Cabletron Systems MICROMMAC-22T, 42T manual UTP Cable Specifications, Attenuation and Impedance

REQUIREMENTS/SPECIFICATIONS

2.1.1 UTP Cable Specifications

The MicroMMAC-22T and MicroMMAC-24T lobe ports and the TPIM-T2 support voice grade Unshielded Twisted Pair (UTP) cable, as described in specifications for 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 building walls. 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. The voltages used in UTP telephone circuits 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 in UTP cable design. Better grades of UTP cable, known as supergrade or level 4, provide improved transmission characteristics and may allow operation at 16 Mbps on longer lobe cables.

Attenuation and Impedance

The values listed in Figure 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	100Ω ±15%	<26 dB/km (8 dB/1000 ft)
4	MHz	100Ω ±15%	<56 dB/km (16 dB/1000 ft)
10	MHz	100Ω ±15%	<98 dB/km (30 dB/1000 ft)
16	MHz	100Ω ±15%	<131 dB/km (40 dB/1000 ft)

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