I have kamailio and rtpproxy running on the same server located behind a router with NAT just like below.

UA(internet)---public ip---router(NAT)--Kamailio+RTPproxy(private ip)--UA(private network)

There are several issues like one way audio.

I need users on the internet to communicate with each other, users on the private network to communicate with each other, and users on the internet and the private network to communicate with each other.

What is the best approach?

Best regards,

Clarence