20252 Loss of Tributary Multi-Frames (LOM)

Description

The tributary cannot locate the initial position of multi-frame.

Alarm ID	Alarm Severity	Alarm Type
20252	Minor	Fault

ID	Name	Meaning
1	Subrack No.	Subrack No.
2	Slot No.	Slot No.
3	Cpu No.	CPU No.
4	Tributary Unit No.	0 - 62(for E1 mode), 0 - 83(for T1 mode).
5	Site No.	The IDs of all sites whose OMLs are on the faulty E1/T1. If BTS are cascade connected,a maximum of 4 sites are shown.Only Abis E1/T1 alarm has this parameter.
6	Site Name	The Names of all sites whose OMLs are on the faulty E1/T1. If BTS are cascade connected,a maximum of 4 sites are shown.Only Abis E1/T1 alarm has this parameter.
7	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".

The service over this tributary might be affected.

None.

The peer frame format over this tributary is not the same with that of the local end, which is E1 CRC4 multi-frame format.
The peer frame format over this tributary is not the same with that of the local end, which is T1 multi-frame format.
The bit error rate over this link exceeds the normal value.

Check whether the local frame format is of E1 CRC4 multi-frame format or T1 multi-frame format.
Y => Go to 2.

N => Go to 4.
Check whether the configuration of the frame format in the peer end is the same with that of the local end.
Y => Please contact Huawei Customer Service Center.

N => Go to 3.
Configure the peer frame format over this tributary the same with that of the local end, and then 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.
Check whether there exists bit error-related alarm.
Y => Go to 5.

N => Please contact Huawei Customer Service Center.
Clear the bit error alarm according to its relevant handling suggestions, and then check whether the multi-frame loss alarm is cleared.
Y => The alarm is cleared. The alarm handling is complete.

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