Performance analysis of highSpeed TCP and its improvement for high throughput and faimess against TCP reno connections

摘要

It was reported that the traditional TCP Reno cannot achieve gigabit level throughput due to the essential nature of its congestion control mechanism. HighSpeed TCP was proposed to overcome this problem. It modifies the increasing/decreasing algorithms of the congestion window size. But the performance of HighSpeed TCP has not been fully investigated. Especially, the fairness between HighSpeed TCP and TCP Reno is not considered. In this paper, we first investigate the throughput and fairness properties of High Speed TCP through mathematical analysis and simulation studies. We present that High Speed TCP can provide higher throughput than TCP Reno, but it cannot fully utilize the link bandwidth because of bursty packet losses at the router buffer. It is also shown that HighSpeed TCP degrades the throughput of TCP Reno when they share the bottleneck link. We then propose a new congestion control algorithm of TCP that alleviates the problems of HighSpeed TCP. The simulation results show that the proposed scheme can achieve higher throughput than HighSpeed TCP, keeping the fairness with TCP Reno connections.