Chapter 16 - The IP Multimedia Subsystem: True Converged Communications

Abstract

This chapter deals with IP Multimedia Subsystem (IMS), which is a next-generation multimedia communication framework that encompasses mobile, fixed, packet-switching, and traditional circuit-switching communication systems. The goal of the IMS is to provide a wide spectrum of services with ease and consistency. These services include videoconferencing, Push-to-Talk (PTT), Text-to-Speech (TTS), instant messaging (IM), content sharing, and multipart gaming. To achieve this goal, IMS uses an open standard IP protocol and extension of Session Initiation Protocol (SIP). IMS enables many feature sets of convergence services but opens the IP network to security vulnerabilities. IMS addresses some security issues like unauthorized use, privacy, and denial of services. A built-in IPSec makes it hard to do packet forgery, eavesdropping, and IP spoofing and session hijacking. It has been proposed by the Third Generation Partnership Project (3GPP) and uses the Voice over Internet Protocol (VoIP) framework, especially the SIP standard. The 3GPP is a standard organization driven by wireless carriers and equipment manufacturers and aims at producing globally applicable specification and reports for Third Generation (3G) Mobile Systems based upon Global System for Mobile Communication (GSM). The 3GPP also is working with the Internet Engineering Task Force (IETF) on SIP-related standards.