Abstract: An all optical cross-connect module is described that, in addition to routing optical signals, provides signal monitoring and signal path identification capabilities. In one embodiment, each bidirectional cross-connect module comprises two four-port wavelength division multiplexing (WDM) filters. One filter has a transmit-signal input (Tx-In) port, a transmit-signal (Tx-Out) output port, a transmit-monitor output (Tx-Mon-Out) port, and a path identification output (Path-ID-Out) port. The second filter has a receive-signal input (Rx-In) port, a receive-signal output (Rx-Out) port, a dual function path identification input/receive-signal monitor output (Path-ID-In/Rx-Mon-Out) port, and one port that is optically terminated to prevent signal reflections. Each of the two filters are designed to couple selected frequencies to the appropriate port. In alternative embodiments, a combination of standard couplers and three-port WDM filters are combined to provide substantially the same functionality.