VoIP Gateways:

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.