Specifications

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Channelized and Electrical Interface Line Card Installation and Configuration
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Configuring and Troubleshooting Line Card Interfaces
Setting the Clock Source for the T3 Controller
To set the selected T3 controller, use the clock source {internal | line} controller configuration
command. The default is clock source internal.
• The following example shows how to configure a line clock source:
Router(config)# controller T3 6/0
Router(config-controller)# clock source line
Router(config-controller)#
• The following example shows how to configure an internal clock source:
Router(config)# controller T3 6/0
Router(config-controller)# clock source internal
Router(config-controller)#
Using T3 Controller Loopback Modes
To test the T3 controller, use the loopback [local | network | remote] controller configuration
commands shown in Table 29. To return the T3 controller to its default condition, use the no form of the
command.
• Use the loopback local controller configuration command to diagnose problems with the 6-port
channelized T3 (T1) line card when it is isolated from the network cables. The following example
is for a 6-port channelized T3 (T1) line card in slot 6 of the Cisco 12000 Series Router:
Router(config)# controller T3 6/0
Router(config-controller)# loopback local
• Network loopback loops the T3 line back toward the network and can be used to diagnose problems
with cables. The following example shows how to configure the T3 controller for network loopback.
The T3 controller is on a 6-port channelized T3 (T1) line card in slot 6 and port 0 of the Cisco 12000
Series Router.
Router(config)# controller T3 6/0
Router(config-controller)# loopback network
Table 29 Supported T3 Controller Loopback Modes
Loopback modes
Configuration
Mode Command
Diagnostic or local
loopback
loopback local Router(config-controller)# loopback local
Network loopback
modes
loopback
network
Router(config-controller)# loopback network
Remote T3 loopback loopback
remote
Router(config-controller)# loopback remote
equipment network
loopback
equipment
network
loopback
Router(config-controller)# equipment network loopback
Default value default value Router(config-controller)# no loopback