Category 5 Cable Article Index for
Category
Website Links For
Category 5
 

Information About

Category 5 Cable




Category 5 cable, commonly known as '''Cat 5''', is an Unshielded Twisted Pair cable type designed for high signal integrity. With the 2001 introduction of the TIA/EIA-568-B standard, the category 5 cabling specification was obsoleted and superseded by the category 5e specification.

The original specification for category 5 cable was defined in ANSI/TIA/EIA-568-A, with clarification in TSB-95. These documents specified performance characteristics and test requirements for frequencies of up to 100 MHz. Category 5 cable included four twisted pairs in a single cable jacket. It was most commonly used for 100Mbit/s networks, such as 100BASE-TX Ethernet, although IEEE 802.3ab defined standards for 1000BASE-T - gigabit Ethernet over category 5 cable. Cat 5 cable typically had three twists per inch of each twisted pair of 24 Gauge copper wires within the cable. The twisting of the cable reduces electrical Interference and Crosstalk . Another important characteristic is that the wires are insulated with a Plastic ( FEP ) that has low Dispersion , that is, the Dielectric Constant of the plastic does not depend greatly on Frequency . Special attention also has to be paid to minimizing Impedance mismatches at connection points.


USAGE AND WIRING METHODS


Cat 5 cables were often used in Structured Cabling for Computer Network s such as Fast Ethernet , although they were also used to carry many other signals such as basic Voice services, Token Ring , and ATM (at up to 155 Mbit /s, over short distances).

Cat 5e cable is an enhanced version of Cat 5 that adds specifications for far-end crosstalk. Although 1000BASE-T was designed for use with Cat 5 cable, the tighter specifications associated with Cat 5e cable and connectors make it 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: horizontal cables are still limited to a maximum of 90 m in length. Cat 5e cable performance characteristics and test methods are defined in TIA/EIA-568-B.2-2001.

Generally solid core cable is used for connecting between the wall socket and the socket in the patch panel whilst stranded cable is used for the patch leads between hub/switch and patch panel socket and between wall port and computer. Cable types, connector types and cabling topologies are defined by TIA/EIA-568-B. RJ-45 Electrical Connector s were nearly always used for connecting category 5 cable.


OTHER CATEGORIES OF NETWORK CABLES

  • Cat 1 : Currently unrecognized by TIA/EIA. Previously used for POTS telephone communications, ISDN and doorbell wiring.

  • networks.

  • Cat 3 : Current cable standard, used for data networks utilizing frequencies up to 16 MHz. 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 16Mbit/s token ring networks.

  • TIA/EIA 568B-2.1. It provides performance of up to 250 MHz, more than double category 5 and 5e.

  • Cat 7 : Draft standard, proposed to include four individually-shielded pairs (ScTP) inside an overall shield. Designed for transmission at frequencies up to 650 MHz.



SEE ALSO



EXTERNAL LINKS