The output-controlled round robin scheduling in differentiated services edge switches

In this paper, we propose a new scheduling technique, called output-controlled round robin (OCRR), for the support of class-based IP networks with variable packet sizes. This technique can be used in edge switches of an optical network to assemble traffic from aggregated flows into bursts/slots. Traffic flows from different classes are scheduled in logical frames. In each logical frame, a flow obtains a grant quantum with respect to its average rate and bandwidth usage in order to pass its traffic. The round robin technique is extended to include smaller cycles to send packets from aggregate flows one by one, thus, eliminating bursty effect from the same flow on the output bandwidth. The amount of the output traffic from each flow is also controlled. Our performance evaluation demonstrated that this output-controlled technique has better performance results than the deficit round robin algorithm in reduction of queuing delay and burst size from the same flow.