UTP cables consist of 4 pairs of wires, where each pair is twisted around each other to combat crosstalk. It is relatively inexpensive and is primarily used to connect or patch devices together in local area networks or to connect telephones to the telephone company master socket located in the home or business. STP (Shielded Twisted Pair) cabling has each of the copper twisted pairs shielded with foil or sometimes has a foil braided shield inside the external insulation to protect all 4 pairs of copper wires. The advantage of STP is in its ability to give greater protection against Electro Magnetic Interference and is often used in 100Mbps Ethernet networks.
The specification for Category 5 cables is defined in TIA/EIA-568-A and ANSI in the U.S. and is tested for performance up to 100Mhz. Cat5 cable supports Ethernet at speeds up to 100Mbps over a maximum cable segment length of 100 Metres (328 feet), with the cables usually terminated using modular connectors known as RJ-45. Where a longer run of cable is required, a repeater, hub or switch will need to be employed. In order to combat crosstalk between each of the 4 pairs of wires, each pair of twisted wires have a precise number of twists per metre.
The Ethernet standards 10BaseT and 100BaseTX use two pairs of wires for transmission and the pinouts on the RJ-45 connector are normally pins 1,2,3 and 6. The 1000BaseT standard requires the use of all 4 pairs of wires.
Although Cat5 cable is capable of carrying signals for the 1000BaseT standard, Cat5e is preferred due to additional specifications that help reduce crosstalk further. Cat5e is defined in the TIA/EIA-568-B standard and has the same maximum cable distance specifications as the original Cat5 standard.
Category 6 cable has been available for some time now, but should I be thinking of replacing my Cat5e cable with Cat6? Cat6 cable was specifically designed for Gigabit speeds and beyond and has performance up to 250Mhz. The cat6 specification significantly reduces the various forms of noise generated by crosstalk and is fully backward compatible with the older Cat5 standards. Maximum cable lengths are the same as for Cat5, except when used with the 10 Gigabit Ethernet standard 10GBaseT. With 10GBaseT maximum cable lengths will be somewhere between 37 and 55 metres depending on the type of installation. For example, if multiple cables are in close proximity to each other such as in a bundle of some sort then the minimum cable distance should apply. If you are looking to use the 10GBaseT standard with copper wiring then the newer Cat6a standard has performance up to 500Mhz and would allow cable lengths of 100 metres with the 10 Gigabit Ethernet standards.
If you are planning on cabling a new installation for your business then you should always look at future proofing, and in this case I would recommend minimum Category 6 cabling. Even the home user should consider Category 6 cabling, particularly if the intention is to use high bandwidth applications that involve any kind of media streaming.
If you are not familiar with attaching the RJ-45 connectors on your Ethernet Patch Cables, then you will probably want to buy ready made patch cables in a length that suits the purpose of your installation. Many vendors provide ready made patch cables in a variety of coloured jackets from 30 centimetre lengths upwards.