Computer technology, communication technology and network technology are developing at an unprecedented speed, and mankind has entered a new era of computer technology development-network era, with the rapid expansion of data, voice, video, multimedia and other information. The high speed, security and reliability of information transmission between arbitrary points and computer network communication put forward higher requirements for information transmission medium and structure. How to adapt to the challenge of current and future network technology to building wiring is a subject that must be considered at the beginning of design. Integrated wiring system has replaced the traditional concept of wiring system with its great flexibility, applicability, reliability and integrity, and has been quickly recognized by supervisors and technicians at all levels in China.
Demand analysis of integrated wiring in campus network
(A) Design objectives
The first phase of campus network construction will achieve the following goals: to build the backbone of gigabit campus network and realize the interconnection of teaching office complex, teaching building and library building; Every classroom, laboratory and office can access the 100M campus network and fully enjoy the information resources. School leaders, teachers and students can access campus network information anytime and anywhere; The campus network will use 200M optical fiber to access China New Unicom network; The campus network will be equipped with WWW service, FTP service and email service; The campus network must install a content filter to filter out the bad information of the website; The campus network will build a complete network anti-virus system to effectively prevent the spread of viruses; Campus network must be able to manage the whole network intelligently, so that system administrators can realize network management conveniently and efficiently; The first phase of campus network construction must reserve space for future network construction; It is required that the switch equipment of the whole network must adopt the products of the same manufacturer and the servers should be of the same brand. The integrated wiring products of the whole network must be unified.
(2) Network topology
According to the concrete analysis of the network structure, it is concluded that the network center is located on the second floor of Qizhi Building, so the core switches of all office buildings, teaching buildings and libraries will be connected by Gigabit controllable network management switches. At the same time, all office buildings, teaching buildings and libraries are equipped with Gigabit convergence switches to connect core switches. For the core computer room, that is, the network center, all anti-static floors are required, and grounding and lightning protection measures are taken. In addition, a LEMUS 10KVA UPS standby power supply and four 8-hour standby batteries are installed for power failure.
(3) System design principles
1. practicability: the communication lines and interfaces of the implemented building automation system and all its subsystems meet international standards. It has a good user interface, and the network management function is perfect and easy to use, which also makes the installation cost can be used to reduce the long-term running cost of the whole campus network, thus achieving good long-term economic benefits.
2. Flexibility: the connection of any part of the system is flexible, that is, the connection from physical wiring to data communication, voice communication and intelligent control equipment is not or rarely limited by the physical location and type of these equipment, which reduces the demand for traditional pipelines. Information port equipment is reasonable, plug and play. At the same time, the structural design of system implementation and management is given.
3. Modularity: All accessories used to connect devices are modular standard parts, and you don't need to master a lot of professional knowledge in these fields to connect these devices. The modular structure design makes it possible to relocate, expand and reinstall the system with minimal additional wiring and changes.
4. Extensibility: Because all the infrastructure (materials, components and communication equipment) of the system adopt international standards, no matter the development of technology, computer equipment, communication equipment and intelligent control equipment may be easily connected to the building automation system in the future. Then, whether now or in the future, it can provide completely compatible support for the environment in the building.
5. Reliability: All components of the system are made of high-quality materials and component equipment, and have been carefully constructed and tested to ensure the reliability of all links of the system.
Solution design of integrated wiring system in campus network
The whole integrated wiring system consists of workspace subsystem, horizontal subsystem, management subsystem, vertical trunk subsystem and equipment subsystem.
(A) the design of the workspace subsystem
Workspace subsystem wiring consists of the connection between information socket and terminal equipment, which is the area from socket to user terminal, including the actual use area of all users. The information socket is installed on the ground or wall. The information socket is RJ45 socket. The bottom of the wall-mounted socket box is 300mm from the ground, and a single-phase three-hole power socket is installed in the wall-mounted socket box and beside the wall-mounted information socket. In order to meet the specific situation of high-speed information transmission, all subsystems in the work area adopt over five series of information modules, and their performance exceeds the international standard ISO IS11801. However, the data point uses the super-5 RJ45 information socket module, and the worst-case crosstalk attenuation is as high as 44dB at 100MHz.
(B) Management subsystem design
The management subsystem connects the horizontal cable and the vertical trunk line, which is the key link in the integrated wiring system. Common equipment includes distribution frame, distribution frame, jumper and necessary network equipment. Its function is to provide a connection means to connect other subsystems, allowing communication lines to be located or relocated to different parts of the building, so that it is convenient to manage communication lines and make jumpers when moving equipment. In order to facilitate maintenance, it is necessary to manage the cables, connecting hardware, space and walkways of the whole wiring system in a unified way. In the campus network design scheme of Xuchang University, the information points of each layer are led to the distribution cabinets of each layer through PVC ducts, and 24 distribution frames with more than five types of ports are placed in the cabinets. The connectors of each information point are equipped with jumpers, and then connected to the switches through the distribution frames. It adopts a 24-port distribution frame with super category 5, which can be installed on the 19 standard rack, occupying only 1U space, occupying little space and being convenient for handling and migration.
(3) Design of vertical trunk subsystem
1. Selection of backbone subsystem
The design of vertical trunk line should not only meet the current needs of users, but also meet their future requirements. Therefore, we use 6-core multimode indoor optical cable to support the transmission of data and information. Its function lies in that the multi-purpose indoor wiring optical cable is composed of a plurality of single-mode or multi-mode single-core tightly-wrapped optical fibers glued around the central reinforcement to synthesize the cable core, then the cladding is added, and then the outer sheath of PVC or LSZH material is put on. Due to the high optical coupling rate of multimode fiber, the requirements for fiber core alignment are relatively loose. When the computer data transmission distance exceeds 100 meters, using optical fiber as the data backbone will be the best choice, which has high bandwidth, high confidentiality and anti-interference compared with large logarithmic cables. With the development of computer network and optical fiber technology, the application of optical fiber is more and more extensive. The data transmission rate of optical fiber can reach above 1Gbp/s, which can meet the demand of campus network informatization and adapt to the development of computer network.
2. Layout method of trunk cable
The function of the vertical trunk subsystem is to connect the main distribution frame and each distribution frame. In the vertical trunk subsystem of xuchang university, the main components connecting the computer room and the floor wiring room are trunk optical fiber and logarithmic cable. At present, it is planned to use multimode optical cable. Because the backbone of gigabit campus network is built, it is also convenient for future network expansion. Trunk cables will be transmitted from the connecting equipment to the equipment room and sent to the final interface by using open metal trunking. The computer data line adopts 6-core indoor multimode optical cable. Its advantages are low transmission loss, strong anti-interference ability and wide frequency band, which is also to meet the requirements of future information technology development. Vertical trunk cables (including twisted-pair cables and optical cables) are laid along the metal trunking (200mm × 100mm) erected in the weak current shaft, and a fixed point is set every meter between the cable and the metal trunking.
(d) subsystem design between equipment rooms
The computer room subsystem is the central unit of the whole wiring data system, which realizes the final management of cables connected to each floor. The computer room is a place where the incoming line equipment is set at an appropriate place in each building for the use of network management and management personnel on duty. It consists of building wiring equipment, data, computer and other host equipment and safety wiring equipment of the integrated wiring system. It is mainly used to connect various IDF, including distribution frame, connecting strip, winding ring, single pair of jumpers, etc. All incoming terminal devices in the computer room subsystem adopt color codes to distinguish the wiring areas for various purposes. To meet the requirements of various computer network systems for wiring systems. Computer networks can be connected through optical fiber jumpers and support various computer networks through various network protocols.
(5) Subsystem design of building complex
The complex subsystem extends the cable of one building to the communication equipment and facilities of other buildings in the complex. It includes copper wire, optical fiber and protective device to prevent surge voltage of cables in other buildings from entering this building. In the comprehensive wiring design scheme of the campus network of Civil Affairs College, when the distance between buildings exceeds 100 m and the computer data transmission distance exceeds 100 m, using optical fiber as the data backbone will be the best choice, which has higher bandwidth, higher confidentiality and anti-interference than large logarithmic cable. Therefore, the connection between buildings adopts 6-core multimode indoor optical cable to support the transmission of data and information. In the comprehensive wiring design scheme of Xuchang University campus network, optical fiber will be used to interconnect the teaching office complex, the teaching building and the library, and it will be concentrated in the network center on the first floor of the library. The laying method is indoor metal bridge and outdoor deep trench filling. In the design, all optical fibers, logarithmic cables and Netcom cables entering the main engine room are protected by metal bridge or steel pipe, and copper cables are electrically protected by IDC line protector to prevent people and equipment from being hurt by external voltage and current.
(6) Slot and cable layout requirements
1. Precautions before installation
The grounding terminal is reserved in the main engine room, and the grounding wire is connected with the building through the grounding system. The junction box on each floor is grounded separately, and the section of grounding conductor is 20mm2. Both ends of each metal bridge and steel pipe shall be electrically connected and well grounded.
2. Conform to standardized standards
The implementation design of structured wiring should not only be rigorous in design to meet the requirements of users, but also make its cost reasonable and conform to standardized standards. There are strict regulations and a series of standardized standards for structured wiring at home and abroad. These standards clearly define each link of structured cabling system, and stipulate its design requirements and technical indicators.
3. Key points of cable laying in trunking
PVC pipeline layout: the pipeline can be laid or embedded, and the turning radius of the pipeline must meet the minimum radius requirement of the cable in the middle of the line. The metal pipe should keep a sufficient distance from the high-voltage system and prevent grounding.
Installation of metal bridge: In this design, metal bridge is used for laying cables of weak current system, so its size requires all cables of weak current system, and it should be noted that the turning radius of bridge must meet the minimum radius requirement of cables. The metal bridge should keep enough distance from the pipeline of high-voltage system as far as possible and be grounded.
Wiring cables: cables of each system are laid and bundled separately in pipes and bridges. When laying cables, excessive and uneven tension should be avoided, and the cable head should be labeled for identification.
Selection of main equipment for campus network
Due to the complex network structure of campus network, the scheme is divided into core layer, convergence layer layer and access layer.
(A) network equipment selection
1. The network center is located on the second floor of Qizhi Building.
The equipment in the school network center should be highly manageable; At the same time, there are many users in the school. If so many users are in the same subnet, broadcast data will inevitably interfere with normal data transmission, resulting in network congestion and packet loss. Dividing virtual network (VLAN) is a solution to solve broadcast interference and isolate different departments. In order to communicate between virtual networks, the network center must have a three-layer routing mechanism. Because the data routing speed of general routers is very slow, using three-layer switches is the key to solve the above problems.
2. convergence layer Switch is located in the center of teaching building, office building and library, and plays the role of managing users in this building. Convergence switches should support comprehensive network management, VLAN, port mirroring, spanning tree, IEEE802 1 1x authentication and other functions.
3. As there are many users in the multimedia classroom and multicast is needed, the aggregation switch of the multimedia classroom must support multicast function; In addition, in order to improve the network speed, it is suggested to use a switch that supports stacking in multimedia classrooms.
4. Non-intelligent switches can be used in laboratories, research institutes, reading rooms and other environments. These switches are three-level access switches, and each switch is set to 1 VLAN through the aggregation switch to isolate the broadcast.
(2) Server selection
According to the application characteristics of campus network servers, the selection of servers should follow the following principles:
(1) requires short response time, and can quickly respond to and handle users' access requirements. (2) It has powerful information throughput, multiple websites and content cache, and can provide more access services and improve user satisfaction with a certain investment. (3) Easy to publish and enjoy information. (4) It is easy to build and run Web applications and simplify business processes. (5) Reliable quality to ensure uninterrupted Web services. (6) Easy to set up and manage, making network management easier and easier to expand, meeting the needs of business expansion and protecting users' investment. In this scheme, the server of Xuchang University campus network adopts DELL series server products.
Technical performance analysis
Through the design and implementation of workspace subsystem, horizontal subsystem, management subsystem, vertical trunk subsystem and equipment subsystem, a complete network wiring system can be provided for the campus network. At the same time, the monitoring system can provide students with life security, can fully adapt to modern and future technological development, realize high-speed data communication and transmission, and support various network equipment, communication protocols and wide applications including management information systems. The network center of xuchang university campus network includes the network.
Network system, monitoring system, etc. All of them are integrated into the central computer room, which is convenient for network administrators to maintain and manage the whole campus. It can also save maintenance and update funds, facilitate data exchange, provide convenience for life, entertainment, study and work, and enable teachers and students to get fast network services.