Problem with calls via 3CX Chrome Addon

[KrzysztofComarch]

Hi all,
Lately with my company I've tried to start 3CX PBX, but we have problem with calls using 3CX Chrome Addon. Using our company's computers everything is working correctly, but when we try to establish connection with our clients there is no sound during calls. We've checked and RTP Packets ( 9000-10999UDP ) from client PC does not reach the gateway. We've switched off antiviruses etc., but the problem still occurs. Maybe GPO from AD could be the reason of it? Does 3CX Chrome Addon need any specific rights (for example for temporary folders)?

 

[JohnS_3CX]

Hello,

Are you able to use the webclient from a different location like outside of the company?

Has it ever worked even once since the beginning?

What about basics like checking your sound under Settings > Personalize?

 

[JohnS_3CX]

You should also run a capture on the PBX, and simultaneously on the PC.

Then call *777 and let it run for over 32 seconds.

Check the captures for UDP packets in the range of 8500-10999. If there are UDP packets sent in both captures, but the other side's capture does not receive them, you are now looking at a network problem.

 

[KrzysztofComarch]

Why UDP packets in the range below 9000 should be allowed? According to the documentation only 9000-10999 should be sufficient.
Moreover, during using Windows app I can see traffic on ports 8093, 8092, 8100, 8106, why does this happen?

 

[JohnS_3CX]

Don't pay too much attention to that for now (unnecessary detail), the main issue to see first is if:

• UDP traffic leaving the PBX -> reaches PC
• UDP traffic leaving the PC - > reaches PBX

You will need both captures to cross-check this. Depending on what you find we can then elaborate further.

 

[KrzysztofComarch]

We have made tests and there is no UDP traffic leaving PC in the client environment.

 

[JohnS_3CX]

Thanks, this is the important part. The next thing I would suggest to check if any policies running on the machine that may control traffic are stopping the traffic flow. This would include things like:

- the Windows firewall
- 3rd party firewalls
- antivirus programs that also install a driver to filter then NIC traffic
- VPN software
- host/dns entries that can override the IP of your FQDN