Black-box and gray-box components as elements for performance prediction in telecommunications system

In order to enable quality impact prediction for newly added functionality to the existing telecommunications system, we introduce new modeling elements to the common development process. In the paper we describe a black-box and grey-box instrumentation and modeling method, used for performance prediction of a distributed system. To verify basic concept of the method, a prototype system was made. The prototype consists of the existing proprietary telephone exchange system and new, open-source components that make an extension of the system. The paper presents conceptual architecture of the prototype and analyzes basic performance impact for introduction of open-source software into existing system. Instrumentation and modeling parameters are discussed, as well as measurements environment. Initial comparison of predicted and experimentally measured values validates current work on the method.