US Patent 7136959 Data storage system having crossbar packet switching network

A system interface having: a packet switching network; a cache memory; and a plurality of directors. One portion of such directors is adapted for coupling to a host computer/server and another portion of the directors is adapted for coupling to a bank of disk drives, the plurality of directors and cache memory being interconnected through the packet switching network. Each one of the directors is coupled to a crossbar switch. The cross bar switch is directly connected to at least two other ones of the cross bar switches networks and indirectly connected to of other ones of the crossbar switches through the at least two directly connected crossbar switches.