Performance Management

Contents


1   Understanding Performance Management

1.1   Key Performance Management Concepts

Performance Management (PM) provides a management interface for performance measurement data handling in the Managed Element (ME) including the following:

Figure 1   Performance Management Overview

Performance measurement data is collected and recorded by the ME regularly. This activity is performed to verify the physical and logical configuration of the network and its functions, to understand how they are used, and to locate potential problems as early as possible. The performance measurement reports can be used by management systems to understand performance trends, to balance traffic load, and to identify problem areas.

Performance threshold alarms can be used by management systems to identify problem areas needing immediate attention.

The Performance Management managed area is represented in the Managed Object Model (MOM) under the Managed Object Class (MOC) Pm. For general information about the MOM, MOCs, cardinality, and related concepts, refer to Managed Object Model User Guide.

1.2   Measurement Types

The measurement types define what measurement data the ME can collect as well as what collection method and aggregation method are used. A measurement type supports one collection method and one aggregation method.

Table 1    Measurement Type Collection Methods

Collection Method

Description

Cumulative counter

An ME uses a cumulative counter for counting events. Each time the event occurs a value is added to the counter. The counter is reset to a well-defined value (usually 0) at the beginning of each Granularity Period (GP). The GP is the time between the initiation of two successive collections of measurement data.

Gauge

A gauge is used for representing a dynamic value that can change in either direction. It can be used for continuous measurements over many GPs, for example, representing a temperature. It can also be used to get a maximum or minimum value during a GP. In this case, the gauge is reset at the beginning of each GP.

Discrete Event Registration (DER)

Using DER, data related to a particular event is captured (same as a gauge). Every nth event is registered, where n can be 1 or larger. The value of n depends on the frequency of occurrence of the event being measured. DER measurements are reset at the beginning of each GP and only have a valid result at the end of the GP.

Status Inspection (SI)

An SI is supported in the same way as a gauge but cannot be used for continuous measurements over several GPs. Status inspection measurements are reset at the beginning of the GP and only have a valid result at the end of the GP.

Table 2    Measurement Type Aggregation Methods

Aggregation Method

Description

Sum

All measured values are added during a GP.

Average

An average value is calculated using all values collected during a GP. For a gauge, an average value can be calculated over several GPs.

Minimum

The minimum value during a GP is collected.

Maximum

The maximum value during a GP is collected.

Last update

The last value during a GP is collected.

Measurement types are categorized and logically grouped into PM groups.

1.3   PM Groups

A PM group is a grouping of the measurements into logical grouping. Grouping is done according to what the measurements are characterizing. For example, a Traffic Counters group would contain measurement types which quantify the traffic on an interface (#requestsReceived, #requestsRejected, #failedConnections, #errors, and so on). A PM group corresponds to NBI CM MOC if CC has OAM model.

1.4   Measurement Jobs

The execution of measurement data collection, aggregation, and reporting is performed by measurement jobs. A measurement job applies to one or more measurement types or to an entire PM group. A measurement job executes the measurement types respective collection method and aggregation method at regular time intervals as defined by its GP.

The supported GP values are 1 minute, 5 minutes, 15 minutes, 30 minutes, 1 h, 12 h, and 24 h. The default value for GP is 15 minutes.

The Measurement reader defines the measurement being counted in a particular measurement job and ties it to the specific measurement types or a PM group.

A measurement job collects measurement data and generates reports as performance measurement XML files.

A measurement job can have three different priorities; low, medium, or high. The measurement jobs with the highest priority have their reports output first or its threshold condition checked first.

1.5   Threshold Alarms

Threshold alarms can be used along with the gauge and cumulative counter collection methods. A threshold monitoring job monitors measurement data and raises an alarm when a threshold is crossed, but do not collect measurement data. A threshold monitoring job raises or clears an alarm based on a comparison of the counter value with the configured high and low threshold values.

At the end of the GP, if the counter value is higher than the high threshold value and no alarm is active, then an alarm is raised. However, if the counter value is lower than the low threshold value and if an alarm is active, then the alarm is cleared.

If two or more threshold monitoring jobs are associated with a measurement type, then a change alarm can be raised to indicate that the counter value has crossed a higher or a lower threshold than previously shown in any earlier alarm.

2   Basic Performance Management Procedures

PM is accessed using NETCONF or the ECLI to manipulate the Management Information Base (MIB).