Category 5 cable, commonly known as Cat 5 is a twisted pair cable type designed for high signal integrity. Many such cables are unshielded but some are shielded. Category 5 has been superseded by the Category 5e specification. This type of cable is often used in structured cabling for computer networks such as Ethernet, and is also used to carry many other signals such as basic voice services, token ring, and ATM (at up to 155 Mbit/s, over short distances).

Category 5e

Cat 5e cable is an enhanced version of Cat 5 that adds specifications for far end crosstalk. It was formally defined in 2001 in the TIA/EIA-568-B standard, which no longer recognizes the original Cat 5 specification. Although 1000BASE-T was designed for use with Cat 5 cable, the tighter specifications associated with Cat 5e cable and connectors make it an excellent choice for use with 1000BASE-T. Despite the stricter performance specifications, Cat 5e cable does not enable longer cable distances for Ethernet networks: cables are still limited to a maximum of 100 m (328 ft) in length (normal practice is to limit fixed ("horizontal") cables to 90 m to allow for up to 5 m of patch cable at each end). Cat 5e cable performance characteristics and test methods are defined in TIA/EIA-568-B.2-2001.