ATT SIP -> pfSense -> Avaya PBX help figuring out

dlogan

Here is the current setup. There are a lot more VLANs on the network but I've tried to keep this to relevant information.

Currently, everything is working. But I know nothing about SIP and how this is supposed to work. Note: I have no idea what 1.1.2.21 and 1.1.2.1 are, why they're assigned to these interfaces, etc. I did an IP lookup on 1.1.2.1 and it's unknown, likely China ??? I'm guessing this is some bastardized LAN coming from ATT's router? Both 1.1.2.1 and 1.1.2.21 ping as long as the pfSense WAN is connected to the ATT router.

I've also read in several places that a firewall should be between WAN and PBX, which makes sense to me.
2021-05-12 10_16_53-avaya1.drawio - diagrams.net.png

Strange thing of note, if I unplug the cable from the ATT router to the WAN of the Avaya box, outbound calls still work, but inbound calls do not -- "Call cannot be completed" -- from example a Verizon cell phone.

My idea last night was the following diagram:

2021-05-12 10_46_03-ATT-pfSense-Avaya-proposed-05-12-2021.drawio - diagrams.net.png

I put this in place and started listening for traffic coming into WAN3. But almost none comes in. Not enough in a short amount of time for me to figure out what needs to be forwarded where. I assume I would need to forward some ports coming in on WAN3 to the 10.10.55.2 address.

OR, maybe I shouldn't even be using the WAN on the Avaya? I really have no idea. I'm not a phone guy, I've just been thrown into this.

I've also read there are issues with NAT'ing VOIP / SIP with pfSense. But I'm not sure how I would go about this without NATing.