Differential Mode Delay - Cisco 7603 - Modular Expansion Base Installation Manual

Determining Cable Distances
Cisco Gigabit Ethernet products have been tested and evaluated to comply with the standards listed in
Note
Appendix A, "Technical Specifications."
Patch Cord Configuration Example
Figure 2-1
Figure 2-1
1000BASE-LX/LH
Patch Cord Installation
Invisible laser radiation may be emitted from disconnected fibers or connectors. Do not stare into
Warning
beams or view directly with optical instruments.
Plug the end of the patch cord labeled "To Equipment" into the GBIC. (See
labeled "To Cable Plant" into the patch panel. The patch cord is 9.84 feet (3 meters) long and has duplex
SC male connectors at each end.
Figure 2-2

Differential Mode Delay

When an unconditioned laser source designed for operation on a single-mode fiber (SMF) cable is
directly coupled to a multimode fiber (MMF) cable, differential mode delay (DMD) might occur. DMD
can degrade the modal bandwidth of the fiber-optic cable. This degradation causes a decrease in the link
span (the distance between the transmitter and the receiver) that can be reliably supported.
Book Title
2-14
shows a typical patch cord configuration.
Patch Cord Configuration
Patch
cord
Rx
Patch
port
panel
Tx
Link span greater than 984 ft
Patch Cord Installation
To equipment
Equivalent cables should also meet these standards.
Building Patch
cable plant cord
Patch
panel
(300 m)
Chapter 2 Preparing for Installation
Tx
1000BASE-LX/LH
port
Rx
Figure 2-2.) Plug the end
To cable plant
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