A device for determining an information indicating a length of a part of a first cable, the first cable connecting a first transceiver unit and a first subscriber device, wherein the part of the first cable extends from the first transceiver unit to a point of the first cable from where a second cable, which connects a second transceiver unit to a second subscriber device, joins the first cable to extend from the second transceiver unit to the second subscriber device, the device comprising an input to couple the device to the second cable, a first apparatus coupled to the input to measure a quiet line noise related to crosstalk from the first cable to the second cable, and a second apparatus to determine information indicating the length of the part of the first cable based on the quiet line noise.