Applying Software Engineering To Protocol Simulation

Communications systems have widely varying equipment, traffic distributions, error characteristics, and measures of performance. To accommodate these characteristics, a simulator for the protocols con trolling the transmission and reception of messages must be modular and flexible ; it must also allow for the handling of concurrent processes and the efficient generation of reports and statistics. One way to construct such a simulator is to use techniques derived from software engineering: design prior to coding, design review, modular design based on information hiding, use of abstract types, code review by peers, co-operating sequential processes, and pseudo-code specifications. In the development of a simulator program for several pro tocols, outside design review, the information- hiding principle, the use of abstract types with a language that supports them (SIMULA), and the use of co-operating sequential processes were the most productive methods.