Transition Networks SM24-100SFP-AH manual Connectivity Rules, 1000BASE-T Cable Requirements

4 Making Network Connections

The maximum length for fiber optic cable operating at Fast Ethernet speed will depend on the fiber type as listed under “100 Mbps Fast Ethernet Collision Domain” on page 4-5. The maximum length for fiber optic cable operating at Gigabit speed will depend on the fiber type as listed under “1000 Mbps Gigabit Ethernet Collision Domain” on page 4-4.

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 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 Collision Domain

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	160 MHz/km		2-220 m (7-722 ft)		LC
multimode fiber
	200 MHz/km		2-275 m (7-902 ft)		LC
50/125 micron multimode	400 MHz/km		2-500 m (7-1641 ft)		LC
fiber
	500 MHz/km		2-550 m (7-1805 ft)		LC
Table 4-3. Maximum 1000BASE-LX Gigabit Ethernet Cable Length
Fiber Size	Fiber Bandwidth		Maximum Cable Length		Connector
9/125 micron	N/A		2 m - 5 km (7 ft - 3.2 miles)		LC
single-mode fiber

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