Structural Models for Specifying Telephone Systems

Mohammed Faci, Luigi Logrippo and Bernard Stépien
University of Ottawa

Abstract

Two approaches, resource-oriented and constraint-oriented, for structuring
telephone systems specifications, are presented. Both approaches
express behaviour by collections of communicating processes, using the
language LOTOS.  However, requirements are distributed differently among
processes.

Examples are taken from specifications of telephone systems, first basic,
and then with features. The features used as examples are call forwarding,
originating call screening, and three-way calling. The two structuring
methods are compared.