Category_6_cable

This article does not cite any references or sources. (February 2008) Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed.

Category 6 cable, commonly referred to as Cat 6, is a cable standard for Gigabit Ethernet and other network protocols that is backward compatible with the Category 5/5e and Category 3 cable standards. Cat-6 features more stringent specifications for crosstalk and system noise. The cable standard provides performance of up to 250 MHz and is suitable for 10BASE-T / 100BASE-TX and 1000BASE-T (Gigabit Ethernet). It is expected to suit the 10GBASE-T (10Gigabit Ethernet) standard, although with limitations on length if unshielded Cat 6 cable is used.

The cable contains four twisted copper wire pairs, just like earlier copper cable standards. Although Cat-6 is sometimes made with 23 gauge wire, this is not a requirement; the ANSI/TIA-568-B.2-1 specification states the cable may be made with 22 to 24 AWG gauge wire, so long as the cable meets the specified testing standards. When used as a patch cable, Cat-6 is normally terminated in 8P8C modular connectors, often incorrectly referred to as "RJ-45" electrical connectors. Cat-6 connectors are made to higher standards that help reduce noise caused by crosstalk and system noise. Attenuation, NEXT (Near End Crosstalk), and PSNEXT (Power Sum NEXT) are all significantly lower when compared to Cat-5/5e.

Some Cat-6 cables are too large and may be difficult to attach to 8P8C connectors without a special modular piece and are technically not standard compliant. If components of the various cable standards are intermixed, the performance of the signal path will be limited to that of the lowest category. As with all cables defined by ANSI/TIA/EIA-568-B, the maximum allowed length of a Cat-6 horizontal cable is 100 meters (330 ft) in length, depending upon the ratio of cord length:horizontal cable length.

The cable is terminated in either the T568A scheme or the T568B scheme. It doesn\'t make any difference which is used, as they are both straight through (pin 1 to 1, pin 2 to 2, etc). Mixing T568A-terminated patch cords with T568B-terminated horizontal cables (or the reverse) does not produce pinout problems in a facility. Although it may very slightly degrade signal quality, this effect is marginal and certainly no greater than that produced by mixing cable brands in-channel. The T568B Scheme is by far the most widely used method of terminating patch cables.

Crossover is used for hub to hub, computer to computer, wherever two-way communication is necessary. All gigabit ethernet equipment, and most new 10/100Mb equipment, supports automatic crossover, meaning that either a straight-through or crossover cable may be used for any connection. However, older equipment requires the use of a straight-through cable to connect a switch to a client device, and a crossover cable to connect a switch to a switch or a client to a client. Crossover cables can be constructed by wiring one end to the T568A scheme and the other end with the T568B scheme. This will ensure that the Transmit (TX) pins on both ends are wired through to the Receive (RX) pins on the other end.

8P8C Wiring (TIA/EIA-568-A T568A)

Pin	Pair	Wire	Color
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 (TIA/EIA-568-B T568B)

Pin	Pair	Wire	Color
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

Augmented Category 6 (Category 6a)

The TIA is working to complete a new specification that will define enhanced performance standards for unshielded twisted pair cable systems. Draft specification ANSI/TIA/EIA-568-B.2-10 specifies cable systems, called "Augmented Category 6" or more frequently as "Category 6a", that operate at frequencies up to 500 MHz and will provide up to 10 Gbit/s bandwidth. The new specification has limits on alien crosstalk in cabling systems.

Augmented Category 6 specifies cable operating at minimum frequency of 500 MHz, for both shielded and unshielded. It can support future 10 Gbit/s applications up to the maximum distance of 100 meters on a 4-connector channel.

v • d • e Unshielded and shielded twisted pair cabling standards
Cat 1: Currently unrecognized by TIA/EIA. Previously used for POTS telephone communications, ISDN and doorbell wiring. Cat 2: Currently unrecognized by TIA/EIA. Previously was frequently used on 4 Mbit/s token ring networks. Cat 3: Currently defined in TIA/EIA-568-B, used for data networks using frequencies up to 16 MHz. Historically popular for 10 Mbit/s Ethernet networks. Cat 4: Currently unrecognized by TIA/EIA. Provided performance of up to 20 MHz, and was frequently used on 16 Mbit/s token ring networks. Cat 5: Currently unrecognized by TIA/EIA. Provided performance of up to 100 MHz, and was frequently used on 100 Mbit/s ethernet networks. May be unsuitable for 1000BASE-T gigabit ethernet. Cat 5e: Currently defined in TIA/EIA-568-B. Provides performance of up to 100 MHz, and is frequently used for both 100 Mbit/s and gigabit ethernet networks. Cat 6: Currently defined in TIA/EIA-568-B. It provides performance of up to 250 MHz, more than double category 5 and 5e. Cat 6a: Future specification for 10 Gbit/s applications. Cat 7: An informal name applied to ISO/IEC 11801 Class F cabling. This standard specifies four individually-shielded pairs (STP) inside an overall shield. Designed for transmission at frequencies up to 600 MHz.
See also: TIA/EIA-568-B • Ethernet • 8P8C • Ethernet crossover cable • Twisted pair

This article is licensed under the GNU Free Documentation License. It uses material from Wikipedia