Attenuation This is the total signal loss over the fiber length. For example, 10GBASE-SR over multimode fiber allows a maximum channel insertion loss of 2. Fiber optic testing of a newly installed system not only verifies that the system meets its design requirements, but also creates a performance baseline for all future testing and troubleshooting of t at system. Corning recommends that all fiber optic systems be tested to a minimum set. ic system. Such a comprehensive approach to fiber optic cable testing. Listing of all FOA standards FOA Standard FOA-1: Testing Loss of Installed Fiber Optic Cable Plant, (Insertion Loss, TIA OFSTP-14, OFSTP-7, ISO/IEC 61280, ISO/IEC 14763, etc.