LM1200 repeatedly dropping link

I will say that using my Verizon MVNO pre-pay plan in router mode is working. I think this is the main conflict or issue of this thread, it is technically working and Verizon themselves give the run around because they want you to buy their gear, but ever since switching to router mode (and failing to open ports, but I think that is on the providers end) and testing failover things work smoothly. As I can't get port forwarding working on a T-Mobile plan either I would agree with the previous poster that these carriers are blocking inbound connections. I'm going to stick with my Verizon card since it provides much more bandwidth and data cap than the T-Mobile pre-pay. At the very least I'll also keep Dynamic DNS on for my network so if I am out and about and try to connect to my VPN, if there is a problem I can look at my log file and determine if my static IP fiber line is down (pulling a VZW IP) or not and go from there.

greenpuddinI will not claim to be a guru or to have inside knowledge of the carriers.  However, from what I understand, it is not so much that the carriers are blocking outside traffic as is that they are just not giving everyone a public IP.  In theory, you can set your port forwarding up and other people on the same cell tower might be able to reach your forwarded ports.  So they NAT your address into their private IP pool, then they have a 2nd router (or maybe virtually so) with a public IP that then NATs your private pool IP and you cannot set forwarding on the public-side router.  That is how Metronet fiber worked when I first signed up, and then I had to pay an extra fee to get a public IP address that could be accessed from the outside.  I asked Verizon about that and they absolutely do not offer that to consumers.  You have to have a business account with a registered business tax ID to get a public IP, and then if you want it to be static, you have to pay an additional one-time $500 fee.  The business accounts also work differently - you get 300GB of data but only 25GB of "prime" (guaranteed fast) data.  And then after 300GB they charge extra fees per GB instead of throttling the speed all the down like they do for consumer plans.

I have considered registering a personal business just to get the public IP address, and I believe the LM1200 would work perfectly in either bridge mode or router mode along with port forwarding in that environment.  Alas, I don't know anyone who could prove that point, and to quote from Verizon's page: "After 25 GB/mo/line, your data may be temporarily slower than other traffic during times of congestion".  My consumer plan gets me 150GB of unthrottled data and then I have no option to extend it, but at least its all fast to that point (in terms of cell speeds anyway) and I have learned to live within that limit.

I'm going to Vegas soon, maybe I can get $500 to blow on a static IP address after forming a business, good grief 🤣

I guess this is what we get for being, God forbid, consumers. I'd take it that even buying something like the Mikrotik Chateau this would still be an underlying problem without a static IP. I'll keep what I have now knowing this but goodness gracious that is too much effort and money to sink in to tunneling to my home network the handful of times it goes down. This will absolutely work as a failover but yeah, wow.