Los (Bits); Los (Ds-N) - Cisco ONS 15327 User Documentation

Alarm Procedures
Perform a soft reset on the far-end card.
Step 6
Step 7 Switch from the far-end working card to the far-end protect card.

14.4.75 LOS (BITS)

•
The XTC card has a loss of signal (LOS) from the BITS timing source. An LOS alarm occurs when a
SONET receiver detects an all-zero pattern for 10 microseconds or longer. An LOS (BITS-N) means the
BITS clock or the connection to the BITS clock failed.
Always use the supplied ESD wristband when working with a powered ONS 15327. Plug the wristband
Caution
cable into the ESD jack located on the lower-right outside edge of the shelf assembly.
Procedure: Clear the LOS Alarm
Verify the wiring connection from the ONS 15327 backplane BITS clock pin fields to the timing source.
Step 1
Check that the BITS clock is operating properly.
Step 2

14.4.76 LOS (DS-N)

•
The LOS is alarm indicates a loss of signal at the card for an XTC card port. LOS occurs when the port
on the card is in service but no signal is being received. The cabling is not correctly connected to the
card, or no signal exists on the line. Possible causes for no signal on the line include upstream equipment
failure or a fiber cut.
Always use the supplied ESD wristband when working with a powered ONS 15327. Plug the wristband
Caution
cable into the ESD jack located on the lower-right outside edge of the shelf assembly.
Procedure: Clear the LOS Alarm on the XTC Card
Step 1 Verify cabling continuity to the port.
Step 2 Verify that the correct port is in service.
Use a test set to confirm that a valid signal exists on the line. Test the line as close to the receiving card
Step 3
as possible.
Ensure that the transmit and receive outputs from the DSx panel to your equipment are properly
Step 4
connected.
If there is a valid signal, replace the DS-N connector on the ONS 15327.
Step 5
Cisco ONS 15327 User Documentation, R3.3
14-56
Major, Service-Affecting
Critical, Service-Affecting
Chapter 14 Alarm Troubleshooting
June 2002