> The way to fix this situation in my view is to make the NAT box SIP > aware by building a SIP proxy capability into the NAT box. The designers > of NAT boxes go to great efforts to try to work around applications. > Leave approaches such as STUN to the case where you are dealing with a > legacy box. > My SIP ATA sits behind a iptables based NAT, and I have never had a problem with it. No STUN either. Symmetric IP Masquerading does the trick. Then again, it is not a commercial NAT device, just a function of the iptables firewalling suite in the linux kernel and associated userland tools. Enjoy, Scott > sleekfreak pirate broadcast http://sleekfreak.ath.cx:81/ _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf