3CX Desktop App & Webclient - Unable to Answer Call

[Sam_PiranTech]

Hi,
In the past 4 weeks or so, we've received a few reports from some of our users that they're unable to answer calls with either the webclient or the Desktop App.
The symptoms are/were:

• Unable to press the answer button
• Unable to then make calls if someone else took the call
• App(s) required a restart to resolve - Sometimes multiple times
• All symptoms are sporadic

On review of the logs there was a common theme in that when this happened it was evident from the desktop app logs that the app was trying to use IPv6 Teredo Tunnelling to complete something.
3CX Support were unable to advise why or what this was, so we trialed a fix to disable some IPv6 Transition technologies as these were (in our customers cases) unused, specifically:

• 6to4
• ISATAP
• Teredo

These can be disabled using Powershell with the below commands

Set-Net6to4Configuration –State disabled
Set-NetTeredoConfiguration –Type disabled
Set-NetIsatapConfiguration –State disabled

On completion reboot the affected client end device and that should be the problem resolved.
Hopefully this helps the community if anyone is scratching their heads over what's causing the problems. This has been seen in two customer locations for us now and the fix has worked both times!

 

[SKDamon]

Hi Sam,

thanks for sharing the fix.
Can you post the log messages indicating this happened?
By "desktop app logs" you mean %appdata%\3CXDesktopApp\logs\main.log ?

I'm having similiar issues (only affecting outbound calls), but I can't see anything obvious in the log.