网络答案（国外英文资料）.docVIP

网络答案（国外英文资料） Problem sets (introduction) Several stages and features of the development of computer networks: Stage 1: the research and development of data communication technology in the 1950s. Phase two: the research and development of ARPAnet and packet switching technology in the 1960s. Stage 3: the research and application of network architecture and protocol standardization in the 1970s to study wan, LAN and packet switching technology. The fourth stage: the wide application of Internet technology in the 1990 s network computing technology research and development of broadband metropolitan area network and access network technology research and development of network and information security technology research and development The computer network should have those key features: The primary purpose of the network is to implement the sharing of computer resources; Interconnected computers are multiple independent autonomous systems distributed in different geographic locations; Networked computers must follow the same network protocol in the communication process. Features of modern network architecture: With the widely application of the microcomputer, a large number of micro computer is through the LAN to wan, LAN and wan, wan and wide area network interconnection is implemented through a router; In the Internet, the users computer to access areas through the campus network, enterprise network or ISP backbone, regional backbone through national backbone links between countries of high-speed backbone, forming a router is interconnected large, hierarchical structure of the Internet. The main characteristics of LAN and metropolitan area wan: LAN: cover limited geographical scope, it is suitable for the company, agency, school, factory, etc limited within the scope of the computer, terminal and the demand of all kinds of information processing equipment networking, High quality data transfer environment with high data transfer rate (10Mb/s ~ 10Gb/s) and low error