).In the mid/late-1990s IMTC released a Voice over IP Implementation Agreement, which specified dual-tone multifrequency (DTMF) data transfer and reproduction, and IP-specific needs such as directory services and dynamic IP address resolution mechanisms to support multi-party voice and voice-band calls over IP networks.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!