[Q] T-Mobile LTE with 4G Router? topic

Hi All,
Thank you for taking my call.

So I want to ditch Comcast. I am thinking about using T-Mobile LTE with a 4G router. Maybe this router: DLink DWR-921 4G LTE Router.

My question is: Do I need to purchase tethering from T-Mobile when I set the 4G router with my T-Mobile service?

Also: T-Mobile says when you do purchase tethering, they limit you to like 5GB of tethered data. If I used the 4G router, would this limit affect me?

Thanks!

Garreett