Test specification in TTCN using interactive editor

Abstract

The International Organisation for Standardisation (ISO) has defined a protocol test language called TTCN (Tree and Tabular Combined Notation) to specify abstract test cases for ISO protocols. After an introduction to the ISO test methodology, test specification in TTCN is discussed. TTCN combines a tree notation for dynamic behaviour description with a tabular representation of various language constructs. Dynamic behaviour description in TTCN is shown to address many important aspects of conformance testing. Weaknesses of this technique are indicated in the areas such as multiparty testing needed for some protocols. Tabular TTCN specifications cannot be developed using traditional text editors. From this arises the need for specialized editors for TTCN. Next an interactive editor is described for the tabular form of TTCN (TTCN-GR), called CONTEST-TTCN, implemented under Sun-Unix in the SunView environment. CONTEST-TTCN allows the user to enter TTCN test suites using keyboard and mouse, and after performing syntax and semantic checks, produces the machine-processable form of TTCN called TTCN-MP. Another module of the tool takes a test specification in TTCN-MP form and generates the corresponding TTCN-GR form for interactive viewing. In case a formal description of the protocol is available in Estelle or Lotos, the tool can inherit the interaction definitions to be used in the TTCN test suite.