思科网络技术学院教程(第二章高层协议).ppt
Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3高层协议高层协议第二章第二章应用层与会话层应用层与会话层Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.33Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3事务应用事务应用字处理字处理图表图表电子表格电子表格数据库数据库设计设计/制造制造课题计划课题计划其他其他应用层应用层选择网络应用支持用户的事务应用选择网络应用支持用户的事务应用网络应用网络应用电子邮件电子邮件文件传输文件传输远程访问远程访问客户端客户端/服务器模式处理服务器模式处理信息定位信息定位网络管理网络管理其他其他4Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3?Graphics?Visual ImagesPICTTIFFJPEGGIF表示层表示层为应用层提供代码格式的转换为应用层提供代码格式的转换?Text?DataASCIIEBCDICEncrypted?Sound?VideoMIDIMPEGQuickTimelogin:5Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3网络文件系统网络文件系统(NFS)结构化查询语言结构化查询语言(SQL)远程过程调用远程过程调用(RPC)X 窗口系统窗口系统互连网浏览器互连网浏览器DNA 会话控制协议会话控制协议(SCP)会话层会话层Service RequestService Reply支持在不同主机上对等应用程序之间的对话支持在不同主机上对等应用程序之间的对话传输层传输层Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.37Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3传输层概览传输层概览将会话层数据分割成较小的分组将会话层数据分割成较小的分组建立端到端的连接建立端到端的连接将分组从一端主机发送到另一端主机将分组从一端主机发送到另一端主机保证数据可靠传输保证数据可靠传输8Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3面向连接的会话面向连接的会话同步同步同步同步确认确认连接协商连接协商数据传输数据传输(发送分组发送分组)SenderReceiver连接建立连接建立连接建立连接建立9Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3流量控制流量控制Buffer FullTransmitSenderReceiver10Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3流量控制流量控制Buffer Full TransmitNot ReadyStopSenderReceiver11Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3流量控制流量控制Buffer Full Process SegmentsBuffer OKTransmitNot ReadyStopSenderReceiver12Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3流量控制流量控制Buffer Full Process SegmentsBuffer OKTransmitNot ReadyStopReadyGoSenderReceiver13Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3流量控制流量控制Buffer Full Process SegmentsBuffer OKTransmitNot ReadyStopReadyGoResume TransmissionSenderReceiver14Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3窗口技术窗口技术Window size=1Send 1Receive 1SenderReceiver15Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3窗口技术窗口技术Window size=1Send 1Receive 1Ack 2SenderReceiver16Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3窗口技术窗口技术Window size=1Send 1Receive 1Ack 2Send 2Receive 2SenderReceiver17Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3窗口技术窗口技术Window size=1Send 1Receive 1Ack 2Send 2Receive 2Ack 3SenderReceiver18Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3窗口技术窗口技术Window size=1Send 1Receive 1Ack 2Send 2Receive 2Ack 3Send 1Send 2Receive 1Receive 2Window size=3Send 3Receive 3SenderReceiverSenderReceiver19Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3窗口技术窗口技术Window size=1Send 1Receive 1Ack 2Send 2Receive 2Ack 3Send 1Send 2Receive 1Receive 2Window size=3Send 3Receive 3Ack 4SenderReceiverSenderReceiver20Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3窗口技术窗口技术Window size=1Send 1Receive 1Ack 2Send 2Receive 2Ack 3Send 1Send 2Receive 1Receive 2Window size=3Send 3Receive 3Ack 4Send 4SenderReceiverSenderReceiver21Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3正向确认正向确认SenderReceiver12345622Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3正向确认正向确认SenderReceiverSend 2Send 1Send 312345612323Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3正向确认正向确认SenderReceiverSend 2Send 1Send 3Ack 4Send 412345612324Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3正向确认正向确认SenderReceiverSend 2Send 1Send 3Ack 4Send 5Send 4Send 61234561234625Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3正向确认正向确认SenderReceiverSend 2Send 1Send 3Ack 4Send 5Send 4Send 6Ack 51234561234626Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3正向确认正向确认SenderReceiverSend 2Send 1Send 3Ack 4Send 5Send 4Send 6Ack 5Send 512345612345627Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3正向确认正向确认SenderReceiverSend 2Send 1Send 3Ack 4Send 5Send 4Send 6Ack 5Send 5Ack 712345612345628Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3正向确认正向确认SenderReceiverSend 2Send 1Send 3Ack 4Send 5Send 4Send 6Ack 5Send 5Ack 712345612345629Copyright?1998,Cisco Systems,Inc.ICRC_revision_11.3分组如何穿过通信网络?分组如何穿过通信网络?Routed packetsRouted packetsEnd-to-end segmentsEnd-to-end segments