Cisco ONS 15454 Troubleshooting Manual page 344

2.7.204 LOF (EC1)
The E1 LOF alarm appears on the DS1/E1-56 card when the card is placed in All E1 mode. It indicates
that the receiving ONS 15454 has lost frame delineation in an incoming E1 data stream. The transmitting
equipment could possibly have its framing set to a format that differs from the receiving node. For more
information about the DS1/E1-56 card, refer to the "Electrical Cards" chapter in the Cisco ONS 15454
Reference Manual.
The DS1/E1-56 card only carries an E1 signal within an STS-3c/VT2 circuit.
Note
Clear the LOF (E1) Alarm
Step 1 Verify that the line framing and line coding match between the DS1/E1-56 port and the signal source:
a.
b.
c.
d.
e.
f.
g.
If the alarm does not clear, log into the Technical Support Website at http://www.cisco.com/techsupport
Step 2
for more information or call Cisco TAC 1 800 553-2447 in order to report a Service-Affecting (SA)
problem.
2.7.204 LOF (EC1)
The EC1/EC1-12 LOF alarm occurs when a port on the reporting EC1/EC1-12 or DS3/EC1-48 card has
an LOF condition. LOF indicates that the receiving ONS 15454 has lost frame delineation in the
incoming data. LOF occurs when the SONET overhead loses a valid framing pattern for 3 milliseconds.
Receiving two consecutive valid A1/A2 framing patterns clears the alarm.
Cisco ONS 15454 Troubleshooting Guide, R8.5
2-150
In CTC, note the slot and port reporting the alarm.
Find the coding and framing formats of the signal source for the card reporting the alarm. You could
need to contact your network administrator for this information.
Double-click the DS1/E1-56 card to open the card view.
Click the Provisioning > Line tabs.
Verify that the line type of the reporting port matches the line type (E1_MF, E1_CRCMF,
AUTOFRAMED, UNFRAMED) of the signal source. If the signal source line type does not match
the reporting port, click the Line Type cell to reveal a drop-down list and choose the matching type.
Verify that the reporting Line Coding matches the signal source line coding. If the signal source line
coding does not match the reporting port, click the Line Coding cell and choose the correct type
from the drop-down list.
Click Apply.
Note When you replace a card with the identical type of card, you do not need to make any
changes to the database.
Default Severity: Critical (CR), Service-Affecting (SA)
SONET Logical Object: EC1
Chapter 2 Alarm Troubleshooting
November 2009