Unshielded vs. shielded twisted-pair cabling.
Unshielded vs. shielded twisted-pair cabling
In "noisy" environments such as airports and manufacturing facilities, shielded twisted-pair (STP) cable is preferred. These environments contain radio-frequency interference (RFI) and/or electromagnetic interference (EMI). The shielding in STP protects the data being transmitted through the cable and it keeps the cable itself from emitting EMI and RFI.
Drain Wire and a Foil Shield
BLACK BOX® STP cables feature the same core and jacket as the widely used Unshielded Twisted Pair (UTP) cables. And they contain a drain wire and a foil shield that covers all four pairs. The plugs on STP cable are also shielded.
Foiled Twisted Pair
Some STP cables use a thick braided shield which can make them harder to install than their UTP counterparts. However, some STP cables use a thin outer foil shield. These cables, called foiled twisted pair (FTP) or screened twisted pair (ScTP), are thinner and less expensive than braided STP cable, but they can still be used in noisy environments in place of UTP.
Although STP cable has yet to be fully covered by an EIA/TIA standard, a footnote does state that 100-ohm shielded cables may be used if they meet UTP transmission standards. BLACK BOX® STP Cables meet or exceed UTP transmission standard - Guaranteed!