Clock Source Command - Cisco 10000 Series Configuration Manual

Chapter 15 8-Port Unchannelized E3/T3 Line Card Configuration
The default value is 450 feet.
Use the no form of this command to restore the default cable length.
In the following example, the cable length is set to 120 feet:
Router(config)# controller dsx3 4/0/6
Router(config-controller)# cablelength 120
The following cable length distances take into consideration line buildout for E3 and T3 controllers:
Interface
E3
E3
T3
T3

Clock Source Command

Use the clock source command to choose whether or not the transmitted clock is derived from the
received clock or is generated by an internal clock source. In some cases a network configuration may
require you to derive network synchronization from a remote master clock.
The clock source command is set in controller configuration mode using the following format:
clock source [internal | line]
Where:
•
•
The default is clock source internal.
In this example, the controller is instructed to use a line clock source.
Router(config)# controller dsx3 4/0/6
Router(config-controller)# clock source line
Never configure both sides of an E3 or T3 link to the clock source line.
Caution
Controller Description Command
Use the description command to identify particulars about the controller. You can enter up 80 characters
in your controller description string using the following format:
description string
In the following example, port 6 is labeled with a description to help identify it:
Router(config)# controller dsx3 4/0/6
Router(config-controller)# description "Company ABC; IP = 240.21.3.8"
OL-8834-04
Cable Length (feet)
0 to 224
225 to 450
0 to 299
300 to 450
internal specifies that the internal clock source is used
line specifies that the network clock source is used
Buildout
no line buildout
line buildout
no line buildout
line buildout
Cisco 10000 Series Router Line Card Configuaration Guide
Controller Configuration Commands
15-7