Interoperability testing of VoIP systems

Voice over IP (VoIP) systems have to be integrated and interoperate with the existing telephone network before they become widely adopted. However, different standards have been proposed and the prevailing standard (H.323) is incomplete, complex, and provides the implementers with "vendors latitudes". As a result, there is no guarantee that even H.323-compliant systems would interoperate properly. Interoperability testing has become indispensable. We present techniques for automatic generation of a minimal set of test cases, covering all the required system interoperations. Our algorithms have been implemented and incorporated in a software tool-ITIS. We report experimental results on VoIP systems interoperability testing, using ITIS