Test development for communication protocols: towards automation
In this paper we give an introduction to methods and tools for testing communication protocols and distributed systems. In this context, we try to answer the following questions: Why are we testing? What are we testing? Against what are we Ž testing?... We present the different approaches of test automation and explain the industrial point of view automatic test . Ž . execution and the research point of view automatic test generation . The complete automation of the testing process requires the
... use of formal methods for providing a model of the required system behavior. We show the importance of Ž . modelling the aspects to be tested the right model for the right problem! and point out the different aspects of interest Ž . control, data, time and communication . We present the problem of testing based on models, in the form of finite state Ž . machines FSMs , extended FSMs, timed FSMs and communicating FSMs, and give an overview of the proposed solutions and their limitations. Finally, we present our own experience in automatic test generation based on SDL specifications, and discuss some related work and existing tools. q Ž . The Open Systems Interconnection OSI Reference Model has been useful in placing existing protocols in an overall communication architecture and the development of new protocol standards. The term open systems means that if a system conforms to a standard, it is open to all other systems conforming to the same standard for communication. In order to assure successful communication between computer systems from different manufacturers, it is not sufficient to develop and standardize communication protocols. It must also be possible to ascertain that the implemented protocols really conform to these standard protocol specifications. One way to do this is by testing the protocol implementa-1389-1286r99r$ -see front matter q 1999 Elsevier Science B.V. All rights reserved. Ž . PII: S 1 3 8 9 -1 2 8 6 9 9 0 0 0 6 3 -8 ( ) R.