DSL is a lot more resilient than people think. It really only requires half of a pair to function. It uses the copper as more of an "antenna" to ride along than an actual loop. I've seen this on many occasions. Of course, speed is incredibly inconsistent and tough to troubleshoot, but it does work. Where I am, CenturyLink's only real option is DSL, although they do sell a good amount of bonded DSL for commercial accounts that works surprisingly well. I've seen some pretty shady "installations" in old mills and factories involving hundreds of feet of junk wire that have supported it just fine. Yes, I walked away scratching my head too. JK wire is perfect for DSL, in fact I believe that the entire concept of DSL service in general was designed around adapting to CAT Zero wiring on the premises.

If it can survive over thousands of feet of aerial 'C' wire, or century-old pulp cable, a few feet of JK is a walk in the park. I stocked up on ivory JK wire before it went out of style and still use it pretty frequently on residential work. We encounter a lot of three-conductor JK wire that was originally installed back in the 60s and 70s by Carolina Telephone, in fact my apartment is fed by one, but I don't remember any Bell companies using it in my lifetime.

Ed Vaughn, MBSWWYPBX