Cable types used for structured cabling

Copper cables used for structured cabling have 4 twisted pairs of wires but there are a number of different types of construction.

The ISO/IEC 11801 standard defines the different types of cable screen constructions as X/YTP, where X is the type of overall screen, Y is the type of screen around the twisted pairs and TP stands for Twisted Pair.
X can be:
     - U for Unscreened
     - F for Foil Screened
     - S for Braid Screen
Y can be:
     - U for Unscreened
     - F for Foil Screened
Some examples of typical cable constructions can be seen in the diagram below.


Image of the different types of cable construction


Cat 5e and Cat 6 cables normally use the U/UTP construction but may also be manufactured as F/UTP.
Cat 6A cables can be U/UTP, F/UTP, U/FTP, F/FTP or S/FTP.
Cat 7A cables use a S/FTP construction.

For details of the relative merits of the the different types of screening click here.