FYI for Verizon FIOS users out there. After a day or so of playing around, calling AT&T tech support (nice guy, tried to be helpful), and reconfiguring my home network I got the microcell to come on-line.
There's a bunch of network ports (not documented in the end-user manual) that need to be opened for the device to phone home and register. Went into my Actiontec Router (Verizon - go with D-Link or even Cisco in the future), identified the microcell and put it into the DMZ. The device came up in less than 15 minutes.
Good news - Got 5 bars in my house and am getting 2.4Mbps down and 48Kbps (?) up on my iPhone. Bad news - can't get my wife's LG G500 to connect to the microcell.
After a month of troubleshooting, replacing routers, dmzing, setting up port triggering, port forwarding, advanced filtering....Today I called verizon and had my ONT switched to ethernet. Then replaced that router with an old Linksys router that I loaded DD-WRT on. I reset everything to default on the DD-WRT router, then I connected my DIR-825 (DHCP turned off) router to that. Did a few tests to check my ping and speed. All was good.
So then I plugged the cat5 cable from my ATT 3G Microcell into the DIR-825 router(YES two routers deep). And in the time it took me to login to the DDWRT router and to make sure that it gave the Microcell an IP, I received a text from ATT saying my microcell was successfully activated.
These actiontec routers are complete junk... case closed!