Research On Refusal Testing Of Multi Input/Output Transition Systems Using The All-Observer

Refusal testing is an important one among the theories of testing labeled transition systems. In refusal testing, observers are not only able to detect whether actions can occur, but also able to detect whether actions can fail (i.e, actions are refused by the system under test). Such observers have a complete distinguishing power between legal and illegal behaviors at any state of the system under test. This work concerns the most recent development in refusal testing – the refusal testing theory for multi input/output transition system. Main contents and conclusions of this work are as follows.A survey is made on the refusal testing of labeled transition system as well as its extended models — input/output transition system (IOTS) and multi input/output transition system (MIOTS). Therein, MIOTS refusal testing is based on a notion of the so-called "singular-observer".A singular observer can only check the output channels one by one in a serial manner, resulting in very big size test suites. To reduce the size of a test suite effectively, the concept of all-observer is proposed, and a kind of MIOTS refusal testing theory based on the all-observer is established. The algorithm and conditions of generating sound and complete all-observer test suites are studied. Application of the all-observer testing in network protocols is discussed. Further, the inefficiency of MIOTS singular-observer factorized test generation is recognized, a better technology with higher efficiency is proposed and applied to MIOTS all-observer factorized test generation.Distributed testing is a kind of testing where multiple testers are used in parallel to test a system. For each of the two types of MIOTS testing based on the singular-observer and all-observer, a correspondent distributed test architecture is proposed, and a distribution algorithm is given to translate a centralized test case to a distributed counterpart. In this manner, the MIOTS refusal testing is developed in the direction of distributed testing. Then for a special case of the MIOTS model – np-FSM (multi-port finite state machine with n ports), a distributed testing method is given, which is simpler and easier to be applied to the distributed testing of real network protocols. We show that np-FSM testing is a special case of MIOTS refusal testing based on the all-observer.In the scope of the np-FSM model and the proposed distributed testing method, a framework is proposed for the testing of routing information processing functions of IP routing protocols. This framework includes a function model, a test architecture and a test description script. A software tester is implemented according to this framework, which enables faster and higher-quality test suite development, and proves a good complement to the existing general testing system in our lab.