How does 3CX determine to use internal RTP ports or external RTP ?

[greychain]

I have a customer that is using a VPN to connect to the SIP provider and I noticed it is using the port range 7000- not the expected 9000-

 

[N_G]

Its the expected and correct behaviour. As its a VPN its considered a local connection so it will use normal LAN ports.

 

[greychain]

Thanks,