Stability of RED with two-way TCP traffic

This paper points out a phase effect with RED-like queue management algorithms and two-way TCP traffic. It is shown by simulation and measurement that the RED (random early detection) queue converges to a state of heavy oscillation in the presence of two-way bulk-data TCP traffic, causing suboptimal link utilization and service differentiation between in-profile and out-of-profile packets. Besides investigating the reasons for the oscillatory behavior, we show that the oscillations persist in scenarios with two-way Web-like TCP traffic and disappear in the case of significant amounts of cross traffic and/or usage of drop-tail instead of RED.