Category 6 cable
Overview
 
Category 6 cable, commonly referred to as Cat 6, is a cable standard for Gigabit Ethernet
Gigabit Ethernet
Gigabit Ethernet is a term describing various technologies for transmitting Ethernet frames at a rate of a gigabit per second , as defined by the IEEE 802.3-2008 standard. It came into use beginning in 1999, gradually supplanting Fast Ethernet in wired local networks where it performed...

 and other network physical layer
Physical layer
The physical layer or layer 1 is the first and lowest layer in the seven-layer OSI model of computer networking. The implementation of this layer is often termed PHY....

s that is backward compatible with the Category 5/5e
Category 5 cable
Category 5 cable is a twisted pair cable for carrying signals. This type of cable is used in structured cabling for computer networks such as Ethernet. It is also used to carry other signals such as telephony and video. The cable is commonly connected using punch down blocks and modular connectors...

 and Category 3 cable
Category 3 cable
Category 3 cable, commonly known as Cat 3 or station wire, is an unshielded twisted pair cable designed to reliably carry data up to 10 Mbit/s, with a possible bandwidth of 16 MHz...

 standards. Compared with Cat 5 and Cat 5e, Cat 6 features more stringent specifications for crosstalk
Crosstalk (electronics)
In electronics, crosstalk is any phenomenon by which a signal transmitted on one circuit or channel of a transmission system creates an undesired effect in another circuit or channel...

 and system noise. The cable standard provides performance of up to 250 MHz and is suitable for 10BASE-T
10BASE-T
Ethernet over twisted pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. Other Ethernet cable standards employ coaxial cable or optical fiber. Early versions developed in the 1980s included StarLAN followed by 10BASE-T. By the 1990s, fast, inexpensive...

, 100BASE-TX (Fast Ethernet), 1000BASE-T/1000BASE-TX (Gigabit Ethernet) and 10GBASE-T (10-Gigabit Ethernet).

Whereas Category 6 cable has a reduced maximum length when used for 10GBASE-T; Category 6a cable, or Augmented Category 6, is characterized to 500 MHz and has improved alien crosstalk characteristics, allowing 10GBASE-T to be run for the same distance as previous protocols.
Like most earlier cables, Category 6 cable contains four twisted wire pairs
Twisted pair
Twisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs...

.
Encyclopedia
Category 6 cable, commonly referred to as Cat 6, is a cable standard for Gigabit Ethernet
Gigabit Ethernet
Gigabit Ethernet is a term describing various technologies for transmitting Ethernet frames at a rate of a gigabit per second , as defined by the IEEE 802.3-2008 standard. It came into use beginning in 1999, gradually supplanting Fast Ethernet in wired local networks where it performed...

 and other network physical layer
Physical layer
The physical layer or layer 1 is the first and lowest layer in the seven-layer OSI model of computer networking. The implementation of this layer is often termed PHY....

s that is backward compatible with the Category 5/5e
Category 5 cable
Category 5 cable is a twisted pair cable for carrying signals. This type of cable is used in structured cabling for computer networks such as Ethernet. It is also used to carry other signals such as telephony and video. The cable is commonly connected using punch down blocks and modular connectors...

 and Category 3 cable
Category 3 cable
Category 3 cable, commonly known as Cat 3 or station wire, is an unshielded twisted pair cable designed to reliably carry data up to 10 Mbit/s, with a possible bandwidth of 16 MHz...

 standards. Compared with Cat 5 and Cat 5e, Cat 6 features more stringent specifications for crosstalk
Crosstalk (electronics)
In electronics, crosstalk is any phenomenon by which a signal transmitted on one circuit or channel of a transmission system creates an undesired effect in another circuit or channel...

 and system noise. The cable standard provides performance of up to 250 MHz and is suitable for 10BASE-T
10BASE-T
Ethernet over twisted pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. Other Ethernet cable standards employ coaxial cable or optical fiber. Early versions developed in the 1980s included StarLAN followed by 10BASE-T. By the 1990s, fast, inexpensive...

, 100BASE-TX (Fast Ethernet), 1000BASE-T/1000BASE-TX (Gigabit Ethernet) and 10GBASE-T (10-Gigabit Ethernet).

Whereas Category 6 cable has a reduced maximum length when used for 10GBASE-T; Category 6a cable, or Augmented Category 6, is characterized to 500 MHz and has improved alien crosstalk characteristics, allowing 10GBASE-T to be run for the same distance as previous protocols.

Category 6

Like most earlier cables, Category 6 cable contains four twisted wire pairs
Twisted pair
Twisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs...

. Although it is sometimes made with 23 AWG
American wire gauge
American wire gauge , also known as the Brown & Sharpe wire gauge, is a standardized wire gauge system used since 1857 predominantly in the United States and Canada for the diameters of round, solid, nonferrous, electrically conducting wire...

 wire, the increase in performance with Cat 6 comes mainly from better insulation; 22 to 24 AWG copper is allowed if the ANSI/TIA-568-B.2-1 performance specifications are met. Cat 6 patch cables are normally terminated in 8P8C modular connectors. Attenuation
Attenuation to crosstalk ratio
Attenuation-to-crosstalk ratio, ACR, is the most important result when testing a link because it represents the overall performance of the cable. ACR is a mathematical formula that calculates the ratio of attenuation to near-end crosstalk for each combination of cable pairs...

, near end crosstalk
Crosstalk (electronics)
In electronics, crosstalk is any phenomenon by which a signal transmitted on one circuit or channel of a transmission system creates an undesired effect in another circuit or channel...

 (NEXT), and PSNEXT
PSNEXT
Power-sum near-end cross talk is the algebraic sum of near-end crosstalk of three wire pairs as they affect the fourth pair in a four-pair cable...

 (power sum NEXT) in Cat 6 cable and connectors are all significantly lower than Cat 5 or Cat 5e, which also uses 24 AWG wire.

The heavier insulation in some Cat 6 cables makes them too thick to attach to 8P8C connectors without a special modular piece, resulting in a technically out-of-compliance assembly.

Connectors use either T568A or T568B pin assignments; the choice is arbitrary provided both ends of a cable are the same.

. If Cat 6 rated patch cables, jacks, and connectors are not used with Cat 6 wiring, overall performance is degraded to that of the cable or connector.

Because the conductor sizes are generally the same, Cat 6 jacks may also be used with Cat 5e cable.

8P8C Wiring (T568A termination)
PinPairWireColor
1 3 1
white/green
2 3 2
green
3 2 1
white/orange
4 1 2
blue
5 1 1
white/blue
6 2 2
orange
7 4 1
white/brown
8 4 2
brown
8P8C Wiring (T568B termination)
PinPairWireColor
1 2 1
white/orange
2 2 2
orange
3 3 1
white/green
4 1 2
blue
5 1 1
white/blue
6 3 2
green
7 4 1
white/brown
8 4 2
brown
USOC/RJ61 Wiring
PinPairWireColor
1 4 1
white/brown
2 3 1
white/green
3 2 1
white/orange
4 1 2
blue
5 1 1
white/blue
6 2 2
orange
7 3 2
green
8 4 2
brown


Note: This is from left to right, with the (plastic) tab faced away from you.

Category 6 cable can be identified by the printing on the side of the cable sheath.

Category 6a

The latest standard from the TIA
Telecommunications Industry Association
The Telecommunications Industry Association is accredited by the American National Standards Institute to develop voluntary, consensus-based industry standards for a wide variety of ICT products, and currently represents nearly 400 companies...

 for enhanced performance standards for twisted pair cable systems was defined in February 2008 in ANSI/TIA/EIA-568-B.2-10. Category 6a (or Augmented Category 6) is defined at frequencies up to 500 MHz—twice that of Cat. 6.

Category 6a performs at improved specifications, in particular in the area of alien crosstalk as compared to Cat 6 UTP, which exhibited high alien noise in high frequencies.

The global cabling standard ISO/IEC 11801 has been extended by the addition of amendment 2. This amendment defines new specifications for Cat. 6A components and Class EA permanent links. These new global Cat. 6A/Class EA specifications require a new generation of connecting hardware offering far superior performance compared to the existing products that are based on the American TIA standard.

The most important point is a performance difference between ISO/IEC and EIA/TIA component specifications for the NEXT transmission parameter. At a frequency of 500 MHz, an ISO/IEC Cat., 6A connector performs 3 dB better than a Cat. 6A connector that conforms with the EIA/TIA specification. 3 dB equals 100% increase of near-end crosstalk noise reduction when measured in absolute magnitudes; see 3dB-point.

Confusion therefore arises because of the different naming conventions and performance benchmarks laid down by the International ISO/IEC and American TIA/EIA standards, which in turn are different from the regional European standard, EN 50173-1. In broad terms, the ISO standard for Cat6A is the highest, followed by the European standard and then the American.

Maximum length

When used for 10/100/1000BASE-T, the maximum allowed length of a Cat 6 cable is 100 metres (328.1 ft)This consists of 90 metres (295.3 ft) of solid "horizontal" cabling between the patch panel and the wall jack, plus 10 metres (32.8 ft) of stranded patch cable between each jack and the attached device. Since stranded cable has higher attenuation than solid cable, exceeding 10 metres of patch cabling will reduce the permissible length of horizontal cable.

When used for 10GBASE-T, Cat 6 cable's maximum length is 55 metres (180.4 ft) in a favourable alien crosstalk environment, but only 37 metres (121.4 ft) in a hostile alien crosstalk environment such as when many cables are bundled together.

Installation caveats

Category 6 and 6a cable must be properly installed and terminated to meet specifications. Incorrect installation practices include kinking or bending the cable too tightly. The cable bend radius should be no less than 4 times the outer diameter of the cable. Incorrect termination practices include untwisting the wire pairs or stripping the outer jacket back more than 1/2 inch.

All shielded cables must be grounded for safety and effectiveness. A continuous shield connection maintained from end to end. Ground loops
Ground loop (electricity)
In an electrical system, a ground loop usually refers to a current, almost always unwanted, in a conductor connecting two points that are supposed to be at the same potential, often ground, but are actually at different potentials. Ground loops created by improperly designed or improperly installed...

 develop when there is more than one ground connection and the difference in common mode voltage potential at these ground connections introduces noise into the cabling.

External links

Information on cable construction and alien crosstalk mitigation. Information on TIA
Telecommunications Industry Association
The Telecommunications Industry Association is accredited by the American National Standards Institute to develop voluntary, consensus-based industry standards for a wide variety of ICT products, and currently represents nearly 400 companies...

 TSB-155 37m versus IEEE 55m limitations.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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