Douglas Comer, author of many successful books and an expert in computer networking, builds a comprehensive picture of the technologies that enable the Internet to provide application services such as web browsing and instant messaging. The book offers an excellent tour that covers everything from Internet applications to the lower levels of packet transmission.

It describes how protocols are arranged in layers and explains how the services of one layer are used by the immediately higher layer. Fully updated, the book includes the following:

• UDP: User Datagram Protocol Transport Service: Introduces the end-to-end User Datagram Protocol and how it is used. The UDP protocol, once considered secondary, now serves as the foundation for streaming and multicast applications, as well as for new audio and video transport applications.
• Network Address Translation: Explains how NAT technology overcomes the Internet's limitations regarding the sharing of an IP address among multiple computers, which is extremely important in home setups and small business environments.
• Voice over IP (VoIP): Examines the exciting application of the Internet; making phone calls over the Internet (VoIP). It describes the competitive standards of IP telephony, including protocols like H.323, Session Initiation Protocol (SIP), and Megaco. It also presents a SIP session example.

The book comes with a multimedia CD-ROM (in English), featuring animations, packet traces, over 200 photographs of networking equipment, code from the book, and copies of protocol standards.