1. Ultraviolet (UV) light - Do not apply cables without UV protection in direct sunlight environments.
2. Heat - Cables are hot inside metal ducts or raceways, and many polymeric materials will have reduced service life at these temperatures.
3. Water - Moisture in a LAN twisted pair cable increases the capacitance of the cable, which reduces the impedance and causes near-end crosstalk problems.
4. Mechanical damage (repair costs) - repair of fiber optic cables is very expensive, requiring at least two terminations at each discontinuity.
5. Grounding - If the shield of the cable needs to be grounded, it must comply with the appropriate standards.
6. Total length of routing (not just between buildings) - The total length of outdoor-grade LAN twisted-pair cable used between buildings should be limited to 90 meters. For 100Mps or 1000Mbps network, the laying distance should not exceed this limit. If the laying distance is between 100m and 300m, then you should choose fiber optic cable.
