Maintaining switching software viability

Abstract

The need for a continuous flow of new functionality in a switch necessitates an approach of focused restructureperiodic maintenance of limited sections of sofware. Executing a program of focused restructure has historically been a non-precise undertaking for switching systems. This paper describes an approach for establishing more formal guidelines for identifying switching system software that is more likely to contain fatilts and is hence a candidate for focused restructure. The Sofiare Architecture-Based Analysis (SABA) methodology is described. This methodology enlightens the common black box perspective of a large sofhare system with gray box details, applies a dynamic, sophisticated statistical analysis, and produces an expert discrimination of critical sofware c o~p~l n e n~s within their sofhvare architecture. Finally, a joint trial of Bellcore's SABA to a large AT&T digital switching system is used to illustrate the approach.