Maintenance termination unit

摘要

Methods and apparatuses are disclosed for locating trouble in a telecommunications network. One method communicates signals from a central office along a local loop. The local loop comprises a ring wire and a tip wire. Voltage polarity between the ring wire and the tip wire is reversed, causing a customer's wiring to be isolated from the local loop. A test of the local loop may then be remotely performed to determine whether trouble exists in the local loop.