基于吞吐量和队列检测的TCP Vegas改进算法

摘要

TCP Vegas protocol employs difference between the expected throughput and the actual throughput to control network congestion. Compared with the TCP Reno protocol, it has better network stability and availability. In this paper we confirm that the TCP Vegas protocol has poorer fairness in coexistence environment by analysing the network performances of these two protocols in complex environment, and then propose an improved network-based adaptive TCP Vegas algorithm. This algorithm exalts the adaptability of TCP Vegas protocol in complex environment by adaptively improving the expected throughput and optimising the detection of queue congestion, it also enhances the fairness of the TCP Vegas when coexisting with TCP Reno. Simulation demonstrates in the end the validity of the improved algorithm.%TCP Vegas协议通过比较期望吞吐量和实际吞吐量的差值来进行网络拥塞控制,相对TCP Reno协议具有更佳的网络稳定性和利用率.通过分析两种协议在复杂环境中的网络性能,证实TCP Vegas协议在共存环境下公平性欠佳的结论,并提出一种基于网络自适应的TCP Vegas改进算法.该算法通过对期望吞吐量自适应改进和对队列拥塞监测的优化,提高了协议在复杂环境中的自适应性,增强了与TCP Reno协议共存环境下的公平性,最后通过仿真证明了改进算法的有效性.