TIA/EIA-568 is a set of telecommunications standards from the Telecommunications Industry Association, an offshoot of the EIA. The standards address commercial building cabling for telecom products and services.
The standard is currently (2009) at revision C, replacing the 2001 revision B, the 1995 revision A, and the initial issue of 1991, which are now obsolete.
Perhaps the best known features of TIA/EIA-568 are the pin/pair assignments for eight-conductor 100-ohm balanced twisted pair cabling. These assignments are named T568A and T568B, and are frequently referred to (erroneously) as TIA/EIA-568A and TIA/EIA-568B. An IEC standard ISO/IEC 11801 provides similar standards for network cables.
The standard defines categories of unshielded twisted pair cable systems, with different levels of performance in signal bandwidth, attenuation, and cross-talk. Generally increasing category numbers correspond with a cable system suitable for higher rates of data transmission. Category 3 cable was suitable for telephone circuits and data rates up to 16 million bits per second. Category 5 cable, with more restrictions on attenuation and cross talk, has a bandwidth of 100 MHz. The 1995 edition of the standard defined categories 3, 4, and 5. Categories 1 and 2 were excluded from the standard since these categories were only used for voice circuits, not for data.
Twisted pair cabling is a type of wiring in which two conductors of a single circuit are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources; for instance, electromagnetic radiation from unshielded twisted pair (UTP) cables, and crosstalk between neighboring pairs. It was invented by Alexander Graham Bell.
SOME OF THE LIMITATION OF UTP
UTP has several drawbacks. Because it does not have shielding like shielded twisted-pair cables, UTP is susceptible to interference from external electrical sources, which could reduce the integrity of the signal. Also, to intercept transmitted data, an intruder can install a tap on the cable or monitor the radiation from the wire. Thus, UTP may not be a good choice when transmitting very sensitive data or when installed in an environment with much electromagnetic interference (EMI) or radio frequency interference (RFI). Despite its drawbacks, UTP is the most common cable type. UTP is inexpensive, can be easily bent during installation, and, in most cases, the risk from the above drawbacks is not enough to justify more expensive cables.
Resource(s) used for this question:
Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 6507-6511). Auerbach Publications. Kindle Edition.
http://en.wikipedia.org/wiki/TIA/EIA-568#cite_note-7
http://en.wikipedia.org/wiki/Twisted_pair
AIOv3 Telecommunication and Networking Security (page 455)
Submit