10-介绍TCP.IP传输层.pdfVIP免费

Ender。乾颐堂CCNAv3.0课程EstablishingInternetConnectivityUnderstandingtheTCP/IPTransportLayer理解传输层Ender乾颐堂CCNAv3.0课程TCP/IPTransportLayerFunctionsEnderICND1—2-48最大分段大小MSS对TCP应用，默认1460（二层负载减去TCP+IP各20字节的包头），超过就segmentationEnder乾颐堂CCNAv3.0课程Reliablevs.Best-EffortTransportReliableBestEffortProtocolTCPUDPConnectionTypeConnection-orientedConnectionlessSequencingYesNoUses•Email•Filesharing•Downloading•Voicestreaming•VideostreamingEnderICND1—2-49Ender乾颐堂CCNAv3.0课程TCPvs.UDPAnalogyEnderICND1—2-50Ender乾颐堂CCNAv3.0课程UDPCharacteristics•OperatesatthetransportlayeroftheTCP/IPstackProvidesapplicationswithaccesstothenetworklayerwithouttheoverheadofreliabilitymechanisms不提供额外的可靠性机制Operatesasaconnectionlessprotocol-无连接•Provideslimitederrorchecking-提供有限的CRC校验•Providesbest-effortdelivery-尽力而为•Providesnodatarecoveryfeatures-无数据恢复EnderICND1—2-51Ender乾颐堂CCNAv3.0课程UDPCharacteristics(Cont.)TheUDPheader:16-BitSourcePort16-BitDestinationPort16-BitUDPLength16-BitUDPChecksumDataEnderICND1—2-52Ender乾颐堂CCNAv3.0课程TCPCharacteristics•TransportlayeroftheTCP/IPstack•Accesstothenetworklayerforapplications•Connection-orientedprotocol•Full-duplexmodeoperation•Errorchecking•Sequencingofdatapackets•Reliabledelivery—acknowledgmentofreceipt•Datarecoveryfeatures数据恢复实在是让我好找•FlowcontrolEnderICND1—2-53Ender乾颐堂CCNAv3.0课程TCPCharacteristics(Cont.)TheTCPheader:SourcePortDestinationPortSequenceNumberAcknowledgmentNumberHeaderLengthReservedFlagsWindowSizeTCPChecksumUrgentPointerOptionsDataEnderICND1—2-54Ender乾颐堂CCNAv3.0课程TCP的封装格式源端口号目标端口号32位序列号32位确认号4位首部长度保留（6位）URGACKPSHRSTSYNFIN16位窗口大小16位校验和16位紧急指针可选项数据0151631发送TCP进程对应的端口号目标端接收进程的端口号0～232-1范围内，数据段标记，用于到目的端对到达包的重组0～232-1范围内，对发送端的确认信息，告诉发送端这个序号之前的数据段都收到了紧急指针有效位，与16位紧急指针配合使用确认序...