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Cisco ONS 15310-CL and Cisco ONS 15310-MA Troubleshooting Guide, R7.0
Chapter2 Alarm Troubleshooting
2.7.148 LOS (EC1)
Step3 If the port is not currently assigned, place the port out of service using the following steps:
a. In node view, double-click the card to display the card view.
b. Click the Maintenance > DS3 tabs.
c. In the Admin State column, click OOS,DSBLD.
d. Click Apply.
Step4 If the port is assigned, verify that the correct port is in service by completing the following steps:
a. To confirm this physically, confirm that the green ACT LED is on.
b. To determine this virtually, double-click the card in CTC to display the card view and complete the
following substeps:
•Click the Provisioning > DS3 > Line tabs.
•Verify that the Admin State column lists the port as IS.
•If the Admin State column lists the port as OOS,MT or OOS,DSBLD, click the column and
choose IS. Click Apply.
Note If ports managed into IS administrative state are not receiving signals, the LOS alarm is
either raised or remains, and the port service state transitions to OOS-AU,FLT.
Step5 Use a test set to confirm that a valid signal exists on the line. Test the line as close to the receiving port
as possible. For specific procedures to use the test set equipment, consult the manufacturer.
Step6 Ensure that the transmit and receive outputs from the DSx panel to your equipment are properly
connected. For more information about cable connections and terminations, refer to the “Install
Hardware” chapter in the Cisco ONS 15310-CL and Cisco ONS 15310-MA Procedure Guide.
Step7 If a valid signal is not present and the transmitting device is operational, replace the cable connecting
the transmitting device to the port. To do this, refer to the “Install Hardware” chapter in the
Cisco ONS 15310-CL and Cisco ONS 15310-MA Procedure Guide for procedures. For more
information about the cards, refer to the CiscoONS 15310-CL and Cisco ONS 15310-MA Ethernet Card
Software Feature and Configuration Guide.
Step8 Repeat Steps 1 to 7 for any other port on the card that reports the LOS.
Step9 If the alarm does not clear, log into the Technical Support Website at http://www.cisco.com/techsupport
for more information or call CiscoTAC (1-800-553-2447) in order to report a Service-Affecting (SA)
problem.
2.7.148 LOS (EC1)
Default Severity: Critical(CR), Service-Affecting (SA)
SONET Logical Object: EC1
LOS on a 15310-CL-CTX, DS1-28/DS3-EC1-3, or DS1-84/DS3-EC1-3 card EC-1 port occurs when a
SONET receiver detects an all-zero pattern for 10 microseconds or longer. An LOS (EC1) most likely
means that the upstream transmitter has failed. If an EC1 LOS alarm is not accompanied by additional
alarms, a cabling problem (such as an incorrect attachment, a fiber cut, or another fiber error) usually
causes this alarm. The condition clears when the problem is corrected, allowing two consecutive valid
frames to be received.