Different applications require different quality of service (QoS). Nowadays, the DiffServ architecture is the most important research area. AF and EF are the well-known forwarding treatments in DiffServ to provide QoS. This study is devoted to develop a scheduler that is suitable to the DiffServ. This scheduler should have capacity to provide the basic requirements in RFCs 2597 and 2598. Furthermore, we design the scheduler to meet the original design goal of EF and to provide a fair sharing among the four AF classes. From the numerical results, it can be found our proposed scheduler can provide excellent bandwidth guarantee, priority of EF, fairness of AF, and isolation from best-effort traffic.