Design And Implementation Of Broadband Access System Based On Ethernet

With the rapid development of network technology and the rapid growth of broadband digital business, backbone network, metropolitan area network and user network are all growing rapidly. Access network, a part of infrastructure network located next to end-user, is a determinant in network construction, provide adequate bandwidth and resolve the "bottleneck" problem between backbone and subscriber have become a hot topic discussed.The traditional WBA (Wide Band Access) system uses ATM technology connecting to metropolitan area network. As ATM technology is complex, and ATM device is expensive, so WBA technology developing trend is from ATM to IP. In other words, WBA uses IP core and IP data which is transmitted between user side and network side to conform to the planning and construction of metropolitan area network. At the same time, WBA technology developing trend should also toward to intelligent direction, in order to supply multiple broadband businesses to users and meet the operable and manageable demands of Internet service provider. In other words, WI3A system should realize some functions of BRAS, such as authentication, accounting.We review the present situation of broadband access networks, analysis the problems in current network topology and present a solution of broadband access system based on Ethernet finally.This dissertation is mainly discussing the key technology and protocols about broadband access and Ethernet. And a solution of broadband access system based on Ethernet is presented. In the part of system design, we discuss the chief function, the hardware design, the software design and the dependence between modules. In the part of system realization, we discuss the realization of Ethernet network interface and Layer 2 transmit in data plane, the realization of IGMP Proxy in control plane, the realization of CLI(Command Line Interface) in management plane, and analysis key technology and difficulties in details finally. In the part of system test, we discuss the environment, configuration and result of functional test and performance test. At last, we summarize the problems which are encountered in system design and system realization, and discuss future work on the broadband access system's evolution.