本书系统地介绍了数据通信与计算机网络领域的基本内容。与前两版相比,第3版在内容和编排上都有较大更新。本书继承了前两版的优点,如系统的理论结构、简洁易懂的叙述语言、每章后面精选的复习题与练习题等。同时,在对基础理论的介绍之外,更加注重与实际应用相结合。对于在应用中比较受关注的方面,如数据压缩、数据完整、数据**、流量控制等,都分别开辟了单独的章节来详细讲述。此外,还极大地丰富了Internet协议与应用、Internet编程等内容,使得本书在作为理论教材的同时,也具有很高的实践指导价值。

PREFACExixCHAPTER1INTRODUCTIONTOCOMMUNICATIONS,STANDARDS,ANDPROTOCOLS1.1WHYSTUDYCOMMUNICATIONS?1ABriefHistory1Applications4Issues81.2COMPUTERNETWORKS9CommonBusTopology10StarTopology11RingTopology12FullyConnectedTopology13CombinedTopologies131.3STANDARDSANDSTANDARDSORGANIZATIONS15TheNeedforStandards15StandardsOrganizations161.4OPEnSYSTEMSANDTHEOSIMODEL18OverviewoftheModel22ConnectionStrategies24PhysicalLayer29DataLinkLayer30NetworkLayer32TransportLayer33SessionLayer36PresentationLayer38ApplicationLayer40IntemetLayers42Summary421.5THEFUTUREOFDATACOMMUNICATIONS44REVIEWQUESTIONS51EXERCISES52REFERENCES53CHAPTER2TRANSMISSIONMEDIAANDCODES2.1INTRODUCTIONS42.2CONDUCTIVEMETAL57TwistedPair57CoaxialCable592.3OPTICALFIBER612.4WIRELESSCOMMUNICATIONS66MicrowaveTransmission67SatelliteTransmission70GeosynchronousSatellites71LowEarthOrbitSatellites77WirelessLANs81Bluetooth82FreeSpaceOptics83Summary842.5CODES87EarlyCodes87ASCIICode89EBCDICCode92Unicode922.6SUMMARY93REVIEWQUESTIONS94EXERCISES95REFERENCES96CHAPTER3ANALOGANDDIGITALSIGNALS3.1INTRODUCTION973.2DIGITALENCODINGSCHEMES98NRZEncoding98ManchesterEncoding1003.3ANALOGSIGNALS101Fourier'sResults103ApplicationsofFourier'sResults1063.4BITRATE107TheNyquistTheoremandNoiselessChannels107NoisyChannels109Shannon'sResult1103.5DIGITAL-TO-ANALOGCONVERSION112FrequencyModulation113AmplitudeModulation114PhaseModulation114QuadratureAmplitudeModulation1153.6ANALOG-TO-DIGITALCONVERSION118PulseAmplitudeModulation119PulseCodeModulation1193.7MODEMS121SignalConstellation122ModemStandards125CableModems1273.8DSL131HowItWorks132DifferentDSLTechnologies,13**DSLLite(G.Lite,ITUstandardITUG.992.2)135SDSL136HDSLandHDSL2136SHDSL137RADSL137IDSL137VDSL1373.9SUMMARY138REVIEWQUESTIONS139EXEROSES141REFERENCES143CHAPTER4MAKINGCONNECTIONS1444.1INTRODUCTION1444.2COMMUNICATIONCARRIERSANDDEVICES145TheTelephoneSystem145CallRouting147PrivateBranchExchanges148CellularPhones149FaxMachines1514.3TRANSMISSIONMODES153SerialandParallelTransmission153Asynchronous,Synchronous,andIsochronousTransmission154Simplex,Half-Duplex,andFull-DuplexCommunications1584.4INTERFACESTANDARDS159EIA-232Interface160EIA-232Subsets162NullModems163X.21Interface164USB166USBConnections166DataTransfer168USBPackets170FireWire172Connections173Communications17**rbitration1764.5MULTIPLEXING178Frequency-DivisionMultiplexing180Time-DivisionMultiplexing182StatisticalMultiplexers183Wave-DivisionMultiplexing1854.6DIGITALCARRIERS186Tl186SONET188DeviceTypes189PayloadsandFrames1914.7CONTENTIONPROTOCOLS19**lohaProtocols196CartierSenseMultipleAccess199CollisionDetection202CollisionAvoidance205TokenPassing205SummaryofProtocols2074.8SUMMARY207RENEWQUESTIONS210EXERCISES212REFERENCES214CHAPTER5DATACOMPRESSION2155.1INTRODUCTION2155.2FREQUENCY-DEPENDENTCODES217HuffmanCode217ArithmeticCompression2205.3RUN-LENGTHENCODING225RunsoftheSameBit225RunswithDifferentCharacters226FacsimileCompression2265.4RELATIVEENCODING2295.5LEMPEL~ZIVCOMPRESSION2295.6IMAGECOMPRESSION235ImageRepresentation235JPEGCompression238DCTPhase238EncodingPhase244GIFFiles2455.7MULTIMEDIACOMPRESSION246MPEG246MP32515.8SUMMARY254REVIEWQUESTIONS254EXERCISES255REFERENCES257CHAPTER6DATAINTEGRITY2586.1INTRODUCTION2586.2SIMPLEERRORDETECTIONTECHNIQUES259ParityChecks259AnalysisofParityChecking260Checksums2616.3CYCLICREDUNDANCYCHECKSFORERRORDETECTION261PolynomialDivision262HowCRCWorks263AnalysisofCRC265CRCImplementationUsingCircularShifts2686.4HAMMINGCODES:ERRORCORRECTION270Single-BitErrorCorrection270Multiple-BitErrorCorrection2736.5SUMMARY274RENEWQUESTIONS275EXERCISES276REFERENCES277CHAPTER7DATASECURITY2797.1INTRODUCTION2797.2ENCRYPTIONALGORITHMS281CaesarCipher282PolyalphabeticCipher284TranspositionCipher284Bit-LevelCiphering285DataEncryptionStandards287DES287TripleDES291AESandtheRijndaelAlgorithm292ClipperChipandtheSkipjackAlgorithm2967.3KEYDISTRIBUTIONANDPROTECTION299Shamir'sMethod300Diffie-HellmanKeyExchange3007.4PUBLICKEYENCRYPTION302RSAAlgorithm302DigitalSignatures30**uthenticationandMessageDigests308PrettyGoodPrivacy3117.5TRANSPORTLAYERSECURITYANDSERVERAUTHENTICATION315TransportLayerSecurity316X.509Certificate317Handshakes3207.6FIREWALLS323PacketFiltering324Application-LevelGateway325StatefulInspection3277.7VIRUSES329InfectingFiles330Memory-ResidentViruses332VirusEvolution333VirusSources3357.8THREATSANDATTACKS336TheIntemetWorm336ComputerHackers338OtherThreats3397.9SUMMARY341RENEWQUESTIONS345EXERCISES346REFERENCES348CHAPTER8FLOWCONTROL3508.1INTRODUCTION3508.2SIGNALING352DTE-DCEFlowControl353X-ON/X-OFF3538.3FRAME-ORIENTEDCONTROL354UnrestrictedProtocol355Stop-and-WaitProtocol356ProtocolEfficiency3588.4GO-BACK-n:ASLIDINGWINDOWPROTOCOL360FrameFormat362Features363Algorithm3668.5SELECTIVEREPEAT:ASLIDINGWINDOWPROTOCOL370Features370Algorithm3748.6EFFICIENCYOFSLIDINGWINDOWPROTOCOLS3778.7PROTOCOLCORRECTNESS380FiniteStateMachines380STDforaSimplifiedGo-Back-nProtocol381StateTransitionDiagramforaFaultyGo-Back-nProtocol383PetriNets3868.8SUMMARY390RENEWQUESTIONS392EXERCISES393REFERENCES395CHAPTER9LOCALAREANETWORKS3969.1INTRODUCTION3969.2DATALINKCONTROL398High-levelDataLinkControlProtocol400FrameFormat402HDLCExample405BinarySynchronousCommunicationsProtocol4089.3ETHERNET:IEEESTANDARD802.3410Concepts411EthernetFrameFormat413PhysicalImplementationsof10MbpsEthernet4159.4FASTETHERNET(100MBPS)417100BaseTX418100BaseFX421100BaseT4422CollisionDomain4249.5GIGABITETHERNET424MACSublayer4251000BaseX4271000BaseT428BeyondGigabitRates4309.6TOKENRING:IEEESTANDARD802.5433TokenandFrameFormats434ReservingandClaimingTokens436RingMaintenance4409.7WIRELESSNETWORKS:IEEESTANDARD802.11443InfraredandRadioWaves444Contention447Addressing449FrameFormat451WiredEquivalentPrivacy453Variationsof802.114549.8SUMMARY455REVIEWQUESTIONS457EXERCISES459REFERENCES461CHAPTER10CONNECTINGNETWORKS46210.1INTRODUCTION46210.2LAYER1CONNECTIONS465RepeatersandHubs46510.3LAYER2CONNECTIONS467Bridges467BridgingDifferentTypesofLANs468Routing469RoutingTables469TransparentBridges471RouteLearning471FramePropagation473SpanningTreeAlgorithm475Source-RoutingBridges479SwitchesandSwitchedEthernet480VirtualLANs48410.4LAYER3CONNECTIONS487RoutingTables488CentralizedRouting490DistributedRouting491StaticRouting492AdaptiveRouting49210.5DIJKSTRA'SALGORITHM49310.6THEBELLMAN-FORDALGORITHM496ProblemswiththeBellman-FordAlgorithm50010.7ADDITIONALROUTINGMETHODS502LinkStateRouting502HierarchicalRouting503RoutingInformationProtocol506OpenShortestPathFirst509BorderGatewayProtocol510SummaryofRoutingTechniques51210.8CONGESTIONANDDEADLOCK512Congestion512Deadlock51510.9SUMMARY517REVIEWQUESTIONS519EXERCISES520REFERENCES523CHAPTER11INTERNETPROTOCOLSANDAPPLICATIONS52411.1INTRODUCTION52411.2INTERNETPROTOCOL525OverviewofTCP/IP526InternetAddressing528ClasslessAddresses531ObtaininganAddress533DomainNameSystem534IPPackets537Fragmentation540IPRouting541Routers546MulticastRouting549ResourceReservationProtocol555InternetControlMessageProtocol55711.3IPv6559IPShortcomings560PacketHeaders561IPSec564lPv6Addressing566CompatibilitywithIPv4569Summary57011.4TRANSPORTPROTOCOLS571TransmissionControlProtocol573TCPSegment574ConnectionManagement577FlowControl580CongestionControl582UserDatagramProtocol584Real-TimeTransferProtocol58511.5INTERNETAPPLICATIONS589VirtualTerminalProtocols589Telnet590SecureShell593FileTransfers596FTP597SecureCopy600SimpleMailTransferProtocol600SimpleNetworkManagementProtocol604ManagementInformationBase605SNMPCommands60611.6SUMMARY608REVIEWQUESTIONS610EXERCISES612REFERENCES614CHAPTER12INTERNETPROGRAMMING61612.1INTRODUCTION61612.2SOCKETPROGRAMMING617Sockets618Client/ServerModel619SocketDataStructures620SocketCommands621Client/ServerExample621ClientSourceCode624ServerSourceCode63112.3WORLDWIDEWEB633WebPageAccess634HypertextMarkupLanguage636Tags637HTMLForms641Client-SideProgrammingandJavaScript64412.4COMMONGATEWAYINTERFACEANDSERVER-SIDEPROGRAMMING:SETTINGUPASEARCHENGINE649Forms650QueryStrings651ExampleSearchEngine65112.5PERLPROGRAMMING:PIZZAORDERINGSYSTEM654CustomerInteraction655VerifyingPhoneNumbers658UpdatingCustomerInformation665PlacinganOrder668VerifyingtheOrder66912.6SUMMARY672REVIEWQUESTIONS673EXERCISES674REFERENCES676CHAPTER13CIRCUITTECHNOLOGIES67713.1INTRODUCTION67713.2INTEGRATEDSERVICESDIGITALNETWORK678Services679Architecture681Protocols683SignalingSystem7684BasicServiceProtocols686CallSetup689BroadbandISDN69113.3VIRTUALCIRCUITPROTOCOLS:X.2**NDFRAMERELAY692Packet-SwitchedNetworkModes693VirtualCircuits693DatagramService695X.25InterfaceStandard696PacketFormat697VirtualCalls698FrameRelay699FrameFormat701CommittedInformationRate702CongestionControl70313.4ASYNCHRONOUSTRANSFERMODE705BenefitsofSmallFixed-SizeCells706OverviewofATMNetwork708Switching709BanyanSwitches710ReferenceModel712CellDefinition713HeaderErrorControl714CellLossPriority716PayloadType716VirtualCircuitsandPaths716ConnectionManagement717ConnectionParameters719AdaptationLayers720AAL1721AAL2723AAL5724Service-SpecificConnection-OrientedProtocol725GigabitEthernetversusATM72613.5SUMMARY727RENEWQUESTIONS727EXERCISES729REFERENCES730GLOSSARYACRONYMSINDEX

本书系统地介绍了数据通信与计算机网络领域的基本内容。与前两版相比,第3版在内容和编排上都有较大更新。本书继承了前两版的优点,如系统的理论结构、简洁易懂的叙述语言、每章后面精选的复习题与练习题等。同时,在对基础理论的介绍之外,更加注重与实际应用相结合。对于在应用中比较受关注的方面,如数据压缩、数据完整、数据**、流量控制等,都分别开辟了单独的章节来详细讲述。此外,还极大地丰富了Internet协议与应用、Internet编程等内容,使得本书在作为理论教材的同时,也具有很高的实践指导价值。