Cabletron Systems STHI 44 STHI-44 - Manual (Page 19)

UTP Cable Categories
Page 2-4
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
Table 2-1. 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.