20122 GESW BAM Trunk Communication Failure

Description

The GSCU sends a heartbeat package to the BAM to determine whether the link can be used. If the heartbeats of two links timeout, this alarm is generated.

Attribute

Alarm ID	Alarm Severity	Alarm Type
20122	Warning	Fault

Parameters

ID	Name	Meaning
1	Subrack No.	Subrack No.
2	Slot No.	Slot No.
3	Cpu No.	CPU No.
4	BAM No.	Number of the faulty BAM
5	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 communications between the GSCU and the BAM is disrupted.

System Actions

None.

Possible Causes

External BAM:

The two Ethernet cables connect to wrong ports.
The two Network adapters in BAM are disabled.
The two Ethernet cables on the panel are disconnected or in loose contact.

Internal BAM:

The BAM or GSCU is not securely inserted.
The two Network adapters in BAM are disabled.

Procedure

The troubleshooting of external BAM fault differs from the troubleshooting of built-in BAM fault. The procedure for troubleshooting external BAM fault is as follows:
1. Check whether the Ethernet cables that connect the BAM are connected to ports on the panel of the GSCU.
  Y => Connect the Ethernet cables properly. The alarm is cleared. The alarm handling is complete. Otherwise, Go to b.
  
  N => The connections are correct. Go to b.
2. Check whether the Ethernet adapter on the BAM that connects to the GSCU is disabled.
  Y => The Ethernet adapter is disabled. Enable the Ethernet adapter. The alarm is cleared. The alarm handling is complete.
  
  N => The Ethernet adapter is not disabled. Please contact Huawei Customer Service Center.
The troubleshooting of external BAM fault differs from the troubleshooting of built-in BAM fault. The procedure for troubleshooting built-in BAM fault is as follows:
1. Insert securely the GSCU and BAM, and then check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  
  N => The alarm is not cleared. Go to b.
2. Check whether the Ethernet adapter on the BAM that connects to the GSCU is disabled.
  Y => The Ethernet adapter is disabled. Enable the Ethernet adapter. The alarm is cleared. The alarm handling is complete.
  
  N => The Ethernet adapter is not disabled. Please contact Huawei Customer Service Center.