Pace 5268AC DMZ Plus mode = terrible Tmobile VoIP performance. Known issue?

@Travel885 So how did you get your setup working? Here is the background to my situation: I have had the Pace 5268AC gateway for a couple years now and it was running just fine on firmware version 10.7. For some reason it upgraded to firmware 11.4. I have my own personal router (Netgear RAX120) setup in the DMZ+ of the Pace gateway. I was getting full internet speeds (Internet 1000 plan) and was able to make calls over WiFi (iPhone 8 plus and Pixel 2 XL on Verizon) with no issue. Now, when trying to make a call when connected to WiFi, the call will connect but after about 10 seconds the person on the other line will not be able to hear me but I can still hear them. The call then eventually disconnects. All other traffic on the router in DMZ+ does not appear to be affected. I need to maintain the DMZ+ on the Netgear router because I run a server from home that I need to have accessible remotely, as well as being able to use my own wireless network to cover my 3500 sq ft home. I too have turned off WiFi calling at this point, and am making calls over Verizon LTE. So any input that you can provide on how you got it working is appreciated.

TL;DR I never got it working. I switched to Pinhole mode for my externally accessible VPNs and now VoIP is fine. DMZ+ is unusable at this point for VoIP calls.

Thanks for the prompt reply. Since I have no idea what is meant by "pinhole mode", I guess I am stuck. I do have VPN service through PIA, but I don't think that is the same thing that you are talking about. May try to go to my local AT&T store and see if I can get a BGW210-700 gateway, as I hear that their IP Passthrough functionality is better than the DMZ+ available on the Pace.

@ATTCares if anyone is listening, you really need to allow your customers to directly connect to the ONT with our own hardware or provide a gateway that has true bridge functionality. This is possible. Google Fiber allows customers to connect their hardware directly to the ONT. It is beyond frustrating to have to deal with this horrible Pace gateway.

Pinhole is just a "regular" opening in the Pace gateway firewall to allow inbound connections on certain ports and protocols. I have three exceptions for all my VPNs, vs. the "wide open" DMZ+ mode. It's under "Applications, Pinholes and DMZ" tab.

Reading this post and others and am somewhat relieved to see I'm not crazy or messing up my own network because I know I've been doing the right thing. It is 1/24/20 and my 5268AC is still running 11.3.1.532191-att. From reading here it appears 11.3 had issues with DMZ+ mode? I tried this the other day. Here is my reason for needing it:

I have a Raspberry Pi 4 hosting Unifi Controller for my 2 Unifi UAP-AC-LITE APs. I also have it running PiHole but in order to have all my traffic go through it, I need another router so I can manage DNS servers. I have a Netgear Nighthawk 1700AC router that I disabled wireless on and attempted the DMZ+ setup but traffic was extremely sporadically getting through to the router. The router would show up and was sharing the WAN IP of the 5268AC but did not deliver Internet connection consistently.

So the question is, why is my modem out-of-date and how do I force update or request the update to be installed on my modem?

@ATTHelp I couldn't agree more with other posters. Why not provide a Gateway with more open settings? What are you so afraid of? Are you working for the customer or for the companies who are tracking us through their ads and other tracking mechanisms?

Hello has anyone solved this yet without needing an additional router? I’m having problems on T-Mobile WiFi Calling where it would can take 10+ for other person to receive my call and somethimes one way audio. Please someone help.