Test Case Specification Based on MSCs and ASN.1

Informal test specifications are formalized by means of MSCs. Message definitions and constraints are included. For this purpose a new concept for the reference and modification of constraints is introduced. The formalized test specifications can be implemented automatically. Our approach is explained by means of a test case for a layer 3 ISDN protocol (ITU-T Rec. Q.931). The method is implemented in a set of prototype tools.