Firewal config - dual homed

[matjaz]

Hi,

I'm having trouble understanding...

We have a Windows installation which is dual homed. One network card is connected to the network where the provider's SIP TRUNK and SBC are and the other network card is in the DMZ and is reachable from the internet and internally.

I have followed the Firewall configuration guide for opening and NATing ports but I have problems with the Windows Desktop App and Webclient which are apparently using ports 9000-10999 for audio. The firewall only mentions opening these ports for the SIP Trunk.

Meanwhile - Android App is working fine.

What am I missing?

Best regards,
matjaz

 

[Evolute IT]

Audio on the Webclient/DesktopApp uses WebRTC on port 443. That's the only port they really use.

9000-10999 is indeed for external trunks.

The other very required port is 5090 for SBCs and mobile apps.

 

[matjaz]

I've tested and retested. If I drop 9000-10999 I lose audio. As soon as I open them again, audio passes through. I have all other ports listed in the Guide.

I've tested this on two different installations now and it's the same.

 

[Evolute IT]

I've tested and retested. If I drop 9000-10999 I lose audio. As soon as I open them again, audio passes through. I have all other ports listed in the Guide.

I've tested this on two different installations now and it's the same.

Then leave the ports opened? Those are just UDP-RTP after all.

 

[SteveITS]

Windows Desktop App and Webclient which are apparently using ports 9000-10999

“Open these ports to allow 3CX to communicate with the VoIP Provider/SIP Trunk and WebRTC:

• …
• Port 9000-10999 (inbound, UDP) for RTP “

Yes it would be clearer if it was in the other section also.

Edit: pass the firewall checker test, then think about restricting ports.