To see if a phone is working, a technician has to check the wiring terminals near the residence. A terminal is a small box which holds up to 600 pairs of wires, although most do not have that many. Each phone line has two parts, one for incoming signals and the other for outgoing signals. Every cable in a terminal is color-coded. Different combinations of colors in wires and bundles represent different residential phone lines.
Technicians use a phone that clips directly to the cables to find out which ones are working.
The most common problems with wires are deterioration from the air or moisture from the ground. Customers or technicians can perform the last step, hooking up the line to a particular jack in the residence. Adding an extra line includes rewiring these jacks. We have to rewire the jacks inside. It's getting to be a problem for us.