一、概说 近年来计算机局部地区网络(Local Area Network简称LAN)的研究发展很引入注意。这是由于计算机科学技术的惊人发展,硬件价格急剧下降使人们倾向于采用一定数量的小型计算机或微型计算机链控来代替单台主机结构。国外许多公司厂家竞相发展计算机分布式控制系统和分布式数据处理系统,就网络的观点来看它们都属于分布式计算机网络。当一个网络联系的地区范围 First, the overview In recent years, the computer local area network (Local Area Network referred to as LAN) research and development is very much attention. This is due to the astonishing development of computer science and technology, and the sharp decline in hardware prices has led to a preference for replacing a single host architecture with a number of small computers or microcomputer chains. Many foreign manufacturers competing to develop computer distributed control system and distributed data processing system, from the point of view of the network they all belong to the distributed computer network. When a network contacts the area