Partial path set-up for fault-tolerant routing in hypercubes

A new technique is proposed for fault-tolerant routing in hypercubes, which needs to set up a partial path based on local safety information. Local safety information is utilized to guide fault-tolerant routing. The proposed local safety is a centralized metric. A feasible path from the source to the destination may not be guaranteed at the source based on local safety information when the system contains a large number of faults although a feasible path is available. A partial path is set up for fault-tolerant routing, where the header flit is forwarded until a maximal safe subcube is found to contain the current node and the destination. Backtracking is adopted only for the header along the minimum paths or nonminimum feasible paths if necessary in order to set up a partial feasible path. Extensive simulation results have shown that the partial path set-up scheme is quite useful for fault-tolerant routing while the extra cost caused by path set-up is trivial.