Study on a Novel Scheduling Algorithm of the Multiple-Plane and Multiple-Stage Switching Fabric

The multiple-plane and multiple-stage (MPMS) switching fabrics are the next step in scaling current crossbar fabrics to many hundreds or few thousands of ports. However, scheduling cells in the MPMS fabric is complex. With the recent blooming of bandwidth sensitive Internet traffic, scheduling cells with guaranteed bandwidth is becoming an urgent demand. The CRRD algorithm delivers high throughput under uniform traffic pattern, but it does not work well under nonuniform traffic and does not provide any bandwidth guarantees. In this paper, we analyze the graphic model of the MPMS fabric, and propose a novel bandwidth-guaranteed scheduling algorithm based on CRRD. Simulation results show that it delivers 100% throughput under uniform traffic, and achieves much higher throughput than that of CRRD under nonuniform traffic, and keeps its implementation complexity low without internal expansion and allocates the output-link bandwidth fairly for the reserved flows in the overloaded case.