On Embeddable Passive Testing*

Despite fruitful research on passive testing algorithms and techniques, the concept of passive testing remains elusive, and is even dismissed as inherently inconsistent or a mere facon de parler. Consequently, passive testing still does not belong to the repository of conceptual, technological, and linguistic devices of computer science and telecommunications research communities. This work aims at “homing in” on the concept of passive testing. To this end, we concentrate on one aspect of this concept, namely on how a passive tester can be represented within the overall architecture of a distributed, reactive Discrete Event System. It is shown that such models in current use are deficient: internally inconsistent, or even “unimplementable”. A new, very simple model is proposed, which allows a passive tester to be treated as any other system entity. This allows the modelling of systems in which a passive tester is embedded. The potential uses of such systems are also identified.