1. Ultraviolet (UV) - Do not apply cables without UV protection to direct sunlight environments.

2. Heat - The temperature of cables in metal pipes or trunking is very high, and many polymers at this temperature will reduce their service life.

3. The moisture in the water LAN twisted pair cable will increase the capacitance of the cable, thereby reducing impedance and causing near end crosstalk.

4. Mechanical damage (repair cost) - The repair of optical cables is very expensive, and each discontinuity requires at least two terminations.

5. Grounding - If the cable shielding layer needs to be grounded, corresponding standards must be followed.

6. Total length of routing (not only between buildings) - Outdoor LAN twisted pair cables are used between buildings, and the total length is limited to 90 meters. For a 100MPS or 1000MBPS network, the laying distance cannot exceed this limit. If the laying distance is between 100 meters and 300 meters, optical cables should be selected.