Which balanced twisted-pair cable type has a foil screen around the individual cable pairs?

The chosen answer is Shielded Foil Twisted Pair (SF/FTP), which is correctly identified because this type of cable features a foil shield surrounding each individual twisted pair of wires. The purpose of this shielding is to protect the signals from electromagnetic interference (EMI) and crosstalk, which can degrade network performance.

SF/FTP cables are typically used in environments with higher levels of electronic interference where added protection for data transmission is essential. The foil shielding provides an extra layer of protection that unshielded cables, such as UTP, do not possess.

Unshielded Twisted Pair (UTP) lacks any shielding, making it more susceptible to interference, while Shielded Twisted Pair (STP) often has shielding around all pairs collectively but does not specify foil coverage for individual pairs. Foil Twisted Pair (FTP) typically includes a foil shield around all of the pairs together, not around each individual pair as in SF/FTP, hence differentiating it from the correct type.

This unique combination of shielding at the individual pair level in SF/FTP provides enhanced performance in noisy environments, making it a preferred choice for specific applications that require a higher integrity of the transmitted signal.