one end is "normal" inside a building, the other is out at a security gate, (outside, subject to temp varation in the summer 80-95 degree, in winter, below zero) for in between i was thinking a 3com building to building bridge,
for the normal end it would plug into a lucent partner phone system, as a loop start line (older then dirt but still works) I want to be getting something that works when it is -10 degrees, as I know when when you get outside the temp range "werid" things start to happen and I don't want to go out there when it is -10 degrees