The ANSI/EIA/TIA-568 designation for 100-ohm unshielded twisted-pair cables and associated connecting hardware whose characteristics are specified for data transmission up to 20 Mb/s.
CATEGORY 4
Meaning of CATEGORY 4 in English
Telecommunication standard terms English vocab. Английский словарь стандартных телекоммуникационных терминов. 2012