Controlling user flows with RIO and WFQ

The volume of Internet traffic increases every year, caused by increased amounts of individual information. Quality of Service (QoS) controls is necessary to manage this traffic. Differentiated Service (Diffserv) is a promising technique to realize scalable QoS control in the internet; extensive efforts have been made for its practical use and it is already introduced in some networks. The control functions for Diffserv are installed in edge and core router, which enables the scalable QoS control. In this paper, we use Diffserv to control QoS on service classes. We propose a new active queue management scheme for Assured Forwarding (AF) services guaranteeing minimum bandwidth provided that Random Early Detection with IN and OUT (RIO) and Weighted Fair Queuing (WFQ) are used as the basic QoS control mechanisms. The proposed method controls the queue threshold values of RIO for each flow and the allocated bandwidth of WFQ for each flow and users´ flows. Simulation results show that the proposed scheme reduces the packet discard rate when packets concentrate on a specific flow.