Parallel Simulation of a High-Speed Wormhole Routing Network

A flexible simulator has been developed to simulate a two-level metropolitan area network which uses wormhole routing. To accurately model the nature of wormhole routing, the simulator performs discretebyte rather than discrete-packet simulation. Despite the increased computational workload that this implies, it has been possible to create a simulator with acceptable performance by writing it in Maisie, a parallel discrete-event simulation language. The simulator provides an accurate model of an actual high-speed, source-routing, wormhole network (the Myrinet) and is the first such simulator. The paper describes the simulator and reports on the performance of parallel implementations of the simulator on a 24-node IBM SP 2 multicomputer. The parallel implementations yielded reasonable speedups. For instance, on 12 nodes, the conservative algorithm yielded a speed-up of about 6 whereas an optimistic algorithm yielded a speed-up of about 4.