Patent ID: 7844715

Claim:
A network system comprising: a plurality of servers operationally coupled to a shared input/output (I/O) subsystem; wherein each of the plurality of servers communicate with the shared I/O subsystem by sending I/O requests and the shared I/O subsystem processes the I/O requests; wherein the shared I/O subsystem includes: (a) a plurality of I/O interface units for providing a connection to the plurality of servers to a different type of network; wherein each I/O interface unit individually provides all the functions of the shared I/O subsystem; and by connecting two or more I/O interface units provides a larger scalable shared I/O subsystem; wherein each I/O interface unit includes: (i) a hardware controller that provides a physical interface between the I/O interface unit and an I/O management link; wherein the hardware controller sends and receives frames over the I/O management link; and (ii) a software driver executed by a processor for the I/O interface unit, the software driver interfacing with the hardware controller which allows multiple protocols to interface with the software driver via a multiplexing interface; and (b) a switch card for operationally coupling the plurality of I/O interface units, wherein the switch card receives a data packet from one I/O interface unit and directs the data packet to another I/O interface unit; and the switch card includes a controller for implementing functions of an I/O management unit and a module management unit that facilitates communication between the I/O management unit and a switching unit.