Los (Bits); Clear The Los (Bits) Alarm - Cisco ONS 15310-CL Troubleshooting Manual

1.7.145 LOS (BITS)

Step 5 If the alarm does not clear, inspect and clean the receive and transmit node fiber connections according
to site practice. If no site practice exists, complete the procedure in the "Maintain the Node" chapter in
the Cisco ONS 15310-CL and Cisco ONS 15310-MA Procedure Guide.
Always use the supplied electrostatic discharge wristband when working with a powered ONS 15310-CL
Caution
or ONS 15310-MA.
If the alarm does not clear, ensure that the fiber is not broken or damaged by testing it with an optical
Step 6
test set. If no test set is available, use the fiber for a facility (line) loopback on a known-good port. The
error reading you get is not as precise, but you generally know whether the fiber is faulty. For specific
procedures to use the test set equipment, consult the manufacturer.
Step 7 If the alarm does not clear, and no faults are present on the other port(s) of the transmit or receive card,
do a facility loopback on the transmit and receive ports with known-good loopback cable. Complete the
"1.2.1 Perform a Facility Loopback on a Source-Node Port" procedure on page 1-4
If a port is bad and you need to use all the port bandwidth, complete the
Step 8
procedure on page
at the next available maintenance window.
Caution Removing a card that currently carries traffic on one or more ports can cause a traffic hit. To avoid this,
perform an external switch if a switch has not already occurred. See the
Lock Initiation, and Clearing" section on page 1-148
Note
If no ports are shown bad and the alarm does not clear, log into the Technical Support Website at
Step 9
http://www.cisco.com/techsupport for more information or call Cisco TAC (1 800 553-2447).

1.7.145 LOS (BITS)

The LOS (BITS) alarm indicates that the 15310-CL-CTX or CTX2500 has an LOS from the BITS timing
source. The LOS (BITS-N) means the BITS clock or the connection to it failed.

Clear the LOS (BITS) Alarm

Step 1 Verify the wiring connection from the BITS clock pin fields on the ONS 15310-CL or ONS 15310-MA
to the timing source.
Always use the supplied electrostatic discharge wristband when working with a powered ONS 15310-CL
Caution
or ONS 15310-MA.
Cisco ONS 15310-CL and Cisco ONS 15310-MA Troubleshooting Guide, R7.0
1-94
1-155. If the port is bad but you can move the traffic to another port, replace the card
When you replace a card with the identical type of card, you do not need to make any changes
to the database.
Default Severity: Minor (MN), Non-Service-Affecting (NSA)
SONET Logical Object: BITS
Chapter 1
"Physically Replace a Card"
"1.10.1 Protection Switching,
for commonly used traffic-switching procedures.
Alarm Troubleshooting
to test the loopback.
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