This paper mainly explains the usage of a Tool for Functional testing, Conformance Testing, Load and Stress Testing, Interoperability Testing, Performance Tests, Sanity Tests, and Regression Test. It is used as a simulator program for testing of communication interfaces between network elements. The legacy, emerging networks along with fixed, mobile network combination leads to different challenges in telecom networks. Some issues may be interworking between different networks Access requires access independence, proprietary specifications and interoperability specifications create architecture independence, proprietary specifications, and interoperability challenges, authentication and security require User independence, coordination between carriers and service providers require Service independence. To overcome the above challenges the network elements are tested with different testing methods mentioned above. The study represents preliminary experimental trials on different architecture like GSM, UMTS, IMS, etc.