Abstract: An asynchronous transfer mode communications network comprising a first communications platform, a second communications platform and an emission control communications link coupling the first and second communications platforms. The network is adapted to provide multicast connections between the first platform and the second platform when the network is in an emission control (EMCON) state.

Abstract: An interface for coupling a standard telephone set to a distributed digital network for allowing digital voice communication over the distributed network such that the utilization of the distributed network is wholly transparent to the user. An interface is provided for each telephone set. Each interface includes a state machine, a coder/decoder and a digital tone generator. The state machine is responsive to analog control signals from the telephone set to generate digital control signals to be transmitted over the distributed network. The state machine is also responsive to digital control signals to control the digital waveform generator to generate supervisory tones which are relayed to the user by the telephone set.