Remote Cisco Phones Just Stopped Working

[mantalope]

I have several remote Cisco 504g phones remotely connected (STUN) to my 3CX (version 14) that have been working flawlessly for more than a year. On Monday, they all lost ability to make and receive calls.

I can provision the phones (factory reset and re-provision) and they appear in the 3CX phone list, but they "timeout" when trying to call any internal or external phone number.

Our phones on the local network are not affected and are working fine.

There were no known changes to any of the phones, no changes to 3CX, no OS server updates (Windows Server 2012), and the firewall was not changed either. The firewall on the server is disabled.

I am quite baffled. Has anyone seen anything like this before.

 

[leejor]

Looking at the 3CX activity log, are the calls even getting to the PBX? Is there an error message of some sorts?

 

[mantalope]

Calls are not showing up in the activity log, so no error messages.
I need to do some further testing to see if they appear in the firewall logs. The NAT settings look correct and have not been changed.
I am also planning to do a 3CX firewall test tonight -- can't take the system down during the day.

 

[YiannisH_3CX]

Hello @mantalope

Are all the phones in the same remote location? If yes have you checked the firewall at the remote location?
run the firewall checker and if the issue persists then run a wireshark capture from the phones end to see where the calls are going the why they are timing out.

 

[mantalope]

Thanks for the help.The phones were at multiple locations and the firewall tests identified no problems.

I ending up uninstalling and reinstalling/restoring the 3CX system on our server and the problem went away. I never did positively identify the problem, but all is back up and running now. I suppose that it was a corrupted file or setting.