1. Ultraviolet (UV) - Do not use cables without UV protection in direct sunlight.

2. Heat - the temperature of the cable in the metal pipe or trunking is very high, and many polymeric materials will reduce the service life at this temperature.

3. Water - Moisture in the twisted pair cable of the LAN will increase the capacitance of the cable, thereby reducing the impedance and causing near-end crosstalk problems.

4. Mechanical damage (repair costs)--The repair of optical cables is very expensive, and at least two terminations are required at each discontinuity point.

5. Grounding - If the shielding layer of the cable needs to be grounded, it must comply with the corresponding standards.

6. The total length of the route (not only refers to the building) - the outdoor-level local area network twisted pair cable is used between the buildings, and the total length should be 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, the fiber optic cable should be selected.