A New TCP Congestion Control for High-Speed Long-Distance Networks

Abstract

It has been reported that TCP Reno underutilizes network bandwidth, especially in High-Speed Long-Distance (HSLD) networks, while it has been widely adopted the dominant transport protocol in current Internet. Moreover, the Additive Increase Multiplicative Decrease (AIMD) congestion control algorithm of the TCP Reno has equilibrium and dynamic problems that become more and more severe as the bandwidth-delay product increases. An ideal TCP congestion control algorithm that achieves a high utilization, a small queueing delay, a stable behavior and fairness in bandwidth allocation has been major objectives of networking research in recent years. In this paper, we propose a new congestion control protocol, called TCP KWIK, a modification to the TCP Reno for HSLD networks. TCP KWIK uses delay-based feedback information to address these problems in order to stabilize a network around a fair and efficient operating point. We argue that the delay-based approach is better than the end-to-end congestion control as the networks capacity increases. Their advantage is small at low speed but decisive at high speed. The simulation results demonstrate the effectiveness of our proposed algorithm.