20093 E1/T1 Excessive Slip Frames Per Hour

Description

This alarm is generated if the BSC detects that the number of slip frames on the E1/T1 port over one hour exceeds 288. This alarm is cleared if the BSC does not detect any slip frame on the E1/T1 port over 10 minutes. During the reception of framed data, a frame slip is caused by frame misalignment due to out-of-synchronization between a received frame and the receiver clock signal, resulting in the loss of the data contained in the received frame.

Attribute

Alarm ID	Alarm Severity	Alarm Type
20093	Warning	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	Number of slip frames	The number of slip frames
6	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.
7	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.
8	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 speech services are not affected, but the data services that require low BER are affected.

System Actions

None

Possible Causes

The clock source of the BSC and that of the peer equipment are different.
The transmission equipment or transmission link between the BSC and the peer equipment is faulty.

Procedure

Check the clock configuration of the BSC.
1. According to the Subrack No. and Slot No. in the alarm location information, check whether the clock status of the BSC interface board is normal.
  Y => The clock status is normal. Go to 2.
  
  N => The clock status is not normal. Go to b.
2. Check whether the clock status of the GSCU located in the same subrack as the board that reports the alarm is normal.
  Y => The clock status is normal. Go to 2.
  
  N => The clock status is not normal. Go to c.
3. Secure the connectors at both ends of the Y-shaped clock signal cable of the GSCU, or remove and then reinstall the GSCU. 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 d.
4. Check whether the status of the BSC clock reference source is normal.
  Y => The status is normal. Go to 2.
  
  N => The status is not normal. Go to e.
5. Reconfigure the BSC clock by referring to the Initial Configuration Guide. 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 2.
Check the transmission between the BSC and the peer NE.
1. Check whether the peer NE is the GMPS/GEPS/GTCS or the BTS.
  Y => If the peer NE is the GMPS/GEPS/GTCS, Go to b. If the peer NE is the BTS, Go to c.
  
  N => The peer NE is not the GMPS/GEPS/GTCS or the BTS. Go to f.
2. Check whether the peer GMPS/GEPS/GTCS reports the following alarms:
  20081 Loss of E1/T1 Signals (LOS)
  
  20082 Loss of E1/T1 Frames (LOF)
  
  20084 E1/T1 Alarm Indication Signal (AIS)
  
  Y => One of these alarms is reported. Rectify the fault according to the alarm help. The alarm handling is complete.
  
  N => None of these alarms is reported. Contact Huawei Customer Service Center.
3. Query the BTS index according to the alarm location information.
4. Check whether the BTS reports the following alarms:
  4714 E1/T1 Local Alarm or other E1 local alarms
  
  4718 AIS Alarm or other AIS alarms
  
  Y => One of these alarms is reported. Go to e.
  
  N => None of these alarms is reported. Contact Huawei Customer Service Center.
5. Rectify the fault and clear the fault found in (d) according to the alarm help. 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.
6. Contact the maintenance engineers of the peer NE. On the peer NE side, perform a loopback on the port towards the BSC. Wait 20 minutes. Then, check whether the alarm is cleared.
  Y => The alarm is cleared. The peer NE is faulty. Contact the maintenance engineers of the peer NE. The alarm handling is complete.
  
  N => The alarm is not cleared. Contact Huawei Customer Service Center.