Chapter 2. Voice and Video Communication Over Packet Networks

• TCP/IP and the OSI Reference Model

• Performance Characteristics of an IP Network

• Measuring IP Network Performance

• Effects of Transport Protocols

• Requirements for Audio/Video Transport in Packet Networks

Before delving into details of RTP, you should understand the properties of IP networks such as the Internet, and how they affect voice and video communication. This chapter reviews the basics of the Internet architecture and outlines typical behavior of a network connection. This review is followed by a discussion of the transport requirements for audio and video, and how well these requirements are met by the network.

IP networks have unique characteristics that influence the design of applications and protocols for audio/video transport. Understanding these characteristics is vital if you are to appreciate the trade-offs involved in the design of RTP, and how they influence applications that use RTP.