Learn how to install a fiber optic termination box step-by-step for FTTH projects. Covers mounting, splicing, routing, labeling, and testing for indoor/outdoor use. If you do not have relevant experience and skills, it is recommended to ask a professional to install it. Preparations: Before installation. It is used in a terminal box to connect the optical fibers in the optical cable, and to connect the optical cable and the jumper through the terminal box coupler (adapter). Fiber Optic Terminal. A Fiber Termination Box, also known as a Fiber Distribution Box, is a crucial component in fiber optic networks.