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ETWORK

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LANNING

2-5

Connectivity Rules
When adding hubs (repeaters) to your network, please follow the
connectivity rules listed below for Ethernet, Fast Ethernet, or
Gigabit Ethernet. 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.

1000 Mbps Gigabit Ethernet Collision Domain

Maximum Fiber Optic Cable Distance for 1000BASE-SX

100 Mbps Fast Ethernet Collision Domain

SMC 3-2 Rule for Class II Repeaters
SMC 2-1 Rule for Class I Repeaters
Fiber Size Fiber Bandwidth Maximum Cable Length
62.5/125 micron 160 MHz/km 7-722 ft. (2-220 m)
200 MHz/km 7-902 ft. (2-275 m)
50/125 micron 400 MHz/km 7-1641 ft. (2-500 m)
500 MHz/km 7-1805 ft. (2-550 m)
Between any two PCs or other stations in the same 100BASE-TX
collision domain, there may be:
•up to 3 link segments and
•up to 2 Class II repeaters (hubs)
Between any two PCs or other stations in the same 100BASE-TX
collision domain, there may be:
•up to 2 link segments and
•up to 1 Class I repeater (hub)