20084 E1/T1 Alarm Indication Signal (AIS)

Description

An AIS alarm is generated if the E1/T1 port of the BSC receives an Alarm Indication Signal (AIS) (that is, all the received signal levels are 1) from the peer NE.

Attribute

Alarm ID	Alarm Severity	Alarm Type
20084	Major	Fault

Parameters

ID	Name	Meaning
1	Subrack No.	Subrack No.
2	Slot No.	Slot No.
3	Cpu No.	CPU No.
4	Port No.	The number of the port
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

If the active board is faulty, the services carried on the port of the board are disrupted.
If the standby board is faulty, the services are not affected.

System Actions

None

Possible Causes

The peer NE is reset.
A self-loop is performed on the peer NE.
A loopback is performed on the transmission equipment towards the peer NE.
The transmission equipment is faulty or the transmission link between the peer NE and the transmission equipment is faulty.
The peer NE is faulty.

Procedure

Check the operation logs of the peer NE.
1. Check whether the board that reports the alarm is the Abis interface board or Ater interface board.
  Y => If the board is an Ater interface board, go to b. If the board is an Abis interface board, go to c.
  
  N => The board is of another type. Go to e.
2. Log in to the LMT and then choose BSC Maintenance > Maintain Logs > Query Operation Logs Online. Check whether the peer GEIUT is reset.
  Y => The peer GEIUT is reset. Go to f.
  
  N => The peer GEIUT is not reset. Go to 2.
3. Query the BTS information according to the alarm location information.
4. Check whether the BTS reports the 4770 Site Reset Alarm or other site reset alarms.
  Y => The BTS is reset. Go to f.
  
  N => The BTS is not reset. Go to 2.
5. Contact the maintenance engineers of the peer NE. Check whether the peer NE is reset.
  Y => The peer NE is reset. Go to f.
  
  N => The peer NE is not reset. Go to 2.
6. When the equipment runs normally after the reset, check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  
  N => The alarm is not cleared. Go to 2.
Check the self-loop status of the peer NE.
1. Check whether the board that reports the alarm is an Abis interface board or an Ater interface board.
  Y => If the board is an Ater interface board, Go to b.
  
  N => If the board is an Abis interface board or of another type, Go to 3.
2. Check whether the link the board of the peer equipment is in local loopback mode.
  Y => The link is in local loopback mode. Go to c.
  
  N => The link is not in local loopback mode. Go to 3.
3. Release the local loopback of the link and ensure that the link is in normal state. 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 transmission between the transmission equipment and the peer NE.
1. On the peer NE side, Perform a loopback on the port of the peer NE towards the BSC. Then, check whether the alarm is cleared.
  Y=> The alarm is cleared. Cancel the loopback and Go to 4.
  
  N => The alarm is not cleared. The transmission link between the peer NE and the transmission equipment is faulty. Contact the transmission engineers. The alarm handling is complete.
Check the E1/T1 cable connected to the interface board of the peer NE.
1. Check the type of the peer NE.
  Y => If the peer NE is the GMPS/GEPS/GTCS or the BTS, Go to b.
  
  N => Contact the maintenance engineers of the peer NE. The alarm handling is complete.
2. Remove and then reinsert the connectors of the E1/T1 cable connected to the interface board of the peer NE. Secure both ends of the E1/T1 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 c.
3. Replace the E1/T1 cable connected to the interface board of the peer NE. Then, check whether the alarm is cleared.
  Y => The alarm is cleared. The alarm handling is complete.
  
  N => The alarm is not cleared. Replace the E1/T1 cable with the original one. Go to 5.
Check the interface board of the peer NE.
1. Check whether the board that reports the alarm is the Ater interface board.
  Y => If the board is an Ater interface board, Go to b.
  
  N => If the board is an Abis interface board, Go to e.
2. Reset the peer GEIUT. Wait five to ten minutes after the board is started 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 c.
3. Remove and then reinstall the peer GEIUT. 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 peer GEIUT. 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.
5. Query the BTS information according to the alarm location information.
6. Reset 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.
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. Contact Huawei Customer Service Center. 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.