Cisco WS-C6503 - Page 88

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Catalyst 6500 Series Supervisor Engine Guide
OL-7397-03
Chapter 3 Installing Supervisor Engines
Attaching the Network Interface Cables
When an unconditioned laser source designed for operation on single-mode optical fiber is directly
coupled to a multimode optical fiber cable, an effect known as differential mode delay (DMD) might
result in a degradation of the modal bandwidth of the optical fiber cable.
This degradation results in a decrease in the link span (the distance between a transmitter and a receiver)
that can be supported reliably. The effect of DMD can be overcome by conditioning the launch
characteristics of a laser source. A practical means of performing this conditioning is to use a device
called a mode-conditioning patch cord.
XENPAK LRM
(XENPAK-10GB-LRM=)
The Cisco XENPAK-10GB-LRM transceiver supports link lengths of
722
feet (220 m) on standard Fiber Distributed Data Interface (FDDI)
grade multimode fiber (MMF). To ensure that specifications are met
over FDDI-grade, OM1 and OM2 fibers, the transmitter should be
coupled through a mode conditioning patch cord. Cisco offers two
mode conditioning patch cords: CAB-GELX-625= (mode conditioning
patch cable 62.5
microns, dual SC connectors) and CAB-MCP50-SC=
(mode conditioning patch cable 50
microns, dual SC connectors). No
mode conditioning patch cord is required for applications over OM3
fiber.
X2 LRM
(X2-10GB-LRM)
The Cisco X2-10GB-LRM transceiver supports link lengths of
220
meters on standard Fiber Distributed Data Interface (FDDI) grade
multimode fiber (MMF). To ensure that specifications are met over
FDDI-grade, OM1 and OM2 fibers, the transmitter should be coupled
through a mode conditioning patch cord. Cisco offers two mode
conditioning patch cords: CAB-GELX-625= (mode conditioning patch
cable 62.5
microns, dual SC connectors) and CAB-MCP50-SC= (mode
conditioning patch cable 50
microns, dual SC connectors). No mode
conditioning patch cord is required for applications over OM3.
X2 LX4
(X2-10GB-LX4)
The Cisco X2-10GB-LX4 transceiver supports link lengths of
300
meters on standard FDDI grade MMF. To ensure that specifications
are met, the transmitter output should be coupled through a mode
conditioning patch cord. Cisco offers two mode conditioning patch
cords: CAB-GELX-625= (mode conditioning patch cable
62.5
microns, dual SC connectors) and CAB-MCP50-SC= (mode
conditioning patch cable 50
microns, dual SC connectors).
Table 3-3 Optical Transceivers Using a Mode-Conditioning Patch Cord
Transceiver Mode-Conditioning Patch Cord Usage