20016 Faulty 32 MHz Clock from the Backplane

Description

This alarm is reported when the 32 MHz TDM clock from the backplane is faulty.

Attribute

Alarm ID	Alarm Severity	Alarm Type
20016	Major	Fault

Parameters

ID	Name	Meaning
1	Subrack No.	Subrack No.
2	Slot No.	Slot No.
3	Cpu No.	CPU No.
4	Alarm Attribute	0=Normal, Alarms period are longer than the Transient Threshold. 1=Transient Count, The times and the period of the alarms whose periods are shorter than the Transient Threshold are summed up. If the sum result is longer than the Alarm Occurrence Period Threshold or Alarm Occurrence Times Threshold, an alarm so called Transient Count Alarm is triggered. Because Transient Count Alarm is based on accumulative result, the recovery of the alarm may occur at least one Summing Cycle later. The Summing Cycle can be query by MML "LST STATSLDWIN".

Impact on the System

The voice quality and data transmission are affected.

System Actions

Handling of the active board in the active/standby operation mode: Perform the switchover if the standby is ready for the operation.
Handling of the standby board in the active/standby operation mode: None.
Handling of the board in the Independent operation mode: None.

Possible Causes

The GSCU rejects clock reference from the backplane.
The GSCU is not securely inserted.
The service board is not securely inserted.
The GSCU is faulty.
The service board is faulty.
The backplane is faulty.

Procedure

Check whether a correlated parent alarm occurs.
Y=> Clear the parent alarm according to the corresponding handling suggestions. Check whether the alarm is cleared.

N=> Go to 2.

Correlated parent alarm

20044 Unavailable Clock Source

The parent alarm and the child alarm have the same Subrack No. in the alarm location information.

The parent alarm must be generated at the active board.

20026 Faulty Phase-Locked Loop of the Board Clock

The parent alarm and the child alarm have the same Subrack No. in the alarm location information.

The parent alarm must be generated at the active board.
Check whether two or more boards report this alarm in the same subrack.
Y => Two or more boards report this alarm. Go to 3.

N => Only one board reports this alarm. Go to 7.
Check whether there is an alarm with the clock source chosen by the active GSCU.
Y => There is an alarm with the clock source. Go to 4.

N => There is no alarm with the clock source. Go to 5.
Clear the clock alarm of the active GSCU according to its relevant handling suggestions, and then check whether the alarm of the board is cleared.
Y => The alarm is cleared. The alarm handling is complete.

N => The alarm persists. Go to 5.
Secure the active GSCU and check whether the alarm is cleared.
Y => The alarm is cleared. The alarm handling is complete.

N => The alarm persists. Go to 6.
Perform the switchover between the active GSCU and standby GSCU, and then check whether the alarm is cleared.
Y => The alarm is cleared. The service might not be affected for the time being, but we suggest changing the standby GSCU in time. The alarm handling is complete.

N => The alarm persists. Please contact Huawei Customer Service Center.
Secure the service board which reports the alarm, and then check whether the alarm is cleared.
Y => The alarm is cleared. The alarm handling is complete.

N => The alarm persists. Go to 8.
Check whether the active board reports the alarm.
Y => The active board reports the alarm. Go to 9.

N => The standby board reports the alarm. Go to 10.
If the alarm is reported by the active board, a switchover between the active and standby boards will be automatically performed. If the standby board has a same- or higher-level alarm, the switchover fails, resulting in the persistence of the alarm within the active board. Clear the alarm of the standby board by adhering to relevant alarm-handling procedures, and then check whether the switchover between the active and standby boards is performed.
Y => The switchover succeeds. Go to 10.

N => The switchover fails. Please contact Huawei Customer Service Center.
Replace the standby board and wait until the board is successfully restarted. Check whether the alarm is cleared.
Y => The alarm is cleared. The alarm handling is complete.

N => The alarm persists. Please contact Huawei Customer Service Center.