Network Cable Tutorial
Category 5e ~ Cat5e ~ Enhanced Cat5
Category 5e cables are enhanced versions of Cat 5 that add specifications for far-end crosstalk. Mechanically, Cat5e twisted pairs are bonded together to maintain twists-per-inch during installation and ensure balanced lines. Cat5e was formally defined in 2001 in the TIA/EIA-568-B standard, which no longer recognizes the original Cat 5 specification. Although 1000BASE-T was designed for use with Cat 5, the tighter specifications associated with Cat 5e cable and connectors make them an excellent choice for use with 1000BASE-T. Despite the stricter performance specifications, Cat 5e cable does not enable longer cable distances for Ethernet networks; cables are still limited to a maximum of 100M (328 ft) in length. Cat 5e cable performance characteristics and test methods are defined in TIA/EIA-568-B.2-2001.
Category 6 ~ Cat6
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 3, 5, and 5e. Cat-6 features more stringent specifications for crosstalk and system noise by requiring 22 to 24AWG conductors. 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 there are limitations on maximum length if unshielded Cat 6 cable is used. 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. As with all cables defined by
ANSI/TIA/EIA-568-B, the maximum allowed length of a Cat 6 patch cable is 100M (328 ft). The cable is terminated in either the T568A scheme or the T568B scheme.
The Bulk Cable
Networking bulk cable exists in both stranded and solid conductor forms. The stranded form is more flexible. Typically, wiring within walls uses solid conductors, while patch cables are stranded. Cable and connector types are defined by TIA/EIA-568 standards. Modular plugs with 8-positions utilizing all 8 conductors (8P8C), often referred to as RJ-45 plugs, are the most common interfaces for networking patch cables. Patch cables are terminated using either the T568A scheme or the T568B scheme. It doesn't make any difference which is used as they are both straight-through connections. However mixed cable types should not be connected in series as the impedance per pair differs slightly and could cause signal degradation.
Crossover Cables
Crossover cables are used for hub to hub, computer to computer, and wherever two-way communication is necessary. All Gigabit Ethernet equipment, and most new 10/100Mb equipment, supports automatic crossover. This means 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.
Cutting Edge Notes ~ Newest Technology
Category 6a
The latest enhanced twisted pair cable standard from the TIA was defined in February, 2008 in
ANSI/TIA/EIA-568-B.2-10. Category 6a, Augmented Category 6, operates at frequencies up to 500 MHz, twice that of Cat 6. It can support 10 Gbit/s applications and 10GBaseT up to a maximum distance of 100M (328ft).
Category 7
Cat 7 is an informal name applied to
ISO/IEC 11801 Class F cabling. This standard specifies four individually-shielded pairs (STP) inside an overall shield. It is designed for transmission at frequencies up to 600 MHz.