Like this, but when I phone is ok, when somebody phones from outside nobody can't hear and speak.
Yes, I forwarding SIP 5060-5070 and range of RTP 16000-2000 ports (the same ports configured in Axon PBX). Also I use STUN server.
By the way, if I use my Linksys PAP2T directly to my SIP provider (without Axon PBX) everything works perfectly!