Verilink Access Manager 2000 (896-502037-001) Product Manual - Manual (Page 322)

Monitoring and Troubleshooting Access Manager
8-52 Access Manager 2000 User Manual
After selecting the loopback activity, the Select Port Number to
Receive Loopback Request screen appears.
4. Select the data port to loop up by typing its number (1 or 2 for a DIU
2130 or DIU 1130;1, 2, 3, 4 or 5 for a DIU 2140) and pressing
, or press to cancel the operation.
5. If you are activating a DIU loopback, a warning message now
appears telling you that the selected test will place the data port out
of service. A prompt also appears, asking you to confirm that you
want to proceed with the loopback. To do so, type
Y . Any other
response aborts the test.
6. If you are deactivating a DIU loopback and previously changed the
timing mode of the CSU, restore the CSU to its original timing.
7. All loopbacks you have activated (i.e., loop up) will remain active
until you deactivate (i.e., loop down) them.
Testing CSUs
This procedure applies to AS2000 CSU circuit elements only.
If the CSU is used with a DIU, and a CSU loopback is required,
determine the appropriate CSU timing for that loopback. For example,
avoid tests with no timing source: when an LLB is set and the network
does not supply timing, then NET timing the unlooped CSU is invalid and
introduces errors in the test.
When this test is complete, you will remove the loopback and restore the
CSU to its original timing.
You will then configure the CSU timing that is required for this test.
F5 F2