Design and Implementation of a New Queue Scheduling Algorithm in DiffServ Networks

In the current queue scheduling algorithm, there is no the algorithm that completely meets the requirements of PHB in DiffServ networks. Therefore, how to improve the scheduling algorithm aiming at the requirements for different traffic Qos is a problem needing to be handled immediately. Firstly, the existing queue scheduling algorithms supporting DiffServ are researched and compared for performance in this paper. Through analyzing the AF scheduling policies, an improved scheduling algorithm, called DWRR+, is presented, which is the resolution for the fairness of bandwidth allocation of WRR algorithm. Eventually, the ns-2 simulations show that the improved scheduling algorithm not only offers the service of assuring minimum bandwidth but also implements the fair allocation of residual bandwidth, so it can meet the performance requirements of the AF queue scheduling.