12-30-2017 12:43 PM
Did you read the Uverse Internet Terms Of Services you agreed to establishing and keeping service.
May find a few references to agreeing to pay for equipment as long as have service.
You agree to pay in full each month: (1) the monthly fee specified when you ordered your Service; (2) any charge(s) for equipment required for your Service; (3) activation fees, connection and/or installation charges, if any; (4) late fees, Service Restoral Fees, and other applicable Service charges; and (4) any applicable taxes, recovery fees and surcharges that AT&T pays to municipalities and other governmental entities and may pass on to you. For a list of additional fees that could apply to the Service, please see the applicable Fee Schedules, which are expressly incorporated herein by reference.
And later in the agreement...
If you have not purchased Internet Equipment from AT&T or if previously purchased Internet Equipment is beyond the one-year (1-year) warranty period (from date of installation) and requires replacement, then you agree to pay a monthly equipment fee for the Internet Equipment, as part of your purchase of or continued use of the Service and/or other AT&T services.
12-30-2017 12:52 PM
You cannot replace the att modem with one of your own. But you can cascade your own modem behind the att modem to support internet network needs that may be deficient in the att modem.
12-30-2017 6:40 PM
I am not a router expert and I am not familiar with the specifics and they vary from att modem (gateway) to modem model. Maybe others who are can give you the specifics. In the meantime here are two google searches on this topic. I've limited these searches to just within these forums: