Network Connectivity - How To Resolve Echo With A Gateway

How to troubleshoot echo on a Sangoma Gateway appliance:

• Test different ports, are they all experiencing echo?

• For analog lines, does an analog handset connected directly to the analog line of the provider have an echo?

• Is the echo on external calls only, or does it happen on calls between extensions? If it occurs on calls between extensions, that is an indication of a handset, or headset issue, not a line issue.

On the gateway appliance:

1. First, verify that the Echo Cancellation option is enabled. If it is not, enable it. On PRI Gateway, go to Configuration > T1/E1 > Advanced: Interface Type > Echo Cancellation. On a G080 gateway, go to Configuration > Telephony > Advanced: Interface Type > Echo Cancellation.

2. If the echo persists, adjust the RX Gain and TX Gain options on the same page. Try these settings for the RX Gain: -12 or -18. Save Settings and test to see if there is an improvement. Try adjusting TX Gain and see if there is any improvement. Increase each setting incrementally and Save Settings to see if there is any difference.

   • RX Gain: Incoming audio on channel. Try changing in increments (multiples) of 3 (-6, -12 to -18 is maximum, usually).

   • TX Gain: This controls the volume of audio sent from this channel group. It is recommended to not increase this value, although lowering it to -3 may improve call quality and/or echo.

   • Echo Cancellation: Whether or not to enable echo cancellation on this line. It can be enabled or disabled.

   • RX Dynamic Range Compression: Amplifies quiet sounds while leaving louder sounds untouched. This setting is useful when linear gain settings cause clipping or if there is a hissing noise.

   • TX Dynamic Range Compression: Amplifies quiet sounds while leaving louder sounds untouched. This setting is useful when linear gain settings cause clipping. 

3. For a G080 gateway, go to Configuration > Telephony > Advanced: Signalling and adjust these settings:

   • Automatic Gain Correction: If enabled, performs gain correction as set to a target volume level

   • Noise Reduction: If enabled, performs noise reduction

4. Finally, you can try running Calibrate FXO Ports under Configuration > Telephony > General Settings tab (on a G080 gateway). This will calibrate each port  separately, and takes about 2 minutes per port.