Cabletron Systems 24, STHI-44, STH-22, 42 manual UTP Cable Categories, Next

UTP Cable Categories

Table 2-1. UTP Cable Category Specifications

UTP	Operating	Electrical		Signal	NEXT
			Attenuation		loss
Cat.	Frequency	Impedance
			per 100m		(@ ≥100m)
3	4 MHz	≤ 100Ω ±15%	≤	5.6 dB	≥ 32 dB
	16 MHz	≤ 100Ω ±15%	≤ 13.1 dB		≥ 23 dB*
4	4 MHz	≤ 100Ω ±15%	≤	4.3 dB	≥ 47 dB
	16 MHz	≤ 100Ω ±15%	≤	8.9 dB	≥ 38 dB
5	4 MHz	≤ 100Ω ±15%	≤	4.3 dB	≥ 63 dB
	16 MHz	≤ 100Ω ±15%	≤	8.2 dB	≥ 44 dB

*below Token Ring performance requirement of ≥ 30.5 dB.

Category 3 consists of (usually) four Unshielded Twisted Pairs of

24 AWG solid wire for data or voice communication. (IBM Type 3 is coincidentally the same as UTP Category 3.) It is typically used to wire cable 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 meet the performance requirements of a Token Ring network. This may impose lower limits on lobe cable distances and ring node counts. See Table 2-1.

Categories 4 and 5 are higher quality versions of category 3. They use the same gauge of wire but demonstrate superior performance due to improvements in material quality and assembly (e.g. more twists per foot).

Warning: Because Near-End Crosstalk (NEXT) contributes the majority of its detrimental effects near the end of a lobe cable, the quality of jumper cables and patch cables is most critical. Seek the highest practical grade. The quality of connectors and terminators is also critical.

Warning: Telephone Battery and Ringing voltages used in UTP telephone circuits could present a shock hazard and can damage Token Ring equipment if connected to Token Ring cabling. DO NOT connect

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