IP SLAs Configuration Guide, Cisco IOS XE Release 3S (Cisco ASR 1000)
Configuring IP SLAs UDP Jitter Operations
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Configuring IP SLAs UDP Jitter Operations

Contents

Configuring IP SLAs UDP Jitter Operations

This document describes how to configure an IP Service Level Agreements (SLAs) UDP jitter operation to analyze round-trip delay, one-way delay, one-way jitter, one-way packet loss, and connectivity in networks that carry UDP traffic in IPv4 or IPv6 networks. This module also explains how the data gathered using the UDP jitter operation can be displayed and analyzed using Cisco software commands.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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 module.

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

Prerequisites for IP SLAs UDP Jitter Operations

  • Time synchronization, such as that provided by the Network Time Protocol (NTP), is required between the source and the target device to provide accurate one-way delay (latency) measurements. To configure NTP on source and target devices, perform the tasks in the “Performing Basic System Management” chapter of the Basic System Management Configuration Guide. Time synchronization is not required for one-way jitter and packet loss measurements. If time is not synchronized between source and target devices, one-way jitter and packet loss data are returned, but values of “0” are returned for the one-way delay measurements provided by the UDP jitter operation.
  • Before configuring any IP Service Level Agreements (SLAs) application, use the show ip sla application command to verify that the operation type is supported on the software image.

Information About IP SLAs UDP Jitter Operations

IP SLAs UDP Jitter Operation

The IP Service Level Agreements (SLAs) UDP jitter operation diagnoses network suitability for real-time traffic applications such as VoIP, video over IP, or real-time conferencing.

Jitter means inter-packet delay variance. When multiple packets are sent consecutively from a source to a destination, for example, 10 ms apart, and if the network is behaving ideally, the destination should receive the packets 10 ms apart. But if there are delays in the network (like queuing, arriving through alternate routes, and so on) the arrival delay between packets might be greater than or less than 10 ms. Using this example, a positive jitter value indicates that packets arrived greater than 10 ms apart. If packets arrive 12 ms apart, then positive jitter is 2 ms; if packets arrive 8 ms apart, negative jitter is 2 ms. For delay-sensitive networks like VoIP, positive jitter values are undesirable, and a jitter value of 0 is ideal.

However, the IP SLAs UDP jitter operation does more than just monitor jitter. As the UDP jitter operation includes data returned by the IP SLAs UDP operation, the UDP jitter operation can be used as a multipurpose data gathering operation. The packets that IP SLAs generate carry packet-sending and receiving sequence information, and sending and receiving time stamps from the source and the operational target. Based on this information, UDP jitter operations are capable of measuring the following:

  • Per-direction jitter (source to destination and destination to source)
  • Per-direction packet loss
  • Per-direction delay (one-way delay)
  • Round-trip delay (average round-trip time)

As paths for sending and receiving data may be different (asymmetric), the per-direction data allows you to more readily identify where congestion or other problems are occurring in the network.

The UDP jitter operation functions by generating synthetic (simulated) UDP traffic. Asymmetric probes support custom-defined packet sizes per direction with which different packet sizes can be sent in request packets (from the source device to the destination device) and in response packets (from the destination device to the source device).

The UDP jitter operation sends N number of UDP packets, each of size S, T milliseconds apart, from a source device to a destination device, at a given frequency of F. In response, UDP packets of size P is sent from the destination device to the source device. By default, ten packet frames (N), each with a payload size of 10 bytes (S), are generated every 10 ms (T), and the operation is repeated every 60 seconds (F). Each of these parameters is user-configurable, so as to best simulate the IP service that you provide, as shown in the table below.

Table 1 UDP Jitter Operation Parameters

UDP Jitter Operation Parameter

Default

Configuration Commands

Number of packets (N)

10 packets

udp-jitter num-packets

Payload size per request packet (S)

10 bytes

request-data-size

Payload size per response packet (P)

The default response data size varies depending on the type of IP SLAs operation configured.

Note    If the response-data-size command is not configured, then the response data size value is the same as the request data size value.

response-data-size

Time between packets, in milliseconds (T)

10 ms

udp-jitter interval

Elapsed time before the operation repeats, in seconds (F)

60 seconds

frequency (IP SLA)

The IP SLAs operations function by generating synthetic (simulated) network traffic. A single IP SLAs operation (for example, IP SLAs operation 10) repeats at a given frequency for the lifetime of the operation.

How to Configure IP SLAs UDP Jitter Operations

Configuring the IP SLAs Responder on a Destination Device


Note


A responder should not configure a permanent port for a sender. If the responder configures a permanent port for a sender, even if the packets are successfully sent (no timeout or packet-loss issues), the jitter value is zero.


SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    Enter one of the following commands:

    • ip sla responder
    • ip sla responder udp-echo ipaddress ip-address port port

    4.    end


DETAILED STEPS
     Command or ActionPurpose
    Step 1 enable


    Example:
    Device> enable
     

    Enables privileged EXEC mode.

    • Enter your password if prompted.
     
    Step 2 configure terminal


    Example:
    Device# configure terminal
     

    Enters global configuration mode.

     
    Step 3Enter one of the following commands:
    • ip sla responder
    • ip sla responder udp-echo ipaddress ip-address port port


    Example:
    Device(config)# ip sla responder
    Device(config)# ip sla responder udp-echo ipaddress 192.0.2.132 port 5000
     

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

    (Optional; required only if protocol control is disabled on the source.) Enables IP SLAs responder functionality on the specified IP address and port.
    • Protocol control is enabled by default.
     
    Step 4 end


    Example:
    Device(config)# end
     

    Exits global configuration mode and returns to privileged EXEC mode.

     

    Configuring and Scheduling a UDP Jitter Operation on a Source Device

    Configuring a Basic UDP Jitter Operation on a Source Device

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    ip sla operation-number

      4.    udp-jitter {destination-ip-address | destination-hostname} destination-port [source-ip {ip-address | hostname}] [source-port port-number] [control {enable | disable}] [num-packets number-of-packets] [interval interpacket-interval]

      5.    frequency seconds

      6.    end

      7.    show ip sla configuration [operation-number]


    DETAILED STEPS
       Command or ActionPurpose
      Step 1 enable


      Example:
      Device> enable
       

      Enables privileged EXEC mode.

      • Enter your password if prompted.
       
      Step 2 configure terminal


      Example:
      Device# configure terminal
       

      Enters global configuration mode.

       
      Step 3 ip sla operation-number


      Example:
      Device(config)# ip sla 10 
       

      Starts configuring an IP SLAs operation and enters IP SLA configuration mode.

       
      Step 4 udp-jitter {destination-ip-address | destination-hostname} destination-port [source-ip {ip-address | hostname}] [source-port port-number] [control {enable | disable}] [num-packets number-of-packets] [interval interpacket-interval]


      Example:
      Device(config-ip-sla)# udp-jitter 192.0.2.135 5000
       

      Configures the IP SLAs operation as a UDP jitter operation and enters UDP jitter configuration mode.

      • Use the control disable keyword combination only if you disable the IP SLAs control protocol on both source and destination devices.
       
      Step 5 frequency seconds


      Example:
      Device(config-ip-sla-jitter)# frequency 30
       

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

       
      Step 6 end


      Example:
      Device(config-ip-sla-jitter)# end
       

      Exits UDP Jitter configuration mode and returns to privileged EXEC mode.

       
      Step 7 show ip sla configuration [operation-number]


      Example:
      Device# show ip sla configuration 10
       

      (Optional) Displays configuration values including all defaults for all IP SLAs operations or a specified operation.

       
      What to Do Next

      To configure the percentile option for your operation, see the “Configuring the IP SLAs—Percentile Support for Filtering Outliers” module.

      Configuring a UDP Jitter Operation with Additional Characteristics


      Note


      • The IP Service Level Agreements (SLAs) UDP jitter operation does not support the IP SLAs History feature because of the large volume of data involved with UDP jitter operations. This means that the following commands are not supported for UDP jitter operations: history buckets-kept, history filter, history lives-kept, samples-of-history-kept, and show ip sla history.
      • The MIB used by IP SLAs (CISCO-RTTMON-MIB) limits the hours-of-statistics kept for the UDP jitter operation to two hours. Configuring a larger value using the history hours-of-statistics hours global configuration change does not increase the value beyond two hours. However, the Data Collection MIB can be used to collect historical data for the operation. For more information, see the CISCO-DATA-COLLECTION-MIB.

      Before You Begin

      Before configuring a UDP jitter operation on a source device, the IP SLAs Responder must be enabled on the target device (the operational target). The IP SLAs Responder is available only on Cisco IOS software-based devices. To enable the Responder, perform the task in the “Configuring the IP SLAs Responder on the Destination Device” section.

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    ip sla operation-number

        4.    udp-jitter {destination-ip-address | destination-hostname} destination-port [source-ip {ip-address | hostname}] [source-port port-number] [control {enable | disable}] [num-packets number-of-packets] [interval interpacket-interval]

        5.    history distributions-of-statistics-kept size

        6.    history enhanced [interval seconds] [buckets number-of-buckets]

        7.    frequency seconds

        8.    history hours-of-statistics-kept hours

        9.    owner owner-id

        10.    request-data-size bytes

        11.    response-data-size bytes

        12.    history statistics-distribution-interval milliseconds

        13.    tag text

        14.    threshold milliseconds

        15.    timeout milliseconds

        16.    Enter one of the following commands:

        • tos number
        • traffic-class number

        17.    flow-label number

        18.    verify-data

        19.    vrf vrf-name

        20.    end

        21.    show ip sla configuration [operation-number]


      DETAILED STEPS
         Command or ActionPurpose
        Step 1 enable


        Example:
        Device> enable
         

        Enables privileged EXEC mode.

        • Enter your password if prompted.
         
        Step 2 configure terminal


        Example:
        Device# configure terminal
         

        Enters global configuration mode.

         
        Step 3 ip sla operation-number


        Example:
        Device(config)# ip sla 10 
         

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

         
        Step 4 udp-jitter {destination-ip-address | destination-hostname} destination-port [source-ip {ip-address | hostname}] [source-port port-number] [control {enable | disable}] [num-packets number-of-packets] [interval interpacket-interval]


        Example:
        Device(config-ip-sla)# udp-jitter 192.0.2.134 5000
         

        Configures the IP SLAs operation as a UDP jitter operation and enters UDP jitter configuration mode.

        • Use the control disable keyword combination only if you disable the IP SLAs control protocol on both source and target devices.
         
        Step 5 history distributions-of-statistics-kept size


        Example:
        Device(config-ip-sla-jitter)# history distributions-of-statistics-kept 5
         

        (Optional) Sets the number of statistics distributions kept per hop for an IP SLAs operation.

         
        Step 6 history enhanced [interval seconds] [buckets number-of-buckets]


        Example:
        Device(config-ip-sla-jitter)# history enhanced interval 900 buckets 100
         

        (Optional) Enables enhanced history gathering for an IP SLAs operation.

         
        Step 7 frequency seconds


        Example:
        Device(config-ip-sla-jitter)# frequency 30
         

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

         
        Step 8 history hours-of-statistics-kept hours


        Example:
        Device(config-ip-sla-jitter)# history hours-of-statistics-kept 4
         

        (Optional) Sets the number of hours for which statistics are maintained for an IP SLAs operation.

         
        Step 9 owner owner-id


        Example:
        Device(config-ip-sla-jitter)# owner admin 
         

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

         
        Step 10 request-data-size bytes


        Example:
        Device(config-ip-sla-jitter)# request-data-size 64 
         

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

         
        Step 11 response-data-size bytes


        Example:
        Device(config-ip-sla-jitter)# response-data-size 25 
         

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

         
        Step 12 history statistics-distribution-interval milliseconds


        Example:
        Device(config-ip-sla-jitter)# history statistics-distribution-interval 10
         

        (Optional) Sets the time interval for each statistics distribution kept for an IP SLAs operation.

         
        Step 13 tag text


        Example:
        Device(config-ip-sla-jitter)# tag TelnetPollServer1 
         

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

         
        Step 14 threshold milliseconds


        Example:
        Device(config-ip-sla-jitter)# threshold 10000
         

        (Optional) Sets the upper threshold value for calculating network monitoring statistics created by an IP SLAs operation.

         
        Step 15 timeout milliseconds


        Example:
        Device(config-ip-sla-jitter)# timeout 10000
         

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

         
        Step 16Enter one of the following commands:
        • tos number
        • traffic-class number


        Example:
        Device(config-ip-sla-jitter)# tos 160 
        Device(config-ip-sla-jitter)# traffic-class 160
         

        (Optional) Defines the ToS byte in the IPv4 header of an IP SLAs operation.

        or

        (Optional) Defines the traffic class byte in the IPv6 header for a supported IP SLAs operation.

         
        Step 17 flow-label number


        Example:
        Device(config-ip-sla-jitter)# flow-label 112233 
         

        (Optional) Defines the flow label field in the IPv6 header for a supported IP SLAs operation.

         
        Step 18 verify-data


        Example:
        Device(config-ip-sla-jitter)# verify-data
         

        (Optional) Causes an IP SLAs operation to check each reply packet for data corruption.

         
        Step 19 vrf vrf-name


        Example:
        Device(config-ip-sla-jitter)# vrf vpn-A 
         

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

         
        Step 20 end


        Example:
        Device(config-ip-sla-jitter)# end
         

        Exits UDP jitter configuration mode and returns to privileged EXEC mode.

         
        Step 21 show ip sla configuration [operation-number]


        Example:
        Device# show ip sla configuration 10
         

        (Optional) Displays configuration values including all defaults for all IP SLAs operations or a specified operation.

         
        What to Do Next

        To configure the percentile option for your operation, see the “Configuring the IP SLAs—Percentile Support for Filtering Outliers” module.

        Scheduling IP SLAs Operations

        Before You Begin
        • All IP Service Level Agreements (SLAs) operations to be scheduled must be already configured.
        • The frequency of all operations scheduled in a multioperation group must be the same.
        • The list of one or more operation ID numbers to be added to a multioperation group must be limited to a maximum of 125 characters in length, including commas (,).
        SUMMARY STEPS

          1.    enable

          2.    configure terminal

          3.    Enter one of the following commands:

          • 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 | schedule-together} [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.    end

          5.    show ip sla group schedule

          6.    show ip sla configuration


        DETAILED STEPS
           Command or ActionPurpose
          Step 1 enable


          Example:
          Device> enable
           

          Enables privileged EXEC mode.

          • Enter your password if prompted.
           
          Step 2 configure terminal


          Example:
          Device# configure terminal
           

          Enters global configuration mode.

           
          Step 3 Enter one of the following commands:
          • 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 | schedule-together} [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:
          Device(config)# ip sla schedule 10 life forever start-time now
          Device(config)# ip sla schedule 10 schedule-period frequency
          Device(config)# ip sla group schedule 1 3,4,6-9 life forever start-time now 
          Device(config)# ip sla schedule 1 3,4,6-9 schedule-period 50 frequency range 80-100
           
          • Configures the scheduling parameters for an individual IP SLAs operation.
          • Specifies an IP SLAs operation group number and the range of operation numbers for a multioperation scheduler.
           
          Step 4 end


          Example:
          Device(config)# end
           

          Exits global configuration mode and returns to privileged EXEC mode.

           
          Step 5 show ip sla group schedule


          Example:
          Device# show ip sla group schedule
           

          (Optional) Displays IP SLAs group schedule details.

           
          Step 6 show ip sla configuration


          Example:
          Device# show ip sla configuration
           

          (Optional) Displays IP SLAs configuration details.

           

          Troubleshooting Tips

          • If the IP Service Level Agreements (SLAs) operation is not running and not generating statistics, add the verify-data command to the configuration (while configuring in IP SLA configuration mode) to enable data verification. When data verification is 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 debug ip sla 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 Service Level Agreements (SLAs) operation, see the “Configuring Proactive Threshold Monitoring” section.

          Verifying IP SLAs UDP Jitter Operations

          SUMMARY STEPS

            1.    enable

            2.    show ip sla configuration

            3.    show ip sla group schedule


          DETAILED STEPS
            Step 1   enable

            Enables privileged EXEC mode.

            • Enter your password if prompted.


            Example:
            Device> enable

            Step 2   show ip sla configuration

            Displays IP SLAs configuration details.



            Example:

            Device# show ip sla configuration
            
            IP SLAs Infrastructure Engine-III
            Entry number: 5
            Owner: ownername
            Tag: text
            Operation timeout (milliseconds): 9999
            Type of operation to perform: udp-jitter
            Target address/Source address: 192.0.2.115/0.0.0.0
            Target port/Source port: 5/0
            Type Of Service parameter: 0x5
            Request size (ARR data portion): 100
            Response size (ARR data portion): 200
            Packet Interval (milliseconds)/Number of packets: 20/10
            Verify data: No
            Operation Stats Precision : microseconds
            Timestamp Location Optimization: enabled
            Operation Packet Priority : high
            NTP Sync Tolerance : 0 percent
            Vrf Name:
            Control Packets: enabled
            
            

            Step 3   show ip sla group schedule

            Displays IP SLAs group schedule details.



            Example:
            Device# show ip sla group schedule
            
            Group Entry Number: 1
            Probes to be scheduled: 6-9,3-4
            Total number of probes: 6
            Schedule period: 10
            Mode: even
            Group operation frequency: Equals schedule period
            Status of entry (SNMP RowStatus): Active
            Next Scheduled Start Time: Pending trigger
            Life (seconds): 3600
            Entry Ageout (seconds): never
            
            

            Configuration Examples for IP SLAs UDP Jitter Operations

            Example: Configuring a UDP Jitter Operation

            In the following example, two operations are configured as UDP jitter operations, with operation 2 starting five seconds after the first operation. Both operations will run indefinitely.

            configure terminal
             ip sla 1
              udp-jitter 192.0.2.115 65051 num-packets 20
              request-data-size 160
              tos 128
              frequency 30
             ip sla schedule 1 start-time after 00:05:00
             ip sla 2
              udp-jitter 192.0.2.115 65052 num-packets 20 interval 10
              request-data-size 20
              tos 64
              frequency 30
             ip sla schedule 2 start-time after 00:05:05
             

            Enter the following command on the target (destination) device to temporarily enable the IP SLAs responder functionality on a Cisco device in response to control messages from the source device.

            ip sla responder

            Additional References for IP SLAs UDP Jitter Operations

            Related Documents

            Related Topic

            Document Title

            Cisco IOS commands

            Cisco IOS Master Command List, All Releases

            Cisco IOS IP SLAs commands

            Cisco IOS IP SLAs Command Reference

            MIBs

            MIBs

            MIBs Link

            • CISCO-DATA-COLLECTION-MIB
            • CISCO-RTTMON-MIB
            • IPV6-FLOW-LABEL-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

            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 UDP Jitter Operations

            Table 2 Feature Information for the IP SLAs UDP Jitter Operation

            Feature Name

            Releases

            Feature Information

            IP SLAs—UDP Jitter Operation

            Cisco IOS XE Release 2.1

            Cisco IOS XE 3.1.0SG

            Cisco IOS XE Release 3.2SE

            The IP SLAs UDP jitter operation allows you to measure round-trip delay, one-way delay, one-way jitter, one-way packet loss, and connectivity in networks that carry UDP traffic.

            IP SLAs for IPv6 (UDP Jitter, UDP Echo, ICMP Echo, TCP Connect)

            Cisco IOS XE Release 2.1

            Cisco IOS XE 3.1.0SG

            Cisco IOS XE Release 3.2SE

            The IP SLAs for IPv6 (UDP Jitter, UDP Echo, ICMP Echo, TCP Connect) feature adds support for operability in IPv6 networks.

            IP SLAs—Asymmetric Probe Support for UDP Jitter

            Cisco IOS XE Release 3.10S

            The IP SLAs—Asymmetric Probe Support for UDP Jitter feature supports the configuration of custom-defined packet sizes in response packets.

            The following command was introduced: response-data-size.

            In Cisco IOS XE Release 3.10S, support was added for the Cisco ASR 1000 Series Routers.