Formal Description Technique

(FDT) A {formal method} for

developing telecomunications services and {protocol}s. FDTs

range from abstract to implementation-oriented descriptions.

All FDTs offer the means for producing unambiguous

descriptions of {OSI} services and {protocol}s in a more

precise and comprehensive way than {natural language}

descriptions. They provide a foundation for analysis and

verification of a description. The target of analysis and

verification may vary from abstract properties to concrete

properties. {Natural language} descriptions remain an

essential adjunct to formal description, enabling an

unfarmiliar reader to gain rapid insight into the structre and

function of services and protocols.

Examples of FDTs are {LOTOS}, {Z}, {SDL} and {Estelle}.

[ISO/IEC DTR10167: "Guidelines for the application of

{Estelle}, {LOTOS} and {SDL}"].

(1994-12-06)