计算机英语网络技术unit 4 Network Technique

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计算机专业英语教程(第4版)全书译文

1We have learned that all computers have similar capabilities and perform essentially the same functions, although some might be faster than others. We have also learned that a computer system has input, output, storage, and processing components; that th e processor is the “intelligence” of a computer system; and that a single computer system may have several processors. We have discussed how data are represented inside a computer system in electronic states called bits. We are now ready to expose the inner workings of the nucleus of the computer system — the processor.我们已经知道，所有的计算机都具有相似的能力，并且在本质上执行相同的功能，尽管一些可能会比另一些快一点。

我们也知道，一个计算机系统具有输入，输出，存储和处理部件；处理器是一个计算机系统智能核心，并且一个计算机系统可以有许多个处理器。

我们已经讨论过如何在计算机系统内部，用被称作“位”的电子状态来表现数据，现在我们要弄明白计算机系统的核心，即处理器，的内在的工作方式。

The internal operation of a computer is interesting, but there really is no mystery to it. The mystery is in the minds of those who listen to hearsay and believe science-fiction writer. The computer is a nonthinking electronic device that has to be plugged into an electrical power source, just like a toaster or a lamp.计算机的内部操作很有意思，但确实没有什么神秘可言。

网络技术第4次课共38页文档

数据链路层是任何网络都必须有的层次。注意还有其他的很多功能。
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2、设备:网络接口卡NIC
网络接口卡（网卡）是连接主机与网络的基本设备每台主机都应配置一个或多个网卡；每个网卡都有一个（或多个）网络接口；不能独立工作，必须依赖于宿主主机。
网卡工作在物理层和数据链路层；
连接不同的局域网需要使用不同的网卡以太网卡令牌环网卡 FDDI网卡 ATM网卡
网络技术第4次课
1、舟遥遥以轻飏，风飘飘而吹衣。 2、秋菊有佳色，裛露掇其英。 3、日月掷人去，有志不获骋。 4、未言心相醉，不再接杯酒。 5、黄发垂髫，并怡然自乐。
第四章网络设备与网络协议
第4/6章
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目录
一网络互连基础二物理层及设备三数据链路层及设备四设备比较与总结
数据发送/接收
发送数据：将主机的并行数据转换成串行位流，并通过MAC进行发送；接收数据：通过MAC接收信号，经解码后由串行位流转换成并行数据；
数据缓存
匹配主机数据处理速率与网络的传输速率不一致问题。
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4. 网卡的结构
▪ 载波检测部件：检测介质上有否载波信号； ▪ 曼彻斯特编码/解码器：对发送的数据编码，变换成适合于在LAN
冲突域/广播域 HUB
总带宽: BW 节点带宽: BW/8
网桥或网络交换机
总带宽: BW*2 节点带宽: BW/4
HUB
网段1 网段2
广播域
HUB
冲突域
冲突域
三、数据链路层及设备
1、数据链路层介绍：
它以物理层为基础，负责网络内部的数据帧传输。一般就是指将网络层的数据报通过路径中的单段链路节点到节点的传送。而且不同的相邻节点间的数据帧的承载协议可能不同。

计算机网络第四版英文答案

计算机网络第四版英文答案【篇一：《计算机网络(第四版)》习题答案】t>习题答案第 1 章概述1-3 the performance of a client-server system is influenced by two network factors: the bandwidth of the network (how many bits/sec it can transport) and the latency (how many seconds it takes for the first bit to get from the client to the server). give an example of a network that exhibits high bandwidth and high latency. then give an example of one with low bandwidth and low latency.客户-服务器系统的性能会受到两个网络因素的影响：网络的带宽（每秒可以传输多少位数据）和延迟（将第一个数据位从客户端传送到服务器端需要多少秒时间）。

请给出一个网络的例子，它具有高带宽和高延迟。

然后再给出另一个网络的例子，它具有低带宽和低延迟。

答：横贯大陆的光纤连接可以有很多千兆位/秒带宽，但是由于光速度传送要越过数千公里，时延将也高。

相反，使用56 kbps调制解调器呼叫在同一大楼内的计算机则有低带宽和较低的时延。

1-4 besides bandwidth and latency, what other parameter is needed to give a good characterization of the quality of service offered by a network used for digitized voice traffic?除了带宽和延迟以外，针对数字化的语音流量，想要让网络提供很好的服务质量，还需要哪个参数？声音的传输需要相应的固定时间，因此网络时隙数量是很重要的。

计算机网络基础知识课件英文版

Introduction to Computer Networks
Discover the world of computer networks, from their definition and significance to their classification and protocols. Explore the fascinating concepts of OSI and TCP/IP models, network topologies, devices, security, performance optimization, applications, and management.
Network Performance Optimization
Data Transmission Rate
Learn about factors that influence transmission speeds, such as bandwidth, latency, and throughput.
Star
A network topology where devices are connected to a central hub or switch.
Ring
A network topology where devices are connected in a circular manner, forming a
Reducing Latency
Discover techniques to minimize latency, ensuring faster response times and smoother network performance.
Increasing Bandwidth

计算机专业英语unit 4-2

Thank You!
Exercises
Find Information Task Ⅰ: 1. Broadband is the name given to any fast, permanent Internet connection. 2. It can be delivered by cable, satellite, mobile phone and ADSL. 3. Your ISP will test and activate the line for you. 4. Yes, they are. 5. Mobile is the newest form of the broadband.
Some cable TV companies offer a cable internet connection via their existing wiring.
Passage-learning
Fibre-optics are tiny wires that transmit pulses of light. Since light is the fastest thing in the universe, they're much faster than ADSL cables. This means you can get internet speeds up to five times faster than the fastest ADSL connections.
Unit four Computer network (2)
Contents
1. Lead-in activity 2. Passage learning
3. Exercises 4. Fun time

计算机专业英语Unit04_SectionA_Computer_Program

解释执行的语言的缺点是，它们执行起来慢，因为每次运行程序，都必须对整个程序一次一条指令地翻译。另一方面，编译执行的语言编译执行的语言只编译一次，因此计算机执行编译执行的语言起来可比解释执行的语言快得多
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Computer Program-Program Development For this reason, compiled languages are more common and are almost always used in professional and scientific applications.
The advantage of interpreted languages is that they can begin executing the program immediately instead of having to wait for all of the source code to be compiled. Changes can also be made to the program fairly quickly without having to wait for it to be compiled again.
操作系统管理计算机以及与之相连的各种资源和设备，如随机随机存储器、硬盘驱动器、监视器、键盘、打印机和调制解调器，存储器以便其他程序可以使用它们。操作系统的例子包括：DOS、 Windows 95、OS/2和UNIX。
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Computer Program-Program Development
程序分为两大类：应用程序和操作系统。应用程序直接为用类户执行某种功能，ห้องสมุดไป่ตู้处理文字或玩游戏.

计算机与网络英语词汇（S4）_计算机英语词汇

stream bitrate 串流位stream file object 串流档案对象stream format 串流格式stream format definition chunk 串流格式定义块stream header 串流标头stream i/o 串流 i/ostream length 串流长度stream mode 串流模式stream name 串流名称stream object 串流物件stream priority 串流优先等级stream quality 串流品质stream rate 串流率stream scale 串流尺度stream socket 串流通讯端stream start 串流起点stream, bit 数元流stream, input job 输入工件流streaming 资料流streaming digital cartridge tape drives 限流数字匣式磁带驱动机streaming drive data verification 限流驱动数据验证streaming formatter/controller 限流格式控制器streaming media 串流媒体streaming video 串流视讯streaming/incremental-recording tape systems 限流/递增记录磁带系统strength 强度strength reduction 复杂运算简化stress 结构工程系统解答器stress testing 压力测试stretch 自动缩放stretched vertically 垂直拉伸strict type semantic 严格类型语意strikeout 删除线string 字符串string break 串破裂string clement 组件串string concatenation operator 字符串串连运算子string constant 字符串常数string editor 字符串编辑器string expression 字符串表达式string file 串檔string identifier 字符串识别码string language 串语言string length 串长string literal 字符串常值string manipulation 串调处string manipulation, data-base 数据库串调处string name 字符串名称string of bits 位串string pooling 字符串共享string process system(sps) 串处理系统string processing 串处理string resources 字符串资源string sorting 串排序string table 字符串数据表string variable 串变数string variable name 字符串变量名称string variable rom 串变量仅读记忆器string variable, alphanumeric 文数串变数string, alphabetic 字符串string, character 字符串string, character(basic) (培基)字符串string-comparison operation 字符串比较作业stringy floopy 串状磁带strip 剥去strip, encoding 编码条纹strip, magnetic-file 磁档条strip, magnetic-tape 磁带条strip-chart recorder 条形图表纸记录器stripe card reader 条纹卡读取机stripe card reader/encoder 条纹卡读取机/编码器stripe card standards 条纹卡标准stripe recording, magnetic 磁条记录striping 加以条文；镶边strips left down 阶梯状往左下扩展strips left up 阶梯状往左上扩展strips right down 阶梯状往右下扩展strips right up 阶梯状往右上扩展strobe 闪控strobe frequency 分解动作频率strobe pulse 闪控脉波strobe release time 闪控释放时间strobe signal 闪控信号stroke 笔划；冲程stroke center line 笔划中线stroke character generator 笔划字符产生器stroke color 笔画色彩stroke edge 笔画边缘stroke edge irregularity 笔划边缘不规则性stroke list 单项工作清单stroke type 笔画类型stroke weight 字体粗细stroke width 笔划宽度stroked charactera 短划字符strong key 增强金钥strong name 强式名称strongly typed 强类型struct 结构structed language 结构化语言structure 结构structure expression 结构表式structure flowcharts 结构流程图structure member 结构组件structure of arrays 数组结构structure query language (sql) 结构化查询语言structure type 结构类型structure(struc) 结构structure, block 块结构structure, priority 优先序结构structured analysis 结构化分析structured exception handling 结构化例外处理structured field syntax 结构化栏语法structured interrupt 结构化岔断structured program testing 结构化程序测试structured programming 结构化程式编制structured programming document-ation 结构化规划文件处理structured programming(sp) 结构化规划structured query language 结构化查询语言 (sql) structured query language (sql) 结构化查询语言structured storage 结构化储存体structuring 结构strudl 结构设计语言sts-1(synchronous transport signal level 1) 同步传输讯号层1 stub card 残卡studio 工作室study date 研读日期study instance 研读实体study ref. physician 研读参考医生study time 研读时间study, application 应用研究stuffing character 填充字符stunt box 制止盒stx 起文字元style 样式style bit 样式位style builder 样式产生器style organizer 样式组织style presets 样式预先设定style sheet 样式表styled text 样式文字stylus 针尖；尖笔stylus printer 针尖印字机stylus, light(pen) 光电笔sub 子sub network mask 子网掩码sub select 细部选取sub task 子任务sub type 子类型sub-dependency 子相依sub-harmonic 分谐波sub-system 分系统sub-wave 副载波subaddress 子地址subalphabet 子字符subblock 子块；分块subchannel 子通道。

计算机网络与技术(双语)课程计算机网络教学大纲(双语)

《Computer Network》课程教学大纲二、课堂教学时数及课后作业题数分配三、单元教学目的、教学重难点和内容设置L1 Course Preparation【teaching objective】to help students know Sentence analyzing of the scientific English and some terms of the computer and communication technology.【keys and difficulties 】Long Sentence analyzing and terms memorizingL2 Introduction of the computer networks【teaching objective】to help students know the basic knowledge of network applications and Communication media, local asynchronous communication and long distance communication. 【keys and difficulties 】understanding the concept and principal of local asynchronous communication and long distance communication.L3 Packet transmission 1【teaching objective】to help students know the basic concept of transmission errors and error detection , LAN topologies, Addressing principal.【keys and difficulties 】understanding the concept of error detection the method to avoid transmission error.L4 Packet transmission 2【teaching objective】to help students know the basic concept fiber modems, repeater, bridges switches ATM technology and W AN technology, to understand the principal of the loop digital technology and Routing ,【keys and difficulties 】understanding the Routing principal and applications of WANL5 Packet transmission 3【teaching objective】to help students know network Characteristics, to understand the relation of the seven layers【keys and difficulties 】understanding the sketch of Information transmission among layers.L6 Internetworking1【teaching objective】to help students know network concepts architecture and protocols, and understand the address resolution.【keys and difficulties 】understanding the principal and work mechanism of ARP protocol.L7 Internetworking2【teaching objective】to help students know concepts of IP datagram, datagram forwarding, IP encapsulation, fragmentation and reassembly, and understand the mechanism of error reporting. 【keys and difficulties 】understanding the principal and work mechanism of error reporting and correcting.L8 Internetworking3【teaching objective】to help students know how to guarantee the reliable transport service andunderstand the mechanism of the address translation and internet routing.【keys and difficulties 】understanding t he mechanism of the address translation and internet routing.L9 and L10 work Application1【teaching objective】to help students know some applications of the computer networks and improve scientific English reading ability.【keys and difficulties 】understanding the concept and use of Computer security。

计算机英语章节知识点unit4

1---for those who are either just beginning programming or those interested in integrating a database into any form of application/web site.Either ---or : 连接两个名词（或代词）其谓语应该与毗邻的主语取得一致。

2 Thanks to the World Wide Web，----Thanks to：owing to .由于，因为Thanks to your help we were successful .3--- DBMS，along with Microsoft SQL Server，----along with: = in company with 意为“伴随着”why don`t you come along with us ?4or otherwise work with the database's data.Otherwise ：通常置于从句的开头。

She was thankful that she`t had her baby in hospital; otherwise, she thought, she might have died. 注意：在otherwise 前不用or5 Another reason databases were infeasible was simply the lack of skilled administrators to install the lack of skilled: 用作名词：缺乏，不足，没有。

用作动词：缺乏，不足I hated the lack of privacy in the dormitory.6----, so did common standards.So : 开头的句子引起部分倒装。

计算机英语unit3 Computer Network Lesson4 Network Security

spamming. 恶意攻击
非法侵入
垃圾邮件
家庭或办公室小型网络只需要基本的安全防护，而大型商业网络则需要更高级维护性和更先进的软硬件来阻止黑客和垃圾邮件的恶意攻击。
Reading
网络安全管理
To small homes, every computer connected to the Internet should be protected by a firewall, and that goes double ---or triples ---for computers on wireless networks.
属性
Dialogue
麦克正向玛丽咨询怎样安装防火墙。
高级选项
启动
Mary:Enter into the advanced tab, enable
the Internet Connection firewall. The
firewall will work on your computer.
Dialogue
垃圾邮件病毒禁止
Look and Learn
spam
firewall
virus
antivirus
Dialogue
麦克正向玛丽咨询怎样安装防火墙。
Mary: Technical support department, what can I do for you?
Michael: Hello, I just want to know how I can set up a firewall for my Windows system.
on the computer to fit for
your demand.

计算机网络双语第4章答案ppt课件

R21:Link state algorithms: Computes the leastcost path between source and destination using complete, global knowledge about the network. Distance-vector routing: The calculation of the least-cost path is carried out in an iterative, distributed manner.A node only knows the neighbor to which it should forward a packet in order toreach given destination along the leastcost path, and the cost of that path from itself to the destination.
Answer of HW
• P447 P8
• a)
• Prefix Match
Link Interface
• 11100000 00000000
0
• 11100000 00000001
1
• 11100000
2
• 11100001
3
• otherwise
4
• b)
• Prefix match for first address is 4th entry: link interface 4
Router 3Longest Prefix Match 11010110 01100001 11111111 0000000 11010110 01100001 11111110 0 11010110 01100001 11111110 0000001

Computer Science (4章)_学生

Computer Science an Overview（10th edition）Chapter 4 Networking and the Internet (组网及因特网) In this chapter we discuss the area of computer science known as networking, which encompass es (vt.包括,包含)the study of how computers can be linked together to share information and resources. Our study will include the construction and operation of networks, applications of networks, and security issues. A prominent (重要的,突出的)topic will be a particular worldwide (遍及世界的,全世界的) network of networks known as the Internet.prominent adj.突起的（突出的），杰出的（重要的，著名的）---a prominent nose大鼻子---a prominent doctor著明的医生本章讨论计算机科学中称为网络的领域，包括学习如何将计算机连接起来共享信息资源。

研究的内容包括网络的结构与操作、网络的应用以及网络安全问题，学习一个重点主题是遍布世界范围的特殊网络——因特网。

The need to share information and resources among different computers has led to (导致) linked computer systems, called networks, in which computers are connected so that data can be transferred from machine to machine. In these networks, computer users can exchange messages and share resources—such as printing capabilities,(功能,能力,容量) software packages, and data storage facilities(设备,容易)—that are scatter ed (v.分散,撒布) throughout the system. The underlying software required to support such applications has grown from simple utility packages into an expanding system of network software that provides a sophisticate d (vt.使复杂,使精巧,使世故)network wide infrastructure. In a sense, network software is evolving into a network wide operating system. In this chapter we will explore this expanding field of computer science.scatter v.分散（散开）, 散播（撒布）①To cause to separate and go in different directions.散开：使朝不同的方向分离和走开---Do not scatter your strength .不要分散精力。

《计算机网络技术教程》课件第4章

保护网络安全，如防火墙、杀毒软件等。
协议组成
TCP/IP协议
传输控制协议（TCP）和网际协议（IP），是互联网的核心协议。
DNS协议
域名系统协议，将域名转换为IP地址。
HTTP协议
超文本传输协议，用于网页浏览。
SMTP协议
简单邮件传输协议，用于发送电子邮件。
03
计算机网络的拓扑结构
总线型拓扑结构
THANKS
感谢观看
网络接口卡
安装在主机上，用于连接主机和传输介质。
集线器、交换机和路由器
用于连接多个主机，实现数据交换和传输。
软件组成
操作系统
提供网络服务和管理功能，如 Windows、Linux等。
网络协议软件
实现网络协议，如TCP/IP协议等。
应用软件
提供各种网络应用服务，如电子邮件、网页浏览器等。
网络安全软件
根据网络覆盖范围分类：局域网、城域网、广域网。
根据传输介质分类：有线网、无线网。
根据网络拓扑结构分类：星型网、总线网、环型网、网状网。
02
计算机网络的组成
硬件组成
主机
包括服务器、工作站、个人电脑等，是网络中的主要设备，负责处理数据和管理网络资源。
传输介质
包括双绞线、同轴电缆、光纤等，负责连接主机并传输数据。
总线型拓扑结构
所有节点共享一条通信通道，通过这条通道进行数据传输。
特点
结构简单，成本低，易于安装和维护，但可扩充性差，一旦总线发生故障，整个网络将瘫痪。
应用场景
适用于节点数目不多的小型局域网。
星型拓扑结构
星型拓扑结构
应用场景
以一个中心节点为核心，其他节点直接与中心节点相连。

计算机专业英语Unit 4

Unit 4 The Fundamentals of ComputerHardwareText 1 O rganization of Computer System Components Exercises1. Fill in the blanks with appropriate words according to the text.（根据课文内容填空）(1)A computer is a fast and accurate symbol manipulating system.(2)The keyboard of a workstation connected online to a computer is an example of device.(3)The input/output and secondary storage units are sometimes called peripheral devices.(4)The heart of a computer system is cpu.(5)Key elements of a computer system include memory, input devices, central processingunit and output devices.(6)The popular output devices used for personal computer are printer.2. Translate and analyze the following sentences.（翻译并分析下面的句子）(1)It is organized to accept, store, and process data and produce output results.句子组成：is organized表是被动，to表目的，and连接并列宾语。

《计算机英语(第4版)》课后练习参考答案

Unit Four/Section BI. Fill in the blanks with the information given in the text:1. Information engineering emphasizes a modeling tool called entityrelationship diagrams.2. One of the disadvantages of model-driven development is the long durationof projects.3. Unlike structured analysis and design and information engineering,object-oriented analysis and design attempt to emerge the data and process concerns into singular constructs called objects.4. Unlike logical models, physical models show not only what a system is ordoes , but also how the system is physically and technically implemented.II. Translate the following terms or phrases from English into Chinese and vice versa:1. check box 复选框.选择框.校验框2. structured design 结构化设计3. building block 积木块.构建模块.构件4. database schema 数据库模式5. radio button 单选（按）钮6. 系统建模技术 system modeling technique7. 模型驱动开发 model-driven development8. 数据流程图 data flow diagram9. 下拉式菜单 drop-down (或pull-down) menu10. 滚动条 scroll barUnit Five: Software ProcessUnit Five/Section AI. Fill in the blanks with the information given in the text:1. New software may be developed from scratch or through the use of existingsystems and off-the-shelf software or system components.2. The three generic process models discussed in the text are often complementaryrather than mutually exclusive, especially for large system development.3. The waterfall model is so named because of the cascade from one phase to anotherin the software development process.4. The fundamental development activities of the waterfall model arerequirements analysis and definition, system and software design, implementation and unit testing, integration and system testing, and operation and maintenance.5. The two fundamental types of evolutionary development are exploratorydevelopment and throwaway prototyping.6. The evolutionary approach is often more effective than the waterfall approachin producing systems that meet the immediate needs of customers, but it is difficult to establish a(n) stable system architecture using this approach.7. CBSE is a(n) reuse-oriented approach to software development, which relieson a large base of reusable software components and an integrating framework for these components.8. While CBSE can reduce the amount of software to be developed and the associatedcost and risks, it cannot avoid requirements compromises which may lead to a system that does not meet the real needs of users.II. Translate the following terms or phrases from English into Chinese and vice versa:1. system specification 系统规格说明2. unit testing 单位（或单元、部件）测试3. software life cycle 软件生命周期（或生存周期）4. system validation testing 系统验证测试5. evolutionary development process 演化开发过程6. linear model 线性模型7. program unit 程序单元8. throwaway prototype 抛弃式原型9. text formatting 正文格式编排.文本格式化10. system evolution 系统演变11. 系统设计范例 system design paradigm12. 需求分析与定义 requirements analysis and definition13. 探索式编程方法 exploratory programming approach14. 系统文件编制 system documentation15. 瀑布模型 waterfall model16. 系统集成 system integration17. 商用现成软件 commercial off-the-shelf (或COTS) software18. 基于组件的软件工程 component-based software engineering (CBSE)19. 软件维护工具 software maintenance tool20. 软件复用 software reuseIV. Translate the following passage from English into Chinese:Software processes are complex and, like all intellectual and creative processes, rely on people making decisions and judgments. Because of the need for judgment and creativity, attempts to automate software processes have met with limited success. Computer-aided software engineering (CASE) tools can support some process activities. However, there is no possibility, at least in the next few years, of more extensive automation where software takes over creative design from the engineers involved in the software process.One reason the effectiveness of CASE tools is limited is because of the immense diversity of software processes. There is no ideal process, and many organization have developed their own approach to software development.Processes have evolved to exploit the capabilities of the people in an organization and the specific characteristics of the systems that are being developed. For some systems, a very structured development process is required while for others a flexible, agile process is likely to be more effective.软件过程比较复杂.而且像所有其他的智能和创造性过程一样.依靠人们作出决定和判断。