Hi: I’ve searched / researched this issue prior to posting - so far, I’ve not come to a solution.
We have a FreePBX (recently upgraded to FreePBX 188.8.131.52) on-site. It generally works great, handling calls inbound/outbound from thousands of phone #s. In the last 6-12 months I’ve received several reports of audio problems with inbound phone calls from certain customers.
For these callers, the issue is always the same:
When they call us, we can hear them but they cannot hear us (we’ve tried placing them on hold - they also cannot hear the hold music). If we hang up and call them back, the connection works fine, with inbound and outbound audio working perfectly. This behavior is always consistent; those inbound calls with have the audio issue every single time, and calling them back always has no issues.
Other inbound calls also continue to work consistently with no audio or other issues.
Our FreePBX server is NAT’d via our router/gateway; the router is configured to forward UDP ports 10000-20000 to the LAN IP of our FreePBX server.
We are located in the United States (NY) and the problem calls are from local numbers; other calls from the same area code work without any issues.
While the “workaround” of calling these customers back has allowed us to continue to do business, there is increasing pressure to resolve this issue. Thanks for any help in resolving this; I can post further details and or call logs as needed.