An OLTS provides the most accurate insertion loss measurement on a link by using a light source on one end and a power meter at the other to measure precisely how much light is coming out at the opposite end. It is required for fiber testing per industry standards. Currently, high-performance TDR instruments, coupled with add-on analysis tools, are commonly used as the tool of choice for failure analysis and signal integrity characterization of board, package, socket, connector and cable interconnects at gigabit speeds. Both TIA and ISO standards use. Ensure the integrity of your fiber optic network with an Optical Time Domain Reflectometer (OTDR). in cable TV, LAN, metropolitan networks or long-haul.