Research And Design Of Access And Authentication System In IP-DSLAM Based On Network Processor

The network processor (NP) integrates the advantages of general purpose CPU and ASIC as a kind of programmable chip with high performance, which can satisfy the information network's requirements of high performance, reliability and expansibility. So the research into IP-DSLAM based on the NP has important scientific research value and practical significance. In addition, with the rapid development of broadband technology, the problem on broadband access technology has become the hot spot which people care about. Especially when the Ethernet technology gradually becomes the mainstream, how to attest and manage users becomes the most important problem to be solved in the Ethernet environment. Because PPPoE combines the most economical LAN-Ethernet with the expansibility and management function of PPP, it becomes the main accessing mode.The content of this paper is one of the important parts of the project called research and design of IP-DSLAM based on NP. First of all, this paper illustrates the broadband access, IP-DSLAM and NP technology; moreover it introduces IP-DSLAM architecture based on NP and the partition of software modules. Secondly, it analyses protocols relating to accessing and authenticating system including PPP protocol, PPPoE protocol, RADIUS protocol etc. After analyzing it describes the access and authentication system operating in IP-DSLAM to provide distributed service for users. Thirdly, it introduces the program design of PPPoE server including data structure and main flow. At last, it introduces development environment of the access and authentication system.The system designed in this paper is a kind of bureau-level equipment which can provides ability of access and authentication based on NP. The system realizes the function of access and authentication in Xscale core, that is, the function of BAS is embedded into IP-DSLAM to provide distributed service. The system supports RADIUS authentication as well as PPPoE local authentication to satisfy network operators'user management requirement.