打开有惊喜计算机英语重点

1.retrieve information检索信息
work architecture网络结构
3.Web-browsing and e-mail applications网页浏览和电子邮件应用
4.application protocol 应用层协议
5.e-mail routing information 电邮路由信息
6.authoritative name server 授权域名服务器
7.datagram communication service 报文通信服务
8.Multipurpose Internet Mail Extensions 多用网络邮件扩展
9.flow control algorithms 流程控制算法 10.check bits 校验位
11.Transmission Control Protocol 传输控制协议 er Datagram Protocol 用户数据报协议13.routing table 路由表 14.Interpret as Command 命令解释
1.subscriber access network 客户接入网络
2.Internet backbone 因特网主干网
3.Cable Television(CATV) network 电缆电视网络
4.co-axial cable 同轴电缆
5.point-to-multipoint optical network 点对多点逛网络
6.Logical Link Identifier 逻辑连接标识
7.channel capacity 信道容量 8.time-division multiple access 时分多路接入9.Asynchronous Transfer Mode 异步传输模式 10.Full Service Access Network 全功能接入网络11.Generic Framing Procedure 通用帧进程 12.Synchronous Digital Hierarchy 同步数字层13.Quality of Service 服务质量
1.point-to-point connections 点对点连接
B Host Controller Interface USB主机控制器接口
3.Bandwidth sharing and allocation 宽带共享和分配
4.Full Speed USB peripherals 全速USB外设
5.Enhanced Host Controller Interface 增强型主机控制器接口
6.detachable cable 可分离电缆
7.tiered-star topology 层叠星状拓扑结构 8.upstream connection 上行连接
9.Isochronous Data Transfers 同步数据传输 10.Interrupt Data Transfers 中断数据传输
11.Bulk Data Transfer 批量数据传输
12.High Mobility Performance Radio Local Area Network 高灵活性无限局域网
1.hypertext-matching analysis 超文本匹配分析
2.Web popularity contest 网站普及性竞争
3.Web crawler 网虫
4.research engine 科研引擎
5.Internet Protocol Television 网络协议电视
6.Broadband access 宽带接入
7.air broadcast channels 无线广播频道 8.Real-time video on demand 实时随选频道
9.client-oriented service 面向客户服务 10.value-added services 增值服务
11.service control architecture 服务控制体系 12.conditional-access management 有条件接入管理13.real-time rating engine 实时速率引擎 14.Extensible Markup Language 可扩展标记语言
mand-line mode 命令行模式
2.Internet Control Message Protocol 网络控制消息协议
3.query/response mechanism 询问/解答机制
4.Path discovery 路径发掘
5.routing table 路由表
6.Traffic Capture Tools 流量捕获工具
7.Protocol analyzer 协议解析器 8.multicast address 多点传送地址
9.capture engine 捕获引擎 10.Type-of-Service 服务类型
1.utility programs 工具程序
2.Virus triggering phase 病毒触发阶段
3.Virus Execution phase 病毒执行阶段
4.executable files 可执行文件
5.Types of Viruses 病毒类型
6.Boot sector virus 引导扇区病毒
7.Stealth virus 隐性病毒 8.Polymorphic virus 变异病毒
9.mutation engine 变异机制 10.encryption key 加密键
11.virus-creation toolkit 病毒制作工具 12.auto-executing macro 自动执行宏
13.password-cracking program 密码破解程序 14.Microsoft Internet Information Server 微软网络信息系统15.Digital Immune System 数字免疫系统 16.Security measures 安全机制
1.Centralized data processing system 集中式数据处理系统
2.Enterprise-wide network 企域网
3.Internet service provide 网络服务提供商
4.incoming IP packet 入网IP包
5.default discard policy 默认遗弃方案
6.packet-filtering level 包过滤层
er authentication schemes 用户认证机制 8.filtering router 过滤路由器
9.Simple Mail Transfer Protocol 简易邮件传输协议 10.screened host firewall 屏蔽主机防火墙
11.firewall types and configurations 防火墙类型及配置
1. The expectations toward the IPTV (Internet Protocol Televison) business rose particularly last year, mainly because of the gradual falling of the technical barriers . Today , IPTV is considered a business Opportunity by telco operators ,not only for the service itself , but also for the prospects it can open up in terms of integration with other services.
翻译去年业界对IPTV(互联网协议电视)的商业预期大大提高了,主要原因是技术障碍逐渐减少了.今天,通信运营商认为IPTV是一个商业机会, 不仅在于IPTV业务本身,而且还在于IPTV与其他业务的结合可能开创的前景
2. In past years,telcos have successfully launched the Broadband access that became a viable replacement for the declining switched voice business,deriving mainly from fixed-mobile substitution . Broadband access is becoming a market that is subject to price declines for the acquisition of the same bandwidth.In many countries ,telcos' market dominance is threatened by cable operators' triple-play offerings,which provide broadband access ,TV,and telephony on a single platform.In this scenario ,it is critical for telcos to support broadband penetration and ARPU through value-added services.
翻译在过去几年里,电信运营商成功地进行了用户的宽带接入,这成为对逐渐衰退的语言交换业务的可用的替代方式,这种衰退主要来自移动电话对固定电话的替代.宽带接入正在成为一个市场的主要原因是获得同样带宽的价格下降了.在很多国家,电信运营商的市场优势受到了有线电视运营商的威胁,他们提出了"三合一"的服务,即在同一个平台上实现宽带接入、电视和电话业务。

在此情况下，电信运营商的关键是要支持宽带的突破，以及通过增值业务来提高单位投入的平均回报ARPU。

3. It is possible to think of people who don't own a PC and who will buy IPTV(e.g.,to see premium content，such as football matches.) The challenge for the telco is to design a client-oriented service which hides completely all the technical aspects ，since the basic users of television service are not aware of ADSL , modems ,LAD ,and other specific components of the service 。

At the beginning ，customers will probably look only for premium or specific video content，but telcos will have the opportunity to stimulate the progressive use of other advanced interactive services offered（e.g.,T-SMS,T-Web,or video communication).IPTV could therefore become an effective means to distribute value-added services to customers not used to high-tech equipment ，but very familiar with the TV。

翻译可以想象那些没有个人电脑的人们将会购买IPTV（例如，观看足球比赛之类的丰富节目）。

对电信运营商的挑战是设计一个面向客户的服务,它对客户完全隐藏有关技术的内容,因为电视业务的基本用户并不知道ADSL,调制解调器,互联网迷,以及此业务的其他有关技术.开始时,客户可能只看到主流的或特定的视频内容,但是电信运营商有机会刺激使用那些它提供的新颖的交互式的业务(例如,T-SMS电视短信息,T-Web,或视频通信).IPTV因此能够成为一个向那些不会用高科技设备而只熟悉电视机的用户推销增值业务的有效手段
4.In order to enter the IPTV offer business ，a telco has to merge its competencies in broadband services with specific expertise in the media industry 。

翻译为了进入IPTV商务领域 ,一个电信运营商必须将它的宽带服务的能力与媒体产业的专门技术融合
5.The decision about the infrastructure to use （STBs，video servers，DSLAMs, etc.）is a point of concern for telcos ，mainly because the market is in the early phases and there are no de facto standards that are driving the evolutions of these services 。

翻译电信运营商要考虑的一个问题是作出使用何种基础设备的决策(机顶盒SYB,视频服务器,数字用户环路DSL的接入多路复用器DSL-AM等),主要是因为此市场还处于早起阶段,还没有驱动这些业务发展的事实上的标准.
6.Today the market offers cheap STBs （less than $100）able to deliver basic IPTV services with old-fashioned interfaces 。

This kind of STB offers a low barrier to customers ，but makes the service less attractive。

On the other side，high-range STBs are available and enable very powerful user expertises （supporting the latest version of Flash and HTML features），offering also advanced features，such as Local-based PVR and TST and advanced gaming 。

翻译如今,市场上可以提供廉价的(不到100美元)可以通过老式的接口实现IPTV业务的机顶盒STB.这类STB对于客户使用起来障碍不大,但是使得此业务不太吸引人.另一方面,高端的STB已经上市了,可以给客户带来功能强大的体验(支
持最新版的FLASH和HTML特性),提供先进的功能,例如基于本机的个人视频记录PVR和有播控功能的点播TST,以及先进的游戏.
7.While there are several useful programs for analyzing connectivity，unquestionably Ping is the most commonly used program。

The Ping program sends an Internet Control Message Protocol echo request packet to the destination host。

When the echo request packet is received ， the remote host immediately
returns an echo reply packet to the sending device 。

The format of the Ping command is：
翻译虽然有几个检测网络连通性的有用程序,但是毫无疑问Ping 命令是最常用的.主机发送Ping 命令后,该程序就发
送一个互联网控制信息协议ICMP的回应请求包给远端目标主机.当远端机收到此回应请求包后,他立即返回一个响应包
给源主机.Ping的命令格式如下:
8.Consistency among repeated queries gives an indication of the quality of the connection .Thus ,ping answers two basic question 。

Do I have a connection？ How good is that connection？
翻译多次重复发送 PING 后收到的多个回应往返时间之间的一致性,标明了网络连接的质量.因此PING 解答了两个基本问题: 此网络设备联通了吗? 联通质量如何?
ers can also Ping the local host ,this will allow you to see if the computer is able to send information out and receive the information back (Experiment 3).Make sure that this does not send information over a network but may allow you to see if the card is being seen .Maybe you would like to Ping 127.0.0.1, the loop-back address for the computer. The Ping is successfully, so that eliminates a possible between the computer , driver configuration,and the NIC card.If the Ping operation is not able to complete this should relay back an unsuccessful message which could be an indication of cable issues, network card issues , hub issue, etc.
翻译用户也可以自己PING自己的主机,由此判断本机是否能发送和接收信息(实验3).这并没有向网上发送信息,只是判断自己的网卡是否正常.你可以PING本机的回传地址127.0.0.1.如果PING操作成功了,就排除了可能存在于计算机、驱动程序设置和网卡之间的问题。

若PING不成功，则将会得到连接失败的信息，可能是线缆、网卡或集线器等出故障
了。

10.These are the tools that will allow a network administrator or ordinary users to remotely monitor and control the network。

As the old saying goes everything has two sides，you must utilize them on the legality ways， not the hacker’s guilty way！
翻译以上这些工具都允许网络管理员或普通用户远程监视和控制网络。

就像古谚所说的事事皆两面，你必须把这些工
具用于合法目的，而不能用于电脑黑客的犯罪行为！
11.If you are looking for basic information quickly ，Microsoft provides one of two programs for this purpose，depending on which version of Windows you use。

The utility Winipcfig is include with Windows 95/98. A command-line program, IPconfig , is included with Windows NT and Windows 2000 and Microsoft's TCP/IP stack for Windows for Workgroups . Both programs provide the same information . These Windows utilities display . IP-addressing information for the local network adapter(s) or a specified NIC.
翻译如果你要很快地查出本机的基本IP配置信息, 微软提供了两个程序之一来完成此工作.具体使用那个程序取决于用户你使用的Windows 版本.在Windows 95/98 下使用Winipcfig .IPconfig 是一个命令行程序,它包含在Windows NT,Windows 2000和微软的Windows 工作组的TCP/IP堆栈里.它们都提供相同的信息.这些Windows 实用工具程序显示了本地网卡或指定网卡上的IP地址信息.
12.Perhaps the most sophisticated types of threats to computer systems are presented by programs that exploit vulnerabilities in computing systems . In this context , we are concerned with application programs as well as utility programs, such as editors and compilers.
翻译对计算机网络系统的最大威胁之一,就是那些利用系统和程序的脆弱性及漏洞进行攻击的恶意软件,这里所说的程序既包括一般的应用程序,也包括工具程序,如编辑器和编译器等.本节首先概览这些软件威胁的领域,之后将具体介绍它们的本质和运行方式,然后分析相应的对抗措施.
13.One of the oldest types of program threat, predating viruses and worms, is the logic bomb. The logic bomb is code embedded in some legitimate program that is set to "explode" when certain conditions are met.Example of conditions that can be used as triggers for a logic bomb are the presence or absence of certain files, a particular day of the week or date, or a particular user running the application . Once triggered, a bomb may alter or delete data or entire files ,cause a machine halt , or do some other damage. A striking example of how logic bombs can be employed was the case of Tim Lloyd , who was convicted of setting a logic bomb that cost his employer , Omega Engineering, more than $10 million , derailed its corporate growth strategy , and eventually led to the layoff of 80 workers . Ultimately, Lloyd was sentenced to 41 months in prison and ordered to pay $2 million in restitution.
翻译逻辑炸弹是出现最早的程序威胁类型之一,在病毒和蠕虫出现之前就有了. 逻辑炸弹实际上是嵌在合法程序中的代码段,在某些条件满足的时候该炸弹将"引爆".这些引爆逻辑炸弹的条件可能包括特定文件的出现或者消失、星期中的一个特定日子、或者某特定的用户运行了一个程序等。

一旦引爆，逻辑炸弹将修改、删除数据和文件，使系统停机或者带来一些其他危害。

一个著名的逻辑炸弹的例子是美国的Tim Lloyd的案例，他倍指控在自己工作的Omega Engineering公司的网络中设置了逻辑炸弹，造成了超过一千万美元的经济损失。

打乱了公司的发展计划，并导致80个工作人员事业。

Lloyd被判41个月监禁，并罚款两百万美元。

14.A zombie is a program that secretly takes over another Internet-attached computer and then uses that computer to launch attacks that are difficult to trace to the zombie’s creator .Zombies are used in denial-of-service (DoS) attacks , typically against targeted Web sites. The zombie is planted on hundreds of computers belonging 头 unsuspecting third parties , and then used to overwhelm the target Web site by launching an overwhelming onslaught of Internet traffic.
翻译蛇神程序事先秘密地进入到连接在网络上的大量的计算机,获取了对这些第三方计算机的控制权,之后以这些被劫持的计算机为跳板实施对网络目标机的攻击行为,这就使得追踪发现真正的攻击者变得十分困难.蛇神程序可以应用于对Web 服务器的拒绝服务攻击,这种攻击的一个典型实例是攻击Web网站.攻击者将蛇神程序植入到成千上万台网络用户的计算机中,然后在某特定时刻控制这些计算机一起向目标网站发起访问,由于网站服务器对每个访问者要发回响应并分配相应的存储资源,由于同时访问的用户量巨大,耗尽了服务器和网络的资源,使得该站点陷入拒绝服务状态,达到攻击的目的.
15.Trojan horse programs can be used to accomplish functions indirectly that an unauthorized user could not accomplish directly . For example , to gain access to the files of another user on a shared system , a user could create a Trojan horse program that , when executed , changed the invoking user's file permissions so that the files are readable by any user . The author could then induce users to run the program by placing it in a common directory and naming it such that it appears to be a useful utility. An example is a program that ostensibly produces a listing of the user's files in a desirable format . After another user has run the program , the author can then access the information in the user's files. An example of a Trojan horse program that would be difficult to detect is a compiler that has been modified to insert additional code into certain programs as they are compiled such as a system login program . The code creates a trap door in the login program that permits the author to log on to the system using a special password . This Trojan horse can never be discovered by reading the source code of the login program.
翻译特洛伊木马程序可以用来间接地实现一些未授权用户无法直接实现的功能.例如,为获得对共享系统中某个用户的文件的访问权限,攻击者设计出一个木马软件 , 它执行后可以将该用户的某文件的存取权限改变为其他用户也可读取.攻击者可以将隐藏了木马程序的软件放置在公共目录下,或者将该程序的名字取为游戏或者有用的工具名,来引诱其他用户执行该程序软件.比如,一个木马程序以某种格式列出了一个用户的文件清单,当其他用户执行该程序后,攻击者就可以得到访问该用户的权限.一种难于检测的特洛伊木马程序是隐藏在编译器中的.当编译器对某程序编译后,该程序中就植入了木马,木马修改了系统的登录程序,在期中设置了一个陷门(用户名),通过该陷门,攻击者可以用一个特殊的口令登录系统,而通过分析登录程序的源代码是不可能检测出这种木马的.
16.Until the current generation of worms , the best known was the worm released onto the Internet by Robert Morris in 1988. The Morris worm was designed to spread on UNIX systems and used a number of different techniques for propagation . When a copy began execution ,its first task was to discover other other hosts known to this host that would allow entry from this host . The worm performed this task by examining a variety of lists and tables , including system tables that declared which other machines were trusted by this host, users' mail forwarding files,tables by which users gave themselves permission for access to remote accounts , and from a program that reported the status of network connections . For each discovered host, the worm tried a number of methods for gaining access :
翻译在新一代蠕虫产生之前,最为著名的蠕虫是1988年Robert Morris 在Internet上发布的Morris蠕虫. Morris蠕虫被设计在为UNIX系统上传播,并才用了很多不同的传播技术, 当该蠕虫开始执行时,他首先要执行的任务是寻找可以冲本地计算机进入的其他主机. 这个任务是通过搜索系统里的很多列表实现的,包括本机信任的其他机器名单列表、用户的电子邮件转发文件、用户可以授权登录的远程账号列表，和一个报告网络连接状态的程序等。

对每一个搜索到的主机，蠕虫将尝试很多方法以获得对他的访问权。

17.Firewalls can be an effective means of protecting a local system or network of systems from network-based security threats while at the same time affording access to the outside world via wide area networks and the Internet。

翻译防火墙对于保护一个本地系统或系统的网络，防止来自基于网络的安全威胁是一种很有效的手段，它同时还提供对外部广域网和互联网的访问。

18.Internet connectivity is no longer an option for most organizations 。

The information and services available are essential to the organization Moreover ， individual users within the organization want and need Internet access ， and if this is not provided via their LAN， they will use dial-up capability from their PC to an Internet service provider（ISP）。

However ， while Internet access provides
benefits to the organization ， it enables the outside world to reach and interact with local network assets 。

This creates a threat to the organization。

While it is possible to equip each workstation and server on the premises network with strong security ， features ， such as intrusion protection ， this is not a practical approach 。

Consider a network with hundreds or even thousands of systems running a mix of various versions of UNIX，plus Windows 。

When a security flaw is discovered， each potentially affected system must be upgraded to fix that flaw 。

The alternative ， increasingly accepted ， is the firewall 。

The firewall is inserted between the premises network and the Internet to establish a controlled link and to erect an outer security wall or perimeter 。

The aim of this perimeter is to protect the premises network from Internet-based attacks and to provide a single choke point where security and audit can be imposed 。

The firewall may be a single computer system or a set of two or more systems that cooperate to perform the firewall function 。

翻译对大多数单位来说接入互联网不再仅仅是一个可有可无的选择，网络信息的查询与服务是不可缺的基本条件。

而且，有些单位内的个人用户需要访问互联网时，如果单位的局域网内不能访问，他们就会用局域网内的PC机的拨号
功能通过电话线访问互联网服务提供商ISP ，这样形成了局域网与外网的连接有了多个出入口。

当接入互联网给单位的工作带来好处的同时，也让外部网络接触了内部网络。

网络间谍、黑客、好奇心的网络搜索者对内网的探索，这就
产生了对单位信息的威胁。

我们也可以将单位的局域网的每个工作站和服务器都配置上入侵保护等增强的安全性能，但这样并不总是可实施的方案。

如果一个网络内包含成百上千的主机系统，运行着各种不同版本的UNIX系统和Windows，当发现一个安全隐患后，必须对每个可能受影响的系统进行升级来解决此隐患，这是难实施的。

可行的替代方案是
采用防火墙对出入内外网的数据包进行隔离与过滤。

防火墙连接在局域网与互联网之间，成为一个可控的连接关口和安全的防护周界。

此周界的目的是保护局域网，防止来自外部互联网的攻击。

在此唯一的对外连接关口上可进行信息安全过滤和日志审计检查。

防火墙的功能可以由一台计算机，或多个的系统互相协作来构成。

19.A firewall defines a single choke point that keeps unauthorized users out of the protected network ，prohibits potentially vulnerable services from entering or leaving the network ，and provides protection from various kinds of IP spoofing and routing attacks 。

The use of a single choke point simplifies security management because security capabilities are consolidated on a single system or set of systems。

翻译防火墙是内网向外部的唯一出口，可以阻止未经授权的用户进入内部网络，禁止有嵌在脆弱性的服务进入或者离
开内部网络，并且对各种各样的IP嗅探和路由攻击提供保护。

使用单一的出口，可以简化安全管理，因为安全措施可
以集中设置在一个或者一组系统中。

20.The firewall cannot protect against the transfer of virus-infected programs or files。

Because of the variety of operating systems and applications supported inside the perimeter ， it would be impractical and perhaps impossible for the firewall to scan all incoming files，e-mail，and messages for viruses。

翻译防火墙不能对那些已经受到病毒感染的程序和文件的传输提供保护。

因为在局域网内支持各种操作系统和应用，
要求防火墙对所有进入的文件、邮件和信息进行病毒扫描是不现实的和不可能的。