Improving the efficiency of adaptive routing in networks with irregular topology

Networks of workstations are emerging as a costeffective alternative to parallel computers. The interconnection between workstations usually relies on switchbased networks with irregular topologies. This irregularity makes routing and deadlock avoidance quite complicated. Current proposals avoid deadlock by removing cyclic dependencies between channels and therefore, many messages are routed along non-minimal paths, increasing latency and wasting resources. In this paper, we propose a general methodology for the design of adaptive routing algorithms for networks with irregular topology that improves over a previously proposed one by reducing the probability of routing over nonminimal paths. The resulting routing algorithms allow messages to follow minimal paths in most cases, reducing message latency and increasing network throughput. As an example of application, we propose an improved adaptive routing algorithm for Autonet.