Connectivity Rules

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4
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 b reak
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 and 6 specifications include 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 802.3ab standards.

1000 Mbps Gigabit Ethernet Collision Domain

Table 4-1. Maximum 1000BASE-T Gigabit Ethernet Cable Length
Table 4-2. Maximum 1000BASE-SX Gigabit Ethernet Cable Lengths
Table 4-3. Maximum 1000BASE-LX Gigabit Ethernet Cable Length
Cable Type Maximum Cable Length Connector
Category 5, 5e, or 6 100-ohm UTP or STP 100 m (328 ft) RJ-45
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
Fiber Size Fiber Bandwidth Maximum Cable Length Connector
9/125 micron
single-mode fiber
N/A 2 m - 5 km (7 ft - 3.2 miles) LC