While a cut or damaged fiber optic cable can temporarily take your network down, it is possible to quickly fix the cable with the right tools. Here are the steps to repair a cut fiber cable. To do this, you can use an OTDR, Optical Time Domain, Reflectometer. No matter how well-planned and well-built a fiber optic line is, chances are that. A fiber cut is a physical interruption to the thin glass strands that form the core of a fiber optic cable, which carry light signals across vast distances. This damage immediately blocks the transmission of data, voice, and video, leading to a loss of connectivity or severe service degradation for.