Some issues in protocol implementation testing

Abstract

Communication between various makes of communication equipment and across international boundaries is becoming easier due to the continuing development of international standards on communication protocols, such as those defined by ISO for Open Systems Interworking (OSI). Although the agreement to use standard protocols by the various parties involved is the first necessary step towards OSI, it is not sufficient without assuring that the protocols be correctly implemented in the communication equipment. The assessment of the adherence of a communication protocol implementation to its specification relies on testing as its main tool. The development of the tests and their application (the architecture of the test system) have properties and constraints which make them different from those currently created for testing hardware and software systems. In the remainder of the presentation, these constraints and problems as related to the successful development of a protocol test system will be reviewed. They will be separated into those aspects which pertain more to the form of the test support system (the system architecture), and to those which influence the selection of effective test interaction sequences. This division is slightly arbitrary, for some of the issues have effect on both of the above components of the test system.