I plugged my Ooma into either the RG or into my router switch
the desktop computer I had connected to the RG would show a pop up message right away that I had to click "OK" to allow the 'device' into the DMZ
I would click on OK
I would unplug the Ooma electric cord
I would reboot the RG & wait for it to completely boot
I would plug the Ooma back in
I could go into the RG router and it showed clearly that it was in the DMZ
I moved and had to give up Uverse a couple of months ago but I have helped two other friends hook their Uverse up this same way recently and they did get the message.
Good luck, and don't give up there is lot's of help here in the forums and great folks willing to work with you.
All your tech solutions are a little beyond my scope of computer knowledge and am not sure they even would address this issue.
My setup is this: I have Uverse 3801HGV Router/Gateway. I don't have Uverse TV (use an antenna). My Telo is connected with a wireless dongle one room away from the Gateway. Call quality is flawless.
Every morning, at some point, and usually every afternoon, my Telo goes to blinking red. I am inclined to think this happens due to a hiccup in internet service but don't know that for a fact. Is my problem fixable on the Ooma end or the Uverse end? Does anyone know? I truly appreciate any help offered.