I've seen a lot of discussions about running rtpproxy behind NAT. The fact is that standard vanilla rtpproxy can run behind NAT without any issues (no patches required). A few things must be addressed: - the proper ports must be forwarded from the public IP to the private IP; - when calling rtpproxy_offer/answer, the second parameter must be properly populated with the external public IP for streams from public network.
I hope this brings some light over this highly debated topic.
Regards, Ovidiu Sas
-- VoIP Embedded, Inc. http://www.voipembedded.com