some of which may not be compatible with a particular version of SCSI. The connectors are:
• DB-25 (SCSI-1)
• 50-pin internal ribbon (SCSI-1, SCSI-2, SCSI-3)
• 50-pin Alternative 2 Centronics (SCSI-1)
• 50-pin Alternative 1 high density (SCSI-2)
• 68-pin B-cable high density (SCSI-2)
• 68-pin Alternative 3 (SCSI-3)
• 80-pin Alternative 4 (SCSI-2, SCSI-3) No matter which version of SCSI you are using, or what type of connector it has, one thing is consistent -- the SCSI bus has to be terminated.

Termination

Termination simply means that each end of the SCSI bus is closed, using a resistor circuit. If the bus were left open, electrical signals sent down the bus could reflect back and interfere with communication between SCSI devices and the SCSI controller. Only two terminators are used, one for each end of the SCSI bus. If there is only one series of devices (internal or external), then the SCSI controller is one point of termination and the last device in the series is the other one. If there are both internal and external devices, then the last device on each series must be terminated.Types of SCSI termination can be grouped into two main categories: passive and active. Passive termination is typically used for SCSI systems that run at the standard bus clock speed and have a short distance, less than 3 feet (1 m), between the devices and the SCSI controller. Active termination is used for Fast SCSI systems or systems with devices that are more than 3 ft (1 m) from the SCSI controller.Another factor in the type of termination is the bus type itself. SCSI employs three distinct types of bus signaling. Signal ling is the way that the electrical impulses are sent across the wires.Single-ended (SE) - The most common form of signaling for PCs, single-ended signaling means that the controller generates the signal and pushes it out to all devices on the bus over a single data line. Each device acts as a ground. Consequently, the signal quickly begins to degrade, which limits SE SCSI to a maximum of about 10 ft (3 m).High-voltage differential (HVD) - The preferred method of bus signaling for servers, HVD uses a tandem approach to signaling, with a data high line and a data low line. Each device on the SCSI bus has a signal transceiver. When the controller communicates with the device, devices along the bus receive the signal and retransmit it until it reaches the target device. This allows for much greater distances between the controller and the device, up to 80 ft (25 m).Low-voltage differential (LVD) - A variation on the HVD signaling method, LVD works in much the same way. The big difference is that the transceivers are smaller and built into the SCSI adapter of each device. This makes LVD SCSI devices more affordable and allows LVD to use less electricity to communicate. The downside to LVD is that the maximum distance is half of HVD -- 40 ft (12 m).Both HVD and LVD normally use passive terminators, even though the distance between devices and the controller can be much greater than 3 ft (1 m). This is because the transceivers ensure that the signal is strong from one end of the bus to the other.

SCSI "Network"

SCSI devices inside the computer (internal) attach to the SCSI controller via a ribbon cable. The ribbon cable has a single connector at each end and may have one or more connectors along its length. Each internal SCSI device has a single SCSI connector. SCSI devices outside the computer (external) attach to the SCSI controller using a thick, round cable. You have already read about the different connectors used on these external cables. The cable itself typically consists of three layers:
• Inner layer - This is the most protected layer. It contains the actual data being sent.
• Media layer - The middle layer contains the wires that send control commands to the device. • Outer layer - This layer includes the wires that carry parity information, which ensures that the data is correct. External devices connect to the SCSI bus in a daisy chain, which refers to the method of connecting each device to the next one in line. External SCSI devices typically have two SCSI connectors -- one is used to connect to the previous device in the chain, and the other is used to connect to the next device in the chain. A good way to think of SCSI is as a tiny local area network (LAN). The SCSI controller is like the network router, and each SCSI device is like a computer on the network. The SCSI adapter built into each device is comparable to the Ethernet card in a computer. Without the adapter, the device can't communicate with the rest of the network. And just as the router in a LAN is used to connect the network to the outside world, the SCSI controller connects the SCSI network to the rest of the computer.

How BIOS Works

One of the most common uses of Flash memory is for the basic input/output system of your computer, commonly known as the BIOS (pronounced "bye-ose"). On virtually every computer available, the BIOS makes sure all the other chips, hard drives, ports and CPU function together. Every desktop and laptop computer in common use today contains a microprocessor as its central processing unit. The microprocessor is the hardware component. To get its work done, the microprocessor executes a set of instructions known as software (see How Microprocessors Work for details). You are probably very familiar with two different types of software:The operating system - The operating system provides a set of services for the applications running on your computer, and it also provides the fundamental user interface for your computer. Windows 98 and Linux are examples of operating systems. (See How Operating Systems Work for lots of details.)The applications - Applications are pieces of software that are programmed to perform specific tasks. On your computer right now you probably have a browser application, a word processing application, an e-mail application and so on. You can also buy new applications and install them.It turns out that the BIOS is the third type of software your computer needs to operate successfully.Now, you'll learn all about BIOS -- what it does, how to configure it and what to do if your BIOS needs updating.

What BIOS Does

The BIOS software has a number of different roles, but its most important role is to load the operating system. When you turn on your computer and the microprocessor tries to execute its first instruction, it has to get that instruction from somewhere. It cannot get it from the operating system because the operating system is located on a hard disk, and the microprocessor cannot get to it without some instructions that tell it how. The BIOS provides those instructions. Some of the other common tasks that the BIOS performs include:• A power-on self-test (POST) for all of the different hardware components in the system to make sure everything is working properly• Activating other BIOS chips on different cards installed in the computer - For example, SCSI and graphics cards often have their own BIOS chips.• Providing a set of low-level routines that the operating system uses to interface to different hardware devices - It is these routines that give the BIOS its name. They manage things like the keyboard, the screen, and the serial and parallel ports, especially when the computer is booting.• Managing a collection of settings for the hard disks, clock, etc.The BIOS is special software that interfaces the major hardware components of your computer with the operating system. It is usually stored on a Flash memory chip on the motherboard, but sometimes the chip is another type of ROM.When you turn on your computer, the BIOS does several things. This is its usual sequence:1. Check the CMOS Setup for custom settings2. Load the interrupt handlers and device drivers3. Initialize registers and power management4. Perform the power-on self-test (POST)5. Display system settings6. Determine which devices are bootable7. Initiate the bootstrap sequenceThe first thing the BIOS does is check the information stored in a tiny (64 bytes) amount of RAM located on a complementary metal oxide semiconductor (CMOS) chip. The CMOS Setup provides detailed information particular to your system and can be altered as your system changes. The BIOS uses this information to modify or supplement its default programming as needed. We will talk more about these settings later.Interrupt handlers are small pieces of software that act as translators between the hardware components and the operating system. For example, when you press a key on your keyboard, the signal is sent to the keyboard interrupt handler, which tells the CPU what it is and passes it on to the operating system. The device drivers are other pieces of software that identify the base hardware components such as keyboard, mouse, hard drive and floppy drive. Since the BIOS is constantly intercepting signals to and from the hardware, it is usually copied, or shadowed, into RAM to run faster.

Booting the Computer

Whenever you turn on your computer, the first thing you see is the BIOS software doing its thing. On many machines, the BIOS displays text describing things like the amount of memory installed in your computer, the type of hard disk and so on. It turns out that, during this boot sequence, the BIOS is doing a remarkable amount of work to get your computer ready to run. This section briefly describes some of those activities for a typical PC.After checking the CMOS Setup and loading the interrupt handlers, the BIOS determines whether the video card is operational. Most video cards have a miniature BIOS of their own that initializes the memory and graphics processor on the card. If they do not, there is usually video driver information on another ROM on the motherboard that the BIOS can load.Next, the BIOS checks to see if this is a cold boot or a reboot. It does this by checking the value at memory address 0000:0472. A value of 1234h indicates a reboot, and the BIOS skips the rest of POST. Anything else is considered a cold boot.If it is a cold boot, the BIOS verifies RAM by performing a read/write test of each memory address. It checks the PS/2 ports or USB ports for a keyboard and a mouse. It looks for a peripheral component interconnect (PCI) bus and, if it finds one, checks all the PCI cards. If the BIOS finds any errors during the POST, it will notify you by a series of beeps or a text message displayed on the screen. An error at this point is almost always a hardware problem.The BIOS then displays some details about your system. This typically includes information about:The ProcessorThe floppy drive and hard driveMemoryBIOS revision and dateDisplayAny special drivers, such as the ones for small computer system interface (SCSI) adapters, are loaded from the adapter, and the BIOS displays the information. The BIOS then looks at the sequence of storage devices identified as boot devices in the CMOS Setup. "Boot" is short for "bootstrap," as in the old phrase, "Lift yourself up by your bootstraps." Boot refers to the process of launching the operating system. The BIOS will try to initiate the boot sequence from the first device. If the BIOS does not find a device, it will try the next device in the list. If it does not find the proper files on a device, the startup process will halt. If you have ever left a floppy disk in the drive when you restarted your computer, you have probably seen this message.

Configuring BIOS

In the previous list, you saw that the BIOS checks the CMOS Setup for custom settings. Here's what you do to change those settings.To enter the CMOS Setup, you must press a certain key or combination of keys during the initial startup sequence. Most systems use "Esc," "Del," "F1," "F2," "Ctrl-Esc" or "Ctrl-Alt-Esc" to enter setup. There is usually a line of text at the bottom of the display that tells you "Press ___ to Enter Setup."Once you have entered setup, you will see a set of text screens with a number of options. Some of these are standard, while others vary according to the BIOS manufacturer. Common options include:System Time/Date - Set the system time and dateBoot Sequence - The order that BIOS will try to load the operating systemPlug and Play - A standard for auto-detecting connected devices; should be set to "Yes" if your computer and operating system both support itMouse/Keyboard - "Enable Num Lock," "Enable the Keyboard," "Auto-Detect Mouse"...Drive Configuration - Configure hard drives, CD-ROM and floppy drivesMemory - Direct the BIOS to shadow to a specific memory addressSecurity - Set a password for accessing the computerPower Management - Select whether to use power management, as well as set the amount of time for standby and suspendExit - Save your changes, discard your changes or restore default settingsCMOS Setup

Updating Your BIOS

Occasionally, a computer will need to have its BIOS updated. This is especially true of older machines. As new devices and standards arise, the BIOS needs to change in order to understand the new hardware. Since the BIOS is stored in some form of ROM, changing it is a bit harder than upgrading most other types of software.To change the BIOS itself, you'll probably need a special program from the computer or BIOS manufacturer. Look at the BIOS revision and date information displayed on system startup or check with your computer manufacturer to find out what type of BIOS you have. Then go to the BIOS manufacturer's Web site to see if an upgrade is available. Download the upgrade and the utility program needed to install it. Sometimes the utility and update are combined in a single file to download. Copy the program, along with the BIOS update, onto a floppy disk. Restart your computer with the floppy disk in the drive, and the program erases the old BIOS and writes the new one.

A Short History

Video games have been around since the early 1970s. The first commercial arcade video game, Computer Space by Nutting Associates, was introduced in 1971. In 1972, Atari introduced Pong to the arcades. An interesting item to note is that Atari was formed by Nolan Bushnell, the man who developed Computer Space. He left Nutting Associates to found Atari, which then produced Pong, the first truly successful commercial arcade video game. That same year, Magnavox offered the first home video game system. Dubbed the Odyssey, it did not even have a microprocessor! The core of the system was a board with about four-dozen transistors and diodes. The Odyssey was very limited -- it could only produce very simple graphics, and required that custom plastic overlays be taped over the television screen. In 1975, Atari introduced a home version of its popular arcade game, Pong. The original home version of Pong was sold exclusively through Sears, and even carried the Sears logo. Pong was a phenomenal success, opening the door to the future of home video games. Although the Fairchild Channel F, released in 1976, was the first true removable game system, Atari once again had the first such system to be a commercial success. Introduced in 1977 as the Atari Video Computer System (VCS), the 2600 used removable cartridges, allowing a multitude of games to be played using the same hardware. The hardware in the 2600 was quite sophisticated at the time, although it seems incredibly simple now. It consisted of:

• MOS 6502 microprocessor

• Stella, a custom graphics chip that controlled the synchronization to the TV and all other video processing tasks

• 128 bytes of RAM

• 4-kilobyte ROM-based game cartridges The chips were attached to a small printed circuit board (PCB) that also connected to the joystick ports, cartridge connector, power supply and video output. Games consisted of software encoded on ROM chips and housed in plastic cartridges. The ROM was wired on a PCB that had a series of metal contacts along one edge. These contacts seated into a plug on the console's main board when a cartridge was plugged into the system. When power was supplied to the system, it would sense the presence of the ROM and load the game software into memory. Systems like the Atari 2600, its descendant, the 5200, Coleco's ColecoVision and Mattel's IntelliVision helped to generate interest in home video games for a few years. But interest began to wane because the quality of the home product lagged far behind arcade standards. But in 1985, Nintendo introduced the Nintendo Entertainment System (NES), and everything changed. The NES introduced three very important concepts to the video game system industry:

• Using a pad controller instead of a joystick

• Creating authentic reproductions of arcade video games for the home system

• Using the hardware as a loss leader by aggressively pricing it, then making a profit on the games themselves Nintendo's strategy paid off, and the NES sparked a revival in the home video game market that continues to thrive and expand even now. No longer were home video game systems looked upon as inferior imitations of arcade machines. New games that would have been impractical to create for commercial systems, such as Legend of Zelda, were developed for the home markets. These games enticed many people who had not thought about buying a home video game system before to purchase the NES. Nintendo continued to develop and introduce new game consoles. Other companies, such as Sega and Sony, created their own home video game systems. In the articles on each of the current systems (see this page), you will learn more about what they can do. But first, let's look at the core parts of any current video game system.

In Essence...

At its core, a video game system is a highly specialized computer. In fact, most systems are based on the same central processing units (CPUs) used in many desktop computers. To keep the cost of the video game system within reasonable limits, most manufacturers use a CPU that has been widely available for long enough to undergo a significant decrease in cost. Why would people buy a game console instead of a computer? There are several reasons:

• It's usually much cheaper. Prices range from a high end of about $300 for the new Sony PlayStation 2, to less than $30 for an older, used system.

• There's no long wait for the game to load.

• Video game systems are designed to be part of your entertainment system. This means that they are easy to connect to your TV and stereo.

• There are no compatibility issues, such as operating system, DirectX drivers, correct audio card, supported game controller, resolution and so on.

• Game developers know exactly what components are in each system, so games are written to take full advantage of the hardware.

• The degree of technical knowledge required to set up and use it is much lower. Most game consoles are truly "plug and play."

• Most video game systems have games that allow multiple players. This is a difficult process with a typical home computer.

How Video Game Systems Work

Home video game systems, also known as consoles, are a popular form of entertainment. In 2000, Sony estimated that one out of every four households in the United States had a Sony PlayStation. That's a huge number! And then there are the homes with one of the many other game systems. Now, you will learn what video game systems are, a little about the history of game consoles, what is inside a game console and what the future holds for these systems. You will also learn a little about the games these systems play. If you're interesting in buying a game console, check out How Buying a Video Game System Works! Let's start with the most basic question: What exactly is a video game console.

How PlayStation Works

For the past five years, the Sony PlayStation (PSX) has been the dominant video game system. Although challenged by the incredible technical features of the Nintendo 64 and the next generation Sega Dreamcast, the PlayStation is so popular that Sony estimates one out of every four households in the United States has one! Now, you will learn about the development of the PSX, what's inside the box and how it all works together. You will also learn about the controller, including the popular Dual Shock version!

History

In 1988, Sony entered into an agreement with Nintendo to develop a CD-ROM attachment, known as the Super Disc, for the soon-to-be released Super Nintendo. Due to many contractual and licensing problems, the Super Disc was never released. Instead, a modified version was introduced by Sony in 1991, in a system called the Play Station. The original Play Station read these Super Discs, special interactive CDs based on technology developed by Sony and Phillips called CD-ROM/XA. This extension of the CD-ROM format allowed audio, video and computer data to be accessed simultaneously by the processor. The Play Station also read audio CDs, and had a cartridge port for accepting Super Nintendo game cartridges. The Play Station was envisioned as the core of a home multimedia center. Sony only manufactured about 200 of them before deciding to retool the design. The new design, dubbed the PlayStation X, or PSX, dropped the Super Nintendo cartridge port and focused solely on CD-ROM-based games. The component hardware inside the console was revamped as well, to ensure an immersing and responsive gaming experience. Launched in Japan in December of 1994, and in the United States and Europe in September of 1995, the PlayStation quickly became the most popular system available.

Console

Let's take a look at the components inside a PlayStation, and what their capabilities are. [Be sure to check out How Video Game Consoles Work first for a general introduction to game consoles.]

• Processor: 32-bit R3000A Processor clock speed: 33.8688 MHz MIPS (Million Instructions Per Second): 30 Bus speed: 132 MB per second Cache:

• Data: 4 KB

• Instruction cache: 1 KB

• Graphics: Resolution: 640x480 maximum (five interlaced and four non-interlaced modes supported) Colors: 24-bit (16,777,216) maximum; other modes supported are 4-bit (16), 8-bit (256) and 15-bit (32,768) Maximum sprite size: 256 pixels high x 256 pixels wide Polygon rendering: 360,000 polygons per second Geometry engine: Provides additional hardware rendering of polygons to include Gouraud shading, texture-mapping and lighting effects Memory: 1 MB RAM MPEG decoder

• Audio: Channels: 24 Sample rate: 44.1 KHz Memory: 512K RAM Digital effects (envelope, looping, reverb) MIDI support

• Memory: 2 MB RAM

• Operating system: Proprietary 512K ROM

• Game medium: CD-ROM Transfer speed: 150 KB per second normal, 300 KB per second double speedAudio CD support Memory buffer: 32K The CPU in the PSX is a RISC processor. RISC stands for reduced instruction set computer, and means that the instructions and computations performed by the processor are simpler and fewer. Also, RISC chips are superscalar -- they can perform multiple instructions at the same time. This combination of capabilities, performing multiple instructions simultaneously and completing each instruction faster because it is simpler, allows the CPU to perform better than many chips with a much faster clock speed. To lower production costs, the CPU, graphics and audio processors are combined into a single application specific integrated circuit, or ASIC. Simply put, the ASIC is a customized chip created to manage all of the components that would otherwise be handled by three separate chips.
The games come on proprietary CD-ROM/XA discs that are read by laser, just like regular CDs. When a game is put in the console, the following happens:

• You turn the power on.

• The disc spins up to speed.

• While the disc is spinning up, the console loads portions of the operating system from ROM into RAM.

• The game initialization sequence is loaded into RAM.

You interact with the game via the controller.

• As each specific part of the game is requested, the application code and hardware-render geometry are loaded into RAM, while the video and audio portions are usually streamed directly from the CD.

The CPU coordinates everything. It receives the input from the controller, pulls the data from RAM and directs the graphics and audio processing.

• You are finally beaten by the game and turn it off.
Since all information is flushed from RAM when the power is turned off, you will lose any personal game data. But you can save it by using one of the special Flash memory cards. The card is inserted into one of the two slots on the front of the PSX, above the port for the controller.

Controller

The controller is the primary user interface for the PlayStation. And just as the gamepad that came with the original Nintendo Entertainment System was a radical departure from previous controllers, the PSX controller changed the rules again. With its winged shape and abundance of well-positioned buttons, it is user-friendly and yet powerful.
The standard PSX controller has 14 buttons! They include:

• four buttons arranged as a directional pad on the top left

• Start and Select buttons in the top middle

• four action buttons on the top right

• two action buttons on the front left

• two action buttons on the front right Although each button can be configured to perform a specific and distinctive action, they all work on the same principle. In essence, each button is a switch that completes a circuit when it is pressed. A small metal disk beneath the button is pushed into contact with two strips of conductive material on the circuit board inside the controller. While the metal disk is in contact, it conducts electricity between the two strips. The controller senses that the circuit is closed and sends that data to the PSX. The CPU compares that data with the instructions in the game software for that button, and triggers the appropriate response. There is also a metal disk under each arm of the directional pad. If you're playing a game in which pushing down on the directional pad causes the character to crouch, a similar string of connections is made from the time you push down on the pad to when the character crouches.
Newer Dual Shock PSX controllers have analog joysticks on them, as well as the standard buttons. These joysticks work in a completely different way from the buttons described above. Two potentiometers (variable resistors) are positioned at right angles to each other below the joystick. Current flows constantly through each one, but the amount of current is determined by the amount of resistance. Resistance is increased or decreased based on the position of the joystick. By monitoring the output of each potentiometer, the PSX can determine the exact angle at which the joystick is being held, and trigger the appropriate response based on that angle. In games that support them, analog features like these allow for amazing control over gameplay.
Another feature of the Dual Shock controller, actually the reason for its name, is force feedback. This feature provides a tactile stimulation to certain actions in a game. For example, in a racing game, you might feel a jarring vibration as your car slams into the wall.
Force feedback is actually accomplished through the use of a very common device, a simple electric motor. In the Dual Shock controller, two motors are used, one housed in each handgrip. The shaft of each motor holds an unbalanced weight. When power is supplied to the motor, it spins the weight. Because the weight is unbalanced, the motor tries to wobble. But since the motor is securely mounted inside the controller, the wobble translates into a shuddering vibration of the controller itself. Now let's take a closer look at how the controller talks to the PSX.
Here's what each pin does:

1. DATA - This pin carries the signal that the controller sends to the PSX each time a button is pressed. It is an 8-bit serial transmission.

2. COMMAND - This pin is used by the PSX to send information to the controller. Such information might trigger the motors in a Dual Shock controller at the proper moment. It also uses an 8-bit serial transmission.

3. Not used

4. GROUND

5. POWER - This pin supplies 5 volts to the controller from the PSX.

6. SELECT - This pin is used by the PSX to notify the controller of incoming data.

7. CLOCK - This pin carries a synchronizing signal sent from the PSX to the controller.

8. Not used

9. ACKNOWLEDGE - This pin sends a signal to the PSX from the controller after each command that is received on Pin

Games

The games on the PSX are CD-ROM-based, so they are limited to a maximum size of 650 Mb. But this is a lot of space. In fact, most games do not use more than a fraction of it for the actual game. What can eat up the space are the incredible full motion video intros and intermissions that PlayStation games are known for. There is a noticeable delay while the game is loaded from the CD, which you do not get in cartridge-based games. Of course, the trade-off for faster loading is a significantly smaller amount of storage on the cartridge. Because they are black instead of the traditional silver, PSX CDs are very distinctive. But don't let that fool you. The CDs are just as susceptible to scratches and intense heat as normal audio CDs -- even more so in fact, since a scratch on a game CD can make it totally unusable. The games available for the PlayStation cover all of the categories. It has, by far, the largest game library of any of the consoles on the market today. Game prices range from under $10, for certain preplayed titles, to over $50 for some of the hottest new games.

Game System

Basics The basic pieces really haven't changed that much since the birth of the Atari 2600. Here's a list of the core components that all video game systems have in common: • User control interface

• CPU

•RAM

• Software kernel

• Storage medium for games

• Video output

• Audio output

• Power supply The user control interface allows the player to interact with the video game. Without it, a video game would be a passive medium, like cable TV. Early game systems used paddles or joysticks, but most systems today use sophisticated controllers with a variety of buttons and special features. Ever since the early days of the 2600, video game systems have relied on RAM to provide temporary storage of games as they're being played. Without RAM, even the fastest CPU could not provide the necessary speed for an interactive gaming experience. The software kernel is the console's operating system. It provides the interface between the various pieces of hardware, allowing the video game programmers to write code using common software libraries and tools. The two most common storage technologies used for video games today are CD and ROM-based cartridges. Current systems also offer some type of solid-state memory cards for storing saved games and personal information. Newer systems, like the PlayStation 2, have DVD drives. All game consoles provide a video signal that is compatible with television. Depending on your country, this may be NTSC, PAL or possibly even SECAM. Most consoles have a dedicated graphics processor that provides specialized mapping, texturing and geometric functions, in addition to controlling video output. Another dedicated chip typically handles the audio processing chores and outputs stereo sound or, in some cases, digital surround sound!

The Games

The software used on these dedicated computer systems has evolved amazingly from the simple rectangular blips used in Pong. Games today feature richly textured, full-color graphics, awesome sound and complex interaction between player and system. The increased storage capacity of the cartridges and discs allows game developers to include incredibly detailed graphics and CD-quality soundtracks. Several of the video game systems have built-in special effects that add features like unique lighting or texture mapping in real-time. There is a huge variety of games available, but most fall into these broad categories:

• 3-D Action/Adventure (Doom, Tomb Raider)

• Simulation (Aero Fighters' Assault, Maestro Music)

• Sports (NFL Gameday, Tony Hawk's Pro Skater)

• Role-playing/Adventure (Zelda, Final Fantasy)

• Fighting (Mortal Kombat, SoulFighter)

• Puzzle (Tetris, Pokemon Puzzle League)

• Shooter (Defender, Silpheed)

• Platform (Sonic, Super Mario Brothers)

• Racing (Mario Kart, Tokyo Xtreme Racer)

• Conversion (American Arcade Pinball, Who Wants to Be a Millionaire?) Of course, a lot of games include aspects from more than one of these categories, and a few games are in a category all their own.

Comparing Consoles

Just like the world of computers, video game systems are constantly getting better. New technology developed specifically for video game systems is being coupled with other new technologies, such as DVD. Here are some system specs: Sony PlayStation 2:
• Processor: 128-bit "Emotion Engine" 300 MHz Floating point unit (FPU) co-processor Maximum bus transfer rate of 3.2 GB per second Includes current PlayStation CPU core • Graphics: "Graphics Synthesizer" 150 MHz Embedded cache 4 MB VRAM 75 million polygons per second
• Audio: SPU2 (+CPU), 48 channels, 44.1- or 48-kHz sampling rate, 2 MB memory
• RAM: 32 MB RDRAM
• Game medium: Proprietary 4.7-GB DVD and original PlayStation CDs
• Drive bay (for hard disk or network inteface)
• Controller: Two controller ports, "Dual Shock 2" analog controller
• Other features: Two memory card slots Optical digital output Two USB ports FireWire port Support for audio CDs and DVD-Video Nintendo GameCube:
• Processor: "Gekko" IBM Power PC microprocessor 485 MHz Cache:
• level 1: 32 KB Instruction and 32 KB Data
• level 2: 256 KB 32-bit address, 64-bit data bus Maximum bus transfer rate of 2.6 GB per second 0.18 micron copper interconnects
• Graphics: "Flipper" ATI graphics chip162 MHz 1 MB embedded texture cache 3 MB Mosys 1T-SRAM (This static RAM uses a single transistor per cell, like DRAM.) Approximately 12 million polygons per second
• Audio: Special 16-bit digital signal processor, 64 channels, 48-kHz sampling rate
• RAM: 40 MB (24 MB 1T-SRAM, 16 MB of 100-MHz DRAM)
• Game medium: Proprietary 1.5-GB optical disc
• Controller: Four game controller ports, Wavebird wireless game controller
• Other features: Handle for carrying Two slots for 4-MB Digicard Flash memory cards or a 64-MB SD-Digicard adapter High-speed parallel port Two high-speed serial ports Analog and digital audio-video outputs Microsoft Xbox:
• Processor: Modified Intel Pentium III 733 MHz Maximum bus transfer rate of 6.4 GB per second
• Graphics: Custom nVidia 3-D graphics chip 250 MHz Approximately 125 million polygons per second
• Audio: Custom 3-D audio processor
• RAM: 64 MB (Xbox has a unified memory architecture -- the memory can be allocated to graphics, audio, textures or any other function as needed.)
• Game medium: Proprietary 4.7-GB DVD
• Modem/network: Media communications processor (MCP), 10/100-Mbps Ethernet, broadband enabled, 56K modem (optional)
• Controller: Four game controller ports
• Other features: 8-GB built-in hard drive 5X DVD drive with movie playback 8-MB removable memory card Expansion port

Where are all the Internet domain names registered and maintained?

One of the greatest things about the Internet is that nobody really owns it. It is a global collection of networks, both big and small, that connect together in many different ways to form the single entity that we know as "the Internet." Since its beginning in 1969, the Internet has grown from four host computer systems to tens of millions. However, just because nobody owns the Internet, it doesn't mean it is not monitored and maintained in different ways. The Internet Society, a non-profit group established in 1992, oversees the formation of the policies and protocols that define how we use and interact with the Internet. When the Internet was in its infancy, you could only make connections by providing the IP (Internet Protocol) address of the computer you wanted to establish a link with. For example, a typical IP address might be 216.27.22.162. This was fine when there were only a few hosts out there, but it became very unwieldy as more and more systems came online. The first solution to the problem was a simple text file maintained by the Network Information Center that mapped names to IP addresses. Soon this text file became so large it was too cumbersome to manage. In 1983, the University of Wisconsin created the Domain Name System (DNS), which maps text names to IP addresses. This way you only need to remember stuff.dewsoftoverseas.com, for example, instead of 216.27.22.162. The Domain Name System is a distributed database, but there are central name servers at the core of the system (see How DNS Works for details). Someone has to maintain these central name servers to avoid conflicts and duplication. In 1993, the U.S. Department of Commerce, in conjunction with several public and private entities, created InterNIC to maintain a central database that contains all the registered domain names and the associated IP addresses in the U.S. (other countries maintain their own NICs (Network Information Centers) -- there's a link below that discusses Canada's system, for example). Network Solutions, a member of InterNIC, was chosen to administer and maintain the growing number of Internet domain names and IP addresses. This central database is copied to Top Level Domain (TLD) servers around the world and creates the primary routing tables used by every computer that connects to the Internet. Until recently, Network Solutions was the only company that provided domain names. However, to ensure that Network Solutions did not become a monopoly, the U.S. government decided that other companies should also be allowed to sell domain names. While these other companies (known as registrars) provide domain names and maintain DNS servers, Network Solutions still maintains the central database to ensure that there are no duplicates. In the U.S., you pay Network Solutions an annual fee to maintain your domain name in the central name se.

The Telephone

Surprisingly, a telephone is one of the simplest devices you have in your house. It is so simple because the telephone connection to your house has not changed in nearly a century. If you have an antique phone from the 1920s, you could connect it to the wall jack in your house and it would work fine! The very simplest working telephone would look like this inside: As you can see, it only contains three parts and they are all simple:

• A switch to connect and disconnect the phone from the network - This switch is generally called the hook switch. It connects when you lift the handset.

• A speaker - This is generally a little 50-cent, 8-ohm speaker of some sort.

• A microphone - In the past, telephone microphones have been as simple as carbon granules compressed between two thin metal plates. Sound waves from your voice compress and decompress the granules, changing the resistance of the granules and modulating the current flowing through the microphone. That's it! You can dial this simple phone by rapidly tapping the hook switch -- all telephone switches still recognize "pulse dialing." If you pick the phone up and rapidly tap the switch hook four times, the phone company's switch will understand that you have dialed a "4." The only problem with the phone shown above is that when you talk, you will hear your voice through the speaker. Most people find that annoying, so any "real" phone contains a device called a duplex coil or something functionally equivalent to block the sound of your own voice from reaching your ear. A modern telephone also includes a bell so it can ring and a touch-tone keypad and frequency generator. A "real" phone looks like this:
Still, it's pretty simple. In a modern phone there is an electronic microphone, amplifier and circuit to replace the carbon granules and loading coil. The mechanical bell is often replaced by a speaker and a circuit to generate a pleasant ringing tone. But a regular $6.95 telephone remains one of the simplest devices ever.

Google Adsense Ads on Apple IPhone and G1

Facing a very strong economic crisis, Google was searching for some new ways to enhance their revenue and finally ended up with an interesting idea: Adwords for Apple IPhone and G1. With this, people can purchase ads specifically for these handheld devices having their own separate reporting & campaigns.

Everything in this idea can be done through Google Adwords interface. Google is claiming that you wont need to modify the ads for IPhone and G1 cellphones unlike the standard mobile ads since these mobile phones have full efatures rich Internet browers for surfing the websites. Hence it is possible to display your normal adwords ads and landing pages on these small handheld devices without any need to modify the ad code.

In other words, I can say advertising on the iPhone or G1 or future Android-powered devices is just as easy as setting up a regular AdWords campaign for the Web.

It was only a matter of time before Google extended AdWords to these devices, wheres a number of startups are already having phenominal success. AdMob, similar to Google adsense is enjoying 4.5 billion impressions each month on mobiles in the month of October itself and are belived to raise a revenue of around $15 million.

300 Million Apple IPhone Applications

Apple declared that more than 300 million Apple IPhone's applications have been downloaded from its App store till date.

You can see some of the top 10 IPhone Application in the above screenshot. Apple is also claiming that now they have passed the 10,000 applications mark. Whewwww.. Thats a great number. On moving back to history, the Apple store was opened 5 months before and had only 500 applications initially. Since the last earnings announcement, Apple has claimed that over 200 million applications have been downloaded since then.

Challenge-Handshake Authentication Protocol (CHAP).

CHAP is an encrypted authentication mechanism that avoids transmission of the actual password on the connection. The NAS sends a challenge, which consists of a session ID and an arbitrary challenge string, to the remote client. The remote client must use the MD5 one-way hashing algorithm to return the user name and an encryption of the challenge, session ID, and the client's password. The user name is sent unhashed.
CHAP is an improvement over PAP because the clear-text password is not sent over the link. Instead, the password is used to create an encrypted hash from the original challenge. The server knows the client's clear-text password and can, therefore, replicate the operation and compare the result to the password sent in the client's response. CHAP protects against replay attacks by using an arbitrary challenge string for each authentication attempt. CHAP protects against remote client impersonation by unpredictably sending repeated challenges to the remote client throughout the duration of the connection.

Microsoft Challenge-Handshake Authentication Protocol (MS-CHAP

MS-CHAP is an encrypted authentication mechanism very similar to CHAP. As in CHAP, the NAS sends a challenge, which consists of a session ID and an arbitrary challenge string, to the remote client. The remote client must return the user name and an encrypted form of the challenge string, the session ID, and the MD4-hashed password. This design, which uses a hash of the MD4 hash of the password, provides an additional level of security because it allows the server to store hashed passwords instead of clear-text passwords. MS-CHAP also provides additional error codes, including a password expired code, and additional encrypted client-server messages that permit users to change their passwords. In MS-CHAP, both the access client and the NAS independently generate an initial key for subsequent data encryption by MPPE. Therefore, MS-CHAP authentication is required to enable MPPE-based data encryption.

MS-CHAP version 2 (MS-CHAP v2)

MS-CHAP v2 is an updated encrypted authentication mechanism that provides stronger security for the exchange of user name and password credentials and determination of encryption keys. With MS-CHAP v2, the NAS sends a challenge to the access client that consists of a session identifier and an arbitrary challenge string. The remote access client sends a response that contains the user name, an arbitrary peer challenge string, and an encrypted form of the received challenge string, the peer challenge string, the session identifier, and the user's password. The NAS checks the response from the client and sends back a response containing an indication of the success or failure of the connection attempt and an authenticated response based on the sent challenge string, the peer challenge string, the encrypted response of the client, and the user's password. The remote access client verifies the authentication response and, if correct, uses the connection. If the authentication response is not correct, the remote access client terminates the connection.
Using this process, MS-CHAP v2 provides mutual authentication the NAS verifies that the access client has knowledge of the user's password and the access client verifies that the NAS has knowledge of the user's password. MS-CHAP v2 also determines two encryption keys, one for data sent and one for data received.
During phase 2 of PPP link configuration, the NAS collects the authentication data, and then validates the data against its own user database or a central authentication database server, such as one maintained by a Windows domain controller, or the authentication data is sent to a Remote Authentication Dial-in User Service (RADIUS) server.

Extensible Authentication Protocol (EAP)

As stated previously, most implementations of PPP provide very limited authentication methods. EAP is an IETF standard extension to PPP that allows for arbitrary authentication mechanisms for the validation of a PPP connection. EAP was designed to allow the dynamic addition of authentication plug-in modules at both the client and server ends of a connection. This allows vendors to supply a new authentication scheme at any time. EAP provides the highest flexibility in authentication uniqueness and variation.
EAP is documented in RFC 2284 and is supported in Microsoft Windows 2000.

Internet Protocol Security (IPSec) Tunnel Mode
IPSec is a Layer 3 protocol standard that supports the secured transfer of information across an IP internetwork. IPSec is more fully described in the Advanced Security section below. However, one aspect of IPSec should be discussed in the context of tunneling protocols. In addition to its definition of encryption mechanisms for IP traffic, IPSec defines the packet format for an IP over IP tunnel mode, generally referred to as IPSec tunnel mode. An IPSec tunnel consists of a tunnel client and a tunnel server, which are both configured to use IPSec tunneling and a negotiated encryption mechanism.

IPSec tunnel mode uses the negotiated security method (if any) to encapsulate and encrypt entire IP packets for secure transfer across a private or public IP internetwork. The encrypted payload is then encapsulated again with a plain-text IP header and sent on the internetwork for delivery to the tunnel server. Upon receipt of this datagram, the tunnel server processes and discards the plain-text IP header, and then decrypts its contents to retrieve the original payload IP packet. The payload IP packet is then processed normally and routed to its destination on the target network.

IPSec tunnel mode has the following features and limitations:
It supports IP traffic only.
It functions at the bottom of the IP stack; therefore, applications and higher-level protocols inherit its behavior.
It is controlled by a security policy-a set of filter-matching rules. This security policy establishes the encryption and tunneling mechanisms available, in order of preference, and the authentication methods available, also in order of preference. As soon as there is traffic, the two computers perform mutual authentication, and then negotiate the encryption methods to be used. Thereafter, all traffic is encrypted using the negotiated encryption mechanism, and then wrapped in a tunnel header.

RADIUS

The Remote Authentication Dial-in User Service (RADIUS) protocol is a popular method for managing remote user authentication and authorization. RADIUS is a lightweight, UDP-based protocol. RADIUS servers can be located anywhere on the Internet and provide authentication (including PPP PAP, CHAP, MS-CHAP, MS-CHAP v2, and EAP) and authorization for access servers such as NASes and VPN servers.
In addition, RADIUS servers can provide a proxy service to forward authentication requests to distant RADIUS servers. For example, many ISPs have joined consortia to allow roaming subscribers to use local services from the nearest ISP for dial-up access to the Internet. These roaming alliances take advantage of the RADIUS proxy service. If an ISP recognizes a user name as being a subscriber to a remote network, the ISP uses a RADIUS proxy to forward the access request to the appropriate network.

How to Manage Internet Information Services

IIS allows you to easily publish information on the Internet, or on your or your company's intranet. You place your Web files in directories on your server and users establish HTTP connections and view your files with a Web browser. IIS for Windows XP Professional is designed for home or small business networks and allows only 10 simultaneous client connections. It also does not provide all the features that the version included with Windows Server 2003 provides.
You will use the Internet Information Services snap-in to manage IIS. The Internet Information Services snap-in helps you manage the content of and access to your Web and FTP sites. To access the Internet Information Services snap-in, click Start, point to All Programs, point to Administrative Tools, and then click Internet Information Services. The Internet Information Services snap-in lets you handle all aspects of administration for IIS. For example, every Web and FTP site must have a home directory. When you install IIS, a default home directory is created. When you create a new Web site,you can use the Internet Information Services snap-in to change your home directory. To change your home directory, in the Internet Information Services snap-in, right click a Web or FTP site, and then click Properties. In the site's Properties dialog box, click the Home Directory tab. You can specify a directory on this computer, a shared directory located on another computer, or a redirection to a URL, and then type the path in the Local Path text box. Click OK and you have changed your home directory.
If your Web site contains files that are located in directories other than your home directory (for example, on another computer), you must create virtual directories to include these files on your Web site. You use the IIS console to create these virtual directories. In the console, select the Web or FTP site to which you want to add a directory. On the Action menu, point to New, and click Virtual Directory. This starts the Virtual Directory Creation Wizard, which will guide you through creating the new directory. When IIS is installed on a computer running Windows XP Professional, an additional tab named Web Sharing becomes available on the Properties dialog box of any folder, you can use this tab to quickly make any folder accessible via your personal Web site. To share a folder on a personal Web site by using the Web Sharing tab, use these steps:
1. In Windows Explorer, right-click the folder you want to share through your Web site, and then click Properties.2. In the Properties dialog box for the folder, on the Web Sharing tab, use the Share On menu to select the site on which you want to share the folder. By default, the Default Web Site is selected. If you have only one Web site, there are no other choices on the menu.3. Click Share This Folder. Windows XP displays the Edit Alias dialog box.4. In the Edit Alias dialog box, type an Alias for the folder. The alias is the name by which the folder is displayed on the Web site. By default, Windows creates an alias that is the same as the folder name.5. Configure access permissions for the folder. Available access permissions are as follows:

• The Read permission allows users to open or download files in the folder.

• The Write permission allows users to modify files in the folder.

• The Script Source Access permission allows users to access source code for scripts in the folder. • The Directory Browsing permission allows users to view the files in the folder. 6. Configure Application Permissions for the folder. This setting determines whether applications can run scripts or executable files in the folder.

7. Click OK to exit the Edit Alias dialog box.8. Click OK again to apply settings and exit the Properties dialog box for the folder. You can also use the Web Sharing tab to create additional aliases for a folder, edit the properties of existing aliases, and remove an alias from a folder.

Nokia unveiled N97

Nokia recently unveiled the much awaited CellPhone. Ya I am talking about Nokia N97 having a large touchscreen which I feel will bolster its smartphone offering.It is claimed to be the world's most advanced mobile or even the world's most advanced personal computer. Nokia is hoping to Apple a very stiff competition with this product. Also N97 is planning to directly hit Sony Ericsson's X1 and HTC's TouchPro both of which uses MS Windows software.

Features of Nokia N97:

It has a QWERTY keyword along with a 3.5 inch touchscreen. The desktop of this smartphone can be customized as per your needs and support widgets. Also, Nokia N97 has a 16:9 aspect ratio for the wide touchscreen and also has a resolution of 640 X 360 pixels. If you are looking to compare the dimentions of this phone to Apple's IPhone, it is slightly more thicker than IPhone, a rough estimate is 30% more thicker.

The most fascinating feature of Nokia N97 is that it comes with a 32GB internal memory with support for microSD in case you want 16 more GBs, that makes overall support of whopping 48GBs. Like Nokia N95, it also supports a 5 Mega Pixel camera with Carl Zeiss lens and a dual LED Flash. It also supports handwriting recognition and also Nokia's N-Gage gaming system. It also has a 3.5MM headset jack along with a microUSP port which can be used for charging up the phone as well as for syncing. It also has a 1500 mAh battery. As the tradition goes, the OS of this phone is S60 which is the latest version of Nokia's Symbian Operating System.

Nokia is also claiming that this Phone has an inbuilt browser which even supports Flash and Flash videos. I just hope they arent exxagerating. You may think of it as a direct attack on Apple's IPhone which is lacking Flash support. Bill Plummer, the Vice President said at a prelaunch event in New York that Nokia N97 supports real Internet browsing which makes it stand ahead of others. Amazingly, they are also claiming that this phone can play upto 37 hours of nonstop audio, 4.5 hours of Video and has 16.5 days of standby time.

Nokia N97 supports 3G connectivity just like Apple's IPhone along with a built in compass and GPS. Other conenctivity options includes: USB port, Bluetooth, WIFI connectivity and tri-band HSDPA. N97 also uses a new feature called as S0-Lo(Social Location). It means on using the GPS receiver along with integreated compass, this phone can always track your exact location and moreover it can broadcast this information to your authoried relatives or even friends.

Another smart featrue of Nokia N97 which makes it unique is that it supports widgets. Comprehensive Reviews have shown that these widgets appear like icons of square and rectangular size and also provides shortcuts to frequent contacts, audio player, calendar, text messages etc. There is also a provision to drag these shortcuts anywhere as per users choice.

Now coming to the release, Nokia is planning to sel this product somewhere in the first quarter of 2009 for some 699$. Thats a great amount. Just for your information, let me tell you that Nokia has sold more than 10 Million N95 till date.

When to Use the Last Known Good Configuration

Situation SolutionAfter a new device driver is installed, Windows XP Professional restarts, but the system stops responding.Use the Last Known Good configuration option to start Windows XP Professional because the Last Known Good configuration does not contain any reference to the new (possibly faulty) driver.You accidentally disable a critical device driver (such as the Scsi port driver).Some critical drivers are written to keep users from making the mistake of disabling them. With these drivers, the system automatically reverts to the Last Known Good control set if a user disables the driver. If the driver does not automatically cause the system to revert to the Last Known Good control set, you must manually select the Last Known Good Configuration option.

Using the Last Known Good configuration does not help in the following situations:

• When the problem is not related to Windows XP Professional configuration changes. Such a problem might arise from incorrectly configured user profiles or incorrect file permissions. • After you log on. The system updates the Last Known Good control set with Windows XP Professional configuration changes after a successful logon.
• When startup failures relate to hardware failures or missing or corrupted files.

Fixing Corrupted Boot Files

Although the Recovery Console is useful for replacing missing and corrupted boot files such as NTLDR and for fixing problematic MBRs, this is an area in which you should be careful. One of the most common reasons for MBR and NTLDR problems is a type of virus known as a boot sector virus-a virus that resides in the MBR.Once entrenched, boot sector viruses can set about corrupting other files, such as NTLDR. Boot sector viruses can also be difficult to get rid of because they can often survive even a full reformatting of a hard disk. Even if you use the Recovery Console to fix a corrupted boot file, you should not assume that you have gotten to the root of the problem.Fortunately, there are some fairly simple steps you can take to help prevent boot sector viruses from ever becoming a problem. First, all computers should be running good antivirus software that is kept up-to-date with the latest virus information. You should configure the antivirus software to perform full system scans regularly-scans that include the MBR. On most computers, you can also configure BIOS to prevent virus-like activity (which essentially means that it will prompt you before it allows any program to write information to the boot sector).

How spoofing is done

The header of every IP packet contains its source address. This is normally the address that the packet was sent from. By forging the header, so it contains a different address, an attacker can make it appear that the packet was sent by a different machine. This can be a method of attack used by network intruders to defeat network security measures, such as authentication based on IP addresses.This method of attack on a remote system can be extremely difficult, as it involves modifying thousands of packets at a time and cannot usually be done using a Microsoft Windows computer. IP spoofing involves modifying the packet header, which lists, among other things, the source IP, destination IP, a checksum value, and most importantly, the order value in which it was sent. As when a box sends packets into the Internet, packets sent may, and probably will arrive out of order, and must be put back together using the order sent value. IP spoofing involves solving the algorithm that is used to select the order sent values, and to modify them correctly. This poses a major problem because if one evaluates the algorithm in the wrong fashion, the IP spoof will be unsuccessful.This type of attack is most effective where trust relationships exist between machines. For example, it is common on some corporate networks to have internal systems trust each other, so that a user can log in without a username or password provided they are connecting from another machine on the internal network (and so must already be logged in). By spoofing a connection from a trusted machine, an attacker may be able to access the target machine without authenticating.

How to stop spoofing

Packet filtering is one defense against IP spoofing attacks. The gateway to a network should perform ingress filtering; blocking of packets from outside the network with a source address inside the network. This prevents an outside attacker spoofing the address of an internal machine. Ideally outgoing packets should also be filtered, dropping packets from inside the network with a source address that is not inside (egress filtering); this prevents an attacker within the network performing filtering from launching IP spoofing attacks against external machines.

Microsoft is on board

Microsoft is now playing heavily in the NAC space (they call it Network Access Protection). It seems that they have not only added the cornerstone services of NAC, but they've also laced in many of the traditional Microsoft services such as AD integration, SMS and antivirus.Microsoft does have a few things that need to be considered.The first is that it runs on Server 2008, which may or may not be in your environment already. You will also need to do some AD configuration and keep an eye on the load limitations on the NAP server.NAC has come a long way in other areas as well. It can now go as far as using the TPM (Trusted Computing Model) chips included on laptops. For those not aware, manufacturers such as Dell, HP and Gateway have integrated the TPM chip that holds security keys and other crypto information. This allows for full disk encryption and pre-boot authentication. Additionally, you can include other hardware solutions such as biometrics, but you will need a third party NAC solution to use in conjunction with TPM.If you sit down and consider what this offers you in the way of effectively managing endpoints, you can see that NAC appears to ready to play in the enterprise, no matter what your requirements may be.

Plug-ins

In the early '90s, the Internet really started to take off in popularity, and the number of Web sites skyrocketed. There was suddenly a wide variety of people producing Web pages, and they had all sorts of multimedia content they wanted to be able to include. Rather than trying to change browsers to recognize and display these many different forms of content, Web innovators launched the idea of browser plug-ins. Plug-ins are programs that work with your browser to read and play a certain type of file. They are relatively small pieces of software, so it doesn't take users forever to download them off the Internet. They are specifically designed to work with a particular type of file, so they can accomplish a lot of things that a basic browser can't.VideoStreaming video generally uses a plug-in approach that lets you view video content on the web. Web video can include sound and much more elaborate animation. These days, Web designers can use dHTML scripts to detect whether or not you have a particular plug-in. If you don't have it, your browser will display a message that tells you how to download the plug-in. This varies from application to application, but it often takes a good while to go through the entire process, which is a definite disadvantage of handling animation this way. If you already have the plug-in, most browsers will start playing the movie as soon as enough of the file has started downloading. Different plug-ins work in different ways. Video player applications such as QuickTime and Media Player show a sequence of still images, just like an animated GIF or a movie on video, but they are able to transmit the images faster by compressing and streaming them. Compressing is the process of simplifying the information that makes up an image so that its file size decreases. Streaming simply means that the player begins displaying the content before the entire file has downloaded. Even with these capabilities, this sort of movie file takes a long time to download or has poor quality if you have a slow connection.

Dynamic HTML

As we've seen, the main problem with GIF animation is that each frame of the "movie" adds considerably to the total file size. One way of getting around this problem is to eliminate individual frames entirely. Instead, you simply tell the computer to take one still image and move it across the screen. In a sense, you do this with your computer all the time, when you move the cursor across the screen with your mouse. Originally, Web pages were, for the most part, static files -- that is, once you loaded them, they pretty much stayed the same. This is inherent in hypertext markup language (HTML), the basic programming language of Web pages. HTML basically consists of simple tags that tell a Web browser where to display Web page elements. As the Internet continued to evolve, Web designers found this static quality fairly limiting. They wanted to add dynamic content to their Web sites -- that is, content that could change once the user had already downloaded a particular Web page. Dynamic HTML, or dHTML, is the term for the software technology that makes this possible. DHTML content is actually produced by using a number of complex scripting languages, such as Javascript, to access something called the document object model on your Internet browser. Basically, the document object model (DOM) controls everything about how a browser displays a Web page. These days, almost all users have browsers that will expose the DOM to scripting languages, so that this script can alter HTML elements (to change the text color as you move the mouse over a word, for example). DHTML was not created with animation in mind, but it will let you alter HTML elements in a way that will add movement to a Web page. A dHTML script can simply tell the browser to keep changing the placement of a particular image on the page, so it travels around the screen. If you do this with several different images, you can move a series of graphic elements around each other to make interesting movies. Like GIF animation, dHTML animation is automatically recognized by most Web browsers, without the user having to download any extra components. However, it is fairly tricky to create dHTML content that works the same way on all browsers, so this sort of animation is not nearly as simple as GIF animation. Actually coding the animation program yourself is quite difficult, but there are user friendly software applications, such as Macromedia's Dreamweaver, that will produce the correct script code for you. DHTML is fairly limited in its animation applications, because all it can really do is move still images around on the screen. It's much more fluid than GIF animation, but for many applications, it is a much less effective way of displaying a changing image. DHTML is pretty much the limit of a Web browser's built-in animation ability. To add more complex animation abilities to the Internet, innovators had to come up with programs that supplemented the users' browsers.Java AppletsAnother way to provide Web animation is through the universal, network-oriented programming languages known as Java. With Java, programmers can create applications that users download off the Internet. Java-enabled browsers use a virtual machine, a piece of software that recognizes the Java language and translates it for the user's computer system (Windows, MacOS, Unix). The virtual machine is basically a kind of plug-in, and it must be installed with your browser. Java Web content is generally created as programs called applets. Applets aren't complete software applications -- they work only in conjunction with a browser. There are all sorts of things Web designers do with applets, and one of the most popular applications is animation. The main advantages of Java are that it works on all operating systems and it is very flexible. You can create an animation program that draws simple vector shapes for the individual frames, or one that uses bitmap images. Java is particularly suited for creating interactive animations and combining animation with other Web page elements. For more information about Java, check out.

Animated GIFs

One of the biggest innovations in the history of the Internet was the ability to integrate photographs and other illustrations with text on a web page. The illustrations come in the form of bitmap files. A bitmap file simply describes the color of each pixel in the image. To decrease the file size of these bitmap images, several different techniques are used to compress the image data. Typically, Web sites post these sorts of images as either JPEG files or GIF files. Animation is just a series of still images shown in sequence, so the most obvious way to add animation to a Web site is to post a series of bitmap images that the user's browser displays in sequence. This sort of animation, called GIF animation, or GIF89, was the first Web animation to catch on, and it is still very popular today. The main advantages of GIF animation are that it is incredibly simple to work with and it is automatically recognizable to most Web browsers. With a shareware program, such as GIF construction set for Windows or GifBuilder for Macintosh, all you have to do is provide the individual bitmap images that make up the frames of your animation. You then post the file and code the tag for the image, just as you would with an ordinary static GIF. The disadvantage is that you have to keep the animation pretty simple to keep the file size down. After all, each frame is a full bitmap image. Four simple frames transmit very easily to most users, but when you get up to something like 20 frames, your file size could be too big. And you can't even accomplish very much with 20 frames -- the fluid animation we see in movies includes at least 24 still images every second -- so animated GIFs are fairly limited. To create a movie of any substantial length, you have to make pretty big jumps between each frame, which means the animation is not very fluid, as you can see in the example below. This is an excellent way of illustrating a simple concept, or just adding some eye-catching decoration to your site; but Web designers and Web users found it to be wholly inadequate for communicating more complex ideas or adding a real sense of motion to Web sites. Furthermore, you can't add sound to a GIF animation.

Flash and Shockwave

Macromedia has had a great deal of success with two closely related formats, Flash and Shockwave. Flash is now the standard format for rich animation on the Web, and Shockwave is a very popular format for presenting more complex animated content. Unlike Real Player and QuickTime files, Flash and Shockwave movies actually appear as part of the Web page and include a high level of interactivity, just like a straightforward HTML page. The Shockwave player not only plays animation, but also recognizes user input and then controls how the browser responds.Flash and Shockwave are not the only formats for this sort of animation, but they have caught on more than any other similar format. Flash in particular has been successful because it comes bundled with most browsers and can transmit fluid, attractive animation very quickly.Quick Download TimeThere are a couple of different factors that make quick download time possible. First, there is the nature of many Flash files and Shockwave files. Unlike GIF animation, Flash and Shockwave files are largely vector-based. This means that instead of saving the picture as a series of pixel values, the authorware program describes the image as a series of lines and shapes, which it records as mathematical values. A straight line, for example, is described by the angle of its ascent, its coordinate position in relation to the other shapes and its length in relation to the other shapes. Describing images this way allows the program to save wide sections of an image -- sections that might consist of hundreds of pixels in a bitmap file -- as a couple of figures. Both Shockwave and Flash can also use bitmap images, which webmasters can condense and scale down to keep file sizes small. These bitmap pictures can also be moved around the screen by paths, much like still images moving around in dHTML animation, which helps keep the total file size down. Most Flash files are completely vector based, however, which makes them especially quick to load.When your images are produced this way, it decreases the number of frames the animator has to create. Flash and Shockwave technology can create tween frames very easily between vector-based key frames, by calculating the change in geometric information between the two images. This takes up a lot less space than straight bitmap animation, which has to store every frame as a unique image.The other chief innovation is the way in which the files are actually transmitted. Flash and Shockwave files are streamed over the Internet so that the browser can begin playing the "movie" before the entire file has downloaded. Just as a server sends the text of a Web page first and then any picture files, a Flash site can be configured to send an introduction movie while the rest of the Flash content is loading. Webmasters can code the file so that a browser will start playing the movie once a certain amount of the file is downloaded. This is timed so that each part of the file is transmitted before the movie plays to that point. This is also the way streaming video works.AvailabilityFlash and Shockwave have caught on with so many Web users and Web designers largely because of Macromedia's dissemination strategy. These days, the plug-ins come packaged with the major Internet browsers and computer operating systems, and it's very easy to get the free plug-in if you don't already have it. All installation procedures occur in the background, so the user doesn't have to exit the browser program for a lengthy download process. The authorware is expensive, but it is readily available.It's also easy to update the plug-ins, allowing Macromedia to continually develop and then distribute new technology. The company intentionally designed the Flash and Shockwave players to adapt to future modifications, so the user doesn't have to do anything to update the player but download the file. And since these files are fairly small in size, it doesn't take much time to do this. Additionally, if a site detects that you don't have the newest version of the plug-in, your browser will tell you, and direct you to the Macromedia site to download the update.The different animation formats on the Web all have particular strengths and weaknesses. But many webmasters end up using Flash, even when another format might be better suited to their needs, simply because they know that most Web users already have Flash capability; and if they don't, it's really easy for them to get it. The universality of Flash and Shockwave leads more webmasters to include Flash content, which further spreads the acceptance of the formats.

The Difference Between Flash and Shockwave

Flash and Shockwave software applications cover a lot of the same ground, and they are produced by the same company, but there are a few significant differences. Most of these are directly related to the origins of the two file formats. Director, the software application used to create Shockwave files, has been around for a long time, longer than the Internet in its current form. It was originally developed to create dynamic content for CD-ROMs, and it is still used for this purpose. As dynamic content has become more popular on the Internet, however, updated versions of Director have included more features that tailor Shockwave files for use on the Web.Flash, on the other hand, was built from the ground up for use on the Web. Macromedia adapted Flash from Future Splash Animator, a vector art animation program. Macromedia's version was tailored specifically for transmission over phone line connections. So at their heart, Flash and Shockwave have two different specialties. Consequently, they have a number of contrasting strengths and weaknesses:• Flash files load more quickly than Shockwave files.• Shockwave is more versatile. You can create more complex games, more elaborate interactivity and more detailed animation.• You can use more types of files with Shockwave. You could, for example, import a Flash file into a Shockwave movie, but it doesn't work the other way around.• Flash is more universal. More than 90 percent of Web users have the Flash plug-in installed, while a little less than 60 percent have the Shockwave plug-in.• Flash creation software is cheaper. Director costs a little less than $1,000, while Flash costs about $400.• Flash is an open-source format. Anybody can see how it works and is free to adapt it for their own purposes. Director uses a compiled file format, so it is extremely difficult to modify the program.With each software update, the two formats move closer and closer together. Shockwave has better Web capability with each version, and Flash gets more versatile. Eventually, the two formats will probably be merged into one comprehensive format that encompasses the best.

Creating Flash and Shockwave Movies

Flash and Director are designed to be fairly easy and fun to use -- they both have a straightforward interface and many automated tasks. The two programs handle movie creation somewhat differently, and they have different names for almost everything, but they share some basic components. To make a movie, you need to manipulate the movie elements in three different ways. You need to:• Create and edit the individual images that make up the movie.• Arrange these images as they will appear in individual frames of your movie.• Order those frames so that they form a movie.Flash and Shockwave both have a means of importing, generating and editing movie elements. In Flash, you store these elements in the library; in Shockwave, they go in the cast. In both programs, you assign these elements any dynamic characteristics and arrange them on the stage. The stage represents what will actually appear in the final movie. Using the stage, you create key frames that you position in sequence to layout the movie. In Flash, the area for arranging your frames is called the timeline, and in Shockwave it's called the score.One reason you see so much Flash animation on the Web today is that it is surprisingly easy to generate. The Flash program, as well as Director, puts a functioning animation studio right on your desktop, and automates a lot of the complex tasks involved in multimedia. If you want a globe to roll from one side of the screen to the other, for example, you don't have to animate every frame of the globe as it moves along; you simply tell Flash where the globe starts and where it stops and assign it a rolling motion in between these frames. For a good introduction on how to make Flash movies, check out Webmonkey's animation tutorial.

The Future of Web Animation

The next big thing for Web animation is 3-D Web graphics. This gives Web users another level of interaction with online content. In 2-D animation, the Web designer decides what you see, just as animators decide what you see when you watch cartoons on television. In 3-D graphics, you can actually access a 3-D model, so you control the display. You can turn the model around, activate certain functions, and in some cases actually alter its dimensions. Stuff.educationverseas.com has featured a few 3-D models of this sort. Click here to see a 3-D champ car, and here to see a 3-D engine.As with Flash and Shockwave 2-D animation, you need to download a plug-in to view 3-D Web graphics. There are already a number of companies that have developed this software. Viewpoint has had some success, and NxView has a plug-in available on their site. In July, Macromedia and Intel announced that they were developing 3-D capabilities for Shockwave. Users will be able to add 3-D to their Shockwave players by simply downloading an update. Intel chose to work with Macromedia on this project because of the success the company has already had with disseminating multimedia players. The companies hope that the Shockwave 3-D format will become the Web standard for 3-D graphics.The Shockwave technology has a way of scaling 3-D graphics so that they work well with different connection speeds. Basically, if you have a slower connection, the Shockwave player will download a model with fewer polygons, the geometric shapes that combine to form a 3-D model. This means that you'll lose some detail, but you won't lose any image clarity or fluidity of movement.This 3-D Web technology allows for all sorts of interesting site content. One of the most promising applications is in e-commerce. Instead of choosing products based on still pictures, online shoppers will be able to look at the object from every angle, as they would if they were shopping for the object in a store at the mall. Some sites are also using 3-D graphics to create "virtual dressing rooms." The user can create a 3-D model of their body shape and see how different clothes fit that body.This technology can also add a new level of content to educational sites like Stuff.dewsoftoverseas.com. We have already published a few articles using 3-D graphics generated by NxView, and we plan to develop more 3-D content in the future. These graphics let users get a clearer picture of technology and processes -- they can look at an engine from any angle, just as if an actual engine were in front of them.This technology is really amazing, and it will most likely revolutionize the look and feel of the Internet, just as still pictures and Flash animation changed everything up to now. In a future article, we'll delve further into how this technology works and what it can do, and focus specifically on what Macromedia and Intel are doing to develop the Shockwave player as the Web standard.With more and more Web users getting high-bandwidth connection, there will definitely be some big changes in Web animation in the future. One such idea is to make the Web less like a book and more like a video game -- you would access information in a 3-D, interactive world. Another notion is to make it more like television, with lots of high quality animation and video. It really all depends on what Web designers want to include on their sites, which in turn depends on what Web users want to see. In any case, there is every indication that the Internet will continue to evolve at breakneck speed.

Yahoo Buzz is out in the market

Great news for all!!!!! Yahoo Buzz has been released by Yahoo which was initially available to very limited segment of publishers before.

The Yahoo buzz can be about any topic - a great story on a major news site, an extraordinary bit from an obscure site, an amazing video, or a great blogging website that you want to come to general public's notice.

See this screenshot from Yahoo buzz:

You can visit Yahoo buzz from here : http://buzz.yahoo.comBy the way the full form of Yahoo! is Yet Another Hierarchial Officious Oracle.

Group Chat in Gtalk

How many of you people always used Yahoo for Group Chat? I think this number is something which is not countable. Now there is a great news for you all. Now you can have a group chat in Google talk as well. the biggest thing Google Talk lacks in the past was its inability to provide Group chatting option. Now you will wonder, how to start!! Dont worry, its pretty simple using the Google talk gadget. Click the below link to get started.

There is one more way to get started with google chat. You will find the "Launch Google Talk Gadget" link from http://www.google.com/talk/

You will get the following screen on clicking this link:

After clicking on "Launch Google talk Gadget" from the above screen, select any of your online friend. Then you will see a screen something like this:

Currently this is a private conversation. In order to start with group conversation, click on the "Group Chat" link in the above screen. Then you will get a small dropdown from where you can invite others to join in conference. Really exciting isn't it...The people whom you have invited will get a link as an Instant Message(IM) from where they can join you. A very exciting feature of this Group Chat is that you can even make calls. Apart from this, as you can see from above screen, you can also use some beautiful smilies to express yourself.To see more information about this Group Chat, you visit the Google's blog via this link:Google's Blog

Microsoft Internet Explorer 8 Beta

The most awaited browser from Microsoft which is Internet Explorer 8 Beta is now finally released to download. Here is the link http://www.microsoft.com/ie8 . This latest release has some exciting features like Privacy and Security Changes. Last but not the least, I can say unlike its predecessors, It is pretty much fast and easy to use. Also, it strictly follows XHTML compliance.

Have a look at the screenshot which I captured from the microsoft website.

This Internet Explorer 8 is much safer from security point of view as well. It has a great feature like website scanner which will immediately warn you before you even start browsing a potentially harmful site.

Worm targetting Apple OS

These days Apple is enjoying a very good market share all over the globe. Security is one of the most important reason why people would prefer Apple's Macintosh machine compared to Windows.One reason for The Apple Mac's low susceptibility to malicious attacks is because the Operating System is based on the UNIX based kernel which is pretty much stable than the windows platform. Moreover, right now the single digit market share of MAC is not looking too lucrative to the professional hackers.Since last few years, the visibility of Apple has increased a lot in the personal computing space. Its compounded by IPhone's stunning success throughout the world and hence controbuted a lot to the visibility of Leopard, its operating system. Mac are now being used by the enterprise segment.The latest malicious threats to the Macintosh OS is a trojan horse named ASthtv05. Some world renowned analysts has classified this issue as a critical one and raised an alert for it. This trojan can compromise the latest patched versions of Leopard and can eventually take the control of the infected computer. Moreover, it also gains complete administrator rights once the user opens the trojan file. It then opens ports in the firewalls, logs all keystrokes, transmits user names and passwords, takes pictures from the Web camera and also turns on file sharing. It also hides in the background and might turn off system logging thus even preventing the user to come to know that the system is even infected.An interesting point to note, however, is that the source code for this trojan is freely available on the net. This has led researchers to think that the several variants of the exploit code may sooner or later will come. Right now, Apple hasn't commented anything about this threat, through SecureMac's security software can disable this malware. The researchers are also confident that soon Apple will release a patch for this exploit.

Apple's coolest iPhone available for Sale

The countdown has finally finished. The most awaited day has come today. Apple announced the launch on January 9, 2007. Its the 11th July today and Good news for Apple users is that iPhone is going to be launched in the US .Other than US ,iPhone 3G will also be launched in various other countries like Australia, Austria, Belgium, Canada, Denmark, Finland, Germany, Hong Kong, Ireland, Italy, Japan, Mexico, Netherlands, New Zealand, Norway, Poland, Portugal, Spain, Sweden, Switzerland and UK today itself.Apple says that the new iPhone 3G will be twice as fast the exsisting iphone without 3G. The new version of this IPhone software is 2.0 and it has lots of exciting features.Apart from this, Apple has also launched a mobile store named App Store , which will be accessible by new iPhone 3G.This App Store will offer many cool applications for your IPhone from many around the globe including a variety of categories including games, business, news, sports, health, reference and travel etc etc.

Nokia Supernova

Supernova is what Nokia has decided to call their upcoming mobile phones. the news is spreading rapidly like a forest fire and the Internet blogs are bubbling with activity. The very first Supernova range is expected to be out later at the end of this year.Now you guys must be wondering why Supernova and not something else??? Me too initially.. Well the term Supernova makes up an image of something unique and spectacular which means something different from what we are actually used to. I heard Nokia is bringing four models in the very beginning. They will be named 7210, 7310, 7510, 7610. I believe the models arent going to be too costly. The most expensive of the four is said to be released at a price of 350$(approx).Regarding features, they are actually somewhat similar to the previous ones. Some new features that are expected from Supernova series is 3.2 MP camera and a TV-Out connectivity. I believe there will be an option to get the GPS maps and an option to upload multimedia content direct to the websites from this series. These fones are for young guys and girls.. Fashion and design is the core of the range and Nokia knows you want it apart from a regular phone. These could be yours very soon at an attractive price.

Drunkard Car!!! Can you imagine

With ever increasing petrol prices, Eco friendly technologies seem to be catching on. The royal UK family has been caught by the bug. It wasn't long before Prince Charles realized that there are a number of wine bottles lying in his detatched house for ages and could be used for some real use. Afterall, how many bottles could Prince can drink.He got an idea of using his unused wine bottles for running his 38 year old Aston Martin car which he got as a birthday present from Queen Elizabeth when he was 21. The prince managed to run his car completely on bio-ethanol to reduce his carbon emissions.The prince has also converted his other cars which are mainly jaguars, Audi and LandRover to run on 100 percent biodiesel fuel made from used cooking oils. I can certainy say "Ecological Commitment".

Orkut for your Mobile

The Search Engine Giant: Google's social networking website as we all know Orkut which is most popular in Brazil, Pakistan and India has now finallylaunched its full fledged mobile website.

You guys can access to this Orkut mobile website by visiting http://m.orkut.com. I even used this on my cell but didn't found too intuitive. Since last year, As you guys must have noticed, Orkut added so many features like Applications, locking profiles etc etc to stay in hunt with other popular social networking websites to regain its lost popularity to other websites like MySpace and Facebook which ranks even higher than Orkut in terms of traffic.
The Orkut mobile User Interface shows features like your recent 4-5 scraps ,birthday reminders, updates from friends, other links like "Home", "Scrapbook", "My Profile", "Friends" and lastly a search box from where you can search users.

I will suggest you guys to get Opera browser for your mobile and browse the complete website instead of the mobile version which is not very intuitive to use.Mobile site’s URL - http://m.orkut.com

What determines if one communicates using half- or full-duplex?

Half-duplex is used to describe communication where only one side can talk at a time. Once one side has finished transmitting its data, the other side can respond. Only one node can talk at a time. If both try to talk at the same time, a collision will occur on the network. As you can understand, this method of communication is not very efficient and requires more time to send/receive larger amounts of data. Older networks used to work in half-duplex mode, due to the constraints of the network medium (coax cable) and hardware equipment (hubs).On the other hand, full-duplex is used to describe communication where both sides are able to send and receive data at the same time. In these cases, there is no danger of a collision and therefore the transfer of data is completed much faster.Today, all networks make use of switches (rather than hubs) and UTP Ethernet cabling, which allow full-duplex communication between all connected hosts.

What are the relative merits of WLAN, Wi-Fi and WiMax over each other? And what are the primary differences between Wi-Fi and WLAN?

Wireless networks have become increasingly popular in both residential and business environments today. Wi-Fi (short for "wireless fidelity") technology has proved successful in providing cheap wireless solutions for Internet access and network connectivity. Created in 1991, Wi-Fi was designed to serve indoor clients within a short proximity of up to 50 or so meters and outdoor clients of up to 100 meters. The speeds offered by Wi-Fi range from 1 Mbps to 200 Mbps with the use of the latest IEEE wireless LAN (WLAN) standard 802.11n. While Wi-Fi technology is also used to cover larger distances (using high gain antennas), its design is mostly suitable for indoor-outdoor clients, rather than point-to-point links. Worldwide Interoperability for Microwave Access (WiMax), on the other hand, is a newer breed of wireless technology designed mostly for outdoor point-to-point links, but obviously not restricted only to that as there are already products allowing clients to connect to WiMax access points (APs). One of the strong points WiMax has over Wi-Fi is that it doesn't require a line of sight to work. This means you can link up to points even if you've got large obstacles between them, making it a very attractive solution in today's point-to-point links. In addition, WiMax technology is able to push significantly larger amounts of bandwidth over the large distances it covers. Some manufacturers have managed to come out with products that can push over 250 Mbps over links of up to 30-50 miles away (50-80 Kms)! While the benefits of WiMax over Wi-Fi are obvious, we must understand that they are two different technologies aiming to cover different needs. Wi-Fi is a cheap solution aimed to cover short distances and clients offering speeds of up to 200 Mbps; while WiMax is the next-generation of wireless technologies that's very expensive and aims to cover long distances without necessarily having a line of sight.

Linksys EtherFast Cable/DSL Router with 4-Port Switch

The good: Web-based configuration; user-friendly manuals. The bad: Short warranty; network cables not included; no serial COM port. The bottom line: It's hard to go wrong with the EtherFast router, but if you do, you'll wish you had a longer warranty.Specifications: Data link protocol: Ethernet, Fast Ethernet; Dimensions (W x D x H): 7.3 in x 6.1 in x 1.9 in; Connectivity technology: Wired;If you want to share a broadband connection among a small group of PCs at home or at the office, check out the Linksys EtherFast four-port, cable/DSL router. Setup is trouble-free, thanks to the intuitive, Web-based interface, and the included uplink port adds out-of-the-box expandability by letting you connect to another switch or hub. However, the EtherFast's short warranty and lack of cables make it hard to recommend over other similarly priced routers.If you want to share a broadband connection among a small group of PCs at home or at the office, check out the Linksys EtherFast four-port, cable/DSL router. Setup is trouble-free, thanks to the intuitive, Web-based interface, and the included uplink port adds out-of-the-box expandability by letting you connect to another switch or hub. However, the EtherFast's short warranty and lack of cables make it hard to recommend over other similarly priced routers.

Standard features

The EtherFast router comes with all the features you'd expect for the price--and then some. A built-in, auto-sensing, 10/100mbps switch gives each node dedicated bandwidth, which dramatically boosts performance when running applications such as videoconferencing, IP telephony, and multiplayer games. The EtherFast router also has an uplink port--a feature noticeably absent on similar routers, such as the D-Link DI-704 Cable/DSL Internet Gateway. The uplink port expands your network by letting you connect to another switch or hub. However, when you use the uplink port, you must sacrifice the first LAN port, which is automatically disabled. For security, the EtherFast router includes a built-in NAT-based firewall for keeping hackers at bay. However, we wish the EtherFast router had is a serial COM port, which lets you share an external analog or ISDN modem connection if your broadband connection fails.

What are three vital pieces of criteria used to evaluate a network?

There are a ton of ways I could answer this particular request. But if I had to pick just three criteria for evaluating a network, I would say: 1. Is there proper connectivity end-to-end with appropriate security controls to ensure unauthorized internal and external access to sensitive areas? 2. Is the network configured to provide adequate bandwidth and latency to critical applications end-to-end?3. Is the routing and switching design consistent?If I can answer yes to all three of these questions with a resounding YES, then I have an amazing network. I'll elaborate a little further with a few things that would help me determine the answers to these questions: 1. First, I would determine if the proper connectivity is configured by the interfaces. This means ensuring that the right duplexing is established and everything is operating at optimal hardware configuration. Often times performance problems may occur due to interfaces acting in half duplex due to auto-negotiation and it's advisable to ensure proper connectivity throughout. This criterion is also geared toward evaluating firewall settings to ensure that proper access is granted in environments where sensitive data is stored. Many companies do not clearly delineate between networks where testing and development equipment overlap with production equipment with backup and maintenance traffic. Each of these traffic types should have a priority and be well understood in a good network environment. 2. With today's amazing world in innovating how users interact with applications, it's increasingly more important to have a very good understanding of end-to-end traffic flow to control latency and bandwidth requirements for applications. The model of application distribution is changing and this requirement evaluates a network for adequate bandwidth provisioning and the implementation of optimization for latency sensitive, business critical applications. 3. Part of a good network is managing and controlling the configurations to ensure consistent configuration/routing and predictable network connectivity. All too often I go into networks that over the years have evolved into a hodge-podge of band aids that, while suitable at the time, can cause significant issues later when that engineer who designed the one-off is no longer in the company. This requirement would be to ensure that the proper configuration parameters are in place end-to-end. For example, deploying QoS end-to-end only works if each router and switch in the path has a consistently defined QoS policy to treat the application traffic correctly. If packets are flowing, there should be a predictable path that is also flexible from host A to host B without fail. Sound easy? Sure given infinite.

wanted to know what a logical network is and what the importance of one is. I also wanted to know what the best solutions or measurements are to impr

The term "logical network" is usually combined with the known term "physical network." When designing a network, the "logical" part refers to the IP addressing scheme used within the network. For example, 192.168.0.0/24 could be the logical network used for our design. Breaking up our example, our logical network consists of a few important points, which we should be aware of:Network ID (192.168.0.0)Subnet mask (/24 = 255.255.255.0)Usable IP addresses (254 IP addresses)Broadcast address (192.168.0.255)This information exists in every logical network and is vital information as it helps us determine how the design will be usable according to our needs.Selecting the appropriate IP numbering scheme and subnet mask will determine how many usable IP addresses will be available for you. If you have many networks within your company, you should then be careful not to have overlapping or similar networks. Each network must be unique, otherwise routing problems can occur.

What makes a WAN different from a LAN and MAN?

The terms you mention in your question are frequently come by in today's network books and discussions. WAN (Wide Area Network) is used to describe large scale networks that extend across areas, cities and even countries around the globe. International companies with offices around the world use various methods to interconnect them between each other, allowing them to freely exchange data, voice and other services. The speed in which these huge networks run at are relatively small, mainly due to the high costs involved. On the other side, LAN (Local Area Networks) are found in every type of company, office and home. These "small" networks (compared to WAN networks) are fast, much cheaper and easy to maintain in most situations. Today, we have LAN networks running at speeds that touch the 10 Gbps mark, making them lightening fast. The equipment required to run these networks is not considered that expensive, plus, they are easy to maintain. MAN (Metropolitan Area Networks) are somewhere in between WAN and LAN networks. They can spread over a city or two and connect smaller office (LAN) networks between them. The equipment required to run them can be a bit expensive and the speeds they usually reach are the 50-100 Mbps mark depending on the way they interconnect. Each type of network uses their own special set of protocols in order to ensure they operate in the most efficient way, without outages and problems. These protocols vary depending on the type of network. For example, LAN networks usually run the Ethernet Protocol allowing local nodes/workstations to communicate between each other. STP (Spanning Tree Protocol) is also another frequently used protocol that makes sure no network loops are created between switches. MAN and WAN protocols may use routing protocols whose job is to make sure everyone knows about the available networks and how they can be reached. In WAN protocols, you also won't find traditional equipment such as switches or hubs. They only exist in the LAN networks. WAN and MAN networks make use of more sophisticated equipment such as routers that are designed to help connect between each other at high speeds. Routers are found at the boundary of a LAN network, connecting them to larger networks (WANs).

I am still a bit confused on how the terms TCP/IP and HTTP are related. Can you offer more explanations on this with examples and analogies about thes

TCP/IP is a big chapter and one that can't be analyzed in a few paragraphs. To help you get the big picture, we'll keep things simple and focus on the details you need, to ensure you get a proper understanding.The term "TCP/IP" stands for Transmission Control Protocol / Internet Protocol and refers to a number of protocols. The "IP" part of the term, which stands for Internet Protocol, is used by TCP and UDP, to transport them from one network to another. Think of IP as a sort of high-way that allows other protocols to get on and find their way to other computers. TCP and UDP are the "trucks" on the highway, and the "load" they are carrying are protocols such as HTTP, File Transfer Protocol (FTP) and more.As you can understand, TCP and UDP are transport protocols used by protocols such as FTP, HTTP, and SMTP. While both TCP and UDP are used to transport other protocols, they have one significant difference; TCP offers guaranteed data transportation, whereas UDP doesn't. What this means is that TCP has a special mechanism that ensures data is safely transferred without errors from one point to another, whereas UDP doesn't provide any such insurance. HTTP (HyperText Transfer Protocol) is a protocol that utilizes TCP to transfer its information between computers (usually Web servers and clients). The client makes an HTTP request to the Web server using a Web browser, and the Web server sends the requested information (website) to the client.Remember, IP is required to connect all networks; TCP is a mechanism that allows us to transfer data safely; and HTTP, which utilizes TCP to transfer its data, is a specific protocol used by Web servers and clients.

Expert appeal

While the EtherFast router is well suited for network beginners, it also offers several advanced features for more seasoned users. The EtherFast router supports firmware updates via the browser-based interface, allowing foolproof upgrades as Linksys adds new features. IP filtering provides user-level access control, and it also lets an administrator block Internet access from any machine on the local network. In addition, you can fully expose one of the computers to the Internet using the DMZ (demilitarized zone) option. The DMZ host computer acts as a buffer between the outside world and your local network. This is a useful option for Internet gaming or videoconferencing. Telecommuting and virtual private networking (VPN) are also fully supported via point-to-point tunneling protocol (PPTP) and IPSec pass-through technologies.One of the few things wrong with the EtherFast is its warranty. Linksys backs the router for just one year, while other such devices CNET has reviewed are covered for anywhere from five years to life. Everything else about the support is sound: Free phone support is available 24/7, and the Linksys Web site offers user guides, firmware upgrades, FAQs, and a searchable knowledge base. If you're looking for a device that lets you share a high-speed Internet connection among multiple PCs, the Linksys EtherFast four-port cable/DSL router is a solid choice. Its feature set and trouble-free, Web-based setup will appeal to users at all levels. We only wish it came with a longer warranty.

802.11g Wireless DSL/Cable Gateway Router

The good: Easy setup; very good performance; compatible with older 802.11b cards; lifetime warranty. The bad: Expensive; no wireless bridge capabilities; sparse Web site support. The bottom line: With its top performance and easy setup, the Belkin 54g wireless router could be all you need to unwire your home.So far we've been disappointed with the industry leaders' first round of 802.11g products, which have come up short on range, bandwidth, and compatibility. Enter the Belkin 54g wireless cable/DSL gateway router. Though it costs about $50 more than the competition, its easy installation, top-notch throughput, reasonable range, and perfect compatibility with old and new data radios put the established leaders to shame. Add in a built-in firewall, a lifetime warranty, and a six-month subscription to a versatile Web-filtering program for parents, and you have a great all-around solution for distributing Internet access, audio, and video throughout a home or a small office.When we opened the box and read Belkin's claim of a three-minute setup for the 54g wireless cable/DSL gateway router, we chuckled for a moment, then we got down to work. But the joke was on us--exactly 2 minutes and 45 seconds later, we had a fully operational 802.11g wireless network with four wired Ethernet ports. As amazing as it sounds, it's all true, thanks to Belkin's excellent start-up utility, which is among the best in the business. The prize for first place, however, still belongs to Netgear's MR814 802.11b cable/DSL wireless router, with its interactive installation assistant, ISP guide, and Smart Setup wizard.If you're running Windows 98, Me, 2000, or XP, simply put the included start-up CD into the computer connected directly to your cable or DSL modem, run the Easy Install wizard, and follow the onscreen instructions. The router does all the work, and the wizard offers helpful pictures and detailed descriptions of what to expect along the way. All aspects worked well, except that the software twice had to run a 30-second check on our Internet connection before we could proceed with the installation. If you're using an operating system that's not listed above, you can set up the router using the Web-based configuration tool, but you'll need to refer to the user manual for instructions.