Cabletron Systems 24 User Manual

UTP Cable CategoriesPage 2-4Category 3 consists of (usually) four Unshielded Twisted Pairs of24 AWG solid wire for data or voice communication. (IBM Type 3 iscoincidentally the same as UTP Category 3.) It is typically used to wirecable runs within the walls of buildings. In some installations, pre-existing UTP building wiring can be used for Token Ring cabling.Warning: At 16 Mb/s ring speeds, some Category 3 cable does not meetthe performance requirements of a Token Ring network. This mayimpose lower limits on lobe cable distances and ring node counts. SeeTable 2-1.Categories 4 and 5 are higher quality versions of category 3. They use thesame gauge of wire but demonstrate superior performance due toimprovements in material quality and assembly (e.g. more twists perfoot).Warning: Because Near-End Crosstalk (NEXT) contributes themajority of its detrimental effects near the end of a lobe cable, thequality of jumper cables and patch cables is most critical. Seek thehighest practical grade. The quality of connectors and terminators isalso critical.Warning: Telephone Battery and Ringing voltages used in UTPtelephone circuits could present a shock hazard and can damage TokenRing equipment if connected to Token Ring cabling. DO NOT connectTable 2-1. UTP Cable Category SpecificationsUTPCat.OperatingFrequencyElectricalImpedanceSignalAttenuationper 100mNEXTloss(@ ≥100m)3 4 MHz ≤ 100Ω ±15% ≤ 5.6 dB ≥ 32 dB16 MHz ≤ 100Ω ±15% ≤ 13.1 dB ≥ 23 dB*4 4 MHz ≤ 100Ω ±15% ≤ 4.3 dB ≥ 47 dB16 MHz ≤ 100Ω ±15% ≤ 8.9 dB ≥ 38 dB5 4 MHz ≤ 100Ω ±15% ≤ 4.3 dB ≥ 63 dB16 MHz ≤ 100Ω ±15% ≤ 8.2 dB ≥ 44 dB*below Token Ring performance requirement of ≥ 30.5 dB.