一种基于链路带宽估计的TCP慢启动算法

A TCP Slow-Start Algorithm Based on Link Band-Width Estimation

在慢启动阶段 ,TCP以指数方式增加其拥塞窗口 ,这导致了慢启动阶段的多包丢失 ,并恶化了TCP的性能 .该文对TCP连接的等效带宽进行了深入的理论分析 .在此基础上 ,提出了一种改进的TCP慢启动算法———基于链路带宽估计的TCP慢启动算法 ,并通过仿真对其吞吐量、公平性和兼容性进行了评估 .仿真的结果表明 ,该算法避免了慢启动阶段的多包丢失 ,并能有效改进TCP的性能 ,是简单。

Because TCP exponentially grows its congestion window during the initial slow start period, many packets are lost during this period. This makes TCP coarse-grained timeout and deteriorates TCP's performance. For the large bandwidth×delay product networks, this is more serious. Based on the deep analysis of the TCP connection, this paper gives the equivalent bandwidth concept and deduces its analytical expression. According to this theoretic analysis, this paper proposes an improved TCP slow-start algorithm based on link band-width estimation. At the same time, we evaluate the algorithm's performance, fairness and compatibility on the NS platform. The results of simulation prove that this algorithm can resolve the problem, of which many packets are lost during the initial slow start period. It increases the good throughput of TCP flow. Because this algorithm only modifies the sender of TCP a little, it is simple, practical and effective.