شبکه‌های کامپیوتری و اینترنت (ویرایش پنجم)

With the advent of the World Wide Web the global Internet has rapidly become the dominant type of computer network. It now enables people around the world to use the Web for E-Commerce and interactive entertainment applications, in addition to those already supported by the Internet such as e-mail and IP telephony. As a result, the study of computer networking is now synonymous with the study of the Internet and its applications. The 5th edition of this highly successful text has been completely revised to focus entirely on the Internet, and so avoids the necessity of describing protocols and architectures that are no longer relevant. As many Internet applications now involve multiple data types ¿ text, images, speech, audio and video ¿ the book explains in detail how they are represented. A number of different access networks are now used to gain access to the global Internet. Users at home and in small businesses gain access through their local switched telephone network using either a low bit rate or broadband modem. For users served by a cable television provider, access is often through a high bit rate cable modem. Wireless networks are now widely used including Internet-enabled mobile phones with cellular phone networks and, within buildings, wireless networks such as Bluetooth. These are in addition to the site networks used by academic institutions and large businesses. Separate chapters illustrate how each type of access network operates and interfaces to the global Internet. This is followed by a detailed account of the architecture and protocols of the Internet itself and the operation of the major application protocols. This body of knowledge is made accessible by extensive use of illustrations and worked examples that make complex systems more understandable at first glance. This makes the book ideal for self-study or classroom use for students in Computer Science or Engineering, as well as being a comprehensive reference for practitioners who require a definitive guide to networking. New in this edition: A separate chapter is devoted to each of the different types of access network: Telephone networks, LANs and intranets, Wireless networks, and Entertainment networks. A chapter is devoted to each of the main components of the global Internet, from modern Internet protocols to the World Wide Web. A whole chapter is devoted to the vital topic of Network Security. An online study guide provides a rich set of resources for both students and instructors: check out www.pearsoned.co.uk/halsall Fred Halsall is an Emeritus Professor of the University of Wales. The previous editions of this book and his companion text on Multimedia Communications have all been widely acclaimed and translated into several different languages. He has carried out many research consultancies for a number of major communication companies and presented seminars at many international conferences. Cover......Page 1 Contents......Page 6 Preface......Page 14 Guided Tour......Page 19 Acknowledgments......Page 21 Acronyms......Page 22 Overview......Page 28 Application and networking terminology......Page 31 Digital communications basics......Page 48 Protocol basics......Page 78 Protocol stacks......Page 110 Summary......Page 113 Exercises......Page 114 Introduction......Page 118 Transmission systems......Page 123 Access network signaling......Page 156 Trunk network signaling......Page 164 Broadband modems......Page 165 Internet service providers......Page 172 Summary......Page 183 Exercises......Page 185 Introduction......Page 189 Ethernet/IEEE802.3......Page 192 LAN interconnection technologies......Page 201 High-speed LANs......Page 207 Virtual LANs......Page 222 LAN protocols......Page 226 Multisite LAN interconnection technologies......Page 233 Summary......Page 245 Exercises......Page 246 Introduction......Page 249 Bluetooth......Page 252 Wireless LANs......Page 267 Cellular radio networks......Page 284 Summary......Page 293 Exercises......Page 294 Introduction......Page 296 Cable television networks......Page 297 Satellite television networks......Page 330 Exercises......Page 341 Introduction......Page 345 IP datagrams......Page 349 Fragmentation and reassembly......Page 352 IP addresses......Page 354 Routing algorithms......Page 365 Routing in the Internet......Page 386 QoS support......Page 421 IPv6......Page 436 IPv6/IPv4 interoperability......Page 452 Summary......Page 458 Exercises......Page 459 Introduction......Page 465 TCP/IP protocol suite......Page 466 TCP......Page 468 UDP......Page 511 RTP and RTCP......Page 516 Summary......Page 524 Exercises......Page 525 Introduction......Page 530 Domain name system......Page 531 Electronic mail......Page 542 FTP......Page 559 TFTP......Page 565 Internet telephony......Page 569 SNMP......Page 581 Summary......Page 590 Exercises......Page 591 Introduction......Page 595 Overview......Page 596 URLs and HTTP......Page 604 HTML......Page 614 Java and JavaScript......Page 635 Audio and video......Page 642 Wireless Web......Page 648 Web operation......Page 651 Summary......Page 655 Exercises......Page 656 Introduction......Page 660 Data encryption......Page 661 Nonrepudiation......Page 676 Authentication......Page 679 Public key certification authorities......Page 683 E-mail privacy......Page 684 Network security......Page 687 Web security......Page 695 Summary......Page 700 Exercises......Page 701 Appendix A Multimedia data representation and compression......Page 704 Appendix B Error detection methods......Page 760 Appendix C Forward error control......Page 773 Appendix D Radio propagation and transmissionbasics......Page 784 Appendix E ATM networks in the Internetback bone......Page 797 Bibliography and further reading......Page 805 Index......Page 812 Cover 1 Contents 6 Preface 14 Guided Tour 19 Acknowledgments 21 Acronyms 22 data communications and networking basics 28 Overview 28 Application and networking terminology 31 Digital communications basics 48 Protocol basics 78 Protocol stacks 110 Summary 113 Exercises 114 telephone networks and modems 118 Introduction 118 Transmission systems 123 Access network signaling 156 Trunk network signaling 164 Broadband modems 165 Internet service providers 172 Summary 183 Exercises 185 local area networks and intranets 189 Introduction 189 Ethernet/IEEE802.3 192 LAN interconnection technologies 201 High-speed LANs 207 Virtual LANs 222 LAN protocols 226 Multisite LAN interconnection technologies 233 Summary 245 Exercises 246 wireless networks 249 Introduction 249 Bluetooth 252 Wireless LANs 267 Cellular radio networks 284 Summary 293 Exercises 294 entertainment networks 296 Introduction 296 Cable television networks 297 Satellite television networks 330 Summary 341 Exercises 341 the Internet protocol 345 Introduction 345 IP datagrams 349 Fragmentation and reassembly 352 IP addresses 354 Routing algorithms 365 Routing in the Internet 386 QoS support 421 IPv6 436 IPv6/IPv4 interoperability 452 Summary 458 Exercises 459 transport protocols 465 Introduction 465 TCP/IP protocol suite 466 TCP 468 UDP 511 RTP and RTCP 516 Summary 524 Exercises 525 Internet applications 530 Introduction 530 Domain name system 531 Electronic mail 542 FTP 559 TFTP 565 Internet telephony 569 SNMP 581 Summary 590 Exercises 591 the World Wide Web 595 Introduction 595 Overview 596 URLs and HTTP 604 HTML 614 Java and JavaScript 635 Audio and video 642 Wireless Web 648 Web operation 651 Summary 655 Exercises 656 security 660 Introduction 660 Data encryption 661 Nonrepudiation 676 Authentication 679 Public key certification authorities 683 E-mail privacy 684 Network security 687 Web security 695 Summary 700 Exercises 701 Appendix A Multimedia data representation and compression 704 Appendix B Error detection methods 760 Appendix C Forward error control 773 Appendix D Radio propagation and transmissionbasics 784 Appendix E ATM networks in the Internetback bone 797 Bibliography and further reading 805 Index 812 Introducing data communications and computer networks, this revised and updated edition takes account of developments in the area. Coverage includes essential theory associated with digital transmission, interface standards, data compression and error detection methods