Computer networks consist of seven layers. At the bottom, providing the foundation for everything, in so-called physical layer, which means cabling. A good cabling is a dream while a bad one is a real nightmare.
Today’s networks usually employ UTP (unshielded twisted pair) cable. It resembles, but should never be confused with, telephone and cable. The tight twist of each pair is tightly spec’ed and is what keeps its noise immunity. For most data networks, category 5E or Cat6 six rated UTP cable is used. We fully recommend that in any new construction, all communication cables whether intended for data or voice, should be category six UTP. The cable that’s permanently installed in walls, ceilings and floors should be solid conductor and not standard cables. In special cases, STP which is shielded twisted pair may be needed. In high electrical noise environments or for what occurred runs in tall buildings, or between buildings, fiber-optic cable make sense. Today, short runs of fiber-optic cable consist of low-cost plastic(not glass) fibers with the low-cost light sources, with multimode. Using five or, rather than copper, between buildings and eliminates electrical hazards caused by lightning strikes and earth differential voltages between buildings.
Plenum rated cable
regardless of whether you run a UTP, STP or fiber-optic cable in your building, the new cable must conform to local building and fire codes. This often means that if the cable runs within the space above false ceilings, it’s jacket must be Plenum rated. In many but not all buildings the space above the false ceiling is used to carry return air act to an air handler. In these cases, Plenum rated cable must be used. If your building has separate air return ducts, you may not need to use Plenum rated cable; check with your local building code enforcement authority before buying cable.