Distributed transport communications manager with messaging subsystem for high-speed communications between heterogeneous computer systems

Methods and apparatus that enable a transport protocol executing on a first computer system to be utilized by applications executing on a second computer system which is directly interconnected and closely coupled to the first computer system. An interconnection couples an input/output (I/O) subsystem of the first computer system to an I/O subsystem of the second computer system and provides a path over which data can be transmitted between the first and second computer systems independent of a network interface card, and an interconnection messaging system executing on the first and second computer systems provides general purpose transport interfaces between said first and second computer systems. A distributed transport communications manager executing on the first and second computer systems controls use of the interconnection messaging system to establish a dialog through which the transport protocol of the first computer system may be used by an application executing on the second computer system in a manner which is transparent to the application. The transport protocol executing on the first computer system may be utilized by a plurality of networked computer systems including the second computer system, where the interconnection messaging system establishes dialogs through which the transport protocol of the first computer system may be used by applications executing on the networked computer systems. Conversely, applications executing on the second computer system may utilize transport protocols executing on a plurality of networked computer systems including the first computer system.