Contents

1   Alarm Description

The threshold alarm CSCF Charging Answers Indicate Protocol Errors is raised when there are problems with Accounting-Requests (ACRs) sent from the CSCF to the charging system.

The alarm is associated to the Performance Management counter cscfACAProtocolErrors.

The alarm is raised when the number of Accounting-Answer (ACA) with protocol errors (code 3xxx) received through Diameter, has reached, or exceeded its corresponding thresholdHigh within the time period configured by thresholdRateOfVariation and granularityPeriod.

The alarm is automatically ceased when it reaches or goes below the thresholdLow value.

The default values related to this alarm are thresholdRateOfVariation=PER_GP, granularityPeriod=FIVE_MIN, thresholdHigh =2, and thresholdLow=0. This means that when the counter value is 2 or higher, the alarm is raised when the Granularity Period is ended. The alarm is ceased when the counter cscfACAProtocolErrors has reached a value of 0 at the end of a Granularity Period.

Note:  

The thresholds for raising and ceasing this alarm are configurable. The default Distinguished Name for the thresholds is; ManagedElement=<node_name>, SystemFunctions=1, Pm=1, PmJob= CscfChargingStatisticsThreshold, MeasurementReader=cscfACAProtocolErrorsMeasReader, PmThresholdMonitoring= cscfACAProtocolErrors. It is not possible to change threshold values once they have been set. To change a threshold, first the PmThresholdMonitoring instance must be deleted and recreated with required thresholdHigh and thresholdLow. For more information, refer to Performance Management.

If the alarm is not solved, there is a limited amount of memory reserved (in the range of a few days) to store the charging information temporarily. When this buffer is full, subsequent charging information is lost, and the alarm CSCF Charging Backup File System Unavailable is also raised.

Table 1    CSCF Charging Answers Indicate Protocol Errors Alarm Causes

Alarm Cause	Description	Fault Reason	Fault Location	Impact
The PM counter cscfACAProtocolErrors has reached or exceeded its configured upper threshold value.	The number of received ACA with Result-Code 3xxx (protocol errors) for sent ACR has reached or exceeded the configured threshold.	Peer entity problems to interpret or manage ACR messages.	Peer entity Charging Data Function (CDF) or protocol compatibilities problems between CSCF and CDF.	Charging information is buffered on persistent media until communication to CDF is reestablished.

Note:  

This alarm can appear as a result of maintenance activity.

Table 2    CSCF Charging Answers Indicate Protocol Errors Alarm Attributes

Attribute Name	Attribute Value
Major Type	193
Minor Type	6684679
Managed Object Class	MeasurementReader
Managed Object Instance	ManagedElement=<node_name>,SystemFunctions=1, Pm=1, PmJob=CscfChargingStatisticsThreshold, MeasurementReader=cscfACAProtocolErrorsMeasReader
Specific Problem	CSCF Charging Answers Indicate Protocol Errors
Event Type	communication (2)
Probable Cause	x733ThresholdCrossed (351)
Additional Text	cscfACAProtocolErrors, possibly caused by configuration problem
Perceived Severity	major (4)

2   Procedure

2.1   Handle Alarm CSCF Charging Answers Indicate Protocol Errors

Prerequisites

• This instruction references the following documents:
  • CSCF Configuration Management
  • Managed Object Model (MOM)
• Before starting this procedure, ensure that the following tool is available:
  • A Diameter protocol sniffer, refer to RFC 3588 Diameter Base Protocol.
• The following condition must apply:
  • The alarm is raised.

Steps

Note:  

If the reason for the alarm has disappeared after the Granularity Period, the alarm automatically ceases.

1. Log on to the System Controller (SC).
2. Make sure that the SC is the primary processor:

   cat/proc/drdb

   The following is the expected output when the SC is the primary processor:

   0:cs:Connected st:Primary/Secondary id:Consistent

   The following is the expected output when the SC is the secondary processor:

   0:cs:Connected st:Secondary/Primary id:Consistent

3. Check the log file for error 3xxx (protocols errors):

   grep “Result-Code= [30” /storage/no-backup/cdclsv/log/lpmsv/*

4. Log off from the SC.
5. Make sure that the alarm matches the errors in the log.
6. Find the cause why the communication with the Charging Data Function node fails.
7. Is the alarm threshold is set too low?

   Yes: Adjust the alarm threshold and then continue with the next step.

   No: Continue with the next step.

8. Has the alarm ceased?

   Yes: Proceed with Step 10.

   No: Continue with the next step.

9. If the alarm is not ceased, consult the next level of maintenance support.

   Further actions are outside the scope of this instruction.

10. Job is completed.