Network topology with asymmetric fabrics

摘要

Enhanced performance is realized in a multi-fabric/multi switch group interconnect network by providing asymmetric fabric topologies wherein at least one link between a user-port and a switch-port (or between a pair of switch ports) is different in the fabrics. Asymmetry in fabric topology can increase lower-distance (distance-1) pairs, increase network bisection capacity, or reduce the number of switches employed. End nodes can choose at the time of connection the fabric which offers a shorter connection or fewer router hops. Alternatively, a connection can be set up to use either fabric with the end node dynamically exercising its preference for the fabric that offers the shorter path at the time of data transfer. While the number of router hops does not significantly alter message latency in wormhole-routed networks, it does lower link occupancy and thereby average link contention.