Working iax config using nat firewall

[general]
autokill=yes
register => foo2:<password>@oooo.ttt.tk
[bar2]
type=friend
secret=<same password as above>
auth=plaintext
host=<same as above>
context=fromiax
trunk=yes
qualify=yes

Cloud instance
[general]
autokill=yes
[foo2]
type=friend
secret=<same pasword as above>
auth=plaintext
host=dynamic          < --  Needed if host is behind a nat firewall
context=twig
trunk=yes
qualify=yes