Introduction to twisted pair network cables

Updated: Jul 23

1, Different types of twisted-pair Ethernet cables

A variety of different cables are available for Ethernet and other telecommunications and networking applications.

These network cables also called LAN cables that are described by their different categories, e.g.

CAT 5e cables, CAT 6 cables, CAT 6a cables, CAT 7 cables, Cat 8 cables, etc, which are often recognized by the TIA, and they are summarised below:

2, Common industry nomenclature for cable construction types

U – unshielded / F – foil shielding / S – screened shielding (outer layer only) / TP – twisted pair


Unshielded Twisted Pair

Unshielded/Unshielded Twisted Pair – a completely unshielded cable, which is still often used for the lower cable categories Cat.5 and Cat.6

This means that they are usually sufficient for the transmission methods of networks up to Gigabit Ethernet, even if they are not optimal.

However, in some cases, it may be better to use unshielded cables.

Firstly, if there are large voltage potential differences between the endpoints of the reference potential and the network devices used are themselves connected to earth or ground potential via the PE contact of the power supply cable, a second earth connection, and an earth loop is created. It generates low-frequency compensation currents via the cable shield, which considerably impair the signal quality.

Second, some AV or USB extender systems use Cat. X cables are more dependent on good crosstalk than good shielding and therefore

work better with unshielded cables.