Internet-Infrastructure(计算机专业英语(第二版))课件.pptx

《Internet-Infrastructure(计算机专业英语(第二版))课件.pptx》由会员分享，可在线阅读，更多相关《Internet-Infrastructure(计算机专业英语(第二版))课件.pptx（15页珍藏版）》请在淘文阁 - 分享文档赚钱的网站上搜索。

1、Lesson Internet Infrastructure191.Where does the name Internet comes from?2.Who owns the Internet?Warm-up Exercises interconnected 互相连接的host computer 主机oversee 监督，审Internet Service Provider(ISP)因特网服务提供者local area network(LAN)局域网Point of Presence(POP)电话接入网点Network Access Points（NAPs）网络接入点Word Prepara

2、tionrack 机架dial into 拨号到corporate 公司fiber optic 光纤intercommunicate 相互通信trillion 万亿Word PreparationOne of the greatest things about the Internet is that nobody really owns it.It is a global collection of networks,both big and small.These networks connect together in many different ways to form the si

3、ngle entity that we know as the Internet.In fact,the very name comes from this idea of interconnected networks.Since its beginning in 1969,the Internet has grown from four host computer systems to tens of millions.However,just because nobody owns the Internet,it doesnt mean it is not monitored and m

4、aintained in different ways.The Internet Society,a non-profit group established in 1992,oversees the formation of the policies and protocols that define how we use and interact with the Internet.Text但是，虽然Internet不真正属于任何人，但仍然以不同方式得到监管和维护。Internet学会是1992年成立的非营利性组织，负责监督相关政策与协议的建立，确定Internet如何使用和交互。Ever

5、y computer that is connected to the Internet is part of a network,even the one in your home.For example,you may use a modem and dial a local number to connect to an Internet Service Provider (ISP).At work,you may be part of a local area network(LAN),but you most likely still connect to the Internet

6、using an ISP that your company has contracted with.When you connect to your ISP,you become part of their network.The ISP may then connect to a larger network and become part of their network.The Internet is simply a network of networks.Text每个连接Internet的计算机都是网络的一部分，即使你的家用计算机也是Internet就是网络的网络Most larg

7、e communications companies have their own dedicated backbones connecting various regions.In each region,the company has a Point of Presence(POP).The POP is a place for local users to access the companys network,often through a local phone number or dedicated line.The amazing thing here is that there

8、 is no overall controlling network.Instead,there are several high-level networks connecting to each other through Network Access Points or NAPs.Text这里的奇怪之处是没有总体控制的网络 Heres an example.Imagine that Company A is a large ISP.In each major city,Company A has a POP.The POP in each city is a rack full of m

9、odems that the ISPs customers dial into.Company A leases fiber optic lines from the phone company to connect the POPs together.Imagine that Company B is a corporate ISP.Company B builds large buildings in major cities and corporations locate their Internet server machines in these buildings.Company

10、B is such a large company that it runs its own fiber optic lines between its buildings so that they are all interconnected.Text公司A从电话公司租用光缆，将POP连接起来。公司B很大，大楼之间有自己的光缆，因此它们都是互连的。In this arrangement,all of Company As customers can talk to each other,and all of Company Bs customers can talk to each othe

11、r,but there is no way for Company As customers and Company Bs customers to intercommunicate.Therefore,Company A and Company B both agree to connect to NAPs in various cities,and traffic between the two companies flows between the networks at the NAPs.In the real Internet,dozens of large Internet pro

12、viders interconnect at NAPs in various cities,and trillions of bytes of data flow between the individual networks at these points.The Internet is a collection of huge corporate networks that agree to all intercommunicate with each other at the NAPs.In this way,every computer on the Internet connects

13、 to every other.Text因此，公司A和B同意连接不同城市的NAP，两个公司间的通信流在NAP处的网络间流动Internet是大公司网络的集合，协定在NAP处进行所有相互通信。POPISP（Internet service provider)is a company which provides other companies or individuals with access to,or presence on,the Internet.Most ISPs are also Internet Access Providers;extra services include he

14、lp with design,creation and administration of World-Wide Web sites,training,and administration of intranets.POP(point of presence)is a site where there exists a collection of telecommunications equipment,usually modems,digital leased lines and multi-protocol routers.An Internet access provider may o

15、perate several PoPs distributed throughout their area of operation to increase the chance that their subscribers will be able to reach one with a local telephone call.The alternative is for them to use virtual PoPs(virtual points of presence)via some third Party.Key TermsISPFiber opticA system of tw

16、o or more computers,terminals,and communications devices linked by wires,cables,or a telecommunications system in order to exchange information.The network may be limited to a group of users in a local area(local area network),or be global in scope,as the Internet is.vt.To link a group of computers

17、or their users so that information can be mutually accessed or exchanged.Use of light transmitted through fibers:the technology of transferring information,for example,in communications or computer technology,through a number of thin flexible glass or plastic tubes(optical fibers)using modulated lig

18、ht waves.Information is transmitted in the form of coded pulses.Key TermsnetworkQuestionspWhere does the name Internet come from?pWhat does the Internet Society do?pWhat may you use to connect to an ISP when you are at home?p What does“POP”mean?p Finally,who owns the Internet?ExerciseTranslate the f

19、ollowing sentences into ChinesepOne of the greatest things about the Internet is that nobody really owns it.It is a global collection of networks,both big and small.These networks connect together in many different ways to form the single entity that we know as the Internet.pSince its beginning in 1

20、969,the Internet has grown from four host computer systems to tens of millions.However,just because nobody owns the Internet,it doesnt mean it is not monitored and maintained in different ways.pMost large communications companies have their own dedicated backbones connecting various regions.ExerciseSimple writingpPlease describe the way you connect to the Internet.Exercise THANK YOU！