The Research And Implementation Of Improving RED Algorithm Fairness

Network congestion control is a complex issues involving network protocol and control theory. It has been a hot topic in the field of computer and communication networks. RED algorithm used to effectively solve the problem of network congestion. However, with the rapid spread and expansion of Internet, Internet applications continuously enriched, more and more users compete for Internet resources, especially in the case of UDP application is now increasingly sought after by the general public, when TCP and UDP flows are sharing the bandwidth, UDP flows will continue to compete with the bandwidth of TCP flows, leading to the TCP flow " starves ", causing unfairness to TCP, and the network congestion problem will be getting worse. The research of the fairness of RED algorithm between TCP and UDP flows is extraordinarily important.For the research of the fairness of RED algorithm, scholars from various countries have put forward many different methods to improve the algorithm. In the beginning, this paper introduces the basic concepts of network congestion, congestion control principles and research status; secondly introduces the congestion control mechanism of TCP protocol and some other classical congestion control algorithms; next section makes deeply analysis and research of the RED algorithm, and to improve the RED algorithm for its flaw, we propose an improved algorithm Fair-RED algorithm:enhancement the methods of calculating packet loss probability of the original algorithms, using the power function and Cauchy distribution curve instead of the original piecewise linear function curve for improving the throughput of TCP flows, to enhance the competitiveness of the bandwidth of TCP,adding the methods of calculating UDP flow packet loss probability to ensure that the algorithm is relative fairness of the TCP flow and UDP flow; Then, using NS2simulation software to simulate the algorithm, based on the experimental results, comparing and analyzing Fair-RED algorithm from the terms of packet loss probability, average queue length, network throughput and other aspects of the data stream with the original RED algorithm, verifying the superiority of the improved Fair-RED algorithm. Finally, make the implementation of Fair-RED algorithm in the soft route.