Specifying Loopbacks - Cisco 10000 Series Configuration Manual

Chapter 5 24-Port Channelized E1/T1 Line Card Configuration

Specifying Loopbacks

This line card supports local and network E1 and T1 loopback modes, and remote T1 loopback modes
for testing, network fault isolation, and agency compliance. You can test E1 and T1 lines in local and
network loopback modes. You can also test T1 lines in remote mode.
Specifying E1 Loopbacks
If problems occur when you configure an E1 interface, you can troubleshoot the line card by using the
following command in controller configuration mode:
[no] loopback {local | network {line | payload}}
Where:
•
Note
•
•
Use the no form of the command to terminate a loopback.
For more information on this command, see the online
Troubleshooting
Example 1:
•
Example 2:
The following commands configure the E1 controller for local loopback at port 0, channel group 1
Router(config)# controller e1 1/0/0
Router(config-controller)# loopback local
Router(config-controller)#
Specifying T1 Loopbacks
If problems occur when you configure an T1 interface, you can troubleshoot the line card by using the
following command in controller configuration mode:
[no] loop {local | network {line | payload} | remote {line | payload | iboc}}
Where:
•
OL-8834-04
local—Configures the line card to loop transmitted traffic back to the line card as E1 received traffic
and sends the local transmit signal to the remote receiver.
An E1 port in local loopback mode cannot send AIS due to hardware limitations. It only
transmits to the line what it loops back to it's receive. As a result, the remote end will keep
receiving packets from a port in local loopback.
network line—Configures the line card to loop received traffic back to the remote device without
passing them through the framer.
network payload—Configures the line card to loop received traffic back to the remote device after
passing them through the framer.
Guide.
Configure an E1 controller port for local loopback.
Router(config)# controller e1 1/0/0
Router(config-controller)# loopback local
Router(config-controller)#
local—Configures the line card to loop transmitted traffic back to the line card as T1 received traffic
and sends the local transmit signal to the remote receiver.
Cisco 10000 Series Internet Router
Cisco 10000 Series Router Line Card Configuaration Guide
Controller Configuration Commands
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