Cabletron Systems STHI - Manual (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
NEXT
loss
(@
≥
100m)
3 4 MHz
≤
100
Ω ±
15%
≤
5.6 dB
≥
32 dB
16 MHz
≤
100
Ω ±
15%
≤
13.1 dB
≥
23 dB*
4 4 MHz
≤
100
Ω ±
15%
≤
4.3 dB
≥
47 dB
16 MHz
≤
100
Ω ±
15%
≤
8.9 dB
≥
38 dB
5 4 MHz
≤
100
Ω ±
15%
≤
4.3 dB
≥
63 dB
16 MHz
≤
100
Ω ±
15%
≤
8.2 dB
≥
44 dB
*below Token Ring performance requirement of
≥
30.5 dB.
WARNING
WARNING