The PFP Splitter Power test application can be accessed via the Fiber menu. Clean and inspect all the optical connectors, before making any connections between the test set and distribution panel. By troubleshooting the PON system, network administrators can identify the root cause of problems and take the necessary steps to fix them, ensuring that the PON continues to deliver high-quality, reliable service to the end users. When troubleshooting potential causes: Determine if the downstream. Use an ONT (Optical Network Terminal) / ONU (Optical Network Unit) Tester to determine if the ONT/ONU at the subscriber's end is responding to downstream signals from the OLT (Optical Line Terminal). The Active ONT /ONUidentifier clamps on to 0. 9mm buffered fiber, or 2mm or 3 mm jacketed fiber, or. A distribution cabinet can house multiple OLTs in which each can have numerous fiber output ports. As part of the PON construction process, the construction crew needs to verify every port is receiving the required power levels before proceeding to build the next section/feed of the optical. The fiber distribution box—sometimes called a fiber box or internet distribution box—is the point where feeder cables from the central office connect with distribution cables going to individual users. The downstream input port features an internal tap that directs some of the signal power to a receiver to measure the downstream power level. FieldSmart Fiber Distribution Hub (FDH) ® Installation Manual _________________________________________________________ FDH Cabinet Component.