计算机网络复习.pptx

,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,#,视觉计算实验室,Vision,Computing,Laboratory,复 习：,15,章,1,Captain Tong,题 型,1,、名词解释,2,、填空题,3,、选择题,5,、简答题,6,、计算题,4,、判断题,3,1,、名词解释,1,),Persistent,HTTP,2,)p2p3)FDM4)Circuit-Switch5)Congestion Control6)Flow Control7)Access Network8)Bandwidth9)Socket10)Computing,Network 11)AIMD,1,）,Packet-Switched Networks:Datagram Networks and Virtual-Circuit Networks,2,）,Protocol Layers 3,）,Nonpersistent and Persistent Connections,4,）,Mail Message Formats and MIME 5,）,IMAP 6,）,TLD 7,）,Flow Control,8,）,Connection-Oriented Transport,9,）,Forwarding and Addressing 10,）,Broadcast and Multicast,Routing 11)CIDR,1)FSM,2,),CSMA/DA,3),MSS,4),NAT,6),Propagation Delay,7),Instant Message,8)Transport-layer Multiplexing and Demultiplexing,9),ARQ,10),Cumulative Acknowledgement11)TDM,4,2,、,填空题,TCP provides a _ service to its applications to eliminate the possibility of the sender over-flowing the receivers buffer.flow-control,5,3,、选择题,Congestion control is implemented in(),A.RouterB.HostC.Network LayerD.Transport Layer,Which field doesnt IPV6 have?(),A.VersionB.Traffic classC.Flow labelD.Check-sum,Which applications not using TCP?(),A.SMTPB.HTTPC.DNSD.All of them,The job of delivering the data in transport layer segment to the correct socket is called?(),A.multiplexingB.demultiplexingC.congestion controlD.data transport,6,4,、,判断题,ICMP is the protocol of transport layertrue/false,7,5,、简述,Briefly,depict the principle of Forwarding and Addressing in the Internet,.,Discuss,the differences between the Link-State Routing Algorithm and the Distance-Vector Routing Algorithm.Represent the unwilling phenomenon in these two algorithms,.,Describe,the differences between Flow Control and Congestion Control.And briefly depict the methods in Congestion Control,.,Whats,the problem with TCP to transmit Real-time Voice Data?And whats the disadvantage with UDP to transmit Data File,?,5),Why,is it said that FTP sends control information“out-of-band”?,8,6,、,计算题,常考题型,1,，子网的划分,2,，,LS,，,DV,算法过程（填写算法的表格）,3,，,TCP,拥塞控制算法（画拥空窗口变化图）,4,，,IP,分片的计算（各字段值）,5,，时延计算（传输时延和传播时延）,6,，,CSMA/DA,计算,7,，,9,10,Suppose the speed-of-light-round-rip propagation delay(,光速往返时延,)between these two end systems,RTT,is approximately 0.5s.The end systems are connected by a channel with a transmission rate,R,of 1Mb/s.With a packet size,L,of 2000bit per packet computing the following utilization of the sender(,发送方或信道利用率,),：,1.Stop-and-Wait,Protocol,2.Go-Back-N,Protocol,W,T,=7 (W,T,is the sender window size),3.Go-Back-N,Protocol,W,T,=127,4.Go-Back-N,Protocol,W,T,=255,11,Consider local forwarding table of router B has the following items,(Three columns indicate,“,destination,”,“,distance,”,“,next router,”,).,Figure Left-router-B Right-router-C,Now B receives routing information from,C(Two columns indicate,“,destination,”,“,distance,”,).,Computing the forwarding table of B after updating?,12,Consider the following network.With the indicated link costs,use Dijkstras shortest-path algorithm to compute the shortest path from w to all network nodes.Show how the algorithm works by computing a table similar to Table 4.3.,13,考虑,GBN,协议，其发送窗口长度为,3,，序列号范围为,1024,。假设在时刻,t,，接收方期待的下一个有序分组的序号是,k,。假设其中的媒体不会对报文重新排序。请回答以下问题：,1.,在,t,时刻，发送方窗口内的报文序号可能是多少？,2.,在,t,时刻，在当前发送方收到的所有报文的,ACK,字段可能的值是多少？,14,1,，,第一章,2,，第二章,3,，第三章,4,，第四章,5,，第五章,串串,15,1,、第一章：计算机网络和因特网,1,、什么是因特网,描述因特网的构成：基本硬件和软件组件,从分布式应用提供服务的联网基础设施角度,2,、网络边缘,网络部件：端系统、客户机、服务器,服务：面向连接、面向无连接,3,、,网络核心,电路交换,分组交换,频分复用,时分复用,数据报网络,虚电路网络,4,、,协议层次和服务模型,类比：航线系统,协议分层,服务模型,16,2,、第二章：应用层,1,、应用层协议,网络应用程体系结构,C/S,模式,P2P,模式,混合模式,进程通信,客户机服务器进程,接口：套接字,进程寻址,应用层协议,如何构造报文,各个字段的意义,服务：指网络应用需要从运输层协议获得什么样的服务,2,、,WEB,应用和,HTTP,协议,什么,HTTP,协议，报文格式,非持久连接和持久连接,WEB,缓存,3,、,具体应用层协议,FTP,，,SMTP,，,POP3,，,IMAP,，,DNS,，,P2P,17,3,、第三章：传输层,1,、概述,传输层作用和服务,与网络层和应用的关系,TCP,和,UDP,的服务模型,端系统见的,IP,交付服务,进程间的交付服务,2,、多路复用和多路分解,传输层报文交付给正确的套接字,从不同套接字搜集数据封装传递到网络层,3,、,TCP UDP,4,、可靠数据传输原理,FSM,有限状态机,完全可靠信道上的可靠数据传输,rdt1.0,具有比特差错信道的可靠数据传输,rdt2.0,处理受损,ACK,，,NAK(,分组编号,)rdt2.1,具有比特差错信道上实现的无,NAK,可靠数据传输,rdt2.2,具有比特差错的丢包信道的可靠数据传输,rdt3.0,18,5,、可靠数据传输协议,停止等待,GBN,选择重传,SR,原理：分析题，计算题,6,、,流量控制,拥塞控制,AIMD,加性增乘性减,慢启动,快速恢复,原理：分析题，计算题,3,、第三章：传输层,19,4,、第,四,章：网络层,1,、网络层概述,转发和选路,网络层服务模型,尽力而为服务,虚电路网络,数据报网络,2,、转发和编址,数据报格式：各字段的意义,IPV4,和,IPV6,ICMP,：,功能和应用,NAT,3,、,选路算法,链路状态算法,距离向量算法,4,、层次选路,RIP,OSPF,BGP,20,5,、第五章：链路层,1,、数据链路层,链路层协议：定义链路两端节点之间交互分组格式等,链路层服务：在独立的链路上移动数据报,数据单元：帧,2,、差错检测和纠错,奇偶校验,校验和,循环冗余检测,3,、多址访问协议,问题：如何协调多个发送和接受节点对一个共享广播信道的访问,信道划分协议,随机访问协议,轮流协议,时分复用,TDM,频分复用,FDM,码分多址,CDMA,时隙,ALOHA,：了解,CSMA/CD,轮询协议,令牌环协议,21,4,、链路层编址,MAC,地址,地址解析协议,ARP,5,、集线器,交换机,原理，优势对比集线器，网桥等设备,6,、,PPP,：点对点协议,了解,Thanks,！,22,