Category 5 cable - Wikipedia Category 5 cable, commonly referred to as Cat 5, is a twisted pair cable for computer networks. The cable standard provides performance of up to 100 MHz and is suitable for most varieties of Ethernet over twisted pair. Cat 5 is also used to carry other signals such as telephony and video.Cable standard · Variants · Applications · Characteristics · Category 6 Cable · Twisted Pair LAN Ethernet Network Cable - NST Wiki Cable Diagram & Pin Out. The diagram above describes the various color coding and pin outs for the network cabling and the RJ45 modular connector. The T568B/T568B was chosen for the straight through cable and T568B/T568A for the cross-over cable. It is also possible to wire it the opposite way (i.e., straight through is a T568A).