QoS scheduling considering flow for assured service in diffserv network

Diffserv (differentiated service) is a promising technique to realize scalable QoS control on the Internet. Extensive effort has therefore been put into the practical use of this technique. Diffserv has already been introduced in some networks. Control functions for Diffserv are installed in edge routers and core routers. This realizes scalable QoS control as mentioned above. This paper proposes a new active queue management scheme for AF (Assured Forwarding) services that guarantees minimum bandwidth provided that RIO (random early detection with IN and OUT) and WFQ (weighted fair queuing) are used as the basic QoS control mechanisms. The proposed method controls the queue threshold values of RIO for each flow. Simulation results show that the proposed scheme reduces packet discards when the packets converge on a specific flow.