Source : Free On-Line Dictionary of Computing

Intelligent Input/Output
     
         /i:-too-oh/ (I2O) A specification which aims to
        provide an {I/O} {device driver} architecture that is
        independent of both the specific device being controlled and
        the host {operating system}.  The Hardware Device Module (HDM)
        manages the device and the OS Services Module (OSM) interfaces
        to the host operating system.  The HDM is portable across
        multiple operating systems, processors and busses.  The HDM
        and OSM communicate via a two layer {message passing}
        {protocol}.  A Message Layer sets up a communications session
        and runs on top of a Transport Layer which defines how the two
        parties share information.
     
        I2O is also designed to facilitate intelligent I/O subsystems,
        with support for {message passing} between multiple
        independent processors.  By relieving the host of {interrupt}
        intensive I/O tasks required by the various layers of a driver
        architecture, the I2O intelligent I/O architecture greatly
        improves I/O performance.  I2O systems will be able to more
        efficiently deliver the I/O throughput required by a wide
        range of high bandwidth applications, such as networked
        {video}, {groupware} and {client-server} processing.  I2O does
        not restrict where the layered modules execute, providing
        support for single processor, {multiprocessor}, and
        {clustered} systems.
     
        I2O is not intended to replace the driver architectures
        currently in existence.  Rather, the objective is to provide
        an open, standards-based approach, which is complementary to
        existing drivers, and provides a framework for the rapid
        development of a new generation of portable, intelligent I/O.
     
        {Home (http://www.i2osig.org/)}.
     
        (1997-11-04)