Network Problem-Determination Aids in Microprocessor-Based Modems

Recent significant developments in large-scale integration (LSI) and in digital signal-processing techniques have combined to provide the base for a new generation of modems. LSI microprocessors now have the characteristics and performance to provide superior modem function as well as a design base for the addition of new function. The extendability afforded by a microprocessor-based modem design is being increasingly used to provide advanced communications network management functions. This paper describes the design objectives, implementation decisions, and design rationale for implementing these characteristics in the IBM 3863, 3864, and 3865 family of data modems. This network management function, which has been integrated into IBM Communications Network Management (CNM) offerings for IBM's Systems Network Architecture user networks, extends the problem-determination capability to cover the modems and communications lines. Support for this new function has been integrated into the 3705 ACF/NCP/VS control program and the System/370 NPDA program product.