They provide a secure, organized, and stable environment for the sensitive points within a fiber network—splices, connectors, and distribution points—safeguarding them from a multitude of external threats. For any organization deploying or maintaining a fiber network, understanding the role and. Fiber Connection Protection Box is a device designed for fiber optic line terminal connection and protection and is widely used in fiber optic communication systems such as fiber to the home (FTTH), local area network (LAN), and metropolitan area network (MAN). Its main functions can be summarized as follows: 1. Fiber closure protects spliced fibers in backbone and feeder lines, fiber box (or fiber distribution box) organizes and splits fibers in.