Abstract: A switch-adjunct integration device uses multiple line appearances of one or more digital telephone lines to gather information on calls destined for an adjunct voice-mail system, to transfer the calls to analog phone lines leading to the voice-mail system, and to detect call completions. Call completion is detected by bridging some of the line appearances to the analog phone lines and monitoring the bridged line appearances for call status reported thereon by the switch. Call-related information, including call completion, is reported from the integration device to the voice mail system over a control link. The analog phone lines are connected to the voice mail system through switch relays on the integration device. The integration device momentarily opens a relay when it detects call completion on the connected analog line to further enhance call-completion signaling.

Abstract: A data transmission system that can controllably transmit data in three different modes between connected data devices. The first mode transmits data at a 64 Kbps rate. The second mode transmits data at a 56 Kbps rate plus control signals at an 8 Kbps rate. The third mode transmits data and control messages at a rate of up to 50 Kbps between connected terminals or other data devices. For all modes, the data is transmitted by inserting it one byte at a time into an information field of successive ones of cyclically reoccurring time multiplexed frames.

Abstract: A data communication method and circuitry which uses a compatible subset of a standard high level data link control (HDLC) protocol to control link level communication between a digital terminal and a switch. The use of the subset of HDLC protocol reduces the complexity of the digital terminal design while maintaining communication compatibility with a switch which uses either the standard HDLC protocol or the subset of HDLC protocol.

Abstract: Protocol support and message buffering circuitry is used to transmit call status, control and terminal management information bidirectionally over associated conductor pairs as signalling messages between a system processor and a phone and/or terminal served by the system and connected to each conductor pair. This information is transmitted serially in a modified HDLC format as a one bit signalling field of a multiplexed data frame. At each transmitting end, the message information is converted from a parallel to a serial format, transmitted serially as the signalling bit of successive frames, and reconverted to parallel at the receiving end.Ports terminate the system end of the conductor pairs and are mounted four to the board. Each board contains circuitry, such as registers and the like, common to the signalling message protocol support and message buffering circuitry of all four ports.

Abstract: There is disclosed a processor controlled digital communication device which accepts message commands from a communication system as part of a communication protocol. These command messages are stripped from the protocol and combined within the communication device to control signaling thereat. Multi-bit time separated information (I) fields are used together with a single bit signaling (S) field. The S field bits are compiled over several frames to become the command messages.

Abstract: There is disclosed a digital telephone having dual voice and data handling capability over a single communication line. Time separated information channels are used to transport the voice and data information between the terminal and the main processor. A separate signaling channel is shared between the two information channels and information on the signaling channel is accumulated for distribution to either the voice device or the data device in accordance with address information contained within the accumulated signaling channel message.