Fusion splicing forms a 'welded' joint between two optical fibers and provides a permanent, low loss, high-strength connection compared to mechanical splicing. Either joining method must have three primary characteristics. The performance of a fiber optic splice is determined by a number of factors, including the quality of the fiber, the cleanliness of the splice, and the techniques used to make the splice., FTTH, FTTP, FTTM), splicing is essential for extending cables, repairing breaks, or connecting backbone and distribution lines.