This book is designed for introductory one-semester or one-year courses in communications networks in upper-level undergraduate programs. The second half of the book can be used in more advanced courses. As pre-requisites the book assumes a general knowledge of computer systems and programming, and elementary calculus. The second edition expands on the success of the first edition by updating on technological changes in networks and responding to comprehensive market feedback.

New to This Edition

• The introduction in Chapter 1 has been simplified by reducing the number of concepts introduced in the discussion of network evolution.
• The introduction of the notion of layering has been improved by elaborating on the interaction between the application layer and transport layer protocols and by simplifying the discussion of the OSI reference model.
• The material in the text has been rearranged so that optional sections can be skipped without a disruption in the topic flow. The sections that contain optional material are still indicated by a diamond in the heading. The optional sections that contain detailed mathematics are now indicated by a sidebar.
• The discussion of PCM speech coding has been moved from Chapter 12 to Chapter 3.
• Chapter 4 provides more detail on SONET and optical transport networks. Satellite cellular networks has been dropped.
• Chapter 5 now consists of two parts to separate the initial focus of the first part, peer-to-peer protocols, from the focus of the second part, data link layer protocols. There is now a new separate section on framing techniques.
• Chapter 6 has also been divided into a section on medium access control in general (Part 1), and the application of medium access controls in LANs (Part 2). We have attempted to concentrate the detailed mathematical discussion of medium access control to the last section in the chapter.
• In Chapter 7 we have streamlined the discussion of packet networks, and we have clearly separated the more advanced discussion of traffic management mechanisms.
• The main change in Chapter 8 is the extensive use of packet capture examples to illustrate the operation of TCP/IP protocols.
• The chapter on advanced network architectures has been revised extensively. The discussion of ATM over IP has been replaced by a discussion of the overlay and peer models to network interconnection. The chapter now contains discussion on virtual networks, and GMPLS. The material on RTP and SIP has been moved from Chapter 12 to this chapter.
• Chapter 11 has been updated with brief discussions of the Advanced Encryption Standard and of 802.11 security.
• Numerous figures. Network diagrams, time diagrams, performance graphs, state transition diagrams are essential to effectively convey concepts in networking.
• Numerous Examples. The discussion of fundamental concepts is accompanied with examples illustrating the use of the concept in practice. Numerical examples are included in the text wherever possible.
• Text Boxes. Commentaries in text boxes are used to discuss network trends and interesting developments, to speculate about future developments, and to motivate new topics.
• Problems. The authors firmly believe that learning must involve problem solving. Each chapter includes problems with a range of difficulties from simple application of concepts to exploring, developing or elaborating various concepts and issues. Quantitative problems range from simple calculations to brief case studies exploring various aspects of certain algorithms, techniques or networks. Simple programming exercises involving sockets and TCP/IP utilities are included where appropriate.
• An Instructor's Solutions Manual is available from the McGraw-Hill web site.
• Chapter Introductions. Each chapter includes an introduction previewing the material covered in the chapter and in the context of the "big picture."
• Chapter Summaries and Checklist of Important Terms. Each chapter includes a summary that reiterates the most important concepts. A checklist of important terms will aid the student in reviewing the material.
• References. Each chapter includes a list of references. Given the introductory nature of the text, references concentrate on pointing to more advanced materials. Reference to appropriate Internet Engineering Taskforce (IETF) RFCs and research papers is made where appropriate, especially with more recent topics.
• A web site. The following Web site contains links to the online version of the solutions manual, the Powerpoint slides, author information, and other related information: www.mhhe.com/leon-garcia.
• The figures in the book are based on a set of MS PowerPoint course presentations that depend heavily on visual representation of concepts. A set of these presentation charts, some of which use animation, have been prepared and are available to instructors.

Features

• The Big Picture is presented first in chapter one and two with a discussion of network-based applications and services such as the WWW, email, and home video entertainment. The essential functions in the operation of a network are discussed, and examples are given hat motivate the notion of layering, and the OSI Reference model.
• Network performance is introduced as an integral part of network design and operation. Quantitative examples are used to show the tradeoffs involved in various situations.
• The Berkeley API sockets are introduced in an optional section in Chapter 2 and socket programming exercises are included.
• Telnet-based exercises to demonstrate the operation of various TCP/IP protocols are also included.
• Many figures, network graphs, time diagrams, performance curves, etc. are found throughout the text. These diagrams are essential to effectively convey concepts in networking. A set of PowerPoint presentations, upon which the book's figures are based, is available to adopters of the text via the web site for the book.

1 Communication Networks and Services
2 Layered Architectures
3 Digital Transmission Fundamentals
4 Circuit-Switching Networks
5 Peer-to-Peer Protocols and Data Link Layer
6 Medium Access Control Protocols and Local Area Networks
7 Packet-Switching Networks
8 TCP/IP
9 ATM Networks
10 Advanced Network Architectures
11 Security Protocols
12 Multimedia Information and Networking

Appendix A Delay and Loss Performance
Appendix B Network Management