软考：网络工程师英文真题.doc

09下半年网络工程师英文真题、译文及答案Routing protocols use different techniques for assigning（71）to individual networksFurther, each routing protocol forms a metric aggregation in a different way. Most routing protocols can use multiple paths if the paths have an equal（72）.Some routing protocols can even use multiple paths when paths have an unequal cost.In either case,load（73）can improve overall allocation of network bandwidthWhen multiple paths are used,there are several ways to distribute the packets. The two most common mechanisms are per-packet load balancing and per-destination load balancing.Per-packet load balancing distributes the（74）across the possible routes in a manner proportional to the route metrics,Per-destination load balancing distributes packets across the possible routes based on（75）.（71）A. calls B. metrics C. links D. destinations（72）A. user B. distance C. entity D. cost（73）A. bracketing B. balancing C. downloading D. transmitting（74）A. destinations B. resources C. packets D. sources（75）A. destinations B. resources C. packets D. sources参考译文各种路由协议使用不同的技术来为网络赋予度量值。进一步说，每一种路由协议都形成了不同的度量汇聚模式。大部分路由协议在各个通路具有相等费用时可以使用多个通路。某些路由协议甚至在各个通路费用不相等时也可以使用多个通路。在上述任何一种情况下负载均衡都可以改进网络带宽的全局分配。当使用多个通路时，可以使用多种方法来分配分组。两种最通常的机制是按分组进行负载均衡和按目标进行负载均衡。按分组进行负载均衡是指按照路由度量的比例向各个可能的路由上分配分组。按目标进行负载均衡是指根据目标向各个可能的路由上分配分组。参考答案（71）B（72）D （73）B （74）C （75）A09上半年网络工程师英文真题、译文及答案The Border Gateway Protocol (BGP) is an interautonomous system （71） protocol.The primary function of a BGP speaking system is to exchange network （72） information with other BGP system. This network reachability information includes information on the list of Autonomous System (ASs) that reachability information traverses. BGP-4 provides a new set of mechanisms for supporting （73） interdomain routing. These mechanisms include support for advertising an IP （74） and eliminate the concept of network class within BGP.BGP-4 also introduces mechanisms that allow aggregation of routes, including （75） of AS paths. These changes provide support for the proposed supernettting scheme.（71）A. connecting B. resolving C. routing D. supernettting（72）A. secubility B. reachability C. capability D. reliability（73）A. answerless B. connectionless C. confirmless D. classless（74）A. prefix B. suffix C. infix D. reflex（75）A. reservation B. relation C. aggregation D. connection参考译文边界网关协议BGP是自治系统时间的路由协议。BGP发布系统的基本功能就是与其他BGP系统交换网络可达性信息。这种网络可到达性信息包含了可到达性信息穿越的自治系统的列表。BGP-4提供了一系列新的机制来支持无类别的域间路由。这些机制包括支持发布IP前缀，从而在BGP中排除了网络类别的概念。BGP-4也引入了路由聚合机制，包括AS通路的聚合。这些改变提供了对提议的超网方案的支持。参考答案（71）C （72）B （73）D （74）A （75）C08下半年网络工程师英文真题、译文及答案The usual way to ensure reliable delivery is to provide the （71） with some feedback about what is happening at the other end of the line. Typically, the protocol calls for the receiver to send back special （72） frame bearing positive or negative （73） about the incoming frames. If the sender receives a positive acknowledgement about a frame, it knows the frame has arrived safely. On the other hand, a negative acknowledgement means that something has gone wrong, and the frame must be transmitted again.An additional complication comes from the possibility that hardware troubles may cause a frame to （74） completely. In this case, the receiver will not react at all, since it has no any reason to react. It should be clear that a protocol in which the sender transmits a frame and then waits for an acknowledgement, positive or negative, will hang forever if a frame is ever lost due to, for example, （75） hardware.（71）A. receiver B. controller C. sender D. customer（72）A. data B. control C. request D. session（73）A. application B. connection C. stream D. acknowledgement（74）A. vanish B. vary C. appear D. incline（75）A. acting B. working C. malfunctioning D. functioning参考译文保证可靠提交的常用方法是向发送端提供一些反馈信息，使它知道在线路的另一端发生了什么情况。典型的情况是：协议要求接收端回送一个承载有关输入帧的肯定或否定应答的特殊控制帧。如果发送端收到了有关帧的肯定应答，它就知道发送的帧已经安全到达。另一方面，否定应答则意味着出现了某种错误，应该重新发送出错的帧。还有一些复杂的情况可能发生，硬件故障可能引起帧完全消失。在这种情况下，接收端完全没有反应，因为它根本无法反应。显然，如果一个帧由于硬件失效而丢失了，那么这样的协议-发送端发出一个帧然后等待肯定或否定应答，就会被永远地挂起了。参考答案（71）C （72）B （73）D （74）A （75）C08上半年网络工程师英文真题、译文及答案WLANs are increasingly popular because they enable cost-effective connections among people and applications that were not possible in the past. For example, WLAN-based applications can enable fine-grained management of supply （71） to improve their efficiency and reduce （72）. WLANs can also enable entirely new business processes. To cite but one example, hospitals are using WLAN-enabled point-of-care （73） to reduce errors and improve overall patient care. WLAN management solutions provide a variety of other benefits that can be substantial but difficult to measure. For example, they can protect corporate data by preventing （74） through rogue access points. They can improve overall network management by integrating with customers existing systems. Fortunately, it isnt necessary to measure these benefits to justify investing in WLAN management solutions, which can quickly pay for themselves simply by minimizing time-（75） deployment and administrative chores.（71）A. custom B. server C. chains D. chances（72）A. overhead B. connection C. supply D. effect（73）A. transportations B. applications C. connections D. translations（74）A. integration B. interest C. instruction D. intrusion（75）A. capable B. consuming C. effective D. connected参考译文无线局域网（WLAN）日益普及起来，这是因为它能在用户和应用之间有效地建立连接，这在过去是难以做到的。例如基于WLAN的应用可以对供应链进行细粒度的管理，从而改进效率，减少开销。WLAN也可以创造全新的商业过程。仅举出其中的一个例子，医院使用基于WLAN的护理点应用来减少差错，全面改进病员护理。WLAN管理解决方案提供的各种实质上的好处是很难度量的。例如，它可以保护公司的数据，防止恶意的访问。它可以全面地改进网络管理，并集成到用户现有的系统中。幸好，我们无需量化这些收益来证明WLAN解决方案的合理性，因为它能很快地补偿由于部署这些应用和管理事务而付出的时间开销。参考答案（71）C （72）A （73）B （74）D （75）B07下半年网络工程师英文真题、译文及答案Traditional Internet access methods like dial-up were so slow that host computers were connected to the dial-up （71） at the customer premise over slow （72） ports. PPP was designed to run directly over these serial links. But with the advent of broadband Internet （73）technologies such as ADSL and cable modems there has been a considerable increase in the bandwidth delivered to the end users. This means that the host computers at the customer premise connect to the （74） or cable modem over a much faster medium such as Ethernet. It also means that multiple （75） can connect to the Internet through the same connection.（71）A. buffer B. modem C. computer D. server（72）A. parallel B. digital C. serial D. variable（73）A. access B. cache C. cast D. storage（74）A. FDDI B. HDSL C. ADSL D. CDMA（75）A. cables B. hosts C. servers D. modems参考译文传统的Internet接入方法（例如拨号接入）速度很慢，这种方式要求客户端主机通过低速串口连接到拨号Modem，在串行链路上运行PPP协议。但是随着宽带Internet接入技术-例如ADSL和线缆调制解调器的发展，提供给端用户的带宽已经有相当大的增加。这意味着客户端主机可以连接到ADSL或者线缆调制解调器，从而获得比以太网还要快得多的传输介质。这也意味着多个主机可以通过同一连接访问Internet。参考答案（71）B （72）C （73）A （74）C （75）B07上半年网络工程师英文真题、译文及答案Serialization delay and （71） delay are the two components of network delay that are improved by increasing bandwidth. Serialization delay, i.e. the amount of time it takes to put the （72） on the wire, and queuing delay (depth of the queue) are improved by increasing the （73） from a 128Kbps circuit to a T1. However, three other components of delay, routing/switching delay, distance delay, and protocol delay are components that can not bepositively affected by an （74） in bandwidth. If the circuits are not over-utilized, thenincreasing the bandwidth to improve the （75） of the application will only result in an increased bandwidth with no positive effects on performance.（71）A. buffering B. queuing C. receiving D. timing（72）A. electricity B. digital C. data D. variable（73）A. memory B. cache C. bandwidth D. delay（74）A. increaseB. decreaseC. maintenance D. extension（75）A. capabilityB. cost C. amount D. performance参考译文串行排序延迟和队列延迟是网络延迟的两个主要因素，这些是可以通过增加带宽加以改进的。串行排序延迟（将数据输出到线路上需要的时间）和队列延迟（队列的长度）可以通过把带宽从128Kbps增加到T1得到改善。然而，另外三种延迟因素-路由/交换延迟、距离延迟和协议处理延迟是不能通过增加带宽来改进的。如果线路没有超量使用，则通过增加带宽来改进应用软件性能的企图只能产生一种结果，那就是带宽的增加对性能并没有产生正面的影响。参考答案（71）B （72）C （73）C （74）A （75）D06下半年网络工程师英文真题、译文及答案1NACs（Network Access Control）role is to restrict network access to only compliant endpoints and （66） usersHowever, NAC is not a complete LAN （67） solution; additional proactive and （68） security measures must be implementedNevis is the first and only comprehensive LAN security solution that combines deep security processing of every packet at 100Gbps, ensuring a high level of security plus application availability and performanceNevis integrates NAC as the first line of LAN security （69） In addition to NAC，enterprises need to implement role-based network access control as well as critical proactive security measures-real-time, multilevel （70） inspection and microsecond threat containment（66）Aautomated Bdistinguished Cauthenticated Ddestructed（67）Acrisis Bsecurity Cfavorable Dexcellent（68）Aconstructive Breductive Creactive Dproductive（69）Adefense Bintrusion Cinbreak Dprotection（70）Aport Bconnection Cthreat Dinsurance参考译文网络访问控制（NAC）的作用是限制对网络的访问，只允许注册的终端和认证的用户访问网络。然而NAC不是一个完整的LAN安全解决方案，另外还要实现主动的和被动的安全手段。Nevis是第一个也是仅有的全面的LAN安全解决方案，它以10Gbps的速率对每一个分组进行深度的安全处理，在提供高级别安全的同时能保证网络应用的可利用性和适当的性能。Nevis集成了NAC作为LAN的第一道安全防线。此外，企业还需要实现基于角色的网络访问控制以及起关键作用的主动安全测试-实时的多级安全威胁检测和微妙级的安全威胁堵截。集中的安全策略配置、管理和报告使其能够迅速地对问题进行分析，对用户的活动进行跟踪，这些都是实时可见的，也是历史可查的。参考答案（66）C （67）B （68）C （69）A （70）C06上半年网络工程师英文真题、译文及答案Originally introduced by Netscape Communications, （66） are a general mechanism which HTTP Server side applications, such as CGI （67）, can use to both store and retrieve information on the HTTP （68） side of the connection. Basically, Cookies can be used to compensate for the （69） nature of HTTP. The addition of a simple, persistent, client-side state significantly extends the capabilities of WWW-based （70）.（66）ABrowsers BCookies CConnections DScripts（67）Agraphics Bprocesses Cscripts Dtexts（68）AClient BEditorCCreator DServer（69）Afixed BflexibleCstableDstateless（70）Aprograms Bapplications Cframeworks Dconstrains参考译文Cookies原来是由Netscape公司引入的，这是HTTP服务器方应用程序的一种通信机制，就像CGI脚本一要产，它可以由HTTP连接的客户方用于存储和检索信息。Cookies的基本功能是弥补HTTP无状态的缺陷。它能通过简单而持续地维护客户方的状态来扩展基于WWW的应用能力。参考答案（66）B （67）C （68）A （69）D （70）B05下半年网络工程师英文真题、译文及答案MIDI enables people to use （66） computers and electronic musical instruments. There are actually three components to MIDI, the communications （67） , the Hardware Interface and a distribution （68） called Standard MIDI Files. In the context of the WWW, the most interesting component is the （69） Format. In principle, MIDI files contain sequences of MIDI Protocol messages. However, when MIDI Protocol （70） are stored in MIDI files, the events are also time-stamped for playback in the proper sequence. Music delivered by MIDI files is the most common use of MIDI today.（66）A. personal B. electronic C. multimedia D. network（67）A. device B. protocol C. network D. controller（68）A. format B. text C. wave D. center（69）A. Video B. Faxmail C. Graphic D. Audio（70）A. messages B packets C. frame D. information参考译文MIDI使得人们能够使用多媒体计算机和电子乐器。实际上MIDI有3种元素：通信协议、硬件接口和被称为标准MIDI文件的发布格式。在WWW环境中，最重要的元素是音频格式。在原理上，MIDI文件包含了MIDI协议报文序列。然而当MIDI协议报文被存储在MIDI文件中时，事件都被加上了时间戳，以便于按照适当的顺序回放。由MIDI文件提供的音乐是MIDI当前最通常的应用。参考答案（66）C （67）B （68）A （69）D （70）A05上半年网络工程师英文真题、译文及答案DOM is a platform-and language-（66） API that allows programs and scripts to dynamically access and update the content, structure and style of WWW documents（currently, definitions for HTML and XML documents are part of the specification）. The document can be further processed and the results of that processing can be incorporated back into the presented （67）. DOM is a （68）-based API to documents,which requires the whole document to be represented in （69） while processing it. A simpler alternative to DOM is the event-based SAX,which can be used to process very large （70） documents that do not fit info the memory available for processing.（66）Aspecific Bneutral Ccontained Drelated（67）Atext Bimage Cpage Dgraphic（68）Atable Btree Ccontrol Devent（69）Adocument Bprocessor Cdisc Dmemory（70）AXML BHTML Cscript Dweb参考译文DOM是一种与平台和语言无关的应用程序接口（API），它可以动态地访问程序和脚本，更新其内容、结构和WWW文档的风格（目前，HTML和XML文档是通过说明部分定义的）。文档可以进一步被处理，处理的结果可以加入到当前的页面DOM是一种基于树的API文档，它要求在处理过程中整个文档都表示在存储器中。另外一种简单的API是基于事件的SAX，它可以用于处理很大的XML文档，由于大，所以不适合全部放在存储器中处理。参考答案（66）B （67）C （68）B （69）D （70）A04下半年网络工程师英文真题、译文及答案Networks can be interconnected by different devices. In the physical layer,networks can be connected by （66） 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 （67）, examine the MAC address, and forward the frames to a different network while doing minor protocol translation in the process. In the network layer, we have routers that can connect two networks. If two networks have （68） network layer, the router may be able to translate between the packet 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 （69）. As an example, gateways between Internet e-mail and X.400 e-mail must （70） the e-mail message and change various header fields.（66）A.reapers B.relays C.connectors D.modems（67）A.frames B.packets C.packages D.cells（68）A.special B.dependent C.similar D.dissimilar（69）A.syntax B.semantics C.language D.format（70）A.analyze B.parse C.delete D.create参考译文网络可以用不同的设备互连。在物理层，用中继器或集线器互连，这些设备只是在相同的网络之间传送比特串。在上面的数据链路层，可以使用网桥或交换机，这些设备接收数据帧，检查MAC地址，并可以实现少量的协议转换，把数据帧转发到不同的网络中。在网络层，我们使用路由器连接两个网络。如果两上网络的网络层不同，路由器能够对分组格式进行转换。在传输层，我们使用传输风头，它可以在两个传输连接之间建立接口。最后，在应用层，应用网关实现消息语法之间的翻译。例如，在Internet邮件和X.400邮件之间的网关可以对邮件报文进行语法分析，对报文的各个报头字段做出改变。参考答案（66）A （67）A （68）D （69）A （70）B