An apparatus for identifying interconnections in a network. The apparatus comprises a plurality of transmitter coupling units, a plurality of receiver coupling units, and an interconnection identification means configured to identify interconnections between the transmitter coupling units and the receiver coupling units by cable lines in the network. In some embodiments, the interconnection identification means is configured to, if any one of the transmitter coupling units is coupled to the same cable line as a selected one of the receiver coupling units, identify the interconnection between the transmitter coupling unit and the selected receiver coupling unit according to by a binary tree search algorithm.