Configuring ICMP Path Jitter Operations
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Configuring IP SLAs ICMP Path Jitter Operations

Last Updated: March 14, 2011

This document describes how to configure an IP Service Level Agreements (SLAs) Internet Control Message Protocol (ICMP) Path Jitter operation to monitor hop-by-hop jitter (inter-packet delay variance). This document also demonstrates how the data gathered using the Path Jitter operations can be displayed and analyzed using Cisco commands.

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 Table at the end of this document.

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.

Prerequisites for ICMP Path Jitter Operations

  • Before configuring any IP SLAs application, you can use the show ip sla application command to verify that the operation type is supported on your software image.
  • In contrast with other IP SLAs operations, the IP SLAs Responder does not have to be enabled on either the target device or intermediate devices for Path Jitter operations. However, the operational efficiency may improve if you enable the IP SLAs Responder.

Restrictions for ICMP Path Jitter Operations

  • The IP SLAs ICMP Path Jitter operation is ICMP-based. ICMP-based operations can compensate for source processing delay but cannot compensate for target processing delay. For more robust monitoring and verifying, use of the IP SLAs UDP Jitter operation is recommended.
  • The jitter values obtained using the ICMP Path Jitter operation are approximates because ICMP does not provide the capability to embed processing times on routers in the packet. If the target router does not place ICMP packets as the highest priority, then the router will not respond properly. ICMP performance also can be affected by the configuration of priority queueing on the router and by ping response.
  • The path jitter operation does not support hourly statistics and hop information.
  • Unlike other IP SLAs operations, the ICMP Path Jitter operation is not supported in the RTTMON MIB. Path Jitter operations can only be configured using Cisco commands and statistics can only be returned using the show ip sla commands.
  • The IP SLAs Path Jitter operation does not support the IP SLAs History feature (statistics history buckets) because of the large data volume involved with Jitter operations.
  • The following commands, available in Path Jitter configuration mode, do not apply to Path Jitter operations:
    • history buckets-kept
    • history distributions-of-statistics-kept
    • history enhanced
    • history filter
    • history hours-of-statistics-kept
    • history lives-kept
    • history statistics-distribution-interval
    • samples-of-history-kept
    • lsr-path
    • tos
    • threshold
    • verify-data

Information About IP SLAs ICMP Path Jitter Operations

ICMP Path Jitter Operation

The IP SLAs ICMP Path Jitter operation provides hop-by-hop jitter, packet loss, and delay measurement statistics in an IP network. The Path Jitter operation functions differently than the standard UDP Jitter operation, which provides total one-way data and total round-trip data.

The ICMP Path Jitter operation can be used a supplement to the standard UDP Jitter operation. For example, results from the UDP Jitter operation may indicate unexpected delays or high jitter values; the ICMP Path Jitter operation could then be used to troubleshoot the network path and determine if traffic is bottlenecking in a particular segment along the transmission path.

The operation first discovers the hop-by-hop IP route from the source to the destination using a traceroute utility, and then uses ICMP echoes to determine the response times, packet loss and approximate jitter values for each hop along the path. The jitter values obtained using the ICMP Path Jitter operation are approximates because ICMP only provides round trip times.

The ICMP Path Jitter operation functions by tracing the IP path from a source device to a specified destination device, then sending N number of Echo probes to each hop along the traced path, with a time interval of T milliseconds between each Echo probe. The operation as a whole is repeated at a frequency of once every F seconds. The attributes are user-configurable, as shown here:

Path Jitter Operation Parameter

Default

Configured Using:

Number of echo probes (N )

10 echos

path-jitter command, num-packets option

Time between Echo probes, in milliseconds (T )

20 ms

path-jitter command, interval option

Note    The operation’s frequency is different than the operation’s interval.

The frequency of how often the operation is repeated (F )

once every 60 seconds

frequency command

How to Configure the IP SLAs ICMP Path Jitter Operation

Configuring the IP SLAs Responder on a Destination Device


Note
An IP SLAs Responder is not required on either the target device or intermediate devices for Path Jitter operations. However, operational efficiency may improve if you enable the IP SLAs Responder.
Before You Begin

The networking device to be used as the responder must be a Cisco device and you must have connectivity to that device through the network.


SUMMARY STEPS

1.    enable

2.    configure terminal

3.    ip sla responder

4.    exit


DETAILED STEPS
 Command or ActionPurpose
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 responder


Example: 


         

Example:
          
Router(config)# ip sla responder


         		 
          
 (Optional) Temporarily enables IP SLAs Responder functionality on
				a Cisco device in response to control messages from source.
			 


          
    
            
  •  Control is enabled by
				  default.
				
    • 

          


         


      
Step 4
          
            exit
          
        
 

Example:
          
Router(config)# exit


         		 
          
 (Optional) Exits global configuration mode and returns to
				privileged EXEC mode.
			 


         


    












Configuring an ICMP Path Jitter Operation on the Source Device



    

Perform only one of the following procedures in this section:


  


Configuring a Basic ICMP Path Jitter Operation


SUMMARY STEPS 
		
1.    
			  
				enable 
			  
		  

 
		
2.    
			  
				configure 
			  
			  
				terminal 
			  
		  

 
		
3.    
			  
				ip 
				sla 
			  
			  
				 
				 
			  
			  
				operation-number 
			  
		  

 
		
4.    
			  
				path-jitter 
			  {destination-ip-address | 
			 destination-hostname} [source-ip {ip-address | 
			 hostname}] [num-packets 
			 packet-number] [interval 
			 milliseconds] [targetOnly]
		  

 
		
5.    
			  
				frequency 
			  
			  
				seconds 
			  
		  

 
		
6.    
			  
				end 
			  
		  

 
	 
DETAILED STEPS
 Command or ActionPurpose
 
		
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 
			  
			  
				 
				 
			  
			  
				operation-number 
			  
		  
 

Example: 
			 
Router(config)# ip sla 10

 
		   		  
			 
 Begins configuration for an IP SLAs operation and enters IP SLA configuration mode.
			 

 
		   

 
		
Step 4 
			  
				path-jitter 
			  {destination-ip-address | 
			 destination-hostname} [source-ip {ip-address | 
			 hostname}] [num-packets 
			 packet-number] [interval 
			 milliseconds] [targetOnly]
		  
 

Example: 
			 
Router(config-ip-sla)# path-jitter 172.31.1.129 source-ip 10.2.30.1 num-packets 12 interval 22

 
		   		  
			 
 Defines an ICMP Path Jitter operation and enters IP SLA Path Jitter configuration mode.
			 

 
		   

 
		
Step 5 
			  
				frequency 
			  
			  
				seconds 
			  
		  
 

Example: 
			 
Router(config-ip-sla-pathJitter)# frequency 30

 
		   		  
			 
 (Optional) Sets the rate at which a specified IP SLAs operation repeats.
			 

 
		   

 
		
Step 6 
			  
				end 
			  
		  
 

Example: 
			 
Router(config-ip-sla-pathJitter)# end

 
		   		  
			 
 Exits to privileged EXEC mode.
			 

 
		   

 
	 


Example

		
		
 In the following example, the 
		  targetOnly keyword is used to bypass the hop-by-hop measurements. With this version of the command, echo probes will be sent to the destination only.
		

 
		
Router(config)# ip sla 1
Router(config-ip-sla)# path-jitter 172.17.246.20 num-packets 50 interval 30 targetOnly



	 












Configuring an ICMP Path Jitter Operation with Additional Parameters


SUMMARY STEPS
      
1.   
          
            enable
          
        


      
2.   
          
            configure
          
          
            terminal
          
        


      
3.   
          
            ip
            sla
          
          
            
            
          
          
            operation-number
          
        


      
4.   
          
            path-jitter
           {destination-ip-address | destination-hostname} [source-ip {ip-address | hostname}] [num-packets packet-number] [interval milliseconds] [targetOnly]


      
5.   
          
            frequency
          
          
            seconds
          
        


      
6.   
          
            owner
          
          
            owner-id
          
        


      
7.   
          
            request-data-size
          
          
            bytes
          
        


      
8.   
          
            tag
          
          
            text
          
        


      
9.   
          
            timeout
          
          
            milliseconds
          
        


      
10.   
          
            vrf
          
          
            vrf-name
          
        


      
11.   
          
            end
          
        


    
DETAILED STEPS
 Command or ActionPurpose

      
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
          
          
            
            
          
          
            operation-number
          
        
 

Example:
          
Router(config)# ip sla 10


         		 
          

Begins configuration for an IP SLAs operation and enters IP SLA configuration mode.


         


      
Step 4
          
            path-jitter
           {destination-ip-address | destination-hostname} [source-ip {ip-address | hostname}] [num-packets packet-number] [interval milliseconds] [targetOnly]
 

Example:
          
Router(config-ip-sla)# path-jitter 172.31.1.129 source-ip 10.2.30.1 num-packets 12 interval 22


         		 
          

Defines an ICMP Path Jitter operation and enters IP SLA Path Jitter configuration mode.


         


      
Step 5
          
            frequency
          
          
            seconds
          
        
 

Example:
          
Router(config-ip-sla-pathJitter)# frequency 30


         		 
          

(Optional) Sets the rate at which a specified IP SLAs operation repeats.


         


      
Step 6
          
            owner
          
          
            owner-id
          
        
 

Example:
          
Router(config-ip-sla-pathJitter)# owner admin 


         		 
          

(Optional) Configures the Simple Network Management Protocol (SNMP) owner of an IP SLAs operation.


         


      
Step 7
          
            request-data-size
          
          
            bytes
          
        
 

Example:
          
Router(config-ip-sla-pathJitter)# request-data-size 64 


         		 
          

(Optional) Sets the protocol data size in the payload of an IP SLAs operation's request packet.


         


      
Step 8
          
            tag
          
          
            text
          
        
 

Example:
          
Router(config-ip-sla-pathJitter)# tag TelnetPollServer1 


         		 
          

(Optional) Creates a user-specified identifier for an IP SLAs operation.


         


      
Step 9
          
            timeout
          
          
            milliseconds
          
        
 

Example:
          
Router(config-ip-sla-pathJitter)# timeout 10000 


         		 
          

(Optional) Sets the amount of time an IP SLAs operation waits for a response from its request packet.


         


      
Step 10
          
            vrf
          
          
            vrf-name
          
        
 

Example:
          
Router(config-ip-sla-pathJitter)# vrf vpn-A 


         		 
          

(Optional) Allows monitoring within Multiprotocol Label Switching (MPLS) Virtual Private Networks (VPNs) using IP SLAs operations.


         


      
Step 11
          
            end
          
        
 

Example:
          
Router(config-ip-sla-pathJitter)# end


         		 
          

Exits to privileged EXEC mode.


         


    














Scheduling IP SLAs Operations


 
		

Note
 
		  
     
			 
  • All IP SLAs operations to be scheduled must be already configured.
			 
    • 

			 
  •  The frequency of all operations scheduled in a multioperation group must be the same. 
			 
    • 
 
			 
  •  List of one or more operation ID numbers to be added to a multioperation group is limited to a maximum of 125 characters, including commas (,). 
			 
    • 
 
		  

 
		

 
	 

SUMMARY STEPS 
		
1.    
			  
				enable 
			  
		  

 
		
2.    
			  
				configure 
			  
			  
				terminal 
			  
		  

 
		
3.    Do one of the following: 
		  
     
			 
  •  
				 
				  ip 
				  sla 
				  schedule 
				 
				 
				  operation-number 
				 [life {forever | 
				seconds}] [start-time {hh 
				: 
				mm[: 
				ss] [month 
				day | 
				day 
				month] | 
				pending | 
				now | 
				after 
				hh 
				: 
				mm 
				: 
				ss}] [ageout 
				seconds] [recurring] 
			 
    • 
 
			 
  •  
				 
				  ip 
				  sla 
				  group 
				  schedule 
				 
				 
				  group-operation-number 
				  operation-id-numbers 
				 
				 
				  schedule-period 
				 
				 
				  schedule-period-range 
				 [ageout 
				seconds] [frequency 
				group-operation-frequency] [life{forever | 
				seconds}] [start-time{hh:mm[:ss] [month 
				day | 
				day 
				month] | 
				pending | 
				now | 
				after 
				hh:mm:ss}] 
			 
    • 
 
		  



 
		
4.    
			  
				exit 
			  
		  

 
		
5.    
			  
				show 
				ip 
				sla 
				group 
				schedule 
			  
		  

 
		
6.    
			  
				show 
				ip 
				sla 
				configuration 
			  
		  

 
	 
DETAILED STEPS
 Command or ActionPurpose
 
		
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 Do one of the following: 
		  
     
			 
  •  
				 
				  ip 
				  sla 
				  schedule 
				 
				 
				  operation-number 
				 [life {forever | 
				seconds}] [start-time {hh 
				: 
				mm[: 
				ss] [month 
				day | 
				day 
				month] | 
				pending | 
				now | 
				after 
				hh 
				: 
				mm 
				: 
				ss}] [ageout 
				seconds] [recurring] 
			 
    • 
 
			 
  •  
				 
				  ip 
				  sla 
				  group 
				  schedule 
				 
				 
				  group-operation-number 
				  operation-id-numbers 
				 
				 
				  schedule-period 
				 
				 
				  schedule-period-range 
				 [ageout 
				seconds] [frequency 
				group-operation-frequency] [life{forever | 
				seconds}] [start-time{hh:mm[:ss] [month 
				day | 
				day 
				month] | 
				pending | 
				now | 
				after 
				hh:mm:ss}] 
			 
    • 
 
		  

 

Example: 
			 
Router(config)# ip sla schedule 10 start-time now life forever

 
		   

Example: 
			 
Router(config)# ip sla group schedule 1 3,4,6-9 

 
		   		  
			 
 For individual IP SLAs operations only: 
			 

 
			 
 Configures the scheduling parameters for an individual IP SLAs operation. 
			 

 
			 
or 
			 

 
			 
 For multioperation scheduler only: 
			 

 
			 
 Specifies an IP SLAs operation group number and the range of operation numbers to be scheduled in global configuration mode. 
			 

 
		   

 
		
Step 4 
			  
				exit 
			  
		  
 

Example: 
			 
Router(config)# exit

 
		   		  
			 
 Exits to privileged EXEC mode. 
			 

 
		   

 
		
Step 5 
			  
				show 
				ip 
				sla 
				group 
				schedule 
			  
		  
 

Example: 
			 
Router# show ip sla group schedule

 
		   		  
			 
 (Optional) Displays the IP SLAs group schedule details. 
			 

 
		   

 
		
Step 6 
			  
				show 
				ip 
				sla 
				configuration 
			  
		  
 

Example: 
			 
Router# show ip sla configuration

 
		   		  
			 
 (Optional) Displays the IP SLAs configuration details. 
			 

 
		   

 
	 




Troubleshooting Tips


 
	 
     
		
  •  If the IP SLAs operation is not running and generating statistics, add the 
		  verify-data command to the configuration of the operation (while configuring in IP SLA configuration mode) to enable data verification. When enabled, each operation response is checked for corruption. Use the 
		  verify-data command with caution during normal operations because it generates unnecessary overhead. 
		
    • 
 
		
  •  Use the 
		  debugipsla 
			 trace and 
		  debug 
			 ip 
			 sla 
			 error commands to help troubleshoot issues with an IP SLAs operation. 
		
    • 
 
	 

 
  



































What to Do Next


 
	 
 To add proactive threshold conditions and reactive triggering for generating traps, or for starting another operation, to an IP SLAs operation, see the "Configuring Proactive Threshold Monitoring" section. 
	 

 
	 
 To view and interpret the results of an IP SLAs operation use the 
		show 
		  ip 
		  sla 
		  statistics command. Checking the output for fields that correspond to criteria in your service level agreement will help you determine whether the service metrics are acceptable. 
	 

 
  












































Configuration Examples for IP SLAs ICMP Path Jitter Operations



    

    


  


Example  Configuring a Path Jitter Operation



    

      

The following example shows the output when the ICMP Path Jitter operation is configured. Because the path jitter operation does not support hourly statistics and hop information, the output for the show ip sla statistics command for the path jitter operation displays only the statistics for the first hop.


      

The following example shows the output when the ICMP Path Jitter operation is configured.


      
Router# configure terminal
Router(config)# ip sla 15011
Router(config-sla-monitor)# path-jitter 10.222.1.100 source-ip 10.222.3.100 num-packets 20
Router(config-sla-monitor-pathJitter)# frequency 30
Router(config-sla-monitor-pathJitter)# exit
Router(config)# ip sla schedule 15011 life forever start-time now
Router(config)# exit
Router# show ip sla statistics 15011
Round Trip Time (RTT) for       Index 15011
        Latest RTT: 1 milliseconds
Latest operation start time: 15:37:35.443 EDT Mon Jun 16 2008
Latest operation return code: OK
---- Path Jitter Statistics ---- 
Hop IP 10.222.3.252:
Round Trip Time milliseconds:
        Latest RTT: 1 ms
        Number of RTT: 20
        RTT Min/Avg/Max: 1/1/3 ms
Jitter time milliseconds:
        Number of jitter: 2
        Jitter Min/Avg/Max: 2/2/2 ms
Packet Values:
        Packet Loss (Timeouts): 0
        Out of Sequence: 0
        Discarded Samples: 0
Operation time to live: Forever


    


  












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 
					 

 
				  		
 
				

 
				
 
				   
					 
 Cisco IOS IP SLAs: general information 
					 

 
				  		
 
				   
					 
 Cisco IOS IP SLAs Overview chapter of the 
						Cisco IOS IP SLAs Configuration Guide. 
					 

 
				  		
 
				

 
			 
 
		  



 
	 

 
	 
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 
					 

 
				  		
 
				

 
			 
 
			  
				
 
				   
					 
 MIB support for the Path Jitter operation is not provided. 
					 

 
				  		
 
				   
					 
 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 
					 

 
				  		
 
				

 
			 
 
			  
				
 
				   
					 
 RFC 18891 
					 

 
				  		
 
				   
					 
 
						RTP: A Transport Protocol for Real-Time Applications ; see the section “Estimating the Interarrival Jitter” 
					 

 
				  		
 
				

 
			 
 
		  




1  Support for the listed RFC is not claimed; listed as a reference only. 
						
 
	 

 
	 
Technical Assistance
 
		 
		

 
			  
			  
			  
				
 
				   
					 
 Description 
					 

 
				  		
 
				   
					 
 Link 
					 

 
				  		
 
				

 
			 
 
			  
				
 
				   
					 
 The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. 
					 

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

 
				  		
 
				

 
			 
 
		  



 
	 

 
  










Feature Information for IP SLAs ICMP Path Jitter Operations


 
	 

		
The following table provides release information about the feature or features described in this module. This table 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.
		

 
		
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. 
		

 
	 


	 
 
		

Table 1 Feature Information for IP SLAs ICMP Path Jitter Operations  
		   
		   
		   
		   
			 
 
				 
				  
 Feature Name
				  

 
						
 
				 
				  
 Releases
				  

 
						
 
				 
				  
 Feature Information
				  

 
						
 
			 

 
		  
 
		   
			 
 
				 
				  
 IP SLAs Path Jitter Operation
				  

 
						
 
				 
				  
 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
				  

 
						
 
				 
				  
 The Cisco IOS IP SLAs Internet Control Message Protocol (ICMP) path jitter operation allows you to measure hop-by-hop jitter (inter-packet delay variance).
				  

 
						
 
			 

 
		  
 
		



 
	 

 
  










 


 
	 
Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco's trademarks can be found at 
		www.cisco.com/go/trademarks. Third party trademarks mentioned 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. (1005R) 
	 

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

 
  




























































































1  Support for the listed RFC is not claimed; listed as a reference only. 
						



Copyright © 2010, Cisco Systems, Inc. All rights reserved.