This Recommendation describes the framework and overview on next generation network (NGN) conformance testing and interoperability testing. The Recommendations for the conformance testing and interoperability testing will be constructed with a single framework Recommendation and a series of Recommendations which include detailed specifications for each functions@ protocols@ services@ QoS and security mobility testing. The framework Recommendation defines four step approaches as follows; ? Step 1: Define the target (service@ application@ protocol@ function.) ? Step 2: Define specifications (Protocol@ Service@ QoS) ? Step 3: Define test specifications to examine tests ? Step 4: Build up test bed and examine tests The framework Recommendation includes procedures@ requirements@ an architecture and base recommendations as well as a scope@ references and definitions. It will be general and provide overview descriptions for NGN conformance testing and the interoperability testing.