Simulation of a telecommunications multiprocessor switching system

Abstract

The stringent real-time operating requirements of telecommunications switching systems have prompted the design of special-purpose processors that allow modular growth and provide high levels of reliabil ity, availability, security, flexibility, and capacity. One such system is the Mark II BL (MKIIBL), a telecommunications-oriented multiproces sor developed by GEC as the controller for the British Post Office's SYSTEM X. The complexity of the Mark II BL makes computer-aided design tools essential in initial design, design evaluation, per formance evaluation, and the writing of applications software.

We have developed a computer-aided design package for the Mark II BL system. It is based on a simulation using the process interaction approach and is imple mented in SIMULA. We have validated the simulation by comparing the performance of simulated applica tions software for a particular digital exchange with the performance of the real system. The simulator has been used to gain insight into the detailed be havior of the system and to test alternative strate gies and design modifications. A typical result of such an investigation is reported. We conclude by mentioning some proposed extensions to the simulator and its application in design.