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Catalyst 6500 Series Ethernet Modules Installation Guide
OL-6265-03
Chapter 3 Installing Ethernet Switching Modules
Attaching the Network Interface Cables
Figure 3-18
Mode Conditioning Patch Cord with LC (SFP Transceiver) Connector
The mode-conditioning patch cord assembly is composed of duplex optical fibers, including a
single-mode-to-multimode offset launch fiber connected to the transmitter, and a second conventional
graded-index multimode optical fiber connected to the receiver. The use of a plug-to-plug patch cord
maximizes the power budget of multimode 1000BASE-LX/LH links.
Note
The mode-conditioning patch cord is required to comply with IEEE standards. The IEEE found that link
distances could not be met with certain types of fiber-optic cable cores. The solution is to launch light
from the laser at a precise offset from the center, which is accomplished by using the mode-conditioning
patch cord. At the output end of the patch cord, the GBIC-LX/LH is compliant with the IEEE 802.3z
standard for 1000BASE-LX.
1
Gray color identifier
2
To gigabit Ethernet interface
3
Blue color identifier
4
Multimode fiber
5
Single-mode fiber
6
Offset junction
7
Beige color identifier
8
To cable plant
/ /
/ /
/ /
TX
Offset
RX
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1
7
2
3
7
4
8
6
5
4