Cisco IOS IP SLAs Configuration Guide, Release 12.4
IP SLAs--Proactive Threshold Monitoring
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IP SLAs—Proactive Threshold Monitoring

Table Of Contents

IP SLAs—Proactive Threshold Monitoring

Contents

Information About Proactive Threshold Monitoring for IP SLAs

IP SLAs Reaction Configuration

IP SLAs Threshold Monitoring and Notifications

Restrictions

How to Configure IP SLAs Reactions and Threshold Monitoring

Configuring Monitored Elements for IP SLAs Reactions

Configuring Triggers for Round-Trip-Time Violations

Configuring Triggers for Jitter Violations

Configuring Triggers for Packet Loss Violations

Configuring Triggers for Mean Opinion Score Violations

Configuring Threshold Violation Types for IP SLAs Reactions

Generating Events for Each Violation

Generating Events for Consecutive Violations

Generating Events for x of y Violations

Generating Events for Averaged Violations

Specifying Reaction Events

Examples of Proactive Threshold Monitoring Using IP SLA

Configuring an IP SLAs Reaction Configuration: Example

Verifying an IP SLAs Reaction Configuraiton: Example

Triggering SNMP Notifications: Example

Where to Go Next

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Feature Information for IP SLAs Proactive Threshold Monitoring


IP SLAs—Proactive Threshold Monitoring


First Published: May 2, 2005
Last Updated: July 18, 2008

This document describes the proactive monitoring capabilities of Cisco IOS IP Service Level Agreements (SLAs) using thresholds and reaction triggering.

Cisco IOS IP SLAs allows you to montior, analyze and verify IP service levels for IP applications and services, to increase productivity, to lower operational costs, and to reduce occurances of network congestion or outages. IP SLAs uses active traffic monitoring for measuring network performance.

Finding Feature Information in This Module

Your Cisco IOS software release may not support all of the features documented in this module. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the "Feature Information for IP SLAs Proactive Threshold Monitoring" section.

Finding Support Information for Platforms and Cisco IOS Software Images

Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.

Contents

Information About Proactive Threshold Monitoring for IP SLAs

How to Configure IP SLAs Reactions and Threshold Monitoring

Examples of Proactive Threshold Monitoring Using IP SLA

Where to Go Next

Additional References

Feature Information for IP SLAs Proactive Threshold Monitoring

Information About Proactive Threshold Monitoring for IP SLAs

To perform the tasks required to configure proactive threshold monitoring using IP SLA, you should understand the following concepts:

IP SLAs Reaction Configuration

IP SLAs Threshold Monitoring and Notifications

IP SLAs Reaction Configuration

IP SLAs can be configured to react to certain measured network conditions. For example, if IP SLAs measures too much jitter on a connection, IP SLAs can generate a notification to a network management application, or trigger another IP SLAs operation to gather more data.

IP SLAs reaction configuration is performed using the ip sla monitor reaction-configuration command. You can configure the ip sla monitor reaction-configuration command multiple times so as to allow reactions for multiple monitored elements (for example, configuring thresholds for operation 1 for destination-to-source packet loss, and also configuring MOS thresholds for same operation). However, issuing the no ip sla monitor reaction-configuration operation-number will clear all reactions for the specified operation. In other words, disabling of granular reaction elements (no ip sla monitor reaction-configuration operation-number react monitored-element) is not currently supported, so as to provide backwards compatibility with the earlier version of this command.

You can check the configuration of the IP SLAs reaction configuration using the show ip sla monitor reaction-configuraiton command.

IP SLAs Threshold Monitoring and Notifications

IP SLAs includes the capability for triggering SNMP notifications based on defined thresholds. This allows for proactive monitoring in an environment where IT departments can be alerted to potential network problems, rather than having to manually examine data.

IP SLAs supports threshold monitoring for performance parameters such as average jitter, unidirectional latency and bidirectional round trip time and connectivity. This proactive monitoring capability provides options for configuring reaction thresholds for important VoIP related parameters including unidirectional jitter, unidirectional packet loss, and unidirectional VoIP voice quality scoring (MOS scores).

IP SLAs can generate system logging (syslog) messages when the reaction threshold increases or decreases beyond the configured values for packet loss, average jitter, or MOS. These system logging messages can then be sent as SNMP notifications (traps) using the CISCO-SYSLOG-MIB.

For packet loss and jitter, notifications can be generated for violations in either direction (source to destination and destination to source) or for round trip values. Packet loss, jitter and MOS statistics are specific to IP SLAs Jitter operations. Notifications can also be triggered for other events, such as round-trip-time violations, for most IP SLAs monitoring operations.


Note Trap generation through the CISCO-SYSLOG-MIB is only needed for packet loss, average jitter, or MOS violations. For other violations, traps can be generated through the CISCO-RTTMON-MIB.


SNMP notifications (traps) for IP SLAs can be configuredas a triggered action, to be sent when monitored values exceed an upper threshold or fall below a lower threshold, or when a set of defined conditions are met. For example, an SNMP trap can be triggered by 5 consecutive timeouts during an IP SLAs operation. The sending of SNMP traps is one of the options for triggered actions that can be configured for IP SLAs violations. The monitored values (also called monitored elements), the threshold type, and the triggered action are configured using the ip sla monitor reaction-configuration global configuration mode command.

SNMP traps for IP SLAs are handled through the system logging (syslog) process. This means that system logging messages for IP SLAs violations are generated when the specified conditions are met, then sent as SNMP traps using the CISCO-SYSLOG-MIB. The ip sla monitor logging traps command is used to enable the generation of these IP SLAs specific traps. The generation of IP SLAs specific logging messages is dependant on the configuration of the standard set of logging commands (for example, logging on). IP SLAs logging messages are generated at the "informational" system logging severity level.


Note Severity levels in the CISCO-SYSLOG-MIB are defined as follows:
SyslogSeverity INTEGER { emergency(1), alert(2), critical(3), error(4), warning(5), notice(6), info(7), debug(8) }
The values for severity levels are defined differently for the system logging process in Cisco IOS software: { emergency (0), alert (1), critical (2), error (3), warning (4), notice (5), informational (6), debugging (7) }.
This means that IP SLAs Threshold violations are logged as level 6 (informational) within the logging process, but are sent as level 7 (info) traps from the CISCO-SYSLOG-MIB.


Restrictions

The MIB used for IP SLAs (CISCO-RTTMON-MIB) does not currently support the reaction configuration described in this document. In other words, the traps available for PacketLossSD, PacketLossDS, JitterSD, jitterDS, maxOflatencySD, maxOflatencyDS, and MOS cannot be generated through CISCO-RTTMON-MIB. These traps are generated through the CISCO-SYSLOG-MIB, and enabled using the ip sla monitor logging traps global configuration mode command.

As MOS, jitterSD, jitterDS, PacketLossSD and PacketLossDS are specific to Jitter operations, reactions (such as triggered notifications) to theshold violations for these monitored elements can only be configured for UDP Jitter operations or VoIP Jitter operations.

How to Configure IP SLAs Reactions and Threshold Monitoring

IP SLAs Reactions are configured using the ip sla monitor reaction-configuration command. The elements of this command are described in the following sections

Configuring Monitored Elements for IP SLAs Reactions [ react monitored-element ]

Configuring Threshold Violation Types for IP SLAs Reactions [ threshold-type violation-condition]

Specifying Reaction Events [action-type trap-or-trigger]

Configuring Monitored Elements for IP SLAs Reactions

IP SLAs reactions are configured to be triggered when a monitored value exceeds or falls below a specified level, or when a monitored event (such as a timeout or connection loss) occurs. These monitored values and events are called monitored elements. The types of monitored elements available are described in the following sections:

Configuring Triggers for Round-Trip-Time Violations

Configuring Triggers for Jitter Violations

Configuring Triggers for Packet Loss Violations

Configuring Triggers for Mean Opinion Score Violations

You can configure the ip sla monitor reaction-configuration command multiple times so as to allow reactions for multiple monitored elements (for example, configuring a threshold for operation 1 for destination-to-sourcepacket loss, and also configuring a MOS threshold for same operation). However, issuing the no ip sla monitor reaction-configuration operation-number will clear all reactions for the specified operation (in other words, disabling of granular reaction elements is not currently supported, so as to provide backwards compatibility with the earlier version of this command).

Configuring Triggers for Round-Trip-Time Violations

Round-trip-time (rtt) is one of the monitored values of all IP SLAs operations. Events (such as traps) can be triggered when the rtt value rises above a specified threshold, or when it falls below a specified threshold. To configure rtt as the monitored element, use the following version of the ip sla monitor reaction-configuration command:

Command or Action
Purpose

ip sla monitor reaction-configuration operation-number react rtt

[threshold-type violation-condition]

threshold-value upper-threshold lower-threshold

[action-type {trapOnly | triggerOnly | trapAndTrigger}]

Example:

Router# ip sla monitor reaction-configuration 10 react rtt threshold-type immediate threshold-value 5000 3000 action-type trapAndTrigger

Configures an action (SNMP trap or IP SLAs trigger) to occur based on violations of thresholds for round-trip-time (rtt).

Configuring Triggers for Jitter Violations

Jitter (interpacket delay variance) is one of the monitored values of IP SLAs UDP Jitter operations. Jitter values are computed as source-to-destination, destination-to-source, and combined round-trip values. Events (such as traps) can be triggered when the average jitter value in either direction, or in both directions, rises above a specified threshold, or when it falls below a specified threshold.

Command or Action
Purpose

ip sla monitor reaction-configuration operation-number react {jitterAvg | jitterDSAvg | jitterSDAvg} [threshold-type violation-type] threshold-value upper-threshold lower-threshold [action-type {trapOnly | triggerOnly | trapAndTrigger}]

Example:

Router# ip sla monitor reaction-configuration 10 react jitterAvg threshold-type immediate threshold-value 5000 3000 action-type trapAndTrigger

Configures an action (SNMP trap or IP SLAs trigger) to occur based on violations of thresholds for average round-trip jitter values.

To configure the average source-to-destination jitter as the monitored element, use the react jitterAvg keyword combination.

To configure average destination-to-source jitter as the monitored element, use the react jitterDSAvg keyword combination.

To configure average round-trip jitter as the monitored element, use the react jitterSDAvg keyword combination.

Configuring Triggers for Packet Loss Violations

Pactket loss is one of the monitored values of IP SLAs UDP Jitter operations. Jitter values are computed as source-to-destination and destination-to-source values. Events (such as traps) can be triggered when the jitter value in either direction rises above a specified threshold, or when it falls below a specified threshold.

To configure source-to-destination packet loss as the monitored element, use the react PacketLossSD syntax in the ip sla monitor reaction-configuration command.

To configure destination-to-source jitter as the monitored element , use the react PacketLossDS syntax in the ip sla monitor reaction-configuration command.

Configuring Triggers for Mean Opinion Score Violations

Mean opinion score (MOS) is one of the monitored values of IP SLAs Jitter VoIP operations. MOS values are computed as numbers to two decimal places, from a value of 1.00 (worst quality) to 5.00 (best quality). Events (such as traps) can be triggered when the MOS value in either direction rises above a specified threshold, or when it falls below a specified threshold.

To configure destination-to-source jitter as the monitored element , use the react mos syntax in the ip sla monitor reaction-configuration command.

Configuring Threshold Violation Types for IP SLAs Reactions

The threhold-type syntax of the ip sla monitor reaction-configuration command defines the type of threshold violation (or combination of threshold violations) that will trigger an event. Threshold violation types are as follows:

immediate—Triggers an event immediately when the value for a reaction type (such as response time) exceeds the upper threshold value or falls below the lower threshold value, or when a timeout, connectionLoss, or verifyError event occurs.

consecutive—Triggers an event only after a violation occurs a specified number of times consecutively. For example, the consecutive violation type could be used to configure an action to occur after a timeout occurs 5 times in a row, or when the round-trip-time exceeds the upper threshold value 5 times in a row.

x of y—Triggers an event after some number (x) of violations within some other number (y) of probe operations (x of y).

averaged—Triggers an event when the averaged totals of a value for x number of probe operations exceeds the specied upper-threshold value, or falls below the lower-threshold value.

Configuring these threshold violation types is described in the following sections.

Generating Events for Each Violation

To generate a trap (or trigger another operation) each time a specified condition is met, use the immediate threshold-type keyword:

ip sla monitor reaction-configuration operation-number react data-type threshold-type immediate threshold-value raising-value falling-value action-type action-value

Generating Events for Consecutive Violations

To generate a trap (or trigger another operation) after a certain number (x) of consecutive violations, use the consecutive keyword with the optional number-of-occurrences argument:

ip sla monitor reaction-configuration operation-number react reaction-condition threshold-type consecutive [number-of-occurances] threshold-value raising-value falling-value action-type action-value

The default value for number-of-occurances is 5.

Generating Events for x of y Violations

To generate a trap (or trigger another operation) after some number (x) of violations within some other number (y) of probe operations (x of y), use the xofy [x-value y-value] syntax:

ip sla monitor reaction-configuration operation-number react reaction-condition threshold-type xofy x-value y-value threshold-value raising-value falling-value action-type action-value

The default x-value and y-value is 5 (xofy 5 5).

Generating Events for Averaged Violations

To generate a trap (or trigger another operation) when the averaged totals of x number of probe operations violate a falling-threshold or rising-threshold, use the average [attempts] syntax:

ip sla monitor reaction-configuration operation-number react reaction-condition threshold-type average [attempts] threshold-value raising-value falling-value action-type action-value

The default value for attempts is 5.

Specifying Reaction Events

Action type options for the ip sla monitor reaction-configuration command are as follows:

none—No action is taken.

trapOnly—Send an SNMP logging trap when the specified violation type occurs for the monitored element. IP SLAs logging traps are enabled using the ip sla monitor logging traps command. For SNMP logging traps to be sent, SNMP logging must be enabled using the appropriate SNMP commands, including the snmp-server enable traps syslog command.

triggerOnly—Have one or more target operation's operational state make the transition from "pending" to "active" when the violation conditions are met. The target operations to be triggered are specified using the ip sla monitor reaction-trigger command. A target operation will continue until its life expires, as specified by the target operation's configured lifetime value). A triggered target operation must finish its life before it can be triggered again.

trapAndTrigger—Trigger both an SNMP trap and start another IP SLAs operation when the violation conditions are met, as defined in the trapOnly and triggerOnly options above.

Examples of Proactive Threshold Monitoring Using IP SLA

This section contains the following examples:

Configuring an IP SLAs Reaction Configuration: Example

Verifying an IP SLAs Reaction Configuraiton: Example

Triggering SNMP Notifications: Example

Configuring an IP SLAs Reaction Configuration: Example

In the following example, IP SLAs operation 10 (a UDP Jitter operation) is configured to send an SNMP logging trap when the MOS value exceeds 4.9 (best quality) of falls below 2.5 (poor quality):

Router(config)# ip sla monitor reaction-configuration 10 react mos threshold-type 
immediate threshold-value 490 250 action-type trapOnly 


The following example shows the default settings for the ip sla monitor reaction-configuration command when none of the optional syntax is used:

Router# show ip sla monitor reaction-configuration 1

Entry number: 1
Reaction Configuration not configured

Router# configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)# ip sla monitor reaction-configuration 1
Router(config)# do show ip sla monitor reaction-configuration 1

Entry number: 1
Reaction: rtt
Threshold Type: Never
Rising (milliseconds): 5000
Falling (milliseconds): 3000
Threshold Count: 5
Threshold Count2: 5
Action Type: None

Verifying an IP SLAs Reaction Configuraiton: Example

In the following example, multiple monitored elements (indicated by the Reaction: value) are configured for a single IP SLAs operation:

Router# show ip sla monitor reaction-configuration 

Entry Number: 1
Reaction: RTT
Threshold type: Never
Rising (milliseconds): 5000
Falling (milliseconds): 3000
Threshold Count: 5
Threshold Count2: 5
Action Type: None

Reaction: jitterDSAvg
Threshold type: average
Rising (milliseconds): 5
Falling (milliseconds): 3
Threshold Count: 5
Threshold Count2: 5
Action Type: triggerOnly

Reaction: jitterDSAvg
Threshold type:  immediate
Rising (milliseconds): 5
Falling (milliseconds): 3
Threshold Count: 5
Threshold Count2: 5
Action Type: trapOnly

Reaction: PacketLossSD 
Threshold type:  immediate
Rising (milliseconds): 5
Threshold Falling (milliseconds): 3
Threshold Count: 5
Threshold Count2: 5
Action Type: trapOnly

Table 1 describes the significant fields shown in this output.

Table 1 show ip sla monitor reaction-configuration Field Descriptions 

Field
Description

Reaction

The configured monitored element for IP SLAs reactions.

Corresponds to the react { connectionLoss | jitterAvg | jitterDSAvg | jitterSDAvg | mos | PacketLossDS | PacketLossSD | rtt | timeout | verifyError } syntax in the ip sla monitor reaction-configuration command.

Threshold type

The configured theshold type.

Corresponds to the threshold-type { never | immediate | consecutive | xofy | average } syntax in the ip sla monitor reaction-configuration command.

Rising (milliseconds)

The upper-threshold value, as configured by the threshold-value upper-threshold lower-threshold syntax in the ip sla monitor reaction-configuration command.

Threshold Falling (milliseconds)

The lower-threshold value, as configured by the threshold-value upper-threshold lower-threshold syntax in the ip sla monitor reaction-configuration command.

Threshold Count

The x-value in the xofy threshold-type, or the number-of-probes value for average threshold-type.

Threshold Count2

The y-value in the xofy threshold-type.

Action Type

The reaction to be performed when the violation conditions are met, as configured by the action-type { none | trapOnly | triggerOnly | trapAndTrigger } syntax in the ip sla monitor reaction-configuration command.

 

Triggering SNMP Notifications: Example

In the following example, CISCO-SYSLOG-MIB traps will be sent to the remote host at 209.165.202.129 if the threshold values for round-trip-time (rtt) or VoIP mean opion score (MOS) are violated:

Router(config)# ip sla monitor 1 
Router(config-sla-monitor)# type jitter dest-ipaddr 209.165.200.225 dest-port 3000 codec 
g711alaw
Router(config-sla-monitor-jitter)# default frequency 
Router(config-sla-monitor-jitter)# exit 

Router(config)# ip sla monitor schedule 1 start now life forever 
Router(config)# ip sla monitor reaction-configuration 1 react rtt threshold-type immediate 
threshold-value 3000 2000 action-type trapOnly 
Router(config)# ip sla monitor reaction-configuration 1 react MOS threshold-type 
consecutive 4 threshold-value 390 220 action-type trapOnly 

Router(config)# ip sla monitor logging traps 
Router(config)#
Router(config)# snmp-server host 209.165.202.129 version 2c public syslog 
! The following command is needed for the system to generate CISCO-SYSLOG-MIB traps.
Router(config)# snmp-server enable traps syslog 

As shown in the following example, the IP SLAs Threshold violations are generated as level 6 (informational) in the Cisco IOS system logging process:

3d18h:%RTT-6-SAATHRESHOLD:RTR(11):Threshold exceeded for MOS 

but are sent as level 7 (info) notifications from the CISCO-SYSLOG-MIB:

3d18h:SNMP:V2 Trap, reqid 2, errstat 0, erridx 0 
 sysUpTime.0 = 32613038 
 snmpTrapOID.0 = ciscoSyslogMIB.2.0.1 
 clogHistoryEntry.2.71 = RTT 
 clogHistoryEntry.3.71 = 7 
 clogHistoryEntry.4.71 = SAATHRESHOLD 
 clogHistoryEntry.5.71 = RTR(11):Threshold exceeded for MOS 
 clogHistoryEntry.6.71 = 32613037

Where to Go Next

If you want to configure an IP SLAs operation, see the "Cisco IOS IP SLAs Overview" chapter of the Cisco IOS IP SLAs Configuration Guide, Release 12.4.

If you want to configure multiple Cisco IOS IP SLAs operations at once, see the "IP SLAs—Multiple Operation Scheduling" chapter of the Cisco IOS IP SLAs Configuration Guide, Release 12.4.

Additional References

The following sections provide references related to configuring Cisco IOS IP SLAs.

Related Documents

Related Topic
Document Title

Overview of Cisco IOS IP SLAs

"Cisco IOS IP SLAs Overview" chapter of the Cisco IOS IP SLAs Configuration Guide, Release 12.4

Cisco IOS IP SLAs commands: complete command syntax, defaults, command mode, command history, usage guidelines, and examples

Cisco IOS IP SLAs Command Reference, Release 12.4


Standards

Standards
Title

No new or modified standards are supported by this feature, and support for existing standards has not been modified by features in this document.


MIBs

MIBs
MIBs Link

CISCO-RTTMON-MIB

To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs


RFCs

RFCs
Title

No specific RFCs are supported by the features in this document.


Technical Assistance

Description
Link

Technical Assistance Center (TAC) home page, containing 30,000 pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.

http://www.cisco.com/public/support/tac/home.shtml


Feature Information for IP SLAs Proactive Threshold Monitoring

Table 2 lists the features in this module and provides links to specific configuration information. Only features that were introduced or modified in Cisco IOS Release 12.3(14)T or a later release appear in the table. Not all features may be supported in your Cisco IOS software release.

For information on a feature in this technology that is not documented here, see the "Cisco IOS IP SLAs Features Roadmap."

Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.

Cisco IOS software images are specific to a Cisco IOS software release, a feature set, and a platform. Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.


Note Table 2 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.


Table 2 Feature Information for IP SLAs Proactive Threshold Monitoring 

Feature Name
Releases
Feature Information

IP SLAs Reaction Threshold

12.3(14)T

Cisco IOS IP SLAs proactive threshold monitoring capability allows you to configure an IP SLAs operation to react to certain measured network conditions.

IP SLAs VoIP Threshold Traps

12.3(14)T

Cisco IOS IP SLAs VoIP proactive threshold monitoring capability allows you to configure an IP SLAs operation to react to certain measured network conditions.