Providing fairness in Diffserv architecture

The differentiated service (Diffserv) architecture does not specify any priority scheme between AF out-profile packets and best-effort (BE) packets. Therefore, a misbehaving AF flow can penalize many BE flows unless a fair bandwidth sharing mechanism is employed in the routers. In this paper, we propose two different techniques for solving the inter- and intra-class fairness problems at the core and edge routers, respectively. For the core routers, we propose a Fair Weighted Round Robin (FWRR) scheduler that protects BE packets from monopolizing AF out-profile packets by dynamically adjusting the service weights and buffer spaces according to the traffic changes. For the edge routers, we propose a scheme, called Fair Dropper (FD), that provides intra-class fairness by penalizing the greedy flows. Simulation results indicate that both these techniques are quite effective in providing inter- and intra-class fairness, while maintaining a low packet loss rate.