Abstract: A device is provided for monitoring a passive optical network (PON) having optical network terminations (ONTs) joined to an optical distribution network (ODN). The device comprises an optical line terminator (OLT) that includes an E/O transmitter and an O/E receiver. The E/O transmitter converts electrical transmit signals to optical transmit traffic, while the O/E receiver converts optical receive traffic to electrical receive signals. The device further includes a combiner/splitter module joined to the OLT and having an ODN port that is configured to communicate with at least one ONT over an ODN. The OLT and combiner/splitter module may be joined to one another through a fiber link. The combiner/splitter module merges and splits the optical transmit and receive traffic that is conveyed to and from the OLT. The combiner/splitter module includes a separate monitor port that is configured to be attached to external monitoring equipment.