The capabilities of Local Area Networks (LAN) to support real-time processing applica-tions are explored. The ISO/ANSI Open Systems Interconnection reference model is summar-ized and its layers examined from the standpoint of implementing functions in VLSI devices. A Network Interface Module (NIM) to the LAN is defined and its characteristics are defined. A discussion of the hardware, firmware, and software network protocol functions and their implementation in the NIM is presented. Using the NIM as the LAN interface, the message paths for different types of network operations are determined. Processing times for these message paths are estimated and used to postulate typical message transfer times. Suggested approaches for continued throughput analyses are presented.