DSL and Old wiring

Hi, I need to get an ATT DSL line into a condo. The problem is that the building has old wiring that doesn't support hi speed dsl signals. I do have the option to run a Cat6 from the 60 pin block in the basement to the closet where the router and switch are going to be installed. Can I ask the ATT technician to install the DSL modem where the phone lines come into the building while maintaining the existing phone line? Thanks, Roger