Experience with an Estelle development system

Estelle is a formal description technique, based on an extended state transition model, by the International Orangization for Standardization (ISO) for specifying protocols and services. The Estelle Development System (EDS) is a comprehensive protocol development environment for protocol designers and implementors for protocols specified in Estelle. Three key components of EDS are an Estelle compiler, a finite state machine analyzer, and a test driver. The Estelle compiler generates C language source code from the Estelle specification file for a protocol for the machine-independent part of the protocol specification which constitutes 50-70’36 of a complete protocol implementation. The finite state machine (FSM) analyzer of EDS is an automated tool to analyze protocol state machines to verify protocol properties such as deadlock-freeness, boundedness, termination and completeness, and to generate user paths or event sequences involving interface events which can be used as test traces. The test driver simulates the network and monitors the behavior of an implementation during tests. EDS is complemented with another set of tools for generating protocol test sequences for the conformance testing of protocols to standards. This Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage, the ACM copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Association for Computing Machinery. To copy otherwise, or to republish, requires a fee and/or specific permission. @ 1990 ACM 089791-4155/90/0010-0008...$1.50 8 paper discusses application of EDS to the verification, semi-automatic implementation, and conformance test generation for protocols. The experience with EDS has shown that it is powerful, flexible and well-suited to application on real protocols.