The three standard methods for testing fiber optic cabling are a visible light source, power meter and light source, and optical time domain reflectometer (OTDR). The Contractor must utilize the correct equipment and testing techniques to gain acceptance, or the work cannot be approved. This testing. Fiber optic testing ensures the performance and reliability of fiber optic networks. If it's a long outside plant cable with intermediate splices, you will. FOA "Quickstart Guides" are short, simple guides to basic fiber optic tests. References to FOA "1. Start fiber testing with VIAVI today! Are you ready to take the next step with one of our fiber optic testers? Learn essential testing methods, get help from fiber experts, and demo the industry's most complete range of fiber testers, including VFL fiber testers.