Cabletron Systems STH-24 User's Guide download pdf (Page 74)

Unshielded Twisted Pair (UTP)

Page B-2

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).

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

critical. Seek the highest practical grade. The quality of

connectors and terminators is also critical.

DO NOT connect UTP cabling to any non-Token Ring

network conductors (telephone, etc.) or ground. If in doubt,

test wiring before using. Telephone Battery and Ringing

voltages used in UTP telephone circuits may present a shock

hazard and may damage Token Ring equipment when

connected to Token Ring cabling.

B.1.2 UTP Lobe Lengths

The physical length of the cable connecting a station to a TCU port on the

STHI is referred to as the lobe length. The maximum lobe length

attainable under ideal conditions, is shown in Table B-2. Cable routing,

connector attenuation, noise, and crosstalk can adversely affect the

maximum lobe length.

Table B-1. UTP Cable Category Specifications

UTP

Cat.

Operating

Frequency

Electrical

Impedance

Signal

Attenuation

per 100m

loss

(@ ≥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.

WARNING

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Cabletron Systems STH-24 User's Guide Page 74