本书是在第一版的基础上修订而成的，在第四版中进行了许多重要的修改。鉴于网络安全的极端重要性，在版本中增加了对网络安全的关注，在第一章的一个新小节中介绍了网络安全问题，并且在其他各章中都加入了与网络安全有关的新内容，同时对第8章中的有关“网络安全”内容进行更新和扩展。此外，本版本还更新和扩展了有关无线网络的内容，并且增加了针对802.11(WiFi)、802.16(WiMAC)以及蜂窝网络的全新内容。在各章内容的结尾，我们加入了新的练习题，以及额外的动手练习“Ethereal labs”。该书可供各大专院校作为教材使用，也可供从事相关工作的人员作为参考用书使用。

Chapter 1 Computer Networks and the Internet

 1.1  What Is the Internet?

1.1.1 A Nuts-and-Bolts Description

1.1.2 A Services Description

1.1.3 What Is a Protocol?

 1.2 The Network Edge

1.2.1 Client and Server Programs

1.2.2 Access Networks

1.2.3 Physical Media

 1.3 The Network Core

1.3.1 Circuit Switching and Packet Switching

1.3.2 How Do Packets Make Their Way Through Packet-Switched Networks?

1.3.3 ISPs and Internet Backbones

 1.4 Delay, Loss, and Throughput in Packet-Switched Networks

1.4.1 Overview of Delay in Packet-Switched Networks

1.4.2 Queuing Delay and Packet Loss

1.4.3 End-to-End Delay

1.4.4 Throughput in Computer Networks

 1.5 Protocol Layers and Their Service Models

1.5.1 Layered Architecture

1.5.2 Messages, Segments, Datagrams, and Frames

 1.6 Networks Under Attack

 1.7 History of Computer Networking and the Internet

1.7.1 The Development of Packet Switching: 1961-1972

1.7.2 Proprietary Networks and Internetworking: 1972-1980

1.7.3 A Proliferation of Networks: 1980-1990

1.7.4 The Intemet Explosion: The 1990s

1.7.5 Recent Developments

 1.8 Summary

Road-Mapping This Book

Homework Problems and Questions

Problems

Discussion Questions

Ethereal Lab

Interview: Leonard Kleinrock

Chapter 2 Application Layer

 2.1 Principles of Network Applications

2.1.1 Network Application Architectures

2.1.2 Processes Communicating

2.1.3 Transport Services Available to Applications

2.1.4 Transport Services Provided by the Internet

2.1.5 Application-Layer Protocols

2.1.6 Network Applications Covered in This Book

 2.2 The Web and HTTP

2.2.1 Overview of HTTP

2.2.2 Non-persistent and Persistent Connections

2.2.3 HTTP Message Format

2.2.4 User-Server Interaction: Cookies

2.2.5 Web Caching

2.2.6 The Conditional GET

 2.3 File Transfer: FTP

2.3.1 FTP Commands and Replies

 2.4 Electronic Mail in the Internet

2.4.1 SMTP

2.4.2 Comparison with HTTP

2.4.3 Mail Message Formats and MIME

2.4.4 Mail Access Protocols

 2.5 DNS--The lnternet's Directory Service

2.5.1 Services Provided by DNS

2.5.2 Overview of How DNS Works

2.5.3 DNS Records and Messages

 2.6 Peer-to-Peer Applications

2.6.1 P2P File Distribution

……

Chapter 3 Transport Layer

Chapter 4 The Network Layer

Chapter 5 The Link Layer and Local Area Networks

Chapter 6 Wireless and Mobile Networks

Chapter 7 Multimedia Networking

Chapter 8 Security in Computer Networks

Chapter 9 Network Management

References

Index