Fast convergence to network fairness

Most AQM algorithms, such as RED, assure fairness through randomness in congestion notification. However, randomness results in fair allocation of network resources only when time limitations are not considered. This is not compatible with the current Internet, where traffic oscillations are frequent and the demand for fair treatment is rather urgent, due to short duration of most applications. Given the short duration of most modern Internet applications, fast convergence to fairness is necessitated. In this paper, we use fairness as the major criterion to adjust traffic and present a corresponding algorithm of active queue management, which is called Explicit Global Congestion Notifier (EGCN). EGCN notifies flows almost simultaneously about incipient congestion by marking packets arriving at the router’s queue, when the load in the network increases and buffer overflow is expected. This is a new approach compared with the random notification policy of RED or ECN. EGCN distributes the burden to adjust backward to more flows and consequently allows for smoother window adjustments. We elaborate on the properties of system-wide response in terms of fairness, smoothness and efficiency. Simulation results demonstrate a clear-cut advantage of the proposed scheme.