Test suites and procedures developed by the IMTC in the late 1990s demonstrated the viability of connecting gatekeepers, gateways, proxies, MCUs, endpoints and network components into integrated rich-media sessions and interoperability and interworking between IP networks and switched-circuit networks including H.323, SIP, the iNOW!
More recently IMTC has begun to highlight the interoperability of multimedia offerings for mobile phone users.