Contents1 Configuration Prerequisites
Before configuring the SAPC in an operational network, assure that:
2 Overload Control Configuration
2.1 Load Regulation Mechanism
It is possible to monitor and modify values for CPU and memory load thresholds.
Load regulation thresholds are defined with following parameters:
|
Parameter |
Description |
Range(%) |
Memory Default Values(%) |
CPU Default Values(%) |
|---|---|---|---|---|
|
utilizationLimit |
Utilization limit for a resource (CPU or memory) |
[0-100] |
80 |
75 |
|
histOnLimit |
Load regulation starts when the resource utilization rises above utilizationLimit - histOnLimit. |
[0-utilizationLimit] |
0 |
0 |
|
histOffLimit |
Load regulation stops when the resource utilization falls below utilizationLimit - histOffLimit. |
[0-utilizationLimit] |
5 |
5 |
Figure 1 Load Regulation Thresholds Parameters| Note: |
To prevent load regulation incorrect behavior, it is not
possible to configure histOffLimit and histOnLimit in a way that the value for histOffLimit is lower than the value for histOnLimit. |
Example 1 Load Regulation Parameters values
------- Regulation Constraint for Memory ------- utilizationLimit 75 histOnLimit 5 histOffLimit 10
In the previous example, load regulation starts when memory utilization reaches 70% (utilizationLimit - histOnLimit) and stops when memory utilization falls below 65% (utilizationLimit - histOffLimit ).
2.1.1 Check Load Regulation Thresholds
To check load regulation thresholds, do the following:
Steps
2.1.2 Modify CPU Threshold for Load Regulation
To modify CPU threshold for load regulation, do the following:
Steps
Example 2 For CPU, utilizationLimit is set to 68% without modifying values for histOnLimit and histOffLimit.
loadRegulationManager --cpu-rc uLim 68
Example 3 CPU threshold indicates not to use more than 72% of the available resource. The SAPC starts load regulation when CPU utilization is above 64%, and stops load regulation when is below 57%.
loadRegulationManager --cpu-rc uLim 72 hOn 8 hOff 15
Example 4 For CPU, histOnLimit is set to 3% without modifying values for utilizationLimit and histOffLimit.
loadRegulationManager --cpu-rc hOn 3
2.1.3 Modify Memory Threshold for Load Regulation
To modify memory threshold for load regulation, do the following:
Steps
Example 5 For memory, utilizationLimit is set to 74% without modifying values for histOnLimit and histOffLimit.
loadRegulationManager --mem-rc uLim 74
Example 6 Memory threshold indicates not to use more than 71% of the available resource. The SAPC starts load regulation when memory utilization is above 68%, and stops load regulation when is below 65%.
loadRegulationManager --mem-rc hOff 6 uLim 71 hOn 3
Example 7 For memory, histOnLimit is set to 4% without modifying values for utilizationLimit and histOffLimit.
loadRegulationManager --mem-rc hOn 4
2.2 Massive Reauthorizations Mechanisms
2.2.1 Disable Massive Reauthorizations Based on Subscriber Update or Removal
To prevent the SAPC overload in case of massive reauthorizations messages based on subscriber profile change or removal, set enableReauthsOnSubsChange attribute in class AppConfig MOC to false. Once the massive provisioning operations are finished, set the attribute to true.
2.2.2 Disable Massive Reauthorizations Associated to Time Conditions
To prevent the SAPC overload in case of massive reauthorization messages associated to time conditions, set enableReauthsOnToD attribute in class AppConfig MOC to false.
2.2.3 Disperse Reauthorizations due to Fair Usage Reset on Specific Dates
To avoid a high amount of reauthorization messages at the same resetPeriod, configure it using the time [hh:mm] part. Messages (reauthorization messages and the corresponding reception of IP session update) are dispersed in following ranges:
|
Time part |
Dispersion range |
|---|---|
|
Do not specify [hh:mm] |
Random number from 0 to the number of seconds in 23 hours, 59 minutes, and 59 seconds |
|
hh:?? |
Random number from 0 to the number of seconds in 59 minutes and 59 seconds. |
For more details, refer to Configuration Guide for Fair Usage.
2.3 Overload Configuration Related to Emergency and Multimedia Priority Services
To prioritize the multimedia priority services in overload situation, configure a list of APNs in the MPS profiles if the MPS profiles are provisioned for the subscriber. For the configuration example, see Configuration Guide for Emergency and Multimedia Priority Services.
In overload situation, the SAPC by default takes multimedia priority services with higher priority than emergency services. Emergency services can be configured with higher priority using class OverloadConfig as in Example 8.
Example 8 Priority Configuration for Overload Control
<edit-config>
<target>
<running/>
</target>
<config>
<ManagedElement xmlns="urn:com:ericsson:ecim:ComTop">
<managedElementId>1</managedElementId>
<PolicyControlFunction xmlns="urn:com:ericsson:ecim:sapcmom">
<policyControlFunctionId>1</policyControlFunctionId>
<OverloadConfig xmlns="urn:com:ericsson:ecim:overloadconfigmom">
<overloadConfigId>1</overloadConfigId>
<OverloadPriority xmlns="urn:com:ericsson:ecim:overloadconfigmom" xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0" nc:operation="merge">
<overloadPriorityId>1</overloadPriorityId>
<priorityOrder>1</priorityOrder>
<serviceTag>MULTIMEDIA_PRIORITY_SERVICES</serviceTag>
</OverloadPriority>
<OverloadPriority xmlns="urn:com:ericsson:ecim:overloadconfigmom" xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0" nc:operation="merge">
<overloadPriorityId>2</overloadPriorityId>
<priorityOrder>0</priorityOrder>
<serviceTag>EMERGENCY_SERVICES</serviceTag>
</OverloadPriority>
</OverloadConfig>
</PolicyControlFunction>
</ManagedElement>
</config>
</edit-config>
3 Overload Control Performance Management
Following performance measurements are provided related to Overload Control:
For more details, refer to Measurements.