Not all OTDRs are created equal! This is especially true when it comes to testing splitter-based Passive Optical Networks (PON). Many OTDRs make the claim that they can test PONs featuring splitters since they can see the end of the fiber but the reality is they simply do not provide usable data to verify the characteristics of the network (splices, connectors, etc.). This application note will provide an overview of the important properties when selecting an OTDR to test PONs and highlight the quality of data needed to accurately measure the fiber route.