Asterisk iax problem

we have 2 server

Asterisk Server 1 with static ip

Asterisk Server 2 with dynamic ip
Ip- dynamic

1:Call always going from Server static ip to local dynamic ip
2: 1 Gsm gateway Attach with Server 2 with
3: can it possible we use mac address in Asterisk Server 1 for Registration Local server

i have see 1 module for same work but it’s not work for me that’s website who already provider for solution like it
That’s iso have same tools but that’s tool use for client side server side must need same file but 1 module no work for me in server side , local side its working fine in that’s iso That’s soltuions working same with Mac address after add mac in server it’s auto configure client side dailplan etc

now i plan use iax2.conf for it but now i have problem how to secure it my 3 requirement 1,2,3 up side if any one know how it possible then pls reply here