how to add external drive gateway

Actually, the diagram for the 5G Mobile Gateway says the first USB-C is for power, and the second is for LAN, meaning a printer or storage can be added.

And a technician I chatted with confirmed that. What I am confused about is how to make my gateway recognize the drive. You’d think instructions could be included since a few customers might want to do that.

But, with all the grief I am going through, maybe I should go the NAS direction (https://www.amazon.com/Buffalo-LinkStation-Private-Storage-Included/dp/B00JKM0A36/), but they don’t come cheap ($129 on Amazon.) It is so frustrating, I’m about to give up on something that should be so easily accomplished.

Thanks for responding.

@drdcrobinson Sure, but where’d you find said diagram, and is it confirmed to have firmware support?  If you’re trying to share the drive for storage, they’d have to enable an interface for this, use some sort of login/security mechanism, folder/object hierarchy, etc., which I bet they’re not apt to do, for a small handful of customers.  Plus, this would likely incur a significant support hit, and require training support people, etc.  

They could just make it wide open, as a raw storage device (which FS not sure, perhaps exFAT, which is another can of worms, depending on the drive size, initial partitions, etc.).  It’d be a bunch of config here too, again I’m sure they’re weighing a cost/return for support and all here.

You’re better off investing in a small-scale NAS, IMHO/IME, which isn’t dependent on your carriers’ whim to support the storage.  This makes it agnostic for ISP changes and such as well, say if you get fiber or similar in the future.  Most WAN NAS functionality won’t work well over CG-NAT, IME.

@nc1037 There have been a couple of these (basically a very simple NAS implementation on a stick), but I haven’t seen one in recent times, perhaps not the last 10 years or so, from a large/reliable vendor (I’m sure you can purchase one of these on a straight-from-somewhere site, good luck with support though), do you have a source?  Almost all current RJ45 ↔ USB-C adapter setups are for Ethernet access from a PC/Laptop/etc.  They’re incredibly handy for this, but are limited to simple protocol support, not storage-sharing. 

I suppose, and I got a bit long-winded, trying to cover all the bases in my response.

Maybe it makes more sense to ask, what exactly do you want to do with the network-attached-storage? Is backup (beyond the attached drive itself) important?  Sharing, security, etc.?

https://www.t-mobile.com/support/home-internet/5g-gateway-g4ar

This is the link to the diagram he was referring to. I have the same issue. 

1.   I have been using a TP Link router with a USB port for 12+ years.
2.   12 years ago, it was a pain to set up. 
3.   2 years ago with Win 11 it was a breeze.
4.   USB drives are preferred over NAS because if you have a problem, you just remove the USB drive from the router and plug it into your PC directly.   Also a great way to troubleshoot whether issue is the USB drive or the USB router port.
5.   If TMobile could provide instructions how to connect my TP LINK router to the gateway, and what settings to use, I would be satisfied with connecting my TP Link router to the gateway via Ethernet, and have my USB drive remain on the TP Link Router.

Not sure why everyone does not have their own in home storage.   Why trust Google, MS, or anyone else.   I can assure you, there LAST PRIORITY is their users.