Computer English Unit 9 The Internet（计算机英语 第九单元 因

Unit 9 The Internet 第九单元： 因特网

Section A The Internet 课文A： 因特网

The most notable example of an internet is the Internet (note the uppercase Ⅰ), which originated from research projects going back to the early 1960s.

最著名的互联网例子是因特网（Internet，注意大写的Ｉ）。因特网起源于20世纪60年代初的研究项目。 The goal was to develop the ability to link a variety of computer networks so that they could function as a connected system that would not be

disrupted by local disasters.

其目标是发展一种能力，将各种计算机网络连接起来，使它们能够作为一个不会因局部灾难而瓦解的互联系统运行。

Most of this original work was sponsored by the

U.S. government through the Defense Advanced Research Projects Agency (DARPA- pronounced DAR-pa).

最初的工作大多是由美国政府通过国防部高级研究计划局（DARPA——读作“DAR-pa”）发起的。 Over the years, the development of the Internet shifted from a defense project to an academic research project, and today it is largely a commercial undertaking that links a worldwide combination of WANs, MANs, and LANs involving millions of computers.

随着岁月的推移，因特网的开发从一个国防项目转变成一个学术研究项目。如今，它在很大程度上是一个商业项目，连接着全世界的广域网、城域网和局域网，涉及数百万台计算机。

Ⅰ. Internet architecture 一、因特网体系结构

Conceptually, the Internet can be viewed as a collection of domains, each of which consists of a network or a relatively small internet operated

by a single organization such as a university, company, or government agency.

从概念上说，因特网可以看作是域的集合。每个域由一个网络或一个相对较小的互联网组成，由一个像大学、公司或政府机构那样的组织负责运行。

Each domain is an autonomous system that can be configured as the local authority desires. 每个域是一个自主系统，可根据本地管理机构的愿望进行配置。

It might consist of a single computer or a complex internet consisting of many LANs, MANs, and even WANs.

它可能由一台计算机或一个包含许多局域网、城域网、甚至广域网的复杂互联网组成。

The establishment of domains is overseen by the Internet Corporation for Assigned Names and Numbers (ICANN), which is a nonprofit corporation established to coordinate the naming of domains and the assignment of Internet addresses. 域的建立由互联网名称与数字地址分配机构（ICANN）

监管。这是一个非赢利公司，其成立的目的是协调域

的命名及因特网地址的分配。

To establish a domain on the Internet, the domain must first be registered via one of the companies, called registrars, that have been delegated for this purpose by ICANN.

要在因特网上建立一个域，该域必须首先通过一个得到ICANN授权做此工作、被称为域名注册服务商的公

司进行注册。

Once a domain has been registered, it can be attached to the existing Internet by means of a router that connects one of the networks in the domain to a network already in the Internet. 一个域一旦注册，即可以使用一个路由器连接到现有的因特网上。这个路由器将该域中的一个网络与已经在因特网内的一个网络相连接。

This particular router is often referred to as the domain’s gateway, in that it represents the domain’s gate to the rest of the Internet. 这个特定的路由器常被称为该域的网关，因为它相当于该域通往因特网其余部分的大门。

From the point of view of a single domain, the

portion of the Internet lying outside of its gateway is sometimes called the cloud, in reference to the fact that the structure of the Internet outside the domain’s gateway is out of the domain’s control and is of minimal concern to the operation of the domain itself. 从单个域的角度看，位于其网关外面的那部分因特网

有时被称为“云”，这是指以下的事实：其网关外面的因特网结构不受其控制，而且与其本身的操作也没有什么关系。

Any message being transmitted to a destination within the domain is handled within the domain; any message being transmitted to an destination outside the domain is directed toward the gateway where it is sent out into the cloud.

传输给该域内一个目的地的任何报文都在该域内处理，传输给该域外一个目的地的任何报文都首先送至网关，然后由网关向外发送到云里。

If one “stood” at a domain’s gateway and “looked out ” into the cloud, one could find a