STM-1 Loss of frame alignment
...................................................................................................................................................................................................................................
Alarm identifier STM1cLOF
Information The position of the frame alignment bytes A1 and A2 in the Section Overhead
of the receive signal cannot be detected correctly. Thus, alignment to the
framing structure of the received signal is not possible, and as a result,
overhead and payload data cannot be extracted.
Alarm category Transmission
ASAP sdhPRS
Alarm severity
(default setting)
Prompt
Reporting state
(default setting)
Reported
Local indications The red fault LED is flashing.
Cause Possible causes of the alarm are:
• Unexpected signal structure in the receive signal (for example STM-4
instead of STM-1)
• Dirty optical connector(s)
• STM-1 not correctly formed in the upstream station
• Equipment fault(s) in the upstream station
Actions Check upstream external cabling and equipment.
Note(s) In the downstream direction, AIS is inserted.
In the upstream direction, “Multiplex Section - Remote Defect Indicator”
(MS-RDI) is inserted.
Alarm messages
...................................................................................................................................................................................................................................
365-312-803R7.2
Issue 4, May 2007
Alcatel-Lucent - Proprietary
See notice on first page
1-169
To Next Page
Loading...
