ADSL with Modem/Router not telco supply

[gusl]

I am a new member and my first query is:
I have Hi Speed Internet service with an old Speedstream 5260 modem (5 years old) and I think it is beginning to show signs of giving up the ghost.
I have talked with AT&T and they would supply me with a new Speedstream 4100. I read several of the comments in one of your forums about difficulties with this model and trying to connect it to a router (which I also have). My question is: do I have to go with AT&T's supplied modem or can I purchase one in the open market? In other words, will AT&T still supply the DSL service even with another modem/router installed?
Any and all comments will be appreciated.
Thanks,
Gusl

 

[Rick]

You should be able to request a different brand. Try it and see what they tell you. If they disagree with you, ask to speak to their lead.