How to activate phone jack for AT&T DSL?

[Idea]

I am renting a room in a house and I signed up for AT&T's DSL internet service. Unfortunately, the only phone jack in the room is not active (no tone). It would cost $100 to have AT&T come in and activate it, and I prefer to do it myself but I know very little about the phone jack and the internet setup. How do I activate the phone jack without bothering the landlord for access to the main box of the property? What are the cheaper options than AT&T? Thanks!!