[londons_explore]

You can do time domain reflectometry to find out where the breaks, sharp corners and reflections are in the cable.

Some modems have special debug modes in that can do this too - then you get to know exactly how many meters along the wire the break is. When you get close, you can hook a resistor to the line and rerun the test and it'll tell you how many meters forward or back you need to go to find the issue.

Pretty easy to track issues down that way.

[mbreese]

Yeah, this was in a neighborhood bundle with many… many lines together. No one was going to dig into that to find which line a mouse or squirrel had chewed the insulation off of. I remember running a few diagnostics, but as it was “working”, no one was going to try to fix it. The ISP couldn’t even convince ATT to move the bad line to a different pair. Which was sad. I was supposed to be in the 40Mbps range, but could only get ~18-20. Also — this was enough bandwidth for us at the time, so I just ran off of the single line and was good. Given some of the dsl horror stories, we weren’t too and off.