Ethernet cable, commonly referred to as Cat 6, is a standardized twisted pair cable for Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards. Compared with Cat 5 and Cat 5e, Cat 6 features more stringent specifications for crosstalk and system noise. The cable standard specifies performance of up to 250 MHz.
Whereas Category 6 cable has a reduced maximum length when used for 10GBASE-T, Category 6A cable (or Augmented Category 6) is characterized to 500 MHz and has improved alien crosstalk characteristics, allowing 10GBASE-T to be run for the same 100 meter distance as previous Ethernet variants.
The standard for Category 6A is ANSI/TIA-568-C.1, defined by the TIA for enhanced performance standards for twisted pair cable systems. It was defined in 2009. Category 6A is defined at frequencies up to 500 MHz—twice that of Cat 6.
Category 6A performs at improved specifications, in particular in the area of alien crosstalk as compared to Cat 6 UTP (unshielded twisted pair), which exhibited high alien noise in high frequencies.
The global cabling standard ISO/IEC 11801 has been extended by the addition of amendment 2. This amendment defines new specifications for Cat 6A components and Class EA permanent links. These new global Cat 6A/Class EA specifications require a new generation of connecting hardware offering far superior performance compared to the existing products that are based on the American TIA standard.
The most important point is a performance difference between ISO/IEC and EIA/TIA component specifications for the NEXT transmission parameter. At a frequency of 500 MHz, an ISO/IEC Cat 6A connector performs 3 dB better than a Cat 6A connector that conforms with the EIA/TIA specification. 3 dB equals 50 % reduction of near-end crosstalk noise signal power; see 3dB-point.
Confusion therefore arises because of the different naming conventions and performance benchmarks laid down by the International ISO/IEC and American TIA/EIA standards, which in turn are different from the regional European standard, EN 50173-1. In broad terms, the ISO standard for Cat 6A is the highest, followed by the European standard, and then the American (1 on 1 matching capability).