Fully adaptive minimal deadlock-free packet routing in hypercubes,meshes, and other networks: algorithms and simulations

This paper deals with the problem of packet-switched routing in parallel machines. Several new routing algorithms for different interconnection networks are presented. While the new techniques apply to a wide variety of networks, routing algorithms will be shown for the hypercube, the two-dimensional mesh, and the shuffle-exchange. Although the new techniques are designed for packet routing, they can be used alternatively for virtual cut-through routing models. The techniques presented for hypercubes and meshes are fully-adaptive and minimal. A fully-adaptive and minimal routing is one in which all possible minimal paths between a source and a destination are of potential use at the time a message is injected into the network. Minimal paths followed by messages ultimately depend on the local congestion encountered in each node of the network. All of the new techniques are completely free of deadlock situations     

Randomized routing with shorter paths

Studies the use of randomized routing in multistage networks. While log N additional randomizing stages are needed to break “spatial locality”, within each permutation, only log log N additional randomizing stages are needed to break “temporal locality” among successive permutations. Thus, log N bits of initial randomization per input, followed by log log N bits of randomization per packet are sufficient to ensure that t permutations are delivered in time t+log N. We present simulation results that validate this analysis     

Routing techniques for massively parallel communication

A survey of some packet-switched routing methods for massively parallel computers is presented. Some of the techniques are applicable to both shared-memory and message-passing architectures. These routing methods are compared in terms of their efficiency in supporting programming models, efficiency in mapping to parallel machines, and practicality. Among the outlined methods, three nonadaptive techniques and some adaptive routing algorithms are discussed