After having good success with STUN (on a separate server) as a method for traversing NAT from many devices, I am endeavouring to get rtpproxy and nathelper configured as a fallback scenario for devices with no/poor STUN support.
The issue I have is that calls from a UA using STUN to a UA registered via nathelper don't transmit/receive any audio information, I assume because the call does not traverse the proxy. Calls the other way are OK, as I am setting a 'natted' flag and forcing rtp_proxy based on that event (e.g. a UA handled via Nathelper CAN call a STUN serviced UA, but not the other way around).
Is there any way to set proxying on/off based on the CALLED UA, not the CALLING one? Can I test to see if a given UA registered via Nathelper, and then enable proxying for all calls to that UA?
Am I even making sense?