Abstract: In a system and method of communication between circuit mode units interconnected by point-to-point circuits in a subnetwork at the core of a communication installation the point-to-point circuits between units are structured and managed identically. A communication circuit is incorporated in each unit of the subnetwork, irrespective of the control unit, auxiliary unit or telephone and/or communication terminal interface controller type. This communication circuit handles the broadcasting over the point-to-point circuits to the other units of data from time-division multiplex circuits connected to it and switching of bytes addressed to it over the circuits.

Abstract: The invention relates to an interface circuit for connecting a digital equipment (2) for sending and receiving data to a time multiplex link (3). The connection interface circuit is provided with a bit send terminal (3E1) and a bit receive terminal (3R1) for connection to the corresponding wires (3E, 3R) of a time multiplex link (3) in parallel with other interface circuits (1 or 8) of equipments for transmitting and receiving digital data (2) or speech signals (4). The interface circuit includes a synchronization arrangement (12) enabling it to be connected to the multiplex link (3) in a manner identical to that provided for the interface circuit (8) of the transmitter/receiver equipments for speech signals (4) and to adapt itself automatically to the bit rate capabilities offered by the multiplex link.