Using my old router I allways had to set up port forwarding before my asterisk server would work.
After changing over to Thomson SpeedTouch 516 my Asterisk server suddenly startet to work before I had done any of my usual configurations. I use 3 different vendors of sip telephony connections and one vendor of a IAX connection.
All of them works for incomming and outgoing connections, and I don’t understand it, becase I have made zero portforwardings.
The only reasonable explanation I can find is that the router is activated for UPnP. Is it possible, could this be the reason ? Does anybody now ?
By the way, I think this is the only time I have complained about things working to nice and to easy 
(Just try to understand …)