[Asterisk-Users] sip+iax+firewall

[Altus Syman]

Good day all
We have a 2 servers setup with asterisk, both servers got 2 network 
cards, public and private ips
I have setup SIP on both side to listen on the private ip and iax to 
listen on the public ip and made the so that people can phone across.
No I want o install a firewall doing MASQUERADING and only allow port 
5036(iax) connection with a source of each others ip.
Will this work?Or will asterisk have a problem connecting to the other 
users now that its being masqueraded?
Thanks
Altus