Abstract: A method for recognizing and releasing unnecessary trunk lines in a private branch exchange telephone system including a plurality of switching nodes, each having a unique node identification number where each pair of nodes is connected by a plurality of trunk lines, includes steps for (a) compiling a telephone call identifier list containing node identification numbers and an associated trunk call identification number used in defining and connecting a call path between a calling party and a called party, (b) examining a call identifier list at each of the switching nodes for information indicative of redundant node identification numbers, and (c) releasing the unnecessary trunk lines between the redundant node identification numbers.