hi is NAT really a problem with asterisk…currently im using NAT with Linux gateway server…and im having problem with the calls, my representatives cannot be heared by the clients…waht would be the best effort for this…
Actually im planning to put my two asterisk server outside my NAT network by using the DMZ…so from WAN to asterisk server then to client PC…it would bypass the nat gateway server…any comment 
hi anyone who have an idea…?
Hi
First things first is to check that you have set up the sip trunks correctly . check exernip and localhost also check the the trunk is set to canreinvite=no and nat=yes.
Ian
Hi,
You know you might find that doing things over IAX2, and over one port, 4569 would be far easier than doing it with SIP. I have a system that is hosted on the Internet, and runs to clients behind NAT routers, and firewall like a greaser.
PM me if you like.
Rob.