Internet Telephony: The Evolution to a Service-Oriented Architecture
The field of telecommunications has evolved to resemble the distributed computing domain, where general-purpose computers communicate over a common network. This evolution has culminated in the Third-Generation Internet Multimedia Subsystem (3G IMS) Architecture. In the computing domain, the Web Services Architecture or, in general, the Service-Oriented Architecture (SOA) is the modern trend in distributed computing today. Both the IMS and the Web Services Architecture provide services built on common, standardized, and well-known protocols. In this chapter, we present our views on the continuing evolution of these two architectures as the boundary between telecommunications and computing services continues to blur. We provide a high-level architectural overview of both the telecommunications and Internet networks to provide a context for the requirements we derive for a telecommunications SOA. Detailed architectures of both the networks will be provided in Chapter 3.