Cabletron Systems 100BASE-FX, Руководство по кабельной продукции

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IEEE 802.5 Unshielded Twisted Pair 10-7
Token Ring Network Requirements
When passive Token Ring technology is used, the link length for each network
operating speed is reduced. A passive 4 Mbps Token Ring network may support
Category 3 or 4 UTP cabling lengths of 100 m (328 ft) or less, while a 16 Mbps
network can support a maximum length of 60 m (196 ft).
Category 5
Category 5 UTP cabling, being of higher construction quality, is capable of
supporting longer link lengths than UTP cabling of Categories 3 or 4. As with
other types of UTP cabling, the type of circuitry used and the speed of the
network affect the maximum link length allowable.
A Token Ring network using active technology and operating at 4 Mbps may
support a Category 5 UTP cable link of 250 m (820 ft), while the same network, if
set to operate at the higher 16 Mbps speed, can support a maximum Category 5
link length of 120 m (393 ft).
The use of passive Token Ring technology reduces the maximum link length to
130 m (426 ft) at 4 Mbps, or 85 m (278 ft) at 16 Mbps.
The maximum link lengths specified for UTP cabling of any Category assume that
all other specifications and limitations for IEEE 802.5-compliant UTP cabling have
been met.
Trunk Cable Length
The length limitations given here assume that the trunk cabling under
examination meets all other specifications of the IEEE 802.5 standard for UTP
cabling.
Category 3/4
The tested requirements for Category 3 or 4 UTP trunk cables are the same as
those required for UTP lobe cables using Category 3 or Category 4 cabling. The
maximum link length of a Category 3 or 4 trunk cable at 4 Mbps is 200 m (656 ft).
A 16 Mbps Token Ring network would allow a maximum Category 3 or 4 UTP
trunk link length of 100 m (328 ft).
NOTE
UTP is not recommended for Ring-In/Ring-Out connections.