[Asterisk-Users] iax phone and asterisk server on different LANs

[gincantalupo]

Hi,
I have a *IAX* phone connected to a LAN and I want to connect to it to 
make calls using an Asterisk server located inside another LAN behind a 
router (* hasn't a public IP)
I bought a IAX phone because SIP had problems with nat and so on.  ::))
How should I configure the IAX phone and Asterisk in order to make 
calls? Is it possible without touching the router configuration?

TIA

Giorgio