So here goes! I got a Motorola 2210-02 DSL modem when I ordered AT&T's DSL service in 2008, just recently it started to mess up on me. My internet cuts out as my modem is unable to keep sync with AT&T countless times a day, it will go into a infinite reboot loop until I unplug it and plug it back in sometimes. It even cut out on me just now as I am typing this question. What can I do to fix this besides buying a new modem? I've reset it, unplugged it and let it sit and every other possible thing I could think of but nothing works.
sounds like the modem is at its end.. i have Time warner cable internet... luckily they provide the modem free of charge to you and when mine quit working i called them and they exchanged it. my advice tell ATT your going to switch company's and see if they give you a free modem 
if that doesn't work and you want to stay with them unfortunately i think you will have to bite the bullet 
Good luck!
if that doesn't work and you want to stay with them unfortunately i think you will have to bite the bullet Good luck!