> Mark Smith wrote: > Does SIP with STUN use similar techniques to Skype > to get around two NATted VoIP peers ? I have to confess that I have not read STUN in much detail, but I understand that one of the "novelties" is that the STUN server replies to the originating SIP client what its public address is, enabling the SIP client to embed the valid public address in the packet instead of the only one it knows which is RFC1918. Combine with what I just posted... I encourage my competitors to keep wasting their energy whining about how NAT breaks their apps: as long as I have an ample supply of 16-years-old that can code how to traverse it I don't have a problem with it. Michel.