Calls Termination by PBX

The FXO device supports various methods for identifying when a call has been terminated by the PBX.

The PBX doesn't disconnect calls, but instead signals to the device that the call has been disconnected using one of the following methods:

■

Detection of polarity reversal/current disconnect: The call is immediately disconnected after polarity reversal or current disconnect is detected on the Tel side (assuming the PBX/CO generates this signal). This is the recommended method.

Relevant parameters: [EnableReversalPolarity], [EnableCurrentDisconnect], [CurrentDisconnectDuration], [CurrentDisconnectDefaultThreshold], and [TimeToSampleAnalogLineVoltage].

■

Detection of Reorder, Busy, Dial, and Special Information Tone (SIT) tones: The call is immediately disconnected after a Reorder, Busy, Dial, or SIT tone is detected on the Tel side (assuming the PBX / CO generates this tone). This method requires the correct tone frequencies and cadence to be defined in the Call Progress Tones file. If these frequencies are unknown, define them in the CPT file. The tone produced by the PBX / CO must be recorded and its frequencies analyzed. This method is slightly less reliable than the previous one.

Relevant parameters: [DisconnectOnBusyTone] and [DisconnectOnDialTone].

■

Special DTMF code: A digit pattern that when received from the Tel side, indicates to the device to disconnect the call.

Relevant parameter: [TelDisconnectCode].

■

Interruption of RTP stream: Relevant parameters: [BrokenConnectionEventTimeout] and [DisconnectOnBrokenConnection].

■

Protocol-based termination of the call from the IP side