FIELD: integrated-service digital networks. SUBSTANCE: terminal adapter that may be useful both for variable-bit- transmission-speed ATM cells and for constant-bit-transmission-speed ATM cells has ATM adapting level means AAL3/4.5 converting variable-bit-transmission-speed data into ATM cells, plurality of constant-bit-speed interfaces converting constant-bit-speed data into ATM cells, physical level means converting physical level data into ATM cells, and multiplexer/demultiplexer that functions to assign priority and to make choice between variable-and constant-bit-speed ATM cells, and then outputs chosen ATM cells to mentioned physical level means in compliance with assigned priority in data transmission from point R to point Sb or determines type of ATM cell and outputs variable-bit-speed ATM cell to mentioned level means AAL3/4.5 and constant-bit-speed one, to one of mentioned constant-bit-speed interfaces in data transmission from point Sb to point R. According to invention during data transmission from point R to point Sb mentioned multiplexer/demultiplexer functions as multiplexer and vice versa, during data transmission from point Sb to point R it functions as demultiplexer. EFFECT: enlarged functional capabilities. 4 cl, 3 dwg
