The Harris 20-20 Integrated Network Switch

This paper describes the system architecture of the Harris 20-20, an integrated voice/data network switch. Both hardware and software aspects of the system are presented. The hardware buses and all major assemblies are identified and described. The architecture is innovative in that the system accommodates both North American and European standard multiplex equipment. The software design permits the subsystems to all run on a single microprocessor or to be distributed over multiple processors with no change to the application-level software.