Specifications
1-51
Cisco ONS 15454 Troubleshooting and Maintenance Guide
November 2001
Chapter 1 Alarm Troubleshooting
This alarm indicates a loss of pointer (LOP) condition at the path level. LOP occurs when valid H1/H2
pointer bytes are missing from the SONET overhead. Receiving equipment monitors the H1/H2 pointer
bytes to locate the SONET payload. A LOP alarm means that eight, nine, or ten consecutive frames do
not have valid pointer values. The alarm clears when three consecutive valid pointers are received.
One of the conditions that can cause this alarm is a transmitted STSc circuit that is smaller than the
provisioned STSc. This condition causes a mismatch of the circuit type on the concatenation facility. For
example, if an STS-3c or STS-1 is sent across a circuit provisioned for STS-12c, a LOP alarm occurs.
Caution Always use the supplied electrostatic discharge wristband when working with a powered ONS 15454.
Plug the wristband cable into the ESD jack located on the lower-right outside edge of the shelf
assembly.
Procedure: Clear the LOP Alarm on a Line Card
Step 1 Verify the cabling and physical connections on the reporting card.
Step 2 Perform a software reset on the reporting card:
a. Display the CTC node view.
b. Position the cursor over the slot reporting the alarm.
c. Right-click to choose RESET CARD.
Step 3 Do a manual switch (side switch) to move traffic away from the card.
a. At the node view, click the Maintenance > Protection tabs.
b. Double-click the protection group that contains the reporting card.
c. Click the Protect/Standby card of the selected groups.
d. Click Manual and OK.
Note If you do not have a protect card for the reporting card, create a new circuit on the reporting
card to achieve the same effect.
Step 4 Clear the manual switch:
a. At the node view, click the Maintenance > Protection tabs.
b. Double-click the protection group that contains the reporting card.
c. Highlight either selected group.
d. Click Clear and click YES at the confirmation dialog box.
Step 5 If the alarm persists, the problem is at the far-end node. Verify the stability of the cabling and physical
connections that connect to the far-end card.
Step 6 Do a soft reset on the far-end card:
a. Display the CTC node view.
b. Position the cursor over the slot reporting the alarm.
c. Right-click and choose RESET CARD.
Step 7 Perform a soft reset on the reporting card:
a. Display the CTC node view.