Configuring Ground- or Loop-Start Signaling per Analog Port

The Port Ground Start table lets you configure the signaling control method per analog (FXS or FXO) port. You can set the port to ground-start or loop-start signaling.

For ground-start signaling, make sure that the device's chassis houses the FXO G module (and not the regular FXO module).
To support FXO ground-start signaling, set the following additional parameters:
EnableCurrentDisconnect to 1
FXOBetweenRingTime to 300
The FXS ground-start interface doesn't generate a ringing voltage; the FXS interface initiates the signaling by grounding the TIP lead.

The following procedure describes how to configure the Port Ground Start table through the Web interface. You can also configure it through ini file (GroundKeyDetection_x).

To configure signaling method per port:
1. Open the Port Ground Start table (Configuration tab > VoIP menu > Media > Port Ground Start Table).

2. For each port, select one of the following from the Ground Start drop-down list:
[0] Disable = (Default) Port uses loop-start signaling.
[1] Enable = Port uses ground-start signaling.
3. Click Apply, and then restart the device with a save-to-flash for your settings to take effect.