What Is Cat 5?

Date First Published: 4th March 2022

Topic: Computer Networking

Subtopic: Data Transmission Technologies

Article Type: Computer Terms & Definitions

Difficulty Level: 5/10

Learn more about what Cat 5 is in this article.

Short for Category 5, Cat 5 is a type of Ethernet cable standard that supports data transfer speeds of up to 100 Mb/s and is made up of eight internal wires or four twisted pairs of copper wire connected by an RJ45 connector. Inside the RJ45 connector, it is possible that the four twisted pairs may be wired two different ways on the RJ45 connector. A 'patch cable' is a Cat 5 cable that has the same wiring on both ends and a 'crossover cable' has different wiring on both ends. Cat 5 is used in Ethernet connections in LANs as well as telephony and other data transfers.

Cat 5 cables can provide data transfer speeds of 100 Mb/s. They can provide a data transfer rate of up to 1000 Mb/s if they are Cat 5e.

Maximum Length

Cat 5 has the ability to extend up to 100 metres between connected devices in both business and home networks. Without the use of a bridge or other network device, exceeding this length could result in network difficulties such as data packet loss and transmission speed reduction.

History

In the late 1990s and early 2000s, Category 5 Ethernet cables were widely used for creating LANs. They were appropriate for 100BASE-T (Fast Ethernet) networks as they supported 100 Mb/s transfer speeds. Cat 5 connections were phased out in 2001 in place of Cat 5e cables, which offer 1000BASE-T (Gigabit Ethernet). Cat 5e and higher cables are used in the majority of wired networks today.