PDF of this tutorialTrue convergence has eluded the world of telecommunications for decades. Until this last decade, the ability to run voice on data networks has not even existed. Though recent advances in technology have allowed voice services to be delivered over digital subscriber line (DSL) using the Class-5 switch/GR303 model, the resulting services are still completely unaware of personal computers (PCs) running voice-over–Internet protocol (VoIP) applications such as NetMeeting or IP phones from companies such as 3Com. And there are still two networks—one for data (and its terminals) and one for voice (and its terminals).
But the 1990s are over, and the next decade is a different story entirely. We are seeing the maturation of next-generation call-control protocols, such as the session initiation protocol (SIP) and media gateway control protocol (MGCP). The protocols are now finding their way into IP–based terminals—IP phones, soft phones, soft private branch exchanges (PBXs)—and network hardware, including access gateways, integrated access devices (IADs), media gateways, DSL access multiplexers (DSLAMs), cable modem termination systems, and cable head ends.
What this means is that now—and only now—can carriers start to entertain deployments of next-generation broadband services that demonstrate the power of what a truly converged, IP–based voice/data network can offer residential and business subscribers. This raises the issue of exactly what convergence really means.
