The value of this object defines how the automatic calling and/or answering data stations is operated on this serial line interface : direct : The 'direct call and/or answer controlled by the DTE (circuit 108/1)' mode gives to the equipment (in DTE mode) the capacity of calling a number pre-recorded in the modem (in DCE mode), by means of the 108/1 control circuit. It gives also to the equipment the capacity of accepting incoming calls on a'per call' basis. addressedAt : The 'addressed call and/or answer authorized by the DTE (circuit 108/2)' mode gives to the equipment (in DTE mode) extensive facilities by means of instructions exchanged between the DTE and the DCE on circuits 103 (transmitted data) and 104 (received data). It gives also to the equipment the capacity to accept 'a priori' an incoming call. The commands / indications use the AT format. addressedV25Bis : The 'addressed call and/or answer authorized by the DTE (circuit 108/2)' mode gives to the equipment (in DTE mode) extensive facilities by means of instructions exchanged between the DTE and the DCE on circuits 103 (transmitted data) and 104 (received data). It gives also to the equipment the capacity to accept 'a priori' an incoming call. The commands / indications use the ITU-T V.25 bis recommendation format. The default value is 'addressedV25Bis'.