Remote phone registration

Hello, I am new to Freepbx and so far its been a great experience. Very straight forward with lots of documentation. We are moving all our phones in-house, we have everything working in the office. Our issue is NAT. We have a block of public IP addresses which one is registered to the PBX. We plan to use the built in firewall with iptables and fail2ban to secure it. Basically our setup is this. The PBX is on a XXX.XXX.130.152/29. We can register phones to another subnet on our XXX.XXX.8.0/24. However as soon as we try to register a phone behind a router on a network it fails. I have followed the tutorial “Using a Remote Extension with FreePBX/Asterisk”.

looking at the tcpdump :

  Via: SIP/2.0/UDP;branch=z9hG4bK-7615b046
 From: <sip:[email protected]XXX.130.156>;tag=f08026d775cdaf5o0
 To: <sip:[email protected]>
 Max-Forwards: 70
 Contact: <sip:[email protected]:5060>;expires=3600

It obviously cant communicate with the phone using the 192 network so basically the phone times out. Then tries to re-register in a endless loop because the server cant communicate with it. I have read though the forums and for the life of me cant figure out whats i need to do here. Any help is much appreciated. I feel this is probably a simple fix of something i am missing.

For troubleshooting purposes i have turned off the firewall, iptables and fail2ban. We are using Freepbx 13.0.19.

@st15jap Can you provide a little more detail from your tcpdump, what is currently provided doesn’t show any of the communication between the system and the end point trying to register.

You have your network/routing/nat set up wrong, why would a sip connection from to want to try routing via an unroutable network without natting on the network interface? Did you you read the wiki yet?