Link allocation in point-to-point multicomputer networks

The allocation of physical links to implement channels between nodes in multicomputer networks that use a point-to-point interconnection topology is examined. There are three basic link allocation options available in the design of the multicomputer: provide half-duplex channels using one link per channel, provide full-duplex channels using two links per channels, or augment the network using additional links as half-duplex channels. The author focuses on the impact of three allocation options on performance, especially the source-to-destination message-transfer delay. Existing performance models are generalized to model both full-duplex and half-duplex channels. The model is applied to the two-dimensional torus and binary hypercube networks. Full-duplex channels significantly reduce delay in the torus, but only marginally reduce delay in the hypercube. A modified hypercube uses additional half-duplex channels to substantially reduce delay