1. A computer system comprising a plurality of processor clusters interconnected by a plurality of global links, each cluster including a plurality of local nodes and an interconnection controller interconnected by a plurality of local links, each cluster having routing information associated therewith for facilitating communication between the local processors and the interconnection controller via the local links, wherein the interconnection controller in each cluster is operable to map locally generated transmissions directed to others of the clusters to the global links, and remotely generated transmissions directed to the local nodes to the local links.