Network Processor-based Communications Agency

As a network processor, IXP1200 has RISC's flexibility and AISC's rapid performance. It means that it can be programmed as RISC and provides flexibility to adapt high-speed development of data communication market. It also means that it has ASIC's ability of rapid transaction. So it is widely used. The implementation of communication agent based on it is a typical example. This paper introduces relative theory. Second the paper presents the design scheme on how to realize communication agent. Last the paper gives module design and realizations and conclusions. Specific contents are as follows:1) Make research on IXP1200's architecture and working principle.2) Lucubrate ARP protocol,including ARP packet format , gratuitous ARP and ARP agent's working principle.3) Put forward the goal of communication agent's realization, software's framework and correlative design based on IXP1200's architecture, ARP working principle and system requirements.In detail, system control runs on IXP1200's ARM core; transmission of Ethernet frames runs on microengines. ARM is charged with initialization of shared memory microengine's start, sending gratuitous ARP notification as a substitute for front veneers and so on. Microengines are charged with Ethernet frames' transmission, modifying Ethernet frames , and restore of IP agent when a host and IXP1200 agent have the same IP,etc.4) Give modules' design and realization at length.5) Give test conclusions and performance analysis.