RED method with dual-fairness metrics cooperating with TCP congestion control

In future IP networks, the main technical challenge will be to guarantee QoS for each flow. However, it has been reported that the typical congestion control scheme, random detection (RED), causes unfairness per flow, especially for TCP flows. The differentiated services (Diffserv) mechanism has also been studied, but as it is a class-based control mechanism, the unfairness per flow still remains within the class. Moreover, to guarantee a flexible QoS, routers require a flow-based control mechanism. In this paper, we propose a flow-based congestion control scheme, called RED with dual-fairness metrics (DRED), to dissolve the unfairness per flow and so provide a feasible QoS. DRED enables to consider backlogged packets in the buffer, and a flow succession time by simple flow management per router. In addition, DRED is a suitable scheme for TCP transmission, cooperating with TCP congestion control mechanism.