Networking Fundamentals

Understanding twisted pair cables and their types

Perhaps the most common type of network cable in use currently, twisted pair cables are, in my experience, possibly the cables that are mislabeled the most. When showing people a twisted pair cable, I've often heard it being called a Cat 5 cable or an RJ-45 cable. As you will see in this section, the Cat 5 cable is a variant of twisted pair cabling, while RJ-45 refers to the type of connector that's used with a twisted pair cable.

I would like to start off by talking about the characteristics that all twisted pair cables have in common. Firstly, each cable is made of eight inner copper wires that carry a voltage. These eight wires are broken down into four pairs, and the wires in each pair ...