思科网络技术学院教程高层协议.pptx

高层协议第二章Copyright ?1998, Cisco Systems, Inc.ICRC_revision_11.3应用层与会话层Copyright ?1998, Cisco Systems, Inc.ICRC_revision_11.3网络应用事务应用电子邮件文件传输远程访问客户端/服务器模式处理信息定位网络管理其他字处理图表电子表格数据库设计/制造课题计划其他应用层选择网络应用支持用户的事务应用表示层?Graphics?Visual Images PICT TIFF JPEG GIF?Text?Data ASCII EBCDIC Encryptedlogin:?Sound?Video MIDI MPEG QuickTime为应用层提供代码格式的转换 会话层网络文件系统 (NFS)结构化查询语言 (SQL)远程过程调用 (RPC)X 窗口系统互连网浏览器DNA 会话控制协议 (SCP)Service RequestService Reply支持在不同主机上对等应用程序之间的对话传输层Copyright ?1998, Cisco Systems, Inc.ICRC_revision_11.3传输层概览将会话层数据分割成较小的分组建立端到端的连接将分组从一端主机发送到另一端主机保证数据可靠传输面向连接的会话SenderReceiver同步连接协商同步确认连接建立数据传输(发送分组)TransmitSenderReceiverBuffer Full流量控制流量控制TransmitSenderReceiverBuffer Full Not ReadyStop流量控制TransmitSenderReceiverBuffer Full Process SegmentsBuffer OKNot ReadyStop流量控制TransmitSenderReceiverBuffer Full Process SegmentsBuffer OKNot ReadyStopReadyGo流量控制TransmitSenderReceiverBuffer Full Process SegmentsBuffer OKNot ReadyStopReadyGoResume TransmissionWindow size = 1Send 1Receive 1SenderReceiver窗口技术Window size = 1Send 1Receive 1Ack 2SenderReceiver窗口技术Window size = 1Send 1Receive 1Ack 2Send 2Receive 2SenderReceiver窗口技术Window size = 1Send 1Receive 1Ack 2Send 2Receive 2SenderReceiverAck 3窗口技术Window size = 1Send 1Receive 1Ack 2Send 2Receive 2SenderReceiverAck 3Window size = 3Send 1Receive 1Receive 2Send 2Receive 3Send 3SenderReceiver窗口技术Window size = 1Send 1Receive 1Ack 2Send 2Receive 2SenderReceiverAck 3Window size = 3Send 1Receive 1Receive 2Send 2Receive 3Send 3Ack 4SenderReceiver窗口技术窗口技术Window size = 1Send 1Receive 1Ack 2Send 2Receive 2SenderReceiverAck 3Window size = 3Send 1Receive 1Receive 2Send 2Receive 3Send 3Ack 4SenderReceiverSend 4正向确认SenderReceiver123456正向确认SenderReceiver123456123Send 1Send 2Send 3正向确认SenderReceiver123456123Send 1Send 2Send 3Ack 4Send 4正向确认SenderReceiver12345612346Send 1Send 2Send 3Ack 4Send 4Send 5Send 6正向确认SenderReceiver12345612346Send 1Send 2Send 3Ack 4Send 4Send 5Send 6Ack 5正向确认SenderReceiver123456123456Send 1Send 2Send 3Ack 4Send 4Send 5Send 6Ack 5Se