Hi,
i have a pfsense router directly behind my ISP router. Currently it is not possible to disable NAT on my ISP router.
I have a Telekom Number connected with my FreePBX-System(PJSIP).
When I connect the FreePBX directly to my ISP´s router, audio is working in both directions. (Tested with Echo *43)
I have no port-Forwarding set up.
But when I connect the FreePBX behind my PFSense, audio is only working in one direction(Outgoing).
I also had a similar problem with Comcast routers. Double NAT just kills SIP.
If you can’t put your router in bridge mode and not have it do NAT, replace it with a third party modem that you can set to bridge mode, if your ISP allows that.
I would try the bridge mode option too. Even if bridge mode isn’t an official option in the webgui of the modem/router combo, a lot of models support pppoe passthrough these days. You can delete your login credentials (if you have access) and then tell pfSense to connect via pppoe with your DSL credentials. You’ll save a lot of headaches with NAT and one-way audio situations.
You could disable NAT and packet filtering on the pfSense and make it a routing only platform but again, that is way more work and is going to more or a headache when it comes to troubleshooting other issues. You would have to set up static routes yourself for the devices to communicate. I would buy a cheaper DSL modem-only unit (you don’t have to use the one provided by your ISP) if you’re really intent on using pfSense. If you need the LTE connection for failover then get a usb dongle and pop in the sim card to utilize pfSense’s WAN failover feature.
