IAXy setup on a different network

I managed to get IAXy to register with the asterisk server if both are running on the same network.As far as i know there are at least two methods to provision the IAXy.Myself i never figured out how to do it with the “iaxyprov” package, but thanks to this forum i’ve been told to use the iax.conf and iaxprov.conf and this is how i use the IAXy box.However, when i try to register the IAXy from a different network, nothing happen.Any hints?

Please define “different network”. Is there a firewall between the Iaxy and Asterisk when it is on the different network? Any NAT going on?

For example asterisk server is behind the public address at and IAXy is behind the public ip address at VPN between and

I have never had much success with Asterisk behind a firewall/NAT. IAX clients work well behind firewalls but the IAX server, Asterisk, does not.