Optimal Scheduling Algorithms for Input-Queued Switches

— The input-queued switch architecture is widely used in Internet routers, due to its ability to run at very high line speeds. A central problem in designing an input-queued switch is choosing the scheduling algorithm, i.e. deciding which packets to transfer from ingress ports to egress ports in a given timeslot. Important metrics for evaluating a scheduling algorithm are its throughput and average delay. The well-studied ‘Maximum-Weight’ algorithm has been proved to have maximal throughput [1]; later work [2]–[4] found a wider class of algorithms which also have maximal throughput. The delay performance of these algorithms is less well understood. In this paper, we present a new technique for analysing scheduling algorithms which can explain their delay performance. In particular, we are able to explain the empirical observations in [2] about the average delay in a parameterized class of algorithms akin to Maximum-Weight. We also propose an optimal scheduling algorithm. Our te...

• Type: Conference
• Year: 2006
• Where: INFOCOM
• Authors: Devavrat Shah, Damon Wischik
• Keywords: Average Delay, Communications, INFOCOM 2006, Input-queued Switch, Scheduling Algorithm