Chapter 18. VoIP and Multimedia Networking


The discussion in the previous chapter on compressed voice and video sets the stage for the discussion in this chapter on multimedia networking. The communication industry has spent considerable effort in designing an IP-based media transport mechanism: voice over IP (VoIP), which can deliver voice- band telephony with the quality of telephone networks. Internet phone services are less expensive and have more features, such as video conferencing, online directory services, and Web incorporation. Multimedia networking is one of the most effective Internet developments. In addition to data, the Internet is used to transport phone calls, audio, and video. This chapter looks at the transportation of real-time signals along with the signaling protocols used in voice telephony, video streaming, and multimedia networking, covering the following major topics:

  • Overview of IP telephony

  • VoIP signaling protocols

  • Real-time media transport protocols

  • Distributed multimedia networking

  • Stream Control Transmission Protocol (SCTP)

  • Self-similarity and non-Markovian streaming analysis

This chapter focuses on transport mechanisms for the delivery of media streams with the highest possible quality. After reviewing how sampled and digitized streams of voice are treated in networks, we look at two VoIP protocols Session Initiation Protocol (SIP) and the H.323 series of protocols and explain their session signaling and numbering. We then present real-time media transport protocols , by which a sender sends a stream of data at a constant rate. The most widely applied protocol for real-time transmission is the Real-Time Transport Protocol (RTP), which is available with its companion version, Real-Time Control Protocol (RTCP).

As detailed in our discussion on video streaming, a video in a single server can be streamed from a video server to a client for each client request. However, when a high-bit-rate video stream must pass through many Internet domains, a significant delay may result. We then present a solution by using content distribution networks (CDNs), which can bring multimedia content to users. The Stream Control Transmission Protocol (SCTP) provides a general-purpose protocol for transporting stream traffic. The chapter ends with a detailed streaming source modeling and analysis and a detailed traffic modeling of streaming sources, using self-similarity patterns.



Computer and Communication Networks
Computer and Communication Networks (paperback)
ISBN: 0131389106
EAN: 2147483647
Year: 2007
Pages: 211
Authors: Nader F. Mir

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