Cannot answer call from 3CX app to softphone

[janbussche]

Hi

We are experiencing technical difficulties when making a call from the 3CX app to a softphone when the mobile user is connected to our in-house Wi-Fi. We have experienced the error with several Snom and Yealink phones so I’m guessing the softphones are not at fault here.

Steps to reproduce:

• Make sure that the smartphone with the 3CX app is connected to a network that has the same public IP as the softphone.
• Make a call with the 3CX app to the softphone.
• Pick up the call with the softphone. The ringing on the softphone will stop but you will hear no sound.
• The 3CX app will keep going on as if nothing happened and user might think other party has not picked up phone.
• Next comes the weird part: after a minute or so the softphone will say “not registered” and confirm it has lost connection with 3CX. Only way to fix this is to reboot the softphone.

Some information:

• The firewall (Zyxel USG 310) logs doesn’t show any blocks. Disabling security policies did not help.
• We have enabled the option “Use 3CX Tunnel for remote connections (3CX App only)”.
• Selected our FQDN at “Network interface for registration and provisioning” (3XC app).
• None of the tested phones have custom templates.
• We have an external hosted 3CX PBX with a sitewide VPN connection to it so phones can connect “locally” to it.
• Our softphones are on a separate VLAN.

I’m clueless. Anybody out there that can help?

Thanks!

Jan

 

[craigreilly]

Sounds like a routing error for the softphone VLAN ??

 

[janbussche]

Sounds like a routing error for the softphone VLAN ??

Yes, that is what I was thinking at first.

But:
- I allowed traffic to pass between VLANs for testing: it did not solve the problem.
- As the option “Use 3CX Tunnel for remote connections (3CX App only)” is enabled and FQDN is pushed as network interface all traffic from calls between softphones and 3CX app should go through PBX, no?

All other calls work! There are no problems when calling between softphones, external calls or calls from an 3CX app that is not connected to our network.

Is there something I missed?