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,