Cisco Systems 7200 VXR manual Mode-Conditioning Patch Cord Description, 3-23

Chapter 3 Installing a Cisco 7200 VXR Router

Connecting I/O Controller, NPE-G1, or NPE-G2 Cables

Table 3-4provides NPE-G2 CWDM SFP module configuration information.

Table 3-4	NPE-G2 CWDM SFP Module Configurations
CWDM Product Number		Color
CWDM-SFP-1470		Gray
CWDM-SFP-1490		Violet
CWDM-SFP-1510		Blue
CWDM-SFP-1530		Green
CWDM-SFP-1550		Yellow
CWDM-SFP-1570		Orange
CWDM-SFP-1590		Red
CWDM-SFP-1610		Brown

Mode-Conditioning Patch Cord Description

Amode-conditioning patch cord can be used with the SFP-GE-L= (SFP module) to allow reliable laser transmission between the single-mode laser source on the SFP module and a multimode optical fiber cable.

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.

A mode-conditioning patch cord is an optical fiber cable assembly that consists of a pair of optical fibers terminated with connector hardware. Specifically, the mode-conditioning patch cord is composed of a single-mode optical fiber permanently coupled off-center (see Offset in Figure 3-17) to a graded-index multimode optical fiber. Figure 3-17shows a diagram of the mode-conditioning patch cord assembly.

Cisco 7200 VXR Installation and Configuration Guide

OL-5013-09 3-23