A manner of managing congestion in a data-traffic network. In one embodiment a network node such as a bridge, switch, or router includes an AQM having a PI controller configured to calculate p′ using the difference between Q and a Target Q, wherein p′ is p0.5 and p is the probability that a received packet will be dropped or marked, and some drop decision functions are configured to indicate that the node should drop a received packet by comparing p′ to two random values. A marking decision function may also be present and configured to indicate that the node should mark a received packet by comparing p′ to one random value. A congestion control classifier, which is in some embodiments an ECN classifier, is also present to classify a received packet and facilitate making the proper dropping or marking decision.