A Novel RED Scheme with Preferential Dynamic Threshold Deployment

Congestion control mechanisms in Internet have attracted more attention in network studies. To the high loss rate and synchronization resulted from drop tail policy, random early detection (RED) and its variations were reported. In this paper, a novel algorithm named preferential dynamic threshold - RED (PDT-RED) and its optimized scheme OPDT-RED are proposed. They can adjust dynamically average queue length thresholds basing on packets´ priority and unused buffer space, and accordingly realizes differentiated service. Compared with RED, OPDT-RED algorithm has three features: 1) it reduces greatly the loss rate of packets with higher priority and the average loss rate of all packets; 2) it is simple for implementation; 3) it satisfies higher buffer utilization.