Allowing PBX to Connect to the MCU via Firewall Whitelist

[artooro]

On the firewall for the PBX we are whitelisting what destinations are accessible, and I'm having a difficult time with the MCU functionality.
I found this post https://www.3cx.com/community/threads/ports-required-to-connect-mcu-webmeeting.73303/ and have whitelisted the domains that it references. Also found another post where someone said you need to allow mcu.3cx.net so did that as well.

But I am seeing the PBX try to connect to port 443 on IPs like
34.125.148.210, 34.145.205.0, 159.65.164.86, 164.92.73.197 and the MCU is still failing to connect. These IPs are not in any DNS records that I can find.

Is there a more recent list somewhere of IP subnets or DNS records that need to be allowed for 3CX to connect to the MCU for web meetings?

 

[Charles_3CX]

Regarding your question, you may check the firewall guide found here and check that the required traffic is allowed as described.

Additionally, an nslookup for v18-vc-qos.3cx.net returns a list of IPs of currently used media processing units (MCU) under various FQDNs within the 3CX.net domain namespace. 443:TCP and 48000-65535:UDP need to be allowed to those endpoints.

 

[artooro]

Thanks Charles, adding v18-vc-qos.3cx.net to the firewall did the trick and it's able to connect now.