DSL modem for ATT Internet 25

Given that it's DSL, I would think that a download speed of 20Mbps is more realistic on a 25Mbps provisioned line but still, 20 is a lot better than 5! As far as the gateway goes, I haven't had AT&T DSL for many years so I don't know what's current. We had a ADSL2+ line provisioned for 20Mbps and routinely got 18Mbps down. I supplied my own modem and separate router.

You have LEGACY DSL... not UVERSE based internet....

To receive internet 25 would require being a VDSL single or bonded pair UVERSE internet with a gateway provided by ATT with related $10 a month equipment fee. Current models are for copper based UVERSE internet would be 589, 599, 5268 and 210-700.

If your address can support internet 25, I would expect this to be a Full Tech Install with a tech on site for several hours as this is most likely BONDED (2 phone lines required) PAIR install. 

There was a point in time (pre 2016) where residential customers could order self install using existing house wiring provided the internet speed ordered was 12 or less as a single pair install and no UVERSE IPTV services.

Full tech installs were required for all meeting any of the 1s  listed)

1) business accounts

2) speeds greater than 12 as company desired dedicated cat5e line from NID to gateway, not existing house (quad, cat3, multiple jacks) wiring.

3) no bonded pairs, requiring 2nd phone line to establish service

4) no fiber, at the time ONTs were outside with inside power supplies such as the 240G.

5) UVERSE IPTV always full tech install due to adding DVR and / or receivers.

Bonded simply means have twice as many connections that can interrupt service compared to single line service. 2 ports at VRAD, 2 outside lines to serving terminal, 2 binding posts in terminal, 2 lines in drop wire, 2 protectors at NID, 2 pairs used for inside wiring, 4 pins used at jack instead of 2, need 2 pair data cable instead of single pair phone cable. 

The bonded pair, in a standard setting would use the blue and orange pairs of RJ11/14 jack (6 pins) Blue pair on 3,4 and orange pair on 5, 2

Most of the work is performed outside with limited time inside...

I an a heart attack survival (quad bypass Sept 2018) at higher risk, going into homes and businesses daily to install and maintain ATT services. 

I protect myself, if not safe in my opinion, I am not entering a location.

Techs will work with you, but if problem(s) are present, access to the home will be necessary.

Thanks very much!  VDSL it is.  Bonded worries me, though.  I had ISDN over 2 lines before my area got DSL, but as I recall one of the pairs got a rat chew in an unknown place, and if DSL hadn't shown up just then I would have been really screwed.  (Why is it that the ATT website method of ordering the service offers a "no-technician visit" option that saves $99 for any of the ATT Internet options?  Perhaps they are only thinking of homes that already have fiber all the way in from the street to an ONT, and not my "Internet 25" situation?)  When I called ATT Sales, they said the tech visit WOULD be mandatory, but didnt know why.

Thanks very much.  So now that VDSL is the way things are done, does that mean that the "bonded" 2 pair for the Internet 25 that I want is just wired as normal lines 1 and 2 in the RJ-11?  That is already what I have wired myself, from the NID to the DSL Gateway using Cat 5 - although line 2 (which was formerly a voice line) now is not in service.  Line 1 is voice and DSL. It looks like the "broadband" jack in the back of the Arris 210-700 is just a green RJ-11.  Perhaps then I am already set up for 2 lines as far as the required 2-pair wiring goes, and I only need to upgrade to a VDSL modem, get ATT to turn line 2 back on, and then start paying for Internet 25?  (I am trying to find a way of doing everything myself, that ATT will agree to, since I am immuno-compromised and quite scared of Covid and don't think I will upgrade if it means having a tech come out.)  Thanks to everyone for all your help!