Flow Aware Traffic Management

TCP congestion control mechanism, while simple and scalable, has several well known limitations: 1) often different flows experience synchronized losses, leading to lower link utilization, and 2) when flows with different Round Trip Times (RTT) share the same bottleneck link, the flows with a smaller RTT will receive a larger share of the capacity. Not only this allocation of capacity is non-optimal in general, but it cannot be modified as long as only drop tail queues and TCP are used. Active Queue Management algorithms aim at improving link utilization by desynchronizing packet losses for different flows, albeit without addressing the fairness issue. Many AQM algorithms have been proposed (like RED, REM, Blue, Stochastic fair blue, just to name a few), but, to the best of our knowledge, none of them is capable of addressing both issues while being easy to configure and supporting different fairness criteria. Another advantage of using AQM algorithms is that routers can use Explicit Congestion Notification, in order to inform a sender that it needs to reduce its sending rate. We propose a new flow-aware traffic management mechanism that aims at addressing the two aforementioned limitations of TCP, while being self-configuring and supporting different fairness criteria. Clearly the fairness criteria has to be