6. Troubleshooting
Send Line Loopback
The remote Line Loopback (LLB) up and down codes are in-band codes that allow
control of a remote device. The LLB Up code invokes a line loopback in the remote
unit while the LLB Down code terminates the remote line loopback. Network
loopbacks are defined in AT&T TR 62411.
A remote LLB cannot be started when one of the following tests is active:
T
T
T
Procedure
To start and stop a remote Line Loopback:
6-24
Main Menu → Test → Network Physical Tests
Any Loopback on the same interface.
Send FT1 Loopback or Data Channel Loopback on the synchronous data port.
Data Channel Loopback on the frame relay link on this network interface.
1. Select Network Physical Tests.
Main Menu → Test → Network Physical Tests
2. Select the code Up or Down in the Send Line Loopback field.
— Up – Puts a remote device in loopback.
— Down – Takes the remote device out of loopback.
3. Highlight Send and press Enter to start the test. The code is sent for
10 seconds.
4. View the length of time that the test has been running in the Result column.
August 2001
9123-A2-GB20-20