(In general, fiber optic cabling is the first choice for data trunk lines in cabling systems. As early as before the introduction of Category 5 UTP (unshielded twisted pair), when the desktop usage rate of computer networks was 10Mbps, the 100Mbps backbone network was FDDI network. FDDI completely Built on fiber optics. Therefore, it can be said that for the data trunk line of general wiring, the vast majority of projects use optical cables, which is a long-standing practice.)