Adaptive packet marking for achieving fairness in DiffServ networks

Current Differentiated Services (DiffServ) networks supporting Assured Forwarding (AF) service succeed in providing minimum rate guarantees, but fail to distribute network capacity in a fair way. To address the unfairness problem we propose simple adaptive markers operating at the network edge, whose marking function adapts to changes of the traffic mix. Extensive simulation experiments indicate that adaptive marking can effectively address the unfairness problem, without decreasing network utilization. The proposed approach can be implemented using a Bandwidth Broker architecture, whereby a centralized Bandwidth Broker sets the control parameter of the adaptive markers, based on the current traffic contracts.