Simulation of a Communication Processor Under Extreme Loading Conditions

The manner in which the performance of a communication processor (CP) can be expected to deteriorate under extreme loading conditions has been studied through general-purpose simulation system (GPSS). Processing of characters to determine their disposition when they initially arrived at the CP was assumed to be the primary factor limiting performance under extreme loads and was hence modeled carefully. The CP proved to have an extremely sharp saturation threshold, with the threshold very sensitive to minor variations in character processing times. Simple design criteria for ensuring satisfactory performance without resorting to an extreme worst case design were developed. Also, the effects of some changes in buffering and in the use of priorities were determined.