Network Firewall Configuration
From Taridium
It is always recommended to use a network firewall to protect your PBX from unwanted access. Please consult with your router/firewall vendor for further details.
The ipbx web interface uses standard port TCP 80 or TCP 443 (secure). If you are planning to use a SIP trunk configure the following ports to be forwarded directly to the server:
SIP Protocol UDP 5060 RTP Protocol UDP 18000-20000 (default range as set in RTP configuration)
Do not use SIP transformations or any other NAT traversal solutions on your network firewall unless you completely understand the implications of doing so. Ipbx is capable of handling far-end NAT traversal by setting the peer option to NAT in the channels configuration.
It is highly recommended to have a public IP address available for your server if using SIP trunking or if you intend to connect SIP phones over the public internet.
IAX2 Protocol UDP 4569