Implementing Distributed Weighted Fair Scheduling Algorithm in CICQ Switches

Traditional input-queued switches based on crossbar are insufficient in providing good QoS performance. As a contrast, the CICQ(Combined Input and Cross-point buffered Queuing) switches can provide almost 100% throughput under different input traffic, the performance of which is very close to the OQ(Output-Queued) switch, and has the potentials to support good QoS. Based on the CICQ switches, a new scheme is put forward, which can realize distributed weighted fair schedule for the packets of variable length, and have both the scalability of input-queued switches and QoS performance of output-queued switches. The issue of updating the virtual time of back-pressured queues is also discussed. Simulation results show the scheme is very effective and has good performance.