references by reading the synchronization messages in the OC-N
transport overhead bytes.
If automatic synchronization reconfiguration is enabled, Metropolis
®
DMXplore automatically selects the highest quality reference. Sync
messaging and automatic synchronization reconfiguration can be
provisioned using the
set-syncn
command or from the WaveStar
®
CIT System View,
Configuration
→
Timing/Sync
. Automatic
synchronization reconfiguration must be enabled for synchronization
reference protection switching to operate.
When a manual revertive reference switch is performed, the system
reports a standing condition indicating a revertive reference switch is
active. A Reset is required to switch back to the designated primary
reference and clear the standing condition. When a manual
nonrevertive reference switch is performed, the system does not report
any standing conditions or alarms since both references are designated
for service.
Synchronization mode
protection switching
The system can be provisioned to revertive or nonrevertive timing
mode switching. If provisioned for revertive mode switching (default),
the system automatically switches from holdover mode to the
provisioned timing mode (line timing) when a timing reference failure
clears. If provisioned for nonrevertive mode switching, the system
must be manually switched from holdover mode to the provisioned
timing mode (line timing) when a timing reference failure clears.
The sources used to supply line timing (either main-1-1 or main-2-1)
can be manually selected in the line timing mode.
Timing modes may be provisioned using the set-syncn command or
from the WaveStar
®
CIT System View menu, select
Configuration
→
Timing/Sync
.
Synchronization reference protection
switching
Maintenance overview
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Lucent Technologies
365-372-333 R2.1
Issue 4, June 2005