Performance comparison between TCP slow-start and a new adaptive rate-based congestion avoidance scheme

Abstract

There have recently been simulation studies of the dynamic behavior of the TCP Slow-Start (TCP-SS) congestion control mechanism, S. Schenker et al. (1990) and L. Zhang et al. (1991), that show problems of oscillatory behavior in packet delay, congestion windows and throughput. The scheme also suffers from rapid fluctuations in queue length, periodic packet losses, and underutilization of the transmission line in a large pipeline size and/or two-way traffic environments. Fairness problems in TCP-SS are also known to occur. Based on the principles of rate control and preventive congestion mechanism, the present authors have developed a new Adaptive Rate-Based (ARB) congestion avoidance scheme that avoids these problems present in TCP-SS. Through simulations, they demonstrate, that ARB outperforms TCP-SS in two important areas: network efficiency and fairness.<>