EQF: An Explicit Queue-length Feedback for TCP Congestion Control in Datacenter Networks

摘要

In recent years, numerous TCP variants have been developed to fit the fast increasing of network capacities and improve the performance of TCP congestion control mechanisms in various scenarios, particularly in the data center network. In this paper, we consider a modification of TCP congestion control in which the congestion window is adapted to explicit bottleneck queue-length feedback and we call this EQF (Explicit Queue-length Feedback). The basic idea of the EQF is to use the queue-length of congested switch port as a congestion signal to trigger TCP congestion control for controlling the sending rate of sender in a TCP connection. We describe how EQF adjusts transmission rates using queue-length variation tendency to keep packet latency low while delivering high bandwidth. The experiments indicate the effectiveness of our proposed methods and cut off most of the timeouts while attaining high goodput under various conditions.