Hey Is it possible to do with openser/nathelper what some other sip/nat gateways do? - for initial register, keep location, but pass registration packets upstream -> save("location", 0x02) - when there's a nat flag set, rewrite response to client with very low "Expire:" header - accept frequent register packets from client, but register on real server, when original expire time is reached It's basically natping done the other way - should be more stable, because when one natping doesn't reach the client, it's lost till next register / invite from that phone. With registers, phone tries to sent packets itself, so when one is lost, next one will reactivate nat anyway. Is there any module that does it now? Or does it need some avp & database hacking?