TOWARDS THE THIRD EDITION OFTTCNJens Grabowski

The third edition of TTCN (Tree and Tabular Combined Notation) will be a complete redesign of the entire test speciication language. The close relation between graphical and textual representation will be removed, OSI speciic language constructs will be cleared away and new concepts will be introduced. The intention of this redesign is to modernize TTCN and to widen its application area beyond pure OSI conformance testing. This paper motivates the need for a new TTCN, explains the design principles and describes the status of the work on the third edition of TTCN. 1. INTRODUCTION The Tree and Tabular Combined Notation (TTCN) is a well established notation for the speciication of test cases for OSI protocol conformance testing. TTCN is deened and standardized in Part 3 of the international standard 9646 'OSI Conformance Testing Methodology and Framework' (CTMF) 2]. OSI conformance testing is understood as functional black-box testing , i.e., a system under test (SUT) is given as a black-box and its functional behavior is deened in terms of inputs to and corresponding out