5G 5G21-12W-A Gateway "Trashcan" Bridge Mode

Unfortunately, all inbound unsolicited traffic is "blocked" by design.

There was much discussion about this late last year/first of this year, but it has all sloughed off to the back pages now.

Basically, it is all tied into how they are managing the dual IP4/IP6 stack situation.  They chose to go the route of 464XLAT, which is a roundabout way of translating v4 addresses to v6 to run packets through their v6 only network.

So there isn't a forward facing v4 address space for us to use--it all gets "tunneled" through TMO's v6 network, and then flipped back to v4 when it exits their network.  Without extra layers to manage the port traversal aspect with this process, it screws up a LOT of what people do on their networks--including things as common as voice chat on gaming consoles, cameras, etc.

Some people have managed to get SOME applications to behave via VPN, but that can still bring some issues with it.  The 464 tunnel drops MTU down to 1420, so some VPN's need to be tweaked to drop MSS low enough to keep packets under that limit (1320 to 1380, depending on the config).  But this doesn't solve all issues...some VPN's only support known peer to peer style communication for known application standard port assignments--meaning they won't always work with custom numbers.  Some may even require you to pay extra to get a "static" IP (not truly static, they may still change periodically with a "hard" lease renewal, kind of like how cable companies do it).

Oh yeah... and we also can't run a pure v6 network on our end either.  We have tried to set up v6 delegation through their older more flexible Askey modems and our routers like we were able to do with our previous ISP's, which APPEARED to work at first... but was a no go in the long run as well.