C
HAPTER
2
| Network Planning
Application Notes
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APPLICATION NOTES
1. Full-duplex operation only applies to point-to-point access (such as when a
switch is attached to a workstation, server, or another switch). When the
switch is connected to a hub, both devices must operate in half-duplex
mode.
2. Avoid using flow control on a port connected to a hub unless it is actually
required to solve a problem. Otherwise back pressure jamming signals may
degrade overall performance for the segment attached to the hub.
3. As a general rule the length of fiber optic cable for a single switched link
should not exceed:
■
1000BASE-SX: 550 m (1805 ft) for multimode fiber.
■
1000BASE-LX: 10 km (6.2 miles) for single-mode fiber.
■
1000BASE-LH: 80 km (50 miles) for single-mode fiber.
■
100BASE-FX: 20 km (12 miles) for single-mode fiber.
However, power budget constraints must also be considered when calculating
the maximum cable length for your specific environment.