Taxonomy and evaluation of TCP-Friendly congestion-control schemes on fairness, aggressiveness, and responsiveness

Abstract

Many TCP-friendly congestion control schemes have been proposed to pursue the TCP-equivalence criterion, which states that a TCP-equivalent flow should have the some throughput with TCP if it experiences identical network conditions as TCP. Additionally, the throughput should converge as fast as TCP when the packet-loss conditions change. This study classifies eight typical TCP-friendly schemes according to their underlying policies on fairness, aggressiveness, and responsiveness. The schemes are evaluated to verify whether they meet TCP-equivalence and TCP-equal share. TCP-equal share is a more realistic but more challenging criterion than TCP-equivalence and states that a flow should have the some throughput with TCP if competing with TCP for the some bottleneck. Simulation results indicate that one of the selected schemes, TCP-friendly rate control (TFRC), meets both criteria under more testing scenarios than the others. Additionally, the results under nonperiodic losses, low-multiplexing, two-state losses, and bursty losses reveal the causes that bring fault cases to the schemes. Finally, appropriate policies are recommended for an ideal scheme.