Design and implementation of a new queue scheduling scheme in DiffServ networks

In this paper, based on analyzing the two existing queue scheduling algorithms WRR and DWRR, an improved scheduling algorithm, called DWRR+, is presented, which is the resolution for the fairness of bandwidth allocation of the WRR algorithm. The ns-2 simulations show that the improved scheduling algorithm not only offers the service of the minimum guaranteed bandwidth but also implements the fair allocation of residual bandwidth. Furthermore, synthesizing the PHB performance requirements of EF, AF and BE in DiffServ, a new two-level scheduling scheme for multi-service networks, called PRI/DWRR+, is designed based on the DWRR+ algorithm. Eventually, in the simulation test of the new scheduling scheme, the PHB parameters are configured according to various service of internet. The simulation results indicate that the new scheduling scheme PRI/DWRR+ can implement Differentiated Services for the business flow with different QOS requirements, so PRI/DWRR+ is completely suitable for DiffServ networks.