First, the determination of the overall design scheme of the campus network
The design goal of campus network should be: relying on modern network technology, advanced technology, strong expansibility, covering the main buildings of the school, connecting all kinds of resources with networking needs in the school through local area network, and connecting with related wide area network through routing equipment to build a campus backbone network with paperless office, computer-assisted teaching and modern computer campus culture as the core; Get educational resources from the Internet, publicize and show the school's elegant demeanor; On this basis, establish a software and hardware environment that can meet the needs of teaching, scientific research and management; Develop all kinds of information bases and application systems to provide full network information services for all kinds of school personnel.
The scientific nature of the overall design scheme of campus network should be reflected in whether it can meet the following basic requirements: (1) overall planning; Distributed implementation and scalability; (2) Advanced, open, highly safe and reliable; (3) simple structure, which is beneficial to maintenance; (4) efficient and practical; (5) Information interaction and collaborative work can be realized, and campus characteristics can be displayed.
To carry out the overall design of campus network, we must first conduct object research and demand investigation, make clear the nature, tasks, characteristics of reform and development, requirements and conditions of system construction, and accurately describe the information environment of the school; Secondly, on the basis of application demand analysis, the service type of campus network is determined, and then the specific objectives of network construction are determined, including network facilities, site setting, development, application and management. Thirdly, the network topology and function are determined, and the system analysis and design are carried out according to the application requirements and the distribution characteristics of the main buildings in the school; Then, the principle requirements of technical design are determined, such as standards and requirements of technical selection, wiring design, equipment selection and software configuration. Finally, the implementation steps of campus network construction are planned.
Second, the construction of campus network application and management platform
Campus network construction, the first thing is to establish a campus network platform based on application and management.
(A) the construction of the network core layer
Designing the core layer is the key to network construction, and its function is to realize high-performance exchange and transmission. Therefore, the core layer equipment should have high performance transmission function, high reliability, manageability and high bandwidth to meet the design requirements of the network.
With the development of Internet, the application characteristics of university campus network have changed greatly, and the data flow is no longer limited to local area network. The demand for excellent course display, teaching management system, online examination system and electronic library is increasing day by day. Therefore, the core backbone switch of campus network should adopt high-performance switching technology products, which can control network traffic and VLAN partition conveniently and effectively. The backbone switch of each central node should support Gigabit Ethernet and have 10/ 100Mbps Ethernet port. Line-speed filtering supports application priority and distributed security control, with little delay. The network structure adopts a ring structure, and the core backbone switches are interconnected into a ring structure. The ring structure can balance the line load and ensure the safety and reliability of the whole system. At the same time, the backbone switch should be equipped with fault-tolerant and load-balanced dual-power modules to improve the bearing function of the network center for business traffic and enhance the reliability and availability of the network. The secondary switch is then connected to the corresponding central node of the star structure and goes directly to the desktop of 100M to ensure the smooth flow of information. Gigabit links are used between the concentrated user groups with more information resources to form a backbone network that meets the requirements of teaching and management.
(2) Design of network distribution layer
Campus network distribution layer equipment is used to access user terminals. According to the characteristics of university users, the port density is required to be high and the price of each port is relatively low. This layer of equipment also needs a high-speed channel to connect with the core layer equipment, and it has certain reliability. The security control of the network is also mainly realized by the distribution layer equipment. Routers in the network center choose the appropriate link access mode to connect to the Internet, and telecom operators also provide many preferential schemes for colleges and universities.
For the sake of security and management, VLAN technology is also one of the effective measures for network application. Using VLAN technology, the applications distributed in different nodes and departments are divided into a virtual subnet, and the access of some users to this subnet is restricted. VLAN works at Layer 2 and Layer 3 of the OSI reference model. VLAN is a broadcast domain, and the communication of VLAN is completed through the router of the third layer. Different VLAN provide different access rights and different security levels. The core of VLAN technology is network segmentation. Network segmentation can be divided into physical segmentation and logical segmentation. In practice, the method of combining physical segmentation with logical segmentation is usually adopted.