T568A

ANSI/TIA-568 is a set of telecommunications standards from the Telecommunications Industry Association (TIA). The standards address commercial building cabling for telecommunications products and services.

As of 2017, the standard is at revision D, replacing the 2009 revision C, 2001 revision B, the 1995 revision A, and the initial issue of 1991, which are now obsolete.

Perhaps the best known features of ANSI/TIA-568 are the pin/pair assignments for eight-conductor 100-ohm balanced twisted pair cabling. These assignments are named T568A and T568B.

An IEC standard ISO/IEC 11801 provides similar standards for network cables.

ANSI/TIA-568 was developed through the efforts of more than 60 contributing organizations including manufacturers, end-users, and consultants. Work on the standard began with the EIA, to define standards for telecommunications cabling systems. EIA agreed to develop a set of standards, and formed the TR-42 committee, with nine subcommittees to perform the work. The work continues to be maintained by TR-42 within the TIA, EIA is not longer in existence and hence EIA removed from the name.

The first revision of the standard, TIA/EIA-568-A.1-1991 was released in 1991. The standard was updated to revision B in 1995. The demands placed upon commercial wiring systems increased dramatically over this period due to the adoption of personal computers and data communication networks and advances in those technologies. The development of high-performance twisted pair cabling and the popularization of fiber optic cables also drove significant change in the standards. These changes were first released in a revision C in 2009 which has subsequently been replaced by the D series.

ANSI/TIA-568 defines structured cabling system standards for commercial buildings, and between buildings in campus environments. The bulk of the standards define cabling types, distances, connectors, cable system architectures, cable termination standards and performance characteristics, cable installation requirements and methods of testing installed cable. The main standard, ANSI/TIA-568.0-D defines general requirements, while ANSI/TIA-568-C.2 focuses on components of balanced twisted-pair cable systems. ANSI/TIA-568.3-D addresses components of fiber optic cable systems, and ANSI/TIA-568-C.4, addressed coaxial cabling components.

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