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.