I believe that is called trippin' the ring. The two wires that make up a phone line are twisted together from beginning to end, one is called a Tip and the other is called a Ring. I've seen phone lines work 25.000ft from where they start, at the Central Office. After so many feet they go through, what is called a load coil, and it's exactly what it sounds like. A big coil, so the signal goes into the coil and builds momentum and comes out faster than it went in. The twist of the pair also builds a momentum of it's own, without it, would never travel so far. The likely hood of your line being too long is probably pretty slim. What is more likely, is that there is a light ground on the Ring wire, it's the one that carries the voltage (around 45-53volts DC, unless it is ringing, then it's around 65-75volts DC).