Does FreePBX trunks work behind NAT

If FreePBX is installed on a local LAN behind NAT will the sip trunking still work or does the FreePBX server need to have access to a public IP for inbound calling/traffic? I do not plan on having phones out side of the local network connected, but I have been told by people that the trunking will tunnel to the trunking servers so it will work behind NAT fine, and others say that it needs port forwarding at the least or to be placed on a public IP. I just need the info to make this work for home use, I have home internet service and my provider is CGNATed so it’s tricky to run some servers from my home internet, would it be better for me to just get a public ip from my provider?

You will need port forwarding. Watch the cross talk YouTube videos. He will walk you through it.

If the trunking provider has NAT traversal logic at their end, you should be able to reliably operate behind CGNAT. Most providers that cater to the residential / very small business market have that. For US or Canada, such providers include Callcentric, and Anveo.

Have you asked your ISP about getting a public IP? Many will supply one upon request, at no additional cost. However, it will still be a dynamic address and in some cases the address may change periodically.

Have you considered running your PBX in the cloud? This costs only a few dollars per month and offers many advantages, besides the public static IP. If your power or internet goes out, the system remains fully functional, sending calls to mobile phones. There is no problem with remote extensions. If the software fails, it’s easy to restore from a snapshot. If the hardware fails, the cloud service provides a replacement. Depending on what you’re running on at home, the cloud service may cost no more than the electricity to power a home server.

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LoL I’m trying to be cheep and not need the cloud hosting, I like keeping it all internal, I can get a Publit IP from Starlink but that jacks my bill up to $250 from $120, I have most every thing installed and setup, my phones can dial each other by ext. #, I just need the trunking provider and it to be setup. I was going to use 2 land lines that come into my home but could not find any doc’s that cover how to setup the FXO card. I’d rather not port forward any thing as that makes holes in my network for hackers to play with so I am wondering if there is another way of doing this, I did see that with the perches of the admin panel it’s got DDNS but that’s only going to keep track of my ip correct? Any help is appreciated, thank you.

I have watched most of the videos, he does not go into much detail on how it all works but just the basic setup for different ways.

For testing, get a trunk from Callcentric. See this thread for settings:

To test for free: Get an ‘IP Freedom’ plan. You can call their test number 17771234567 (set your Outbound Route to allow this number). To test incoming, call into a SIPBroker gateway; see

and dial *462 followed by your 1777 number.

You can also call out to US toll-free numbers by dialing (for example) **275*18004377950 (set your Outbound Route to allow).

If satisfied, you could sign up for (for example) North America Basic for outgoing and Dollar Unlimited for incoming.

Alternatively, you can do usable testing for free with or Anveo (in most cases less expensive but IMO support is not as good).

" I’d rather not port forward any thing as that makes holes in my network for hackers to play with so I am wondering if there is another way of doing this"

Everyone who has set up a PBX has had to solve this issue. There are always risks with every solution. There are ways to lock down port forwarding fairly okay give or take. There are options for VPN’s, overlay networks, and cloud hosted solutions. All have pluses and minuses. Look at your budget, if your trying to do this job for low costs, please re-watch any pbx videos you can get your hands on again and scrape these forums. All your answers are there. If you get frustrated and need to get a quote there a lot of folks in these forums that could get you one.

It depends on the trunk provider. For a lot of SIP trunks you only need an outgoing registration. So your pbx can sit behind NAT and establishing a connection to the trunk provider without the need to forward port 5060 for example.
But with a dynamic IP you will definitly running into audio problems without using an external STUN server.

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