英语作业课文翻译

The InternetThe most famous example is the Internet internet. The Internet originated in the nineteen sixties initial research project. Its goal is to develop a kind of ability, the computer connected to the network, enabling them to act as a not for local disaster and collapse of the interconnected system operation. The initial work is mostly by the United States government through the Department of Defense Advanced Research Projects Agency launched. As the years passed, the Internet 's development from a national defense project into a research project. Today, it is largely a commercial project, connecting with the world wide area network, metropolitan area network and local area network, involving millions of computers.One, the Internet ArchitectureConceptually, the Internet can be viewed as the set of fields. Each domain is represented by a network or a relatively small Internet component, like university, by a company or government agency that is responsible for operation of the organization. Each domain is a independent system, according to the local authority desire configuration. It may be produced by a computer or a contains many metropolitan area network, wide area network, even the complex Internet. Field created by the Internet Corporation for Assigned Names and numbers ( ICANN ) supervision. It is a non-profit company, which was established to coordinate the domain name and IP address allocation. To be on the Internet to build a domain, the domain must first pass through a ICANN authorized to do this work, known as the domain name registration services company registration.A domain once registered, namely can use a router connected to the existing internet. The router will be the domain in a network and has been on the Internet within a network connection. This particular router is often referred to as the domain of the gateway, because it is equivalent to the domain to the Internet theremaining portion of the gate. From the perspective of a single domain, located at the gateway out of that part of the Internet is sometimes called the " cloud ", which refers to the following facts: the Internet Gateway outside structure that is not under its control, and its operation is no relationship. Transfer to a destination within the domain of any message in the domain processing, transmission to the outside of a destination any message is first sent to the gateway, and then by the gateway sends out into the clouds.If a person " station " in a domain gateway " outward looking " cloud, you will find a variety of structure. Indeed, with the domain to find and establish a connection point cloud, the Internet also to a casual way of development. However, a popular structure, some domain gateway connected together, formed by a gateway regional network. For example, a group of university can choose to focus its resources, for the construction of such a network. The regional network and then connected to a larger network, the latter which is also connected with other regional network. Thus, the parts of the cloud assumes a hierarchical structure ( Figure 9A-1 ).In two, connecting to the InternetIn order to simplify the process of connecting to the Internet, many called the Internet service provider companies allow customers through the company's equipment to their domain to connect to the Internet, or have become the company has established a domain part. With the Internet service provider 's economic connection is perhaps through temporary telephone link established connection, this connection is called a dial-up connection. Using this method, a personal computer connected to the local telephone line, and then run a software package, the Internet service provider computer sends out a call. At this time, Internet service providers to provide Internet access services, continuous time to call time length. The temporary connection model in mobile phone / computer domain ( actually more popular application more and more ). However, in a fixedposition in the temporary connection application, fast in permanent connection, this connection via DSL, cable television lines and satellite links are relatively high system bandwidth. These techniques greatly reduces the broadband Internet access ( mass ) ( once available only to afford dedicated Internet connection of large institutions ) costs, so that home users can visit today's multimedia applications.At the family level there is another development, home computer system from single computer equipment expanded into a plurality of computer network, the network are usually implemented as Ethernet bus network. These networks using a home router access the Internet, and the router through the digital subscriber line, cable television line or a satellite link with internet service providers to permanently connected, thus allowing the system to become a home Internet service providers to establish a domain in local network. From home to home local network router computer connection often adopts a wireless mode. That is to say, each computer to use a distance of about 100 feet of small transmitter / receiver and communications router. The wireless local area network outside the home is also very popular, being used for establishing thehot zone. In the hot zone range, any has wireless Internet capable computer ( laptop or handheld computers ) can access the internet. The hot examples include office, Internet cafes, public plaza and the city. Finally, we should emphasize, Internet service providers, far more to offer Internet access service. In many cases, they are also the construction and maintenance of Internet infrastructure company. Moreover, they generally include the service for their customers to provide a series of extensive hardware and software support. In fact, the Internet service provider may also provide customers the computing resources ( such as data storage and data processing services in a large part of ).Three, the internet addressingAn Internet must be associated with an internet addressing system is linked to the system, system of each computer with a logo address. On the Internet, the address is called a IP address. Each IP address is a 32 bit mode, but it is currently implementing the extension to 128 plan. Each of the 32 bit address consists of two parts: a part identifies the computer domain model, another part is the identification of domain specific computer model. Address the knowledge domain that part, namely the network identifier, is a registered domain according to the ICANN authorized distribution. Therefore, the Internet in each domain is through the registration process to ensure that possess a unique network identifier. The address identifying the domain specific computer that is called the host address. Host address domain by local authority (usually a network administrator or system administrator and other titles .) distribution.The IP address is traditionally dotted decimal notation for writing. Wherein, each byte address using dot-separated, each word with an integer to integer representation, which is the traditional 10 to the end of the notation. With the bit pattern representation addresses are rarely able to contribute to the understanding of memory. For this reason, each domain is also assigned a unique mnemonic address, domain name. For example, Addison - Wesley publishing company domain name is . Note that the name system reflects the domain classification. As shown by the suffix com, Addison Wesley publishing company belongs to the commercial domain. Such a category called top-level domain name. Top level domain for many educational institutions, including the representation of edu, said the United States government agency gov, said non-profit agencies, said org Museum, said the museum for unrestricted use of info and net. Net initially intended for Internet service providers, but is now used in a much wider range. In addition to these generic top-level domain name, and used to express specific national two letter domain ( known as the country code top-level domain ), such as that Au of Australia and Ca said canada.因特网最著名的互联网例子是因特网。