In general, there are several terminals that require several cores. However, redundancy will be considered during the design and construction of the actual scheme. If the cost is considered, the entire line can also be redundant. Fiber optic splicing is often the preferred way to connect two fiber optic cables because it has lower light loss (attenuation) and back reflection than connectorization. Fusion splicing and mechanical splicing are the two most common methods of fiber optic splicing. In contrast, 12-core single-mode indoor fiber optic cables are used with single-mode fibers, which have a. According to the IBDN standard, it is generally recommended to use 12 cores for communication rooms in each building and 24 cores for building rooms. When an optical fiber network is subjected to very high optical intensity (typically greater than 2 MW/cm 2.