计算机网络习题

Chapter 1计算机网络和internet1.the()is a world wide computer network，that is，a network that interconnects millions of computing devices throughput the world .a public internet宾特网Cswitch netDtlevisionnet2.which kind of media is not a guided media？（）Atwisted-pair copper wireBa coaxial cableCfiber光学器件Ddigital satellite channel3.which kind of media is a guided media？（）Ageostationary satelliteBlow-altitude satelliteCfiber光学器件d无线LAN4.the units of data exchanged by a link-layer protocol are called()。AFramesBSegmentsCDatagramsDbit流5.which of the following option belongs to the circuit-switched networks？（）AFDMBTDMCVC networksDboth A and B6.()means that the switch must receive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link。AStore-and-forward transmissionBFDMCEnd-to-end connectionDTDM7.processing delay does not include the time to()。Aexamine the packets headerb wait to transmit the packet onto the linkc determine where to direct the packetDcheck bit-error in the packet8.the internet s network layer is responsible for moving network-layer packets known as()from one host to another。a帧BdatagramCsegmentDmessage9.access networks can be lookey classified into three categories : residental access，company access and () access。Acabledb无线CcampusDcity区域Question 10至11Suppose，a is the average rate at which packets arrive at the queue，r is the transmission rate，and all packets conist of l bits，Then10.ALR/aBla/rCra/lDlr/a11.A2B1C0D112.in the internet，end systems are connected toget herby()。铜丝B coaxial电缆Ccommunication linksDfiber optics13.end systems access to the internet through its()。A modemBprotocolsCISPDsockets14.end systems、packet switches、and other pieces of the internet，run()that control the sending and receiving of information witionAprogramsBprocessesCapplicationsDprotocols15.()defines the format and the order of messages exhanged between two or more communicating entities，as well as the actions taken on the transesa互联网BprotocolCintranetd网络16.in the following options，which does not belong to the network edge？（）Aend systems布罗陀CclientDservers17.in the following options，which belongs to the network core？（）Aend systems布罗陀CclientDservers18.there are two fundamental approachs to building a network core，()and packet switching。Aelectrical current switchingBcircuit交换Cdata switchingDmessage switching19.in () networks，the resources need along a path to provide for communication between the end system are reserved for the duration of the communication between the end system are reservedApacket-switchedBdata-switchedCcircuit-switchedDmessage-switched20.in () networks，the resources are not reserveda session s messages use the resources on demand，and as a consequence，may have to wait for access to communication link。Apacket-switchedBdata-switchedCcircuit-switchedDmessage-switched21.in a circuit-switched network，if each link has n circuits，for each link used by the end-to-end connection，the connection gets()Aa fraction 1/n球C1/2Dn times22.()means that the switch must receive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link。Aquing delayBStore-and-forward transmissionCPacket lossDPropagation23.the time required to examine the packet s header and determine where to direct the packet is part of the()。Aquing delayBprocessing delayCpropagation delayDtransmission delay24.the time required to propagate from the beginning of the link to the next router is()。Aquing delayBprocessing delayCpropagation delayDtransmission delay25.in the four following options，which application is not c/s architecture？A.DNS b . web应用程序C.P2P文件共享d .电子邮件26.the PDU of application layer is called()。A.message b . segmentc . datagram d . frame27，the units of data exhanged by an internet s transport layer protocol are called()。A.Frames B. SegmentsC.Datagrams D. bit streams28.consider sending a packet of 3000 bits over a path of 5 link