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Avaya CM cmgSyncSignalFault

Jeremy Boilard

Problem Statement

A Major alarm is raised on Avaya Communication Manager (Core) with maintenance object cmgSyncSignalFault and alarm code ACT. The alarm description indicates that the synchronization signal was lost for the provisioned clock-sync source.

Impact

The media gateway or E1/T1 span may be using an unintended timing reference or may have lost its external synchronization source. This can affect clocking stability for the associated E1/T1 media module or MM710 Media Module.

Alarm

cmgSyncSignalFault

Troubleshooting Steps

  1. Access the Media Gateway Processor (MGP) CLI for the affected media gateway.
  2. Run show sync timing to check whether the provisioned clock-sync source is present, active, and receiving a good signal.
  3. If an E1/T1 media module or MM710 is expected to provide timing, confirm that the DS1 has been added properly on the server using the System Access Terminal (SAT). If it has not been added, use the add DS1 command before attempting MGP CLI sync configuration commands.
  4. From the MGP CLI, configure the primary and secondary clock sources for the E1/T1 span using the set sync interface command. The internal local clock is built in and is not configured as a primary or secondary source from the CLI.
  5. Set the specific MM710 E1/T1 Media Module to be used as the active clock reference using the set sync source command.
  6. Run show sync timing again to verify that the intended source is provisioned and active.
  7. If onsite visual inspection is available, check the Yellow LED on the MM710 Media Module. Yellow LED on for approximately 2.7 seconds and off for 0.3 seconds indicates active mode using an external synchronization source. Yellow LED on for approximately 0.3 seconds and off for 2.7 seconds indicates active mode using the internal on-board clock, which means the external sync timing configuration was not successful.
  8. If the external synchronization source is not active or does not show a good signal, investigate the upstream E1/T1 provider, cabling, span status, and media module condition before reapplying synchronization settings.

Resolution

Restore or correct the provisioned external synchronization source, then configure the primary/secondary sync interface and active sync source from the MGP CLI. Confirm recovery with show sync timing showing the intended source provisioned and active, or by verifying the MM710 Yellow LED pattern that indicates external synchronization is being used. The alarm should clear after the media gateway has a valid synchronization signal.