Optical fiber transmission system mapping arrangement

A mapping system and method for mapping optical fiber communication networks which have several stages has switches at each stage which have an input, a home position stage, and a plurality of outputs. An optical signal is applied to the input of one of the switches and the energy appearing at its home port is measured and applied to a CPU. The switch is then stepped to apply the optical energy to the output ports, and the optical energy appearing at the home ports of the switches in the next stage affords an indication of which output port of the first stage switch is connected to the input of which switch in the second stage. The same procedure is performed for the switches in the third stage, until the network, or a portion thereof, is mapped.