The Man Of Chinaunicom Construct

Metropolitan Area Network was a computer communication network which was established in a city scope, was called MAN. Because it used t he active switching element LAN technology, the transmission latency wa s short. Its transmission medium mainly used the optical cable. The speed of transmission was above 100 Mbit/s. An important use of the MAN is t o use as the backbone network, by which connected the host, database, L AN and so on in the different place of the same city.At present, with the expansion of network scale and the increasing of the Internet users, the speed of network had been affected. At the same ti me, the popularization and development of Internet market, not only mad e the network application gradually rich, new services constantly emergin g, but also the services development proposed the new demand to the net work bandwidth. It needed the IP backbone network to make support and needed to rely on the extension of Internet access toward user side.The paper mainly covered the following aspects:1. This paper introduced the Metropolitan Area Network technology. It introduced with emphasis on the QoS, VPN and MPLS technology status and development, its application in communication network was introduced briefly in this paper.2. Investigating and studying the Metropolitan Area Network status, including the device and connecting link of the core layer, service control layer, access layer, autonomous domain division, deployment of MPLS VPN,QOS and so on, routing strategy between Metropolitan Area Network and province network, status of network management system and authentication system, connection of related network. We used the trend extrapolation method, penetration method, regression method, three methods to do service forecasting, and forecasted the demand of traffic and bandwidth according to the results and services carrying model. Then, we proposed the network existing problem by comprehensive analysis.3. According to the current network problems, we proposed the construction scheme, aiming at the core layer, service control layer, access layer. We planned the autonomous domain division, MPLS VPN and the QoS deployment, analyzed the effect of this construction on related systems and the construction demand, proposed the future Metropolitan Area Network construction approach.