Chapter 1 Computer Networks and the Internet.doc

Chapter 1 Computer Networks and the Internet1The ( ) is a worldwide computer network, that is, a network that interconnects millions of computing devices throughout the world. ppt3Apublic Internet 公共网络 BIntranet 企业内部互联网Cswitch net 交换网 Dtelevision net 电视网2Which kind of media is not a guided media(引导媒体)? ( )Atwisted-pair copper wire 双绞线铜线 Ba coaxial cable 同轴电缆Cfiber optics 纤维光学 Ddigital satellite channel 数字卫星频道3Which kind of media is a guided media? ( )Ageostationary satellite 地球同步卫星Blow-altitude satellite 低空卫星Cfiber optics 纤维光学Dwireless LAN 无线局域网4The units of data exchanged by a link-layer protocol are called ( ).AFrames BSegmentsCDatagrams Dbit streams5Which of the following option belongs to the circuit-switched(电路交换) networks? ( )AFDM BTDMCVC networks Dboth A and B6( )makes sure that neither side of a connection overwhelms the other side by sending too many packets too fast.AReliable data transfer BFlow controlCCongestion control DHandshaking procedure8Datagram networks and virtual-circuit networks differ in that ( ).Adatagram networks are circuit-switched networks, and virtual-circuit networks are packet-switched networks.Bdatagram networks are packet-switched networks, and virtual-circuit networks are circuit-switched networks.Cdatagram networks use destination addresses and virtual-circuit networks use VC. numbers to forward packets toward their destination.Ddatagram networks use VC. numbers and virtual-circuit networks use destination addresses to forward packets toward their destination.9In the following options, which one is not a guided media? ( )Atwisted-pair wire Bfiber opticsCcoaxial cable Dsatellite10Processing delay does not include the time to ( ).Aexamine the packets headerBwait to transmit the packet onto the linkCdetermine where to direct the packetDcheck bit-error in the packet12The Internets network layer is responsible for moving network-layer packets known as ( ) from one host to another.Aframe BdatagramCsegment Dmessage13The protocols of various layers are called ( ).Athe protocol stack BTCP/IPCISP Dnetwork protocol14There are two classes of packet-switched networks: ( ) networks and virtual-circuit networks.Adatagram Bcircuit-switchedCtelevision Dtelephone15Access networks can be loosely classified into three categories: residential access, company access and ( ) access.Acabled BwirelessCcampus Dcity area18In the Internet, the equivalent concept to end systems is ( ).Ahosts BserversCclients Drouters19In the Internet, end systems are connected together by ( ).Acopper wire Bcoaxial cableCcommunication links 通信链路 Dfiber optics20End systems access to the Internet through its ( ).Amodems BprotocolsCISP 网络运营商 Dsockets21End systems, packet switches, and other pieces of the Internet, run ( ) that control the sending and receiving of information within the Internet.Aprograms BprocessesCapplications Dprotocols22There are many private networks, such as many corporate and government networks, whose hosts cannot exchange messages with hosts outside of the private network. These private networks are often referred to as ( ).Ainternets BLANCintranets DWAN23The internet allows ( ) running on its end systems to exchange data with each other.Aclients applications Bserver applicationsCP2P applications Ddistributed applications24The Internet provides two services to its distributed applications: a connectionless unreliable service and () service.Aflow control Bconnection-oriented reliableCcongestion control DTCP25It defines the format and the order of messages exchanged between two or more communicating entities, as well as the actions taken on the transmission and/or receipt of a message or other event. The sentence describes ( ).AInternet BprotocolCintranet Dnetwork26In the following options, which does not define in protocol? ( )Athe format of messages exchanged between two or more communicating entitiesBthe order of messages exchanged between two or more communicating entitiesCthe actions taken on the transmission of a message or other eventDthe transmission signals are digital signals or analog（模拟） signals27In the following options, which is defined in protocol? ( ) Athe actions taken on the transmission and/or receipt of a message or other event Bthe objects exchanged between communicating entities Cthe content in the exchanged messages Dthe location of the hosts28In the following options, which does not belong to the network edge? ( )Aend systems BroutersCclients Dservers29In the following options, which belongs to the network core? ( )Aend systems BroutersCclients Dservers30In the following options, which is not the bundled with the Internets connection-oriented service? (在下面选择，哪一个不是捆绑了互联网的面向连接的服务？ )Areliable data transfer Bguarantee of the transmission timeCflow control Dcongestion-control31An application can rely on the connection to deliver all of its data without error and in the proper order. The sentence describes ( ).Aflow control Bcongestion-controlCreliable data transfer Dconnection-oriented service32It makes sure that neither side of a connection overwhelms the other side by sending too many packets too fast. The sentence describes ( ).Aflow control Bcongestion-controlCconnection-oriented service Dreliable data transfer33It helps prevent the Internet from entering a state of gridlock. When a packet switch becomes congested, its buffers can overflow and packet loss can occur. The sentence describes ( ).Aflow control Bcongestion-controlCconnection-oriented service Dreliable data transfer34The Internets connection-oriented service has a name, it is ( ).ATCP BUDPCTCP/IP DIP35In the following options, which service does not be provided to an application by TCP?( )Areliable transport Bflow controlCvideo conferencing 视频会议 Dcongestion control36The Internets connectionless service is called ( ).ATCP BUDPCTCP/IP DIP37In the following options, which does not use TCP?( )ASMTP Binternet telephoneCFTP DHTTP38In the following options, which does not use UDP?( )AInternet phone Bvideo conferencingCstreaming multimedia Dtelnet39There are two fundamental approaches to building a network core(有2个基本方法建立一个网络核心)，（）and packet switching.Aelectrical current switching Bcircuit switchingCdata switching Dmessage switching40In ( ) networks, the resources needed along a path to provide for communication between the end system are reserved for the duration of the communication session.Apacket-switched Bdata-switchedCcircuit-switched Dmessage-switched41In ( ) networks, the resources are not reserved; a sessions messages use the resources on demand, and as a consequence, may have to wait for access to communication link.Apacket-switched Bdata-switchedCcircuit-switched Dmessage-switched 44( )（是指交换机必须接收整个数据包之前就可以开始传递的第一位的数据包上出站链接。） 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.AQueuing delay BStore-and-forward transmission 存储转发传输CPacket loss DPropagation45The network that forwards packets according to host destination addresses is called ( ) network.Acircuit-switched Bpacket-switchedCvirtual-circuit Ddatagram46The network that forwards packets according to virtual-circuit numbers is called ( ) network.Acircuit-switched Bpacket-switchedCvirtual-circuit Ddatagram47In the following entries, which is not a kind of access network?( )Aresidential access Bcompany accessCwireless access Dlocal access 49The time required to examine the packets header and determine where to direct the packet is part of the ( ).Aqueuing delay Bprocessing delayCpropagation delay Dtransmission delay50The time required to propagate from the beginning of the link to the next router is ( ).Aqueuing delay Bprocessing delayCpropagation delay 传播延迟Dtransmission delayChapter 2 Application Layer1. In the following four descriptions, which one is correct? A In C/S architecture, clients communicate with each other directly.B In C/S architecture, client has a fixed well-known address.C In P2P architecture, peers communicate with each other directly. 在对等网络结构中，同行相互直接联系。D In P2P architecture, peer has a fixed well-known address.2. In the context of a communication session between a pair of process, the process that initiates the communication is labeled as the , the process that waits to be contacted to begin the session is labeled as the .A client process, server process B sending process, receiving processC input process, output process D communicating process, connecting process3. A socket is the interface between within a host. A the network layer and the link layerB the link layer and the physical layerC the application layer and the transport layerD the transport layer and the network layer4. In the following applications, which one is a loss-tolerant application? A E-mail B file transfer C instant messaging D real-time audio5. In the following applications, which one is a bandwidth-sensitive application? A E-mail B web application C real-time audio D file transfer6. The service of TCP cant guarantee .A delivery of all data without error B delivery of all data in the proper orderC the rate of delivery D congestion control7. In the following applications, which one uses UDP （User Datagram Protocol 用户数据报协议）? A E-mail B web application C file transfer D DNS Domain Name Server,域名服务器8. In the following descriptions about HTTP（Hypertext Transfer Protocol）, which one is not correct? A HTTP uses non-persistent connections in its default mode. 超文本传输协议使用非持久连接的默认模式。B HTTP uses TCP as its underlying transport protocol. 超文本传输协议使用协议作为底层传输协议C HTTP is a stateless protocol. 是一种无状态协议D HTTP is client-server architecture.10. In HTTP response message, if the requested HTTP protocol version is not supported, the status code is .A 200 B 301 C 400 D 50511. The port number of web application is .A 25 B 20 C 80 D 5312. A network entity that satisfies HTTP requests on the behalf of an origin web server is .A server farm B server stack C proxy server（代理服务器） D edge server13. In the following descriptions about persistent connection持久连接, which one is not correct? A The server leaves the TCP connection open after sending a response.B Each TCP connection is closed after the server sending one object.C There are two versions of persistent connection: without pipelining and with pipelining.D The default mode of HTTP uses persistent connection with pipelining.14. FTP（File Transfer Protocol 文件传送输协议） uses two parallel TCP connections to transfer a file, there are .A control connection and data connectionB receiving connection and sending connectionC client connection and sever connectionD program connection and process connection15. In the following descriptions about FTP, which one is correct?A FTP is p2p architecture. B FTP sends its control information out-of-band. 服务器发送的控制信息带C FTP uses persistent connection. D FTP is a stateless protocol. 17. The Internet mail system has three components which they are .A user agent, SMTP, POP3 B SMTP, POP3, IMAPInternet Message Access Protocol消息访问协议C user agent, SMTP, IMAP D user agent, SMTP（Simple Message Transfer Protocol 简单邮件传输协议）, mail server18. If the status code in HTTP response message is 404, it means .A Request succeeded. B The requested document doesnt exit on this server.C This is a generic error code indicating that the request could not be understood by the server.D Requested object has been permanently mover.19. Comparison HTTP with SMTP, the correct is .A HTTP is a push protocol, and SMTP is a pull protocol.B In the default mode, both of them use persistent connection.C HTTP places all of the messages objects into one message, and SMTP sends every object one by one.D HTTP requires each message to be in 7-bit ASCII format, and SMTP doesnt impose this restriction.21. In the following protocol, which one is stateless? A POP3和HTTP B SMTP C FTP D IMAP22. DNS means .A Data Name System B Data National SystemC Domain Name System域名服务器 D Domain National System23. There are three classes of DNS server except .A Root DNS server B Local DNS serverC TLD server D Authoritative DNS server24. DNS provides some services except .A Host aliasing B Mail server aliasingC Load distribution D A single point of failure28. The time it takes for a small packet to travel from client to server and then back to the client is .A round-travel time B next-hop timeC round-trip time 往返时间 D prefix-matching time29. Suppose A ( with a Web-based e-mail account ) sends a message to B ( who accesses his mail server using POP3), which application-layer protocol is not used? A HTTP B SMTP C POP3 D IMAP30. In the four following options, which protocol is included in Mail Access Protocol? A SMTP B DHCP C IMAP D FTP31. In FTP commands, is used to send user password to the server.A User B Pass C Retr D Stor32. The function of the additional header field in MIME多用途的网际邮件扩充协议Content-Type is .A to convert the message body to its origin non-ASCII formB to determine what actions it should take on message bodyC to send an E-mail to the receiving user agentD to indicate what type the message is33. In the four following options, which application is organized as hybrid of C/S and P2P peer-to-peer architecture? A E-mail B OICQ C File transfer D Web application35. In the following options, from the application developers perspective, which is not correct? A the network architecture is fixedB the network architecture provides a specific set of services to applicationsC the application architecture is designed by the physical devices设备；装置D the application architecture dictates how the application is organized over the various end systems36. There are three predominant主要的，占主导地位的architectures used in modern network applications, which one is not included? A the client-server architecture B the P2P architectureC a hybrid of the client-server and P2P architectureD a hybrid of the client-server and browser-server architecture37. In the following options about C/S architecture, which is not correct? A In C/S architecture, there is an always-on host, called the server.B In C/S architecture, there is an always-on host, called the client.C The server has a fixed, well-known address, called IP address.D Clients do not directly communicate with each other.39. A process sends messages into, and receives messages from, the network through its .A socket B program C client D peer40. Which one is not defined by an application-layer protocol? A the types of messages exchangedB the syntax of various message typesC the semantics of the fieldsD rules for determining when and how to translate the socket41. HTTP can use two types of connections, which are .A persistent and non-persistent connectionB connection with pipelining流水线操作and without pipeliningC TCP and UDPD parallel and serial connection42. takes for a small packet to travel from client to server and then back to the client.A RDT B threshold C RTT D overhead43. The def