An architecture for residential Internet telephony service

Network gateways are used to set up calls between the public switched telephone network (PSTN) and the Internet, but existing gateways support a relatively small number of lines. To meet the scalability and availability requirements of mass-market deployment of carrier-grade telephony services, the authors propose an architecture based on the decomposition of Internet gateway functionality. The media transformation function of today's H.323 gateways is separated from the gateway control function, and intelligence is centralized in a call agent. The Media Gateway Control Protocol is introduced; MGCP is an Internet draft currently under discussion by the IETF for standardizing the interface between a call agent and the media transformation gateway.