Mechanical Durability: The connector should withstand repeated mating cycles without significant performance degradation. Environmental Stability: Performance shouldn't change drastically with temperature, humidity, or vibration. Even if only a single fusion splice fails, an entire optical fiber span or optical fiber device, as well as adjacent devices or spans, could be rendered inoperable. Typical good values: >20 dB (often >30 dB is desired)., FTTH, FTTP, FTTM), splicing is essential for extending cables, repairing breaks, or connecting backbone and distribution lines.