WICI: an efficient switching scheme for large scalable networks

Many recent supercomputers employ either some kind of cluster-based design or other highly scalable networks. Clustering is built-in in the hierarchical system, while highly scalable networks like mesh or torus could be easily partitioned into modules to form several clusters. The paper explores potential use of prevalent routing schemes of wormhole and virtual cut-through and outline their relative drawbacks. Then, it introduces a new switching method, called Wormhole Intracluster Cut-through Intercluster (WICI) routing, to improve the network performance and to reduce the buffer cost in large networks. WICI routing, in general, is applicable to any hierarchical or large networks and its usefulness has been demonstrated for some practical networks including dBCube, mesh and torus. Simulation results of WICI routing are compared with wormhole and virtual cut-through routings