They serve as protective enclosures where fiber optic cables are joined, split, or terminated. In our hyper-connected world, the seamless flow of data is powered by a vast, underlying infrastructure of fiber optic networks. These devices ensure that data signals travel efficiently without interference or damage. Fiber-optic splice boxes ensure continuously reliable data transmission in real-time via fiber optics, enabling cloud-based technologies such as the Internet of Things to bring us to a state of ubiquitous computing. Main types—dome. A Fiber Joint Box (also called fiber closure, splice closure, or cable joint enclosure) is a sealed outdoor or underground enclosure designed to protect fiber optic cable splices from environmental hazards while providing mechanical strength and cable management. Safe and reliable high-speed.