Configuring Proactive Threshold Monitoring for Cisco IP SLAs Operations

First Published: August 14, 2006
Last Updated: September 10, 2010

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

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for IP SLAs Proactive Threshold Monitoring" section.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Contents

•Information About Proactive Threshold Monitoring

•How to Configure Proactive Threshold Monitoring

•Configuration Examples for Proactive Threshold Monitoring

•Additional References

•Feature Information for IP SLAs Proactive Threshold Monitoring

Information About Proactive Threshold Monitoring

•IP SLAs Reaction Configuration

•IP SLAs Threshold Monitoring and Notifications

Note For general information about IP SLAs operations, see the Cisco IOS IP SLAs Overview.

IP SLAs Reaction Configuration

IP SLAs reactions are configured to trigger when a monitored value exceeds or falls below a specified level or when a monitored event, such as a timeout or connection loss, occurs. If IP SLAs measures too high or too low of any configured reaction, IP SLAs can generate a notification to a network management application or trigger another IP SLA operation to gather more data.

IP SLAs Threshold Monitoring and Notifications

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

Notifications for IP SLAs are configured as a triggered reaction. Packet loss, jitter, and Mean Operation Score (MOS) statistics are specific to IP SLAs jitter operations. Notifications can be generated for violations in either direction (source-to-destination and destination-to-source) or for out-of-range RTT values for packet loss and jitter. Events, such as traps, are triggered when the RTT value rises above or falls below a specified threshold.

IP SLAs can generate system logging (syslog) messages when a reaction condition occurs. System logging messages can be sent as Simple Network Management Protocol (SNMP) traps (notifications) using the CISCO-RTTMON-MIB. SNMP traps for IP SLAs are supported by the CISCO-RTTMON-MIB and CISCO-SYSLOG-MIB.

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. Severity levels for the system logging process in Cisco IOS software are defined as follows: {emergency (0), alert (1), critical (2), error (3), warning (4), notice (5), informational (6), debugging (7)}.

IP SLAs Threshold violations are logged as level 6 (informational) within the Cisco IOS system logging process but are sent as level 7 (info) traps from the CISCO-SYSLOG-MIB.

Notifications are not issued for every occurrence of a threshold violation. Figure 1 illustrates the sequence for a triggered reaction that occurs when the monitored element exceeds the upper threshold. An event is sent and a notification is issued when the rising threshold is exceeded for the first time. Subsequent threshold-exceeded notifications are issued only after the monitored value falls below the falling threshold before exceeding the rising threshold again.

Figure 1 IP SLAs Triggered Reaction Condition and Notifications for Threshold Exceeded

1

An event is sent and a threshold-exceeded notification is issued when the rising threshold is exceeded for the first time.

2

Consecutive over-rising threshold violations occur without issuing additional notifications.

3

The monitored value goes below the falling threshold.

4

Another threshold-exceeded notification is issued when the rising threshold is exceeded only after the monitored value first fell below the falling threshold.


Note A lower-threshold notification is also issued the first time that the monitored element falls below the falling threshold (3). As described, subsequent notifications for lower-threshold violations will be issued only after the rising threshold is exceeded before the monitored value falls below the falling threshold again.

RTT Reactions for Jitter Operations

RTT reactions for jitter operations are triggered only at the end of the operation and use the latest value for the return-trip time (LatestRTT), which matches the value of the average return-trip time (RTTAvg).

SNMP traps for RTT for jitter operations are based on the value of the average return-trip time (RTTAvg) for the whole operation and do not include RTT values for each individual packet sent during the operation. For example, if the average is below the threshold, up to half of the packets can actually be above threshold but this detail is not included in the notification because the value is for the whole operation only.

Only syslog messages are supported for RTTAvg threshold violations. Syslog nmessages are sent from the CISCO-RTTMON-MIB.

How to Configure Proactive Threshold Monitoring

•Configuring Proactive Threshold Monitoring.

Configuring Proactive Threshold Monitoring

Perform this task to configure thresholds and reactive triggering for generating traps or starting another operation.

Prerequisites

•IP SLAs operations to be started when violation conditions are met must be configured.

Restrictions

•RTT reactions for jitter operations are triggered only at the end of the operation and use the latest value for the return-trip time (LatestRTT).

•SNMP traps for RTT for jitter operations are based on the average value for the return-trip time (RTTAvg) for the whole operation only and do not include return-trip time values for individual packets sent during the operation. Only syslog messages are supported for RTTAvg threshold violations.

•Only syslog messages are supported for RTT violations during Jitter operations.

•Only SNMP traps are supported for RTT violations during non-Jitter operations.

•Only syslog messages are supported for non-RTT violations other than timeout, connectionLoss, or verifyError.

•Both SNMP traps and syslog messages are supported for timeout, connectionLoss, or verifyError violations only.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip sla reaction-configuration operation-number react monitored-element [action-type option] [threshold-type {average [number-of-measurements] | consecutive [occurrences] | immediate | never | xofy [x-value y-value]}] [threshold-value upper-threshold lower-threshold]

4. ip sla reaction-trigger operation-number target-operation

5. ip sla logging traps

6. snmp-server enable traps rtr
or
snmp-server enable traps syslog

7. snmp-server host {hostname | ip-address} [vrf vrf-name] [traps | informs] [version {1 | 2c | 3 [auth | noauth | priv]}] community-string [udp-port port] [notification-type]

8. exit

9. show ip sla reaction configuration [operation-number]

10. show ip sla reaction trigger [operation-number]

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

ip sla reaction-configuration operation-number react monitored-element [action-type option] [threshold-type {average [number-of-measurements] | consecutive [occurrences] | immediate | never | xofy [x-value y-value]}] [threshold-value upper-threshold lower-threshold]

Example:

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

Configures the action (SNMP trap or IP SLAs trigger) that is to occur based on violations of specified thresholds.

Step 4 

ip sla reaction-trigger operation-number target-operation

Example:

Router(config)# ip sla reaction-trigger 10 2

(Optional) Starts another IP SLAs operation when the violation conditions are met.

•Required only if the ip sla reaction-configuration command is configured with either the trapAndTrigger or triggerOnly keyword.

Step 5 

ip sla logging traps

Example:

Router(config)# ip sla logging traps

(Optional) Enables IP SLAs syslog messages from CISCO-RTTMON-MIB.

Step 6 

snmp-server enable traps rtr

or

snmp-server enable traps syslog

Example:

Router(config)# snmp-server enable traps rtr

or

Example:

Router(config)# snmp-server enable traps syslog

(Optional) Enables system to generate CISCO-RTTMON-MIB traps.

or

Enables system to generate CISCO-SYSLOG-MIB traps.

Step 7 

snmp-server host {hostname | ip-address} [vrf vrf-name] [traps | informs] [version {1 | 2c | 3 [auth | noauth | priv]}] community-string [udp-port port] [notification-type]

Example:

Router(config)# snmp-server host 10.1.1.1 public syslog

(Optional) Sends traps to a remote host.

•Required if the snmp-server enable traps command is configured.

Step 8 

exit

Example:

Router(config)# exit

Exits global configuration mode and returns to privileged EXEC mode.

Step 9 

show ip sla reaction configuration [operation-number]

Example:

Router# show ip sla reaction configuration 10

(Optional) Displays the configuration of proactive threshold monitoring.

Step 10 

show ip sla reaction trigger [operation-number]

Example:

Router# show ip sla reaction trigger 2

(Optional) Displays the configuration status and operational state of target operations to be triggered.

Configuration Examples for Proactive Threshold Monitoring

•Example: Configuring an IP SLAs Reaction Configuration

•Example: Verifying an IP SLAs Reaction Configuration

•Example: Triggering SNMP Notifications

Example: Configuring an IP SLAs Reaction Configuration

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

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


The following example shows the default configuration for the ip sla reaction-configuration command: 

Router# show ip sla 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 reaction-configuration 1

Router(config)# do show ip sla 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

Example: Verifying an IP SLAs Reaction Configuration

The following example shows that multiple monitored elements are configured for the IP SLAs operation (1), as indicated by the values of Reaction: in the output: 

Router# show ip sla 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

 

Example: Triggering SNMP Notifications

The following example shows how to configure proactive threshold monitoring so that CISCO-SYSLOG-MIB traps are sent to the remote host at 10.1.1.1 if the threshold values for RTT or VoIP MOS are violated: 

! Configure the operation on source.

Router(config)# ip sla 1 

Router(config-ip-sla)# udp-jitter 10.1.1.1 3000 codec g711alaw

Router(config-ip-sla-jitter)# exit 

Router(config)# ip sla schedule 1 start now life forever 

! Configure thresholds and reactions.

Router(config)# ip sla reaction-configuration 1 react rtt threshold-type immediate 
threshold-value 3000 2000 action-type trapOnly 

Router(config)# ip sla reaction-configuration 1 react MOS threshold-type consecutive 4 
threshold-value 390 220 action-type trapOnly 

Router(config)# ip sla logging traps 

! The following command sends traps to the specified remote host.

Router(config)# snmp-server host 10.1.1.1 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 

 

The following sample system logging messages shows that IP SLAs threshold violation notifications are generated as level 6 (informational) in the Cisco IOS system logging process: 

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

 

This following sample SNMP notification from the CISCO-SYSLOG-MIB for the same violation is a level 7 (info) notification: 

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

Additional References

Related Documents

Related Topic
Document Title

Cisco IOS commands

Cisco IOS Master Commands List, All Releases

Cisco IOS IP SLAs commands

Cisco IOS IP SLAs Command Reference


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

•CISCO-SYSLOG-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

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

http://www.cisco.com/cisco/web/support/index.html


Feature Information for IP SLAs Proactive Threshold Monitoring

Table 1 lists the features in this module and provides links to specific configuration information.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Note Table 1 lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Table 1 Feature Information for IP SLAs Proactive Threshold Monitoring 

Feature Name
Releases
Feature Information

IP SLAs Reaction Threshold

12.2(31)SB2
12.2(33)SRB1
12.2(33)SXH
12.3(14)T
15.0(1)S
Cisco IOS XE 3.1.0SG

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

12.2(31)SB2
12.2(33)SRB1
12.2(33)SXH
12.3(14)T
15.0(1)S

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


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Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.

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