Requirements-driven model-based testing of the IP multimedia subsystem

IP Multimedia Subsystem (IMS) is an architectural framework for delivering Internet protocol multimedia to mobile users. The functionality of the system is specified and standardised to allow interoperability between equipment from different vendors. We study how to build the system models for model-based testing of an IMS configuration in a way which provides easy means of linking a requirement, i.e. some paragraph in the specification to a specific part of the model. In addition, it allows to find out which requirements listed in the specification are violated in case of an error. Requirements-based approach in testing is extensively used in the industry in manual and script-based testing. The same should be possible for model-based testing. The current case study describes how to model a fragment of the IMS protocols from the point of view of the requirements and provides solutions using either a network of Uppaal automata or NModel model programs.