Summary
International Conference on Emerging Technologies for Communications
2020
Session Number:D2
Session:
Number:D2-2
Convergence Improvement for Practical Delay-based Congestion Control
Shotaro Ishikura, Miki Yamamoto,
pp.-
Publication Date:2020/12/2
Online ISSN:2188-5079
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Summary:
Copa is a practical delay-based end-to-end congestion control which controls its window size based on the measured delay. Its target rate is proved to attain Nash equilibrium among flows sharing the bottleneck link. Copa algorithm measures the smallest RTT over a time window, RTTstanding, and also measures the minimum RTT over long period. Queue length can be estimated as the difference between these two measured RTT (RTTstanding -RTTmin) and Copa calculates its target rate based on this measured standing queue. However, rather large time window causes slightly large control delay and overshoot of window size especially when a difference between the current rate and the ideal throughput is large, e.g. this situation happens when a flow initiates its transmission. This paper proposes adaptive time window in order to shorten control delay adequately and prevent severe overshoot of congestion window. Evaluation results show that our proposed approach improves overshoot of window size and reduces maximum queue length significantly without any degradation of throughput.