Category 5 (Cat 5) Cabling.
Category 5 (often shortened to Cat 5) cable is a multipair (4 twisted pair) cable used for data or combined data and voice communications. The twisted pairs of cables reduce interference through crosstalk. Cat 5 can be used for applications such as 10baseT and 100baseT Ethernet, RS-232, RS-422, RS-485, and can even be used for analogue phone cabling, CCTV cabling, audio cabling, video cabling and security cabling.
Category 5E (enhanced) cable is essentially identical to standard Cat 5 cable, apart from the fact that it is tested to higher standards, which enable it to be used for data transmission speeds of up to 1 Gigabit per second (Gbps). As a conseqeunce of this, for data cabling, Cat 5E is recommended over Cat 5, since it enables Gigabit Ethernet data networks.
As with other cabling categories, Cat 5 and Cat 5E cables are often referred to as UTP (Unshielded Twisted Pair), or STP (Shielded Twisted Pair) cables. Each of the 8 individual cables within the Cat 5 cable, is 24 guage (AWG) wire, and each pair is twisted approximately 3 twists per inch, in order to reduce the electrical interference through crosstalk.
Generally, Cat 5 cabling uses solid wire cores for long cable runs (e.g. networking an office or a house), and stranded, flexible wire cores for patch cables. As a result of using solid wire cores, care and attention must be taken when using solid wire cored Cat 5 cable, to ensure it is not kinked, or bent at too tight an angle, otherwise individual cable cores can break.
EIA/TIA 568A and 568B
The wiring within the Cat 5 and Cat 5E cables should follow one of 2 recognised wiring schemes. These are designated 568A and 568B, and form part of a standard called EIA/TIA 568A. It should be noted that the most widely used of the 2 wiring schemes is the 568B wiring scheme.
Physically, and in terms of performance and capability, there is no difference between the 2 wiring schemes. The only difference is in the way the wires are connected to a device at either end (e.g. a patch panel, an RJ-45 plug, an RJ-45 socket module).
The important point to note when installing a Cat 5 or Cat 5E cabled network, is that once the cable is wired for one of the 2 wiring schemes; 568A or 568B, it is essential that the same wiring scheme is then followed for the rest of the wiring network.
EIA/TIA 568A Wiring Scheme
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EIA/TIA 568B Wiring Scheme
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Cat 5 Connections / Interface
Cat 5 cabling is generally connected to 8-way connectors called RJ45 connectors, as detailed in socket form below. More details are available on the RJ45 connector and on the functions that each of the pinouts / cables is used for, on the RJ-45 connector page on this site.
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See also:
RJ-45, Cabling information, Ethernet, Network commands / troubleshooting,