2. Optical Fiber Distribution Box (OCC)
According to the definition in YD/T 988-2015, an optical fiber distribution box is an interface device used outdoors to connect trunk optical cables and distribution optical cables. Optical fiber distribution boxes are often simply referred to as "optical junction boxes" (OCCs), but they are often installed indoors (e.g., in basements). Depending on their location within the ODN, optical junction boxes are further divided into "trunk optical junction boxes" and "distribution optical junction boxes." In some provinces, to distinguish between trunk and distribution optical junction boxes, the trunk optical junction box is called an optical junction box, and the distribution optical junction box is called an optical distribution box (optical cable distribution box).
2.1 Trunk Optical Junction Box
Trunk optical junction boxes typically do not contain optical splitters; the fiber cores of the trunk optical cable and the distribution optical cable are connected via single-core patch cords.