mscGsmBcModemReceiverTransmitter 1.3.6.1.4.1.562.36.2.1.128.4.10.1.5

This attribute indicates whether the fax data modem is in receive or transmit mode. If this is not a fax data modem call, then the value is set to notApplicable. Valid values are: notApplicable, Not an applicable field. rxOnTxOff, Receiver is on, transmitter is off. rxOffTxOn, Receiver is off, transmitter is on. rxTxOn, Reciever is on, transmitter is on.