Twisted pair cable - Base-T

What is "twisted pair" and what are the types of twisted cables?

A twisted cable, commonly known as "twisted pair", is made of four sets of pairs of copper wires twisted together. Therefore, the cable has twisted wires, as this helps to eliminate electromagnetic interference. This type of cable is often used in building a computer network based on a star topology.

In a twisted cable, each wire is marked with a different color, i.e.:

  • Green
  • Orange
  • Blue
  • Brown
  • White and orange
  • White and blue
  • White and green
  • White and brown


All wires in the cable are marked with a uniform and similarly mixed color. (for example, green and white-green are a twisted pair). To reduce the noise level and create the self-shielding effect, all twisted pairs should be twisted again.


What types of twisted pair are there??


  • U / UTP – it is a type of unshielded twisted cable. It is the most popular means of data transmission, usually used indoors.
  • F/UTP – is a type of foil-shielded twisted cable with a grounding conductor. Also a popular solution in computer networks, used outdoors or in corridors.
  • S/FTP – a type of twisted shielded cable in the form of a foil braid of each single pair and an external mesh.
  • SF/UTP – is a type of twisted cable with a double outer shield in the form of a foil braid and mesh.


All cables of the "twisted pair" type are connected to sockets and terminals called RJ45. As for the maximum length that can be used to connect this type of solution, this is it 100 Metres. Active network devices must be used when the length is exceeded, to strengthen the signal.