A Graphical Tool for Protocol Design with Estelle

A new tool is described which enables the user to develop a protocol specification in the formal description technique. Estelle by working on graphical representations of Estelle constructs and objects. Only some parts of the specifications are handled in textual form (e.g., Pascal code), since they are of an intrinsically textual nature. The problems of combining graphical abstractions with pure textual information have been addressed and solved by designing an appropriate database structure and by enabling the user to access files containing the most extensive parts of text via an editor. The tool automatically produces a complete textual Estelle code which is syntactically correct. Moreover, the total can be interfaced with a simulator, so as to animate a specificatio