The Design And Implementation Of PPP Based On Distributed System

With the rapid development of internet, the demand of the higher performance ofrouter is increasing. The centralized router will be replaced gradually by distributedrouter. The point-to-point protocol (PPP) which the most widely used on link layer isstill used for transmitting data packets between distributed routers. PPP providesfull-duplex operation on synchronous link and asynchronous link to supportpoint-to-point packets transmission. When data volume is increasing and service qualityneeds to improve, the bandwidth of a single PPP link cannot meet the requirement ofusers. Then, Multilink PPP (MP) is a good solution.The work of this paper is based on the second phase of PPP project in H3C. Thispaper studies the distributed PPP system which is based on the basic function ofcentralized PPP system and implements distributed design of PPP system on routerplatform of H3C.Firstly, this paper introduces some concepts of PPP and MP. Then, it describes linkestablishment process of PPP and analyses detailedly negotiation process of link controlprotocol, authentication protocol and network control protocol. Otherwise, the routersoftware platform of H3C and distributed design technology are introduced.Secondly, the overall architecture of distributed PPP is designed and implemented.The paper implements some important functions of PPP, including real-timesynchronization configuration of PPP module, configuration information and runninginformation recovery of PPP module and MP module, which designed with distributedtechnology. In order to further improve user’s online rate, multithread processingmechanism is adopted to optimize the distributed PPP system.Finally, functional test and performance test for distributed PPP are carried out.Functional test verifies the validity of the distributed function of PPP. Performance testconsists of load test and stress test. The load test makes a comparison on the online rateamong centralized PPP, distributed PPP and optimized PPP. The test results show thatthe performance of distributed PPP is better than centralized PPP and the optimized PPPis best among three kinds of systems. The stress test results show that the performanceof system is stable and reliable, which meet the design requirement of system reliability.