A test instrument can be coupled to a test point in a passive optical network (PON) to perform an optical network unit (ONU) assignment determination test. The ONU assignment determination test determines a one-to-one assignment of an ONU to an optical line terminal (OLT) in the PON from a downstream signal received during an activation process. The test instrument can capture downstream signals for OLTs of different PONs simultaneously operating on the same optical distribution network to determine ONU assignment for the different PONs in a single test. The test instrument can be a termination mode device.

A system for organizing network cabling termination while reducing clutter in the media converter is provided. Clutter is reduced because the network provider can consolidate two pieces of cabling termination equipment within one compartment, minimizing space and the number of wires required in the media converter. The system is particularly valuable to office buildings, warehouses, places of educations, hospitals, and other institutions where localized networks are needed. The system is housed within a media converter and includes at least 24 termination ports, an output port, a number of data cables compatible to connect to the termination ports, a single data cable capable of connecting to the output port, and a test port. The media converter box is encased between 2 post racks and secured upon a shelf. When the media convert is set up, network managers can more easily troubleshoot and maintain the localized network server.