To Construct A New MAN With BRAS

Along with the fast development of Internet, MAN becomes an important part of network construction. Now most of major Service Providers, such as China Netcom ,Telecom, Unicom, etc., is building their High-speed IP MAN to meet market demand on a large scale. It is not because of the lower cost of Ethernet, but its simple access and high speed. While at the begining, IP technology is not originally designed for public network and it has not any traditional telecom features. IP is a layer 3 technology without any end to end connections. Its QoS can not be guaranteed due to big latency and instable packets dropping rate. The way of setting Ethernet network of traditional Layer 3 which is short of capability of user authentication, accounting and bandwidth management, has many limits acting as the operation IP MAN in enterprise network. So for SPs, the main issue is to solve the operational problems of IP MAN when planning and constructing it.This paper analyses the present models of the constructing network, and points out the drawbacks in the existing models from both network aspect and application respect:network security, end user isolation, end user service QoS, user authentication and accounting management. Broadband IP MAN has many access users, so centralized management is necessary. But the traditional Ethernet is short of user management,including user account creation/deletion, account management, and user bandwidth control, etc, which result in the network unmanageable and unreachable. So user authentication, accounting management are the key factors to operate broadband IP MAN.This paper focuses on the key technology of operational IP MAN, detailedly compares current major user authentication modes, and also thoroughly analyses the construction of IP MAN. Then it puts forward a technical method to improve the presently existing models by using BRAS. A detailed description on technical features of BRAS and what BRAS can bring about have also been given in the paper. And at the end of the paper, the author brings light to how to settle the already existing problems in present MAN and how to improve MAN to a new kind of operational and manageable network.Finally, this paper introduce the actuality of JINING network, put forward the plan for JINING broad-band IP city network baseed on REDBACK' SE800 BRAS.