User's Manual

M AKING N ETWORK C ONNECTIONS
4-6
Connectivity Rules
When adding hubs (repeaters) to your network, please follow the
connectivity rules listed in the manuals for these products. However, note
that because switches break up the path for connected devices into
separate collision domains, you should not include the switch or connected
cabling in your calculations for cascade length involving other devices.
1000BASE-T Cable Requirements
All Category 5 UTP cables that are used for 100BASE-TX connections
should also work for 1000BASE-T, providing that all four wire pairs are
connected. However, it is recommended that for all critical connections, or
any new cable installations, Category 5e (enhanced Category 5) or
Category 6 cable should be used. The Category 5e specification includes
test parameters that are only recommendations for Category 5. Therefore,
the first step in preparing existing Category 5 cabling for running
1000BASE-T is a simple test of the cable installation to be sure that it
complies with the IEEE 802.3-2005 standards.
1000 Mbps Gigabit Ethernet Cable Lengths
Table 4-1 Maximum 1000BASE-T Gigabit Ethernet Cable Length
Cable Type Maximum Cable
Length
Connector
Category 5, 5e, 6 100-ohm UTP or STP 100 m (328 ft) RJ-45
Table 4-2 Maximum 1000BASE-SX Gigabit Ethernet Cable Length
Fiber Size Fiber Bandwidth Maximum Cable
Length
Connector
62.5/125 micron
multimode fiber
160 MHz/km 2-220 m (7-722 ft) LC
200 MHz/km 2-275 m (7-902 ft) LC
50/125 micron
multimode fiber
400 MHz/km 2-500 m (7-1641 ft) LC
500 MHz/km 2-550 m (7-1805 ft) LC