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Cisco IOS IP SLAs Configuration Guide, Release 12.4
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Cisco IOS IP SLAs Features Roadmap
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Cisco IOS IP SLAs Overview
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IP SLAs--Analyzing IP Service Levels Using the UDP Jitter Operation
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IP SLAs--Analyzing Service Levels Using the VoIP Jitter Operation
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IP SLAs--Analyzing VoIP Service Levels Using the Gatekeeper Registration Delay Operation
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IP SLAs--Analyzing VoIP Service Levels Using the Call Setup Operation
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IP SLAs--Analyzing IP Service Levels Using the UDP Echo Operation
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IP SLAs--Analyzing IP Service Levels Using the HTTP Operation
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IP SLAs--Analyzing IP Service Levels Using the TCP Connect Operation
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IP SLAs--Analyzing IP Service Levels Using the ICMP Echo Operation
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IP SLAs--Analyzing IP Service Levels Using the ICMP Path Echo Operation
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IP SLAs--Analyzing IP Service Levels Using the ICMP Path Jitter Operation
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IP SLAs--Analyzing IP Service Levels Using the FTP Operation
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IP SLAs--Analyzing IP Service Levels Using the DNS Operation
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IP SLAs--Analyzing IP Service Levels Using the DHCP Operation
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IP SLAs--Analyzing IP Service Levels Using the DLSw+ Operation
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IP SLAs--Multiple Operation Scheduling
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IP SLAs--Proactive Threshold Monitoring
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Feedback
Table Of Contents
IP SLAs—Proactive Threshold Monitoring
Information About Proactive Threshold Monitoring for IP SLAs
IP SLAs Reaction Configuration
IP SLAs Threshold Monitoring and Notifications
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
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
Feature Information for IP SLAs Proactive Threshold Monitoring
IP SLAs—Proactive Threshold Monitoring
First Published: May 2, 2005Last Updated: July 18, 2008This 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
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Information About Proactive Threshold Monitoring for IP SLAs
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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:
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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.
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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.
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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
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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
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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:
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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:
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.
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:
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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:
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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 trapOnlyThe 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 1Entry number: 1Reaction Configuration not configuredRouter# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# ip sla monitor reaction-configuration 1Router(config)# do show ip sla monitor reaction-configuration 1Entry number: 1Reaction: rttThreshold Type: NeverRising (milliseconds): 5000Falling (milliseconds): 3000Threshold Count: 5Threshold Count2: 5Action Type: NoneVerifying 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-configurationEntry Number: 1Reaction: RTTThreshold type: NeverRising (milliseconds): 5000Falling (milliseconds): 3000Threshold Count: 5Threshold Count2: 5Action Type: NoneReaction: jitterDSAvgThreshold type: averageRising (milliseconds): 5Falling (milliseconds): 3Threshold Count: 5Threshold Count2: 5Action Type: triggerOnlyReaction: jitterDSAvgThreshold type: immediateRising (milliseconds): 5Falling (milliseconds): 3Threshold Count: 5Threshold Count2: 5Action Type: trapOnlyReaction: PacketLossSDThreshold type: immediateRising (milliseconds): 5Threshold Falling (milliseconds): 3Threshold Count: 5Threshold Count2: 5Action Type: trapOnlyTable 1 describes the significant fields shown in this output.
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 1Router(config-sla-monitor)# type jitter dest-ipaddr 209.165.200.225 dest-port 3000 codec g711alawRouter(config-sla-monitor-jitter)# default frequencyRouter(config-sla-monitor-jitter)# exitRouter(config)# ip sla monitor schedule 1 start now life foreverRouter(config)# ip sla monitor reaction-configuration 1 react rtt threshold-type immediate threshold-value 3000 2000 action-type trapOnlyRouter(config)# ip sla monitor reaction-configuration 1 react MOS threshold-type consecutive 4 threshold-value 390 220 action-type trapOnlyRouter(config)# ip sla monitor logging trapsRouter(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 syslogAs 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 MOSbut are sent as level 7 (info) notifications from the CISCO-SYSLOG-MIB:
3d18h:SNMP:V2 Trap, reqid 2, errstat 0, erridx 0sysUpTime.0 = 32613038snmpTrapOID.0 = ciscoSyslogMIB.2.0.1clogHistoryEntry.2.71 = RTTclogHistoryEntry.3.71 = 7clogHistoryEntry.4.71 = SAATHRESHOLDclogHistoryEntry.5.71 = RTR(11):Threshold exceeded for MOSclogHistoryEntry.6.71 = 32613037Where to Go Next
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Additional References
The following sections provide references related to configuring Cisco IOS IP SLAs.
Related Documents
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
No new or modified standards are supported by this feature, and support for existing standards has not been modified by features in this document.
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MIBs
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:
RFCs
Technical Assistance
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
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All other trademarks mentioned in this document or Website are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (0807R)
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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