Research On Distributed Testing Method For Communication Protocols And Implementation Of Test System

With the development of computer networks and distributed systems, communication protocols are getting larger to fulfill more complicated tasks. However, they are also becoming less reliable. Conformance testing, which aims to ensure the quality of the protocol implementation, is often realized by generating a test sequence (input sequence) from the specification, applying it to the implementation in a test architecture and analyzing the resulting output sequence to determine whether the implementation conforms to the specification.In distributed testing where there are multiple testers, the testing procedure can be complicated by the fact that testers may encounter coordination problems relating to controllability and observability. Controllability is the capability of the test system to force the Implementation Under Test (IUT) to receive inputs in a given order. Observability is the capability of the test system to observe the output of the IUT and to determine which input triggers the particular output. Controllability and observability have a great influence on several aspects of the testing activity such as the execution of test sequence, the fault detectability of test system and the interpretation of testing results. This dissertation researches these two problems from the aspects of test generation and test execution. The main contributions of the dissertation are the following: 1. Test Generation for Distributed TestingTo resolve the controllability and observability problems in distributed testing, it is often necessary for testers to exchange coordination messages directly through reliable communication channels which are independent of the IUT. Considering the costs of coordination messages and input/output operations, it is desirable to generate a minimum-cost test sequence where there are no potential controllability and observability problems. Based on the Multi-port Finite State Machine model of the protocol, a new method is proposed to construct a digraph in which every path represents a test sequence which is free from controllability and observability problems and test generation involves finding a Rural Chinese Postman Tour (RCPT)...