【计算机类职业资格】网络工程师-计算机专业英语及答案解析.doc

1、网络工程师-计算机专业英语及答案解析(总分：80.00，做题时间：90 分钟)Networks can be interconnected by different devices in the physical layer networks can be connected by (1) or hubs. Which just move the bits from one network to an identical network. One layer up we find bridges and switches which operate at data link layer. Th

2、ey can accept (2) examine the MAC address and forward the frames to a different network while doing minor protocol translation in the process in me network layer, we have routers that can connect two networks, If two networks have (3) network layer, the router may be able to translate between the pa

3、cker formats. In the transport layer we find transport gateway, which can interface between two transport connections Finally, in the application layer, application gateways translate message (4) . As an example, gateways between Internet e-mail and X.400 e-mail must (5) the e-mail message and chang

4、e various header fields.（分数：5.00）A.reapersB.relaysC.packagesD.modemsA.frimesB.packetsC.packagesD.cellsA.specialB.dependentC.similarD.dissimilarA.syntaxB.semanticsC.languageD.formatA.analyzeB.parseC.deleteD.createThe purpose of the requirements definition phase is to produce a clear, complete, consis

5、tent, and testable (6) of the technical requirements for the software product. During the requirements definition phase, the requirements definition team uses an iterative process to expand a broad statement of the system requirements into a complete and detailed specification of each function that

6、the software must perform and each (7) that it must meet. The starting point is usually a set of high level requirements from the (8) that describe the project or problem.In either case, the requirements definition team formulates an overall concept for the system and then defines (9) showing how th

7、e system will be operated publishes the system and operations concept document and conducts a system concept review(SCR).Following the SCR, the team derives (10) require merits for the system from the high level requirements and the system and operations conceptusing structured or object-oriented an

8、alysis, the team specifies the software functions and algorithms needed to satisfy each detailed requirement.（分数：5.00）A.functionB.definitionC.specificationD.statementA.criterionB.standardC.modelD.systemA.producerB.customerC.programmerD.analyserA.rulesB.principlesC.scenariosD.scenesA.cotailedB.outlin

9、edC.totalD.completeFor each blank, choose the best answer from the four choices and write down on the answer sheet.(11) is a protocol that a host uses to inform a router when it joins Or leaves an Internet multicast group.(12) is an error detection code that most data communication networks use.(13)

10、 is an interior gateway protocol that uses a distance vector algorithm to propagate routing information.(14) is a transfer mode in which all types of information are organized into fixed form cells on an asynchronous or non-periodic basis over a range of media.(15) is an identifier of a web page.（分数

11、5.00）A.ICMPB.SMTPC.IGMPD.ARPA.4B/SBB.CRCC.Manchester CodeD.Huffman CodeA.OSPFB.RIPC.RARPD.BGPA.ISDNB.X.25C.Frame RelayD.ATMA.HTYPB.URLC.HTMLD.TAGIn the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet.Spread spectrum simply means that data is s

12、ent in small pieces over a number of the (16) frequencies available for use at any time in the specified range. Devices using (17) spread spectrum(DSSS) communicate by (18) each byte of data into several parts and sending them concurrently on different (19) . DSSS uses a lot of the available (20) ,

13、about 22 megahertz(MHz).（分数：5.00）A.continuousB.highC.lowD.discreteA.direct-sequenceB.discrete-sequenceC.duplicate-sequenceD.dedicate-sequenceA.splittingB.combiningC.packingD.compactingA.bitsB.frequenciesC.packetsD.messagesA.rateB.velocityC.bandwidthD.periodFor each blank, choose the best answer from

14、 the four choices and write down on the answer sheet.(21) is a six bytes OSI layer 2 address which is burned into every networkingdevice that provides its unique identity for point to point communication.(22) is a professional organization of individuals in multiple professions which focuses on effo

15、rt on lower-layer protocols.(23) functions with two layers of protocols. It can connect networks of different speeds and can be adapted to an environment as it expands.(24) is the popular LAN developed under the direction of the IEEE802.5.(25) is the popular backbone technology for transmitting info

16、rmation at high speed with a high level of fault tolerance which is developed under the direction of ANSI.（分数：5.00）A.The MAC addressB.The IP addressC.The subnet addressD.The virtual addressA.ISOB.ANSIC.CCYITD.IEEEA.The hubB.The bridgeC.The routerD.The proxyA.EthernetB.Token BusC.Token RingD.DQDBA.X.

17、25B.ATMC.FDDID.SMDSIn the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet.Microwave communication uses high-frequency (26) waves that travel in straightlines through the air. Because the waves cannot (27) with the curvature of the earth, they c

18、an be (28) only over short distance. Thus, microwave is a good (29) for sendingdata between buildings in a city or on a large college campus. For longer distances, the waves must be relayed by means of “dishes“ or (30) . These can be installed on towers, high buildings, and mountain tops.（分数：5.00）A.

19、opticalB.radioC.electricalD.magneticA.reflexB.distortC.bendD.absorbA.transmittedB.transformedC.convertedD.deliveredA.materialB.equipmentC.mediumD.channelA.repeatersB.radarsC.telephonesD.antennasIn the following essay, each blank has four choices. Choose the most suitable one from the four choices an

20、d write down in the answer sheet.A socket is basically an end point of a communication link between two applications. Sockets that extend over a network connect two or more applications running on (31) computers attached to the net-work. A socket (32) two addresses: (33) . Sockets provide a (34) com

21、munication channel between one or more systems. There are (35) sockets separately using TCP and UDP.（分数：5.00）A.uniqueB.separateC.sameD.dependentA.is made ofB.composed ofC.is composed ofD.is consisted ofA.Email address and IP addressB.MAC address and port addressC.MAC address and IP addressD.port num

22、ber and IP addressA.full-duplexB.half-duplexC.simplexD.complexA.message and packetB.packet and frameC.stream and datagramD.flow and blockIn the following essay, each blank has four choices. Choose the most suitable one from the four choices and write down in the answer sheet.Open Shortest Path First

23、 (OSPF) is a (36) routing algorithm that (37) work clone on the OSI IS-IS intradomain routing protocol. This routing, as compared to distance-vector routing, requires (38) processing power. The (39) algorithm is used to calculate routes. OSPF routing table updates only take place when necessary, (40

24、) at regular intervals.（分数：5.00）A.distance-vectorB.link-stateC.flow-basedD.selective floodingA.derived fromB.deviated fromC.was derived fromD.was deviated fromA.moreB.lessC.sameD.mostA.Bellman-FordB.Ford-FulkersonC.DijkstraD.RIPA.but ratherB.rather tooC.rather thanD.rather thatPacket-switching wirel

25、ess networks are preferable (41) when transmissions are (42) because of the way charges are (43) per packet. Circuit-switched networks are preferable for transferring large files or for other lengthy transmissions because customers are (44) for the (45) of time they use the net-work.（分数：5.00）A.toB.f

26、orC.thanD.onlyA.longB.shortC.largeD.smallA.computingB.incuriousC.incurvedD.incurredA.chargedB.finedC.freeD.controlledA.pointB.startC.lengthD.endMultipurpose Internet Mail Extension (MIME) is a (46) document messaging standard in the Internet enviroment, with MIME, users can send (47) Email messages

27、that include audio, video, graph-ices, and text to any other user of a TCP/IP network. Richtext information can also be (48) into messages. It defines the fonts, formats, and (49) features of a document so the document can be easily (50) on many different types of systems.（分数：5.00）A.completeB.compou

28、ndC.simpleD.efficientA.analogB.manyC.multmediaD.digitalA.incorporatedB.filledC.storedD.fliedA.colorB.sizeC.designD.layoutA.restoredB.redisplayedC.storedD.executedFrame Relay is simplified form of (51) , similar in principle to (52) , in which synchronous, frames of data are routed to different desti

29、nations depending on header information.Packets are routed throught one or more Virtual Circuits known as (53) . Most Virtual Circuits are (54) , which means that the network provider sets up all DLCI connections at subscription time. (55) are also part of the Frame Relay specification. They privide

30、 a link that only lasts only as long as the session.（分数：5.00）A.Datagram SwitchingB.Datagram RoutingC.Packet SwitchingD.packet RoutingA.X.21B.X.25C.X.28D.X.29A.DLCIsB.HDLCsC.SDLCsD.DLsA.Permanent CircuitsB.Permanent Virtual CircuitsC.Switched Virtual CircuitsD.Switching CircuitsA.Permanent CircuitsB.

31、Permanent Virtual CircuitsC.Switched Virtual CircuitsD.Switched Circuits(56) is a one-way function that takes an arbitrarily long piece of plaintext and from it computes a fixed-length bit string.(57) is a protocol that most USENET machines now use it to allow news articles to propagate from one mac

32、hine to another over a reliable connection.(58) is an approach preferred by cable TV providers. In this solution the fiber terminates at an opto-electrical converter and the final segment is a shared coaxial cable.(59) is a device used to connect two separate network that use different communication

33、 protocol.(60) is a digital-to-digital polar encoding method in which the signal level is always either positive or negative.（分数：5.00）A.MDB.RSAC.DESD.MIBA.RTPB.RTTPC.FTPD.NNTPA.ADSLB.FTTCC.HFCD.FTTHA.RouterB.GatewayC.BridgeD.hubA.NNIB.NRZC.NAKD.NVTIn low-speed network, it is usually adequate to wait

34、 for congestion to occur and then react to it by telling the source of packets to slow down. In high-speed networks, this approach often works poorly, because in the (61) between sending the notification and notification arriving at the source, thousands of additional (62) may arrive. In ATM network

35、 a major tool for preventing (63) is (64) control. When a host wants a new virtual (65) , it must describe the traffic to be offered and the service expected.（分数：5.00）A.intervalB.timeC.slotD.delayA.packetsB.cellsC.messageD.filesA.collisionB.congestionC.dropD.delayA.flowB.admissionC.trafficD.timeA.p

36、athB.routC.circuitD.wayFlow control is a function that prevents network congestion by ensuring that (66) do not over-whelm (67) with data. There are three commonly used methods for handling network congestion. (68) is used by network devices to temporarily store bursts of excess data in memory until

37、 they can be processed. (69) are used by receiving devices to help prevent their buffers from overflowing. (70) is a flow-control scheme in which the source device requires an acknowledgment from the destination after a certain number of packets have been transmitted.（分数：5.00）A.transmitting devicesB

38、transmitted devicesC.receiving devicesD.received devicesAtransmitting devicesB.transmitted devicesC.receiving devicesD.received devicesA.BufferB.Source-quench messagesC.windowD.WindowingE.BufferingA.BufferB.Source-quench messagesC.windowD.WindowingE.BufferingA.BufferB.Source-quench messagesC.window

39、D.WindowingE.BufferingSDLC was invented by IBM to replace the older Bisynchronous protocol for wide area connections between IBM equipment. A varietion of the (71) protocol called NRM is essentially the same as SDLC. SDLC is (72) protocol like HDLC, Frame Relay or X.25.An SDLC network is made up of

40、73) that controls all communications, and (74) . It is capable of (75) operation, but almost all practical applications are strictly half duplex.（分数：5.00）A.HDLCB.Frame RelayC.X.25D.X.21A.a peer to peerB.a point-to-pointC.not a peer to peerD.a peer to peersA.a primary stationB.one or more primary st

41、ationsC.a secondary stationD.one or more secondary stationsA.a primary stationB.one or more primary stationsC.a secondary stationD.one or more secondary stationsA.half duplexB.full duplexC.half or full duplexD.half and full duplexIn the following essay, each blank has four choices. Choose the most s

42、uitable one from the four choices and write down in the answer sheet.The key to SNMP (76) is its simplicity. It has a small command set that does a good job of collecting information from (77) any network device. In a SNMP environment, (78) of the work is handled by the network management system. De

43、vices that are being managed are not (79) with processing (80) that might affect their performance.（分数：5.00）A.popularityB.functionC.efficiencyD.powerA.manyB.almostC.a lot ofD.nearlyA.mostB.manyC.muchD.a lotA.burdenedB.influencedC.destroyedD.mitigatedA.timeB.powerC.speedD.overhead网络工程师-计算机专业英语答案解析(总分

44、80.00，做题时间：90 分钟)Networks can be interconnected by different devices in the physical layer networks can be connected by (1) or hubs. Which just move the bits from one network to an identical network. One layer up we find bridges and switches which operate at data link layer. They can accept (2) exa

45、mine the MAC address and forward the frames to a different network while doing minor protocol translation in the process in me network layer, we have routers that can connect two networks, If two networks have (3) network layer, the router may be able to translate between the packer formats. In the

46、transport layer we find transport gateway, which can interface between two transport connections Finally, in the application layer, application gateways translate message (4) . As an example, gateways between Internet e-mail and X.400 e-mail must (5) the e-mail message and change various header fiel

47、ds.（分数：5.00）A.reapers B.relaysC.packagesD.modems解析：A.frimes B.packetsC.packagesD.cells解析：A.specialB.dependentC.similarD.dissimilar 解析：A.syntax B.semanticsC.languageD.format解析：A.analyzeB.parse C.deleteD.create解析：解析 可以通过不同的设备实现网络的互连。在物理层，网络可以通过中继器或者 HUB 相连，这些设备仅仅是将比特源目的网络之间传输；在数据链路层，通过交换机和网桥实现网络的互连；它们

48、可以接收帧，检测 MAC 地址，并且能够将帧传向另一个网络，同时，还可以进行少量的协议转换工作。在网络层，使用路由器来连接两个网络。如果两个网络拥有不同的网络层，路由器能够在不同帧格式之间相互转换。在传输层有传输网关，能够在两个传输层之间建立端口连接。最后，应用层有应用网关实现消息语法之间的转化。作为例子，在 Internet e-mail 和 X.400 e-mail 之间的应用网关可以对 e-mail 的消息进行语法分析，并且能够变换消息头。The purpose of the requirements definition phase is to produce a clear, com

49、plete, consistent, and testable (6) of the technical requirements for the software product. During the requirements definition phase, the requirements definition team uses an iterative process to expand a broad statement of the system requirements into a complete and detailed specification of each function that the software must perform and each (7) that it must meet. The starting point is usually a set of high level requirements from the (8) that describe the project or problem.In either case, the requirements definition team formulates an overall concept for the system and then define