Abstract: A communications controller for interfacing multiple analog telephone terminals to an integrated services digital network (ISDN) line connected to a telecommunications network, the ISDN line having two bearer (B) channels and a data (D) channel. The controller comprises an ISDN interface providing a physical bi-directional interface to the two B-channels and the D-channel of the ISDN line. A base logic processor, and D-channel protocols process supports a Q.931 protocol with a central office of the telecommunications network and an X.25-based protocol with a remote device, via the ISDN interface and D-channel over which command and response packets to and from the base logic processor with the central office or the remote device are transmitted. Multiple analog interfaces are adapted to support respective telephone terminals for passing bi-directional analog voice signals.

Abstract: A system includes a plurality of end-user devices coupled to a communications controller which is connected to an integrated services digital network (ISDN) line of a telecommunications network. The ISDN line has two bearer channels bandwidth and a data channel. A method of subchannel bandwidth allocation from the bearer channels is initiated by establishing, as demanded for a particular end-user device, a call connection though the telecommunications network between the communications controller and another network terminator. The controller inquires, over the data channel, whether the network terminator is a compatible communications controller.

Abstract: In system having a plurality of telephones coupled to a communications controller which is connected to an integrated services digital network (ISDN) line of a telecommunications network, the ISDN line having two bearer channels of predetermined bandwidth and a data channel and the plurality of telephones being represented by a plurality of identifiers, a method for convenient incoming call acceptance comprises the communications controller associating each identifier for the plurality of telephones with a distinctive ring pattern. The controller receives, on the data channel, a dialed identifier of the plurality of identiers which was dialed in connection with an incoming call and rings all idle telephones of the plurality of telephones according to the distinctive ring pattern associated with the dialed identifier. The controller connects a first telephone of the idle telephones which goes off-hook, through a voice subchannel extracted from the bandwidth of the two bearer channels, to the incoming call.

Abstract: A system for interfacing a plurality of analog telephones to an integrated services digital network (ISDN) line of telecommunications network is disclosed. The system comprises a plurality of line interface units connected to respective telephones and a distribution line, and a communications controller interconnects the distribution line and the ISDN line. The communications controller transmits digital data frames on the distribution line, each frame having a frame start and a plurality of control channels and voice channels of which respective voice and control channels are associated with respective line interface units. The controller can instruct each line interface unit on the control channel of that unit, to issue ringing voltage, dial tone, busy tone or ringing tone, and it selectively couples the voice channels to the ISDN line.