Cat 4 (Category 4) A type of cabling that is specified in ANSI/EIA/TIA 568, and ISO/IEC 11801. Originally developed in support of 16 Mbps IBM Token Ring LANs, Cat 4 is an orphaned category. Cat 4 runs over 24 AWG unshielded twisted pair (UTP) and is rated at 20 MHz. In ISO/IEC 11801 terms, Cat 4 falls into Class D (≤ 100 MHz). See also AWG, LAN, Token Ring, and UTP. 74570c03.qxd 9/11/07 12:19 PM Page 86 |