全国计算机四级网络工程师知识点整理190269961（国外英文资料）.docVIP

全国计算机四级网络工程师知识点整理190269961（国外英文资料） The basic principle of network architecture and design The Local Area Network (LAN) is divided into Shared LAN and exchange LAN based on the technology, scope and protocol criteria used 1.2 LAN features: Cover a limited geographic area High quality data transfer environment with high data transfer rate (10Mbps - 10Gbps) and low error rate Low cost, easy to build, maintain and extend The computer network is divided into logical functions: resource subnets and communication subnets The 1.4 host (host) includes the user terminal device (personal computer, digital device), the server, which is the main unit of the resource subnet 1.5 resources subnet: Composition: main computer system, terminal, terminal controller, network external equipment, various software resources, network services Functions: to handle the data processing business and provide various network resources and network services to Internet users 1.6 communication subnet: Composition: communication control processor, communication line, other communication equipment Functions: complete network data transfer, forwarding and other communication processing tasks 1.7 communication control processor: network node in network topology Connect the host and terminal to the network as a host and terminal connector to the resource subnet 2. As the grouping store-and-forward node communication subnet, complete group receive, check, store and forward function, realize the source host accurate message sent to the destination host 1.8 communication lines: communication control processor and communication control processor, communication control processor and provide a communication channel between host, computer networks use a variety of communication lines, such as telephone lines, twisted pair, coaxial cable, optical fiber, wireless communication channel, microwave and satellite communication channel, etc The connection between LAN and the Metropolitan Area Network (MAN), the wans a