VIRTUAL TRANSPORT LAYER INTERFACE AND MESSAGING SUBSYSTEM FOR HIGH-SPEED COMMUNICATIONS BETWEEN HETEROGENEOUS COMPUTER SYSTEMS

Methods and apparatus that enable network applications executing on respective directly interconnected computer systems to communicate at high speed, with low latency, over the interconnection therebetween such that both systems may use their native mechanisms to communicate with each other without change in those mechanisms, rather than over conventional network communication paths such as Ethernet. Communication between applications in co-resident, closely coupled processing environments is provided by replacing the conventional TCP transport layer and the conventional IP network layer with a reliable messaging subsystem ("MSS") for data transfers between the closely coupled systems which provides an interface which is independent of the communication protocol of the interconnect and a virtual transport layer ("VTL") which simulates a known transport layer protocol, such as TCP/IP, to the network applications. MSS is a system interconnect independent messaging transport which presents to its users many different delivery and notification mechanisms for the transfer of both control and data information between different heterogeneous environments, while VTL uses the MSS connection to provide a consistent, interconnect independent interface to the session layer.