计算机网络（第4版）（影印版） (2008 年度畅销榜NO.326 )

本书是国内外使用最为广泛的计算机网络经典教材。全书按照网络协议模型（物理层、数据链路层、介质访问控制子层、网络层、传输层和应用层），自下而上系统地介绍了计算机网络的基本原理，并给出了大量实例。在讲述各网络层的同时，还融合进了近年来迅速发展起来的各种网络技术，如Internet、SONET、ADSL、CDMA、WLAN和蓝牙等。另外，针对当前计算机网络的发展现状以及计算机安全的重要性，本书用了一整间的篇幅对计算机安全进行了深入讨论。\r\n 本书的适用对象很广泛。对于学习计算机网络课程的本科生以及研究生，本书都可以作为教材或教学参考书，每一章后面的大量练习题，可用于课程作业或者复习要点。对于从事网络研究、网络工程以及使用和管理网络的科研和工程技术人员，本书也是一本很有价值的参考读物。

1 INTRODUCTION\r\n 1.1 USES OF COMPUTER NETWORKS\r\n 1.1.1 Business Applications\r\n 1.1.2 Home Applications\r\n 1.1.3 Mobile Users\r\n 1.1.4 Social Issues\r\n 1.2 NETWORK HARDWARE\r\n 1.2.1 Local Area Networks\r\n 1.2.2 Metropolitan Area Networks\r\n 1.2.3 Wide Area Networks\r\n 1.2.4 Wireless Networks\r\n 1.2.5 Home Networks\r\n 1.2.6 Internetworks\r\n 1.3 NETWORK SOFTWARE\r\n 1.3.1 Protocol Hierarchies\r\n 1.3.2 Design Issues for the Layers\r\n 1.3.3 Connection-Oriented and Connectionless Services\r\n 1.3.4 Service Primitives\r\n 1.3.5 The Relationship of Services to Protocols\r\n 1.4 REFERENCE MODELS\r\n 1.4.1 The OSI Reference Model\r\n 1.4.2 The TCP/IP Reference Model\r\n 1.4.3 A Comparison of the OSI and TCP/IP Reference Models\r\n 1.4.4 A Critique of the OSI Model and Protocols\r\n 1.4.5 A Critique of the TCP/IP Reference Model\r\n 1.5 EXAMPLE NETWORKS\r\n 1.5.1 The Internet\r\n 1.5.2 Connection-Oriented Networks:X.25,Frame Relay,and ATM\r\n 1.5.3 Ethernet\r\n 1.5.4 Wireless LANs:802.11\r\n 1.6 NETWORK STANDARDIZATION\r\n 1.6.1 Who''s Who in the Telecommunications World\r\n 1.6.2 Who''s Who in the International Standards World\r\n 1.6.3 Who''s Who in the Internet Standards World\r\n 1.7 METRIC UNITS\r\n 1.8 OUTLINE OF THE REST OF THE BOOK\r\n 1.9 SUMMARY\r\n2 THE PHYSICAL LAYER\r\n 2.1 THE THEORETICAL BASIS FOR DATA COMMUNICATION\r\n 2.1.1 Fourier Analysis\r\n 2.1.2 Bandwidth-Limited Signals\r\n 2.1.3 The Maximum Data Rate of a Channel\r\n 2.2 GUIDED TRANSMISSION MEDIA\r\n 2.2.1 Magnetic Media\r\n 2.2.2 Twisted Pair\r\n 2.2.3 Coaxial Cable\r\n 2.2.4 Fiber Optics\r\n 2.3 WIRELESS TRANSMISSION\r\n 2.3.1 The Electromagnetic Spectrum\r\n 2.3.2 Radio Transmission\r\n 2.3.3 Microwave Transmission\r\n 2.3.4 Infrared and Millimeter Waves\r\n 2.3.5 Lightwave Transmission\r\n 2.4 COMMUNICATION SATELLITES\r\n 2.4.1 Geostationary Satellites\r\n 2.4.2 Medium-Earth Orbit Satellites\r\n 2.4.3 Low-Earth Orbit Satellites\r\n 2.4.4 Satellites versus Fiber\r\n 2.5 THE PUBLIC SWITCHED TELEPHONE NETWORK\r\n 2.5.1 Structure of the Telephone System\r\n 2.5.2 The Politics of Telephones\r\n 2.5.3 The Local Loop:Modems,ADSL,and Wireless\r\n 2.5.4 Trunks and Multiplexing\r\n 2.5.5 Switching\r\n 2.6 THE MOBILE TELEPHONE SYSTEM\r\n 2.6.1 First-Generation Mobile Phones:Analog Voice\r\n 2.6.2 Second-Generation Mobile Phones:Digital Voice\r\n 2.6.3 Third-Generation Mobile Phones:Digital Voice and Data\r\n 2.7 CABLE TELEVISION\r\n 2.7.1 Community Antenna Television\r\n 2.7.2 Internet over Cable\r\n 2.7.3 Spectrum Allocation\r\n 2.7.4 Cable Modems\r\n 2.7.5 ADSL versus Cable\r\n 2.8 SUMMARY\r\n3 THE DATA LINK LAYER\r\n4 THE MEDIUM ACCESS CONTROL SUBLAYER\r\n5 THE NETWORK LAYER\r\n6 THE TRANSPORT LAYER\r\n7 THE APPLICATION LAYER\r\n8 NETWORK SECURITY\r\n9 READING LIST AND BIBLIOGRAPHY\r\nINDEX

This book is now in its fourth edition. Each edition has corresponded to a different phase in the way computer networks were used. When the first edition appeared in 1980, networks were an academic curiosity. When the second edition appeared in 1988, networks were used by universities and large businesses. When the third edition appeared in 1996, computer networks, especially the Internet, had become a daily reality for millions of people. The new item in the fourth edition is the rapid growth of wireless networking in many forms. The networking picture has changed radically since the third edition. In the mid-1990s, numerous kinds of LANs and WANs existed, along with multiple protocol stacks. By 2003, the only wired LAN in widespread use was Ethernet, and virtually all WANs were on the Internet. Accordingly, a large amount of material about these older networks has been removed. However, new developments are also plentiful. The most important is the huge increase in wireless networks, including 802.11, wireless local loops, 2G and 3G cellular networks, Bluetooth, WAP, i-mode, and others. Accordingly, a large amount of material has been added on wireless networks. Another newly-important topic is security, so a whole chapter on it has been added. Although Chap. 1 has the same introductory function as it did in the third edition, the contents have been revised and brought up to date. For example, introductions to the Internet, Ethernet, and wireless LANs are given there, along with some history and background. Home networking is also discussed briefly. Chapter 2 has been reorganized somewhat. After a brief introduction to the principles of data communication, there are three major sections on transmission (guided media, wireless, and satellite), followed by three more on important examples (the public switched telephone system, the mobile telephone system, and cable television). Among the new topics covered in this chapter are ADSL, broadband wireless, wireless MANs, and Internet access over cable and DOCSIS. Chapter 3 has always dealt with the fundamental principles of point-to-point protocols. These ideas are essentially timeless and have not changed for decades. Accordingly, the series of detailed example protocols presented in this chapter is largely unchanged from the third edition. In contrast, the MAC sublayer has been an area of great activity in recent years, so many changes are present in Chap. 4. The section on Ethernet has been expanded to include gigabit Ethernet. Completely new are major sections on wireless LANs, broadband wireless, Bluetooth, and data link layer switching, including MPLS. Chapter 5 has also been updated, with the removal of all the ATM material and the addition of additional material on the Internet. Quality of service is now also a major topic, including discussions of integrated services and differentiated services. Wireless networks are also present here, with a discussion of routing in ad hoc networks. Other new topics include NAT and peer-to-peer networks. Chap. 6 is still about the transport layer, but here, too, some changes have occurred. Among these is an example of socket programming. A one-page client and a one-page server are given in C and discussed. These programs, available on the book's Web site, can be compiled and run. Together they provide a primitive remote file or Web server available for experimentation. Other new topics include remote procedure call, RTP, and transaction/TCP. Chap. 7, on the application layer, has been more sharply focused. After a short introduction to DNS, the rest of the chapter deals with just three topics: email, the Web, and multimedia. But each topic is treated in great detail. The discussion of how the Web works is now over 60 pages, covering a vast array of topics, including static and dynamic Web pages, HTTP, CGI scripts, content delivery networks, cookies, and Web caching. Material is also present on how modern Web pages are written, including brief introductions to XML, XSL, XHTML, PHP, and more, all with examples that can be tested. The wireless Web is also discussed, focusing on i-mode and WAP. The multimedia material now includes MP3, streaming audio, Internet radio, and voice over IP. Security has become so important that it has now been expanded to a complete chapter of over 100 pages. It covers both the principles of security (symmetric- and public-key algorithms, digital signatures, and X.509 certificates) and the applications of these principles (authentication, e-mail security, and Web security). The chapter is both broad (ranging from quantum cryptography to government censorship) and deep (e.g., how SHA-1 works in detail). Chapter 9 contains an all-new list of suggested readings and a comprehensive bibliography of over 350 citations to the current literature. Over 200 of these are to papers and books written in 2000 or later. Computer books are full of acronyms. This one is no exception. By the time you are finished reading this one, the following should ring a bell: ADSL, AES, AMPS, AODV, ARP, ATM, BGP, CDMA, CDN, CGI, CIDR, DCF, DES, DHCP, DMCA, FDM, FHSS, GPRS, GSM, HDLC, HFC, HTML, HTTP, ICMP, IMAP, ISP, ITU, LAN, LMDS, MAC, MACA, MIME, MPEG, MPLS, MTU, NAP, NAT, NSA, NTSC, OFDM, OSPF, PCF, PCM, PGP, PHP, PKI, POTS, PPP, PSTN, QAM, QPSK, RED, RFC, RPC, RSA, RSVP, RTP, SSL, TCP, TDM, UDP, URL, UTP, VLAN, VPN, VSAT, WAN, WAP, WDMA, WEP, WWW, and XML But don't worry. Each will be carefully defined before it is used. To help instructors using this book as a text for a course, the author has prepared various teaching aids, including A problem solutions manual. Files containing the figures in multiple formats. PowerPoint sheets for a course using the book. A simulator (written in C) for the example protocols of Chap. 3. A Web page with links to many tutorials, organizations, FAQs, etc. The solutions manual is available directly from Prentice Hall (but only to instructors, not to students). All the other material is on the book's Web site: http://www.prenhall, com/tanenbaum From there, click on the book's cover. Many people helped me during the course of the fourth edition. I would especially like to thank the following people: Ross Anderson, Elizabeth BeldingRoyer, Steve Bellovin, Chatschik Bisdikian, Kees Bot, Scott Bradner, Jennifer Bray, Pat Cain, Ed Felten, Warwick Ford, Kevin Fu, Ron Fulle, Jim Geier, Mario Gerla, Natalie Giroux, Steve Hanna, Jeff Hayes, Amir Herzberg, Philip Homburg, Philipp Hoschka, David Green, Bart Jacobs, Frans Kaashoek, Steve Kent, Roger Kermode, Robert Kinicki, Shay Kutten, Rob Lanphier, Marcus Leech, Tom Maufer, Brent Miller, Shivakant Mishra, Thomas Nadeau, Shlomo Ovadia, Kaveh Pahlavan, Radia Perlman, Guillaume Pierre, Wayne Pleasant, Patrick Powell, Thomas Robertazzi, Medy Sanadidi, Christian Schmutzer, Henning Schulzrinne, Paul Sevinc, Mihail Sichitiu, Bernard Sklar, Ed Skoudis, Bob Strader, George Swallow, George Thiruvathukal, Peter Tomsu, Patrick Verkaik, Dave Vittali, Spyros Voulgaris, Jan-Mark Warns, Ruediger Weis, Bert Wijnen, Joseph Wilkes, Leendert van Doom, and Maarten van Steen. Special thanks go to Trudy Levine for proving that grandmothers can do a fine job of reviewing technical material. Shivakant Mishra thought of many challenging end-of-chapter problems. Andy Dornan suggested additional readings for Chap. 9. Jan Looyen provided essential hardware at a critical moment. Dr. F. de Nies did an expert cut-and-paste job fight when it was needed. My editor at Prentice Hall, Mary Franz, provided me with more reading material than I had consumed in the previous 7 years and was helpful in numerous other ways as well. Finally, we come to the most important people: Suzanne, Barbara, and Marvin. To Suzanne for her love, patience, and picnic lunches. To Barbara and Marvin for being fun and cheery all the time (except when complaining about awful college textbooks, thus keeping me on my toes). Thank you. ANDREW S. TANENBAUM