Selective-Request Round-Robin Scheduling for VOQ Packet Switch Architecture

Virtual Output Queuing (VOQ) is widely used by input-queued (IQ) packet switches to eliminate the head-of-line (HoL) blocking problem. A lot of research has been devoted to design iterative arbitration algorithms to maximize the throughput of this architecture. Nevertheless, these approaches require either a high computation complexity or large contention resolution times for high-speed switches. We investigate in this paper the performance of various such algorithms and based on the analysis of pointer desynchronization effect, we propose a new algorithm approximating maximum size matching (MSM) called Selective Request Round Robin (SRRR) which performs extremely well under various traffic models and is easy to implement in hardware.