GXW4104 Can't detect hangup


I’m working on interfacing an Avaya Definity G3 PBX (using an analog line) to my company’s VOIP product using a GXW4104.
It is not reporting to me when the user hangs up.
The LED on the 4104 will go out as soon as the caller hangs up.
The phone technician tells me that the line has 7 volts during a call, and 24V after the caller hangs up and the LED goes out.
What do I configure in the 4104 device to translate this into a hangup request on the SIP side?


Hi pheitkemper,

There are a couple of ways you can correct the disconnect method:

  1. On the web UI–>FXO lines, there’s a couple of parameters that relate to current disconnect. They are :
    Enable Current Disconnect(Y/N) : ch1-4:Y;
    If enabled, use threshold: ch1-4:100;

You can configure the threshold to be higher or lower. Adjust this by increments of 50ms to see which best suites your lines requirements.

  1. If you do not like this method, you can also try performing the “FXO Line Test”, which requires you to have at least 2 active lines connected and also be able to call one another. This method allows you to apply the configuration to your device automatically. Please check the usage description under the FXO Line Test on the web UI for further details.


hello there
i have the same problem but only when i use ivr on the Inbound Route.
when the call enters ivr and the caller hang up the GXW410X still show on the status of the line Line 1: busy, PSTN Incoming (caller#).
even if the caller speaks with an extension the call never hangs from GXW410X