Interrupting live networks is painful. But sometimes you’ve got to do work in the cable closets, server rooms, and other crowded and complex rivers of wire that are your responsibility. Does there have to be an acceptable amount of downtime for tracing and testing wires? There are a few low-impact methods for locating cable ends which are popular but disruptive. There is one newer strategy, though, which can lead you right to the cable end you seek without network disruption or disconnection.