This paper studies a system design of testifying next generation convergence network. Next generation convergence network includes such elements as not only various gateway systems interworking with conventional PSTN(Public Switched Telephone Network) but also various protocols communicating between gateway systems and softswitches or gateway controllers. Discussed are an effective system solution to verify functionalities and performance of protocols professing. From such discussion, the study identifies functional blocks and operational flows required for establishing a test system, and then with a basis of these proposes a system architecture. Finally this paper presents system design results and its implemented functional details.