135 BSC Unable to Unblock a Packet Circuit

Description

The alarm is reported when the BSC sends Unblock messages for N times to the PCU but has not received any response from the PCU. The parameter N indicates "Max Retrans Maintenance Message on the Pb Interface". The value of N can be set on the LMT. To set the value of N, log in to the LMT, and choose Configure BSC Attributes > Software Parameters. Then you can set the value.

Attribute

Alarm ID	Alarm Severity	Alarm Type
135	Minor	Event

Parameters

ID	Name	Meaning
1	AlarmNum	Numbers of Identification code of the packet circuits those are unsuccessfully unblocked
2	CIC	Identification code of the packet circuit that is unsuccessfully unblocked
3	PCU No.	Packet control unit (PCU) of the E1 carrying the unsuccessfully unblocked circuit
4	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 circuit state in the BSC is inconsistent with that in the PCU. If the PCU assigns the circuit for a packet service, the packet service fails.

System Actions

None.

Possible Causes

The LAPD signalling link between the BSC and the PCU is faulty.

Procedure

Check whether any E1/T1 alarm is reported ( 20081 Loss of E1/T1 Signals (LOS),20082 Loss of E1/T1 Frames (LOF),20083 Remote E1/T1 Alarm (RAI),20084 E1/T1 Alarm Indication Signal (AIS)).
Y => Refer to the handling suggestions for clearing the E1/T1 alarms.

N => Go to 2.
Contact PCU maintenance engineers to check whether the signaling link at the PCU is manually blocked.
Y => The alarm handling is complete.

N => Go to 3.
Contact PCU maintenance engineers to check whether the PCU equipment is faulty.
Y => The alarm handling is complete.

N => Please contact Huawei Customer Service Center.