20246 Low-Order Path Remote Defect Indication (LPRDI)

Description

The alarm is generated when the low-order path of the optical port of the BSC interface board receives the Low order-Path Remote Defect Indication (LPRDI) from the peer equipment. The LPRDI is used to notify the receiving end of the Lower order-Path UNEQuipped (LPUNEQ) or Lower order-Path Singal lable Mismatch (LPSLM) alarm on the peer NE.

Attribute

Alarm ID	Alarm Severity	Alarm Type
20246	Major	Fault

Parameters

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".

Impact on the System

The services carried on the lower order path of the optical port are disrupted.

System Actions

If the APS function is enabled on the interface board, no handling is performed.

If the APS function is disabled on the interface board, the handling varies with the operation modes of the board.

When the active interface board is faulty, an active/standby switchover is performed if the standby board allows a switchover. Otherwise, no handling is performed.
When the standby interface board is faulty, no handling is performed.
When the faulty interface board works in independent mode, no handling is performed.

Possible Causes

The data configurations of the BSC optical port and peer port are inconsistent.
The transmission line or transmission equipment is faulty.
The optical cable connected to the BSC interface board is faulty.
The BSC interface board is faulty.
The peer NE is faulty.

Procedure

Check the data configuration of the BSC interface board.
1. Check the type of board that generates the alarm.
  Y => If the board is an Ater interface board or an Abis interface board, Go to 2.
  N => The the board is of another type. Go to b.
2. Check whether the configuration of the C2 byte for the BSC interface board is the same as that of the C2 byte for the interface board of the peer NE.
  Y => The configuration of the C2 byte for the BSC interface board is the same as that of the C2 byte for the interface board of the peer NE. Go to 2.
  N => The configuration of the C2 byte for the BSC interface board is different from that of the C2 byte for the interface board of the peer NE. Go to c.
3. Change the C2 byte of the peer NE interface board into 0x02. Then, check whether the alarm is cleared.
  NOTE:
  The C2 byte of the BSC interface board is set to 0x02 and cannot be modified. Therefore, if the C2 byte of the BSC board is different from that of the peer NE interface board, only the C2 byte of the peer NE interface board can be modified.
  
  Y => The alarm is cleared. The alarm handling is complete.
  N => The alarm is not cleared. Go to 2.
Check the loopback status of the port of the BSC interface board.
1. Run DSP OPT. Check whether the parameter Loopback Status is set to TRIBUTARY SYSTEM.
  Y => The parameter Loopback Status is set to TRIBUTARY SYSTEM. Go to b.
  N => The parameter Loopback Status is not set to TRIBUTARY SYSTEM. Go to 3.
2. Stop the port loopback. 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 3.
Check the BSC interface board.
1. Perform a loopback on the optical ports of the BSC interface board. Then, check whether the alarm is cleared.
  Y => The alarm is cleared. The BSC interface board is normal, and the optical cable is properly connected to the BSC interface board. Reconnect the optical cable to the optical port, and Go to 4.
  N => The alarm is not cleared. The BSC interface board is faulty or the optical cable connected to the BSC interface board is faulty. Go to b.
2. Perform a loopback on the optical ports of the BSC interface board. Then, check whether the alarm is cleared.
  Y => The alarm is cleared. The optical cable connected to the BSC interface board is faulty. Go to c.
  N => The alarm is not cleared. The BSC interface board is faulty. Go to d.
3. Replace the optical cable. 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 4.
4. Reset the BSC interface board. Then, check whether the BSC interface board is reset successfully.
  Y => The reset is successful. Go to e.
  N => The reset fails. Go to f.
5. Check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  N => The alarm is not cleared. Go to f.
6. Remove and then reinstall the BSC interface board. After the data of the BSC interface board is loaded, check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  N => The alarm is not cleared. Go to g.
7. Replace the BSC interface board. 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 4.
Check the interface board of the peer NE.
1. Check whether the Ater interface board or Abis interface board reports the alarm.
  Y => If the Ater interface board reports the alarm, Go to b. If the Abis interface board reports the alarm, Go to e.
  N => The Ater interface board or Abis interface board does not report the alarm. Go to i.
2. At the remote end, perform a loopback on the GOIUT port towards the local end. Then, check whether the alarm is cleared.
  Y => The alarm is cleared. The remote GOIUT is faulty. Go to c.
  N => The alarm is not cleared. The transmission equipment or transmission link between the local and remote GOIUTs is faulty. Contact Huawei Customer Service Center.
3. Remove and then reinstall the remote GOIUT. Check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  N => The alarm is not cleared. Go to d.
4. Replace the remote GOIUT. Check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  N => The alarm is not cleared. Contact Huawei Customer Service Center.
5. Query the BTS information according to the alarm location information.
6. On the BTS side, perform a loopback on the E1/T1 port of the E1 lightning protection board towards the BSC. Then, check whether the alarm is cleared.
  Y => The alarm is cleared. The E1 lightning protection board or the TMU in the BTS is faulty. Go to g.
  N => The alarm is not cleared. The transmission equipment or transmission link between the BSC and the BTS is faulty. Contact the transmission engineers. The alarm handling is complete.
7. Remove and then install the E1 lightning protection board or the TMU. 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 h.
8. Replace the E1 lightning protection board or replace the TMU. Then, check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  N => The alarm is not cleared. Contact Huawei Customer Service Center.
9. Contact the maintenance engineers of the peer NE. On the peer NE side, perform a loopback on the E1/T1 port towards the BSC. Then, check whether the alarm is cleared.
  Y => The alarm is cleared. The interface board of the peer NE is faulty. Contact the maintenance engineers of the peer NE. The alarm handling is complete.
  N => The alarm is not cleared. The transmission equipment or transmission link between the BSC and the peer NE is faulty. Contact the transmission engineers. The alarm handling is complete.