Alcatel-Lucent 7950 XRS Series, Configuration Manual

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Forcing a Specific Reference
Page 312 7950 SR OS Basic System Configuration Guide
Forcing a Specific Reference
Note: The debug sync-if-timing force-reference command should only be used to test and debug
problems. Network synchronization problems may appear if network elements are left with this
manual override setting. Once the system timing reference input has been forced, it may be cleared
using the no force-reference command.
You can force the CPM clock to use a specific input reference using the force-reference command.
When the command is executed, the CPM clock on the active CPM immediately switches its input
reference to that specified by the command. If the specified input is not available (shutdown), or
in a disqualified state, the CPM clock shall use the next qualified input reference based on the
selection rules.
This command also affects the BITS output port. If the BITS output port selection is set to line-
reference and the reference being forced is not the BITS input port, then the system uses the forced
reference to generate the signal out the BITS output port. If the BITS output port selection is set to
internal-clock, then the system uses the output of the CPM clock to generate the signal for the
BITS output port.
On a CPM activity switch, the force command is cleared and normal reference selection is
determined.
Debug configurations are not saved between reboots.
CLI Syntax:
debug>sync-if-timing
force-reference {ref1 | ref2 | bits}
Example: debug>sync-if-timing# force-reference