通信与电子信息工程专业英语第六单元TEXTAB.pptVIP

Unit 6 Network Protocol Text A TCP/IP architectural model Unit 6 TCP/IP architectural model The TCP/IP protocol suite is so named for two of its most important protocols: Transmission Control Protocol (TCP) and Internet Protocol (IP). A less used name for it is the Internet Protocol Suite, which is the phrase used in official Internet standards documents. Unit 6 TCP/IP architectural model The main design goal of TCP/IP was to build an interconnection of networks, referred to as an internetwork, or internet, that provided universal communication services over heterogenous physical networks. The clear benefit of such an internetwork is the enabling of communication between hosts on different networks, perhaps separated by a large geographical area. TCP/IP的主要设计目标是实现网络的互联，在不同的网络上提供通用的通信业务。这种网络互联的明显优势是，可以实现相距遥远的不同网络主机之间的相互通信。 Unit 6 TCP/IP architectural model The words internetwork and internet are simply a contraction of the phrase interconnected network. However, when written with a capital I, the Internet refers to the worldwide set of interconnected networks. Therefore, the Internet is an internet, but the reverse does not apply. The Internet is sometimes called the connected Internet. Unit 6 TCP/IP architectural model Unit 6 TCP/IP architectural model Regional networks connecting, for example, universities and colleges. Commercial networks providing access to the backbones to subscribers, and networks owned by commercial organizations for internal use that also have connections to the Internet. Local networks, such as campus-wide university networks. Unit 6 TCP/IP architectural model In most cases, networks are limited in size by the number of users that can belong to the network, by the maximum geographical distance that the network can span, or by the applicability of the network to certain environments. For example, an Ethernet network is inherently limited in terms of geographical size. Unit 6 TCP/IP architectural model Therefore, the