Whether you're a professional or a DIY enthusiast, knowing how to test fiber optic cables is crucial. First, we'll show you the. While there are many different fiber optic cable tests, the most common version is an insertion loss test, also known as an attenuation, jumper, or connectivity test. Using a visible light source tests. In this guide, we'll explore effective methods to check your fiber connection, including tools required and common issues to look out for. If you are unable to access the internet or.