Abstract:

To enhance the TCP transmission performance in high packet loss rate environment, we propose an intelligent response mechanism of round-trip time delay changes. The variation of round-trip time delay is normalized to a standard  delay factor, and then the standard delay factor is used to amend the congestion window growth and the reduction rate, which makes the increasing rate of the congestion window adaptable to the round-trip time delay changes and can distinguish random packet losses from network congestion. The mechanism is implemented as a LINUX kernel module, which enables its quick deployment to all congestion control mechanisms based on AIMD. Simulation results show that the average throughput of the proposed mechanism is 57% higher than the cubic algorithm, so it can effectively improve the bandwidth utilization in high packet loss rate environment.

Key words: TCP transmission, packet loss rate, round trip-time delay, congestion control