Cabletron Systems TRXI-24 - Manual (Page 13)

REQUIREMENTS/SPECIFICATIONS
Page 2-2
2.1.1 UTP Cable Specifications for the TRXI-22/24 Lobe Ports
and TPIM-T2
The TRXI-22 and TRXI-24 lobe ports and the TPIM-T2 support voice
grade Unshielded Twisted Pair (UTP) cable, as described in EIA/TIA
TSB 568, and IBM Type 3 cable.
UTP consists of four pairs of 24 AWG solid wire for data or voice
communication and is typically used to wire cable runs within the
walls of buildings. In some installations, existing UTP building wiring
can be used for token ring cabling. UTP cable must conform to the
limits shown in Table 2-1.
Warning : 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, could present a shock hazard and can damage token ring
equipment when connected to token ring cabling.
The increased popularity and cost advantages of UTP cable have
driven refinements to UTP cable design. As a result, better grades of
UTP cable, known as supergrade or level 4, are available that exhibit
improved transmission characteristics. These improved grades of UTP
can often be used to permit operation at 16 Mbps on longer lobe cables.
Attenuation and Impedance
The values listed in Table 2-1 include the maximum attenuation of the
cables, connectors, patch panels, and reflection losses due to
impedance mismatches in the segment.
Table 2-1. UTP Voice Grade and Category 3 Specifications
Frequency Impedance Attenuation
1 MHz 100
Ω ±
15% <26 dB/km (8 dB/1000 ft)
4 MHz 100
Ω ±
15% <56 dB/km (16 dB/1000 ft)
10 MHz 100
Ω ±
15% <98 dB/km (30 dB/1000 ft)
16 MHz 100
Ω ±
15% <131 dB/km (40 dB/1000 ft)