IBM PC Server 325, Руководство пользователя

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10BASE-T Cables
b. If the port on the repeater is not a crossover port (also
known as an MDI port), use a UTP cable that is wired as a
crossover cable.
Do not use telephone extension cables to connect the server to a
10BASE-T repeater. The wire pairs in those cables are not twisted
and the cable does not meet other requirements for use in a
10BASE-T network. You can identify telephone extension cables by
their flat and thin appearance. UTP cables are rounder and thicker
than telephone extension cables.
Table 10 describes the specifications for UTP cable used in
10BASE-T link segments.
The following figure illustrates the RJ-45 connector.
10BASE-T UTP Cable
RJ-45 Modular Plug Connector
1
2
3
Pins 6
Table 10. Cabling Specifications for 10BASE-T Link Segments
Characteristic Specification ñ
Cable type UTP cable with 2 twisted pairs of 22, 24,
or 26 AWG
ò
Nominal impedance 100 ohms
Velocity of propagation 0.585 c ó
Maximum attenuation 8 to 10 dB per 100 m at 10 MHz
ñ Cables that have been certified as EIA/TIA-568 Category 3, 4, and 5 are among
the cable types that meet all of the 10BASE-T specifications.
ò
The cable can contain two to four twisted pairs, but only two of the pairs will be
used by the 10BASE-T network.
ó The c represents the velocity of light traveling in a vacuum, which is
300 000 km/sec (186 400 mi/sec).
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PC Server 325 User's Handbook