Configuring VoIP Call Setup Monitoring

The Cisco IOS IP Service Level Agreements (SLAs) VoIP Call Setup (Post-Dial Delay) Monitoring feature provides the ability to measure your network’s response time for setting up a Voice over IP (VoIP) call over either H.323 or Session Initiation Protocol (SIP).

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.

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 VoIP Call Setup Monitoring

  • The Cisco IOS software image on the source and destination gateway must support the IP SLAs VoIP test-call and IP SLAs VoIP Responder applications. To determine if your Cisco IOS software image is configured with these applications, use the show call application voicecommand in EXEC mode.

Router# show call application voice summary
NAME             DESCRIPTION
...
ipsla-testcall   Basic app to place a simple call
ipsla-responder  Basic app to respond to a simple call
...
TCL Script Version 2.0 supported.
Call Treatment Action Application - Version 1.

Note


The IP SLAs VoIP Responder application is different from the IP SLAs Responder, which is configured using a Cisco IOS command.


Information About VoIP Call Setup Monitoring

IP SLAs VoIP Call Setup Monitoring Using H.323 or SIP

The Cisco IOS IP SLAs VoIP Call Setup Monitoring feature provides the ability to measure your network’s response time for setting up a VoIP call. Prior to configuring an IP SLAs VoIP call setup operation, you must enable the IP SLAs VoIP test-call application on the originating gateway (source). With the IP SLAs VoIP test-call application enabled, H.323 or Session Initiation Protocol (SIP) call messages can be sent to and received by the originating (source) and terminating (destination) gateways. The configuration for the IP SLAs VoIP call setup operation is essentially the same for both protocols.

The IP SLAs VoIP call setup operation can measure the total time from when an source gateway sends a call message, containing a call number, to when the sourcegateway receives a response from the destination gateway indicating that either the called number rang or the called party answered the call. As with all Cisco IOS IP SLAs operations, you can configure the VoIP call setup operation to repeat at specified time intervals, for a specified number of repetitions, and over a specified duration of time.

If a gatekeeper (GK) or directory gatekeeper (DGK) is involved in the H.323 call signaling, additional messages are sent and received between the source and destination gateways before the call message is actually sent. The additional time required for these messages is included in the IP SLAs VoIP call setup response time measurement. Likewise, if a proxy server or redirection server is involved in the SIP call signaling, any additional time required for messages to be sent and received prior to sending the call message, is included in the VoIP call setup response time measurement.

A plain old telephone service (POTS) IP phone can be set up at the terminating gateway to respond to an IP SLAs VoIP call setup test call. As an alternative to an actual IP phone, you can enable the IP SLAs VoIP Responder application in the destination gateway. The IP SLAs VoIP Responder application will respond to incoming call setup messages from the source gateway using H.323 or SIP.

How to Configure VoIP Call Setup Monitoring

Configuring the Source Gateway


Note


The required configuration for setting up the dial peer will vary slightly depending on whether you are using H.323 or SIP.


SUMMARY STEPS

    1.    enable

    2.    call application session start instance-name [application-name]

    3.    configure terminal

    4.    dial-peer voice tag voip

    5.    destination-pattern [+] string [T]

    6.    session target {ipv4: destination-address | dns:[$s$. | $d$. | $e$. | $u$.] host-name | enum: table-num | loopback:rtp | ras | sip-server}

    7.    session protocol sipv2

    8.    exit


DETAILED STEPS
     Command or ActionPurpose
    Step 1 enable


    Example:
    Router> enable
     

    Enables privileged EXEC mode.

    • Enter your password if prompted.

     
    Step 2 call application session start instance-name [application-name]


    Example:
    Router# call application session start ipsla-testcall ipsla-testcall
     

    Starts a new session of the Cisco IOS IP SLAs VoIP test-call application.

     
    Step 3 configure terminal


    Example:
    Router# configure terminal
     

    Enters global configuration mode.

     
    Step 4 dial-peer voice tag voip


    Example:
    Router(config)# dial-peer voice 6789 voip
     

    Defines a VoIP dial peer and enters dial-peer configuration mode.

     
    Step 5 destination-pattern [+] string [T]


    Example:
    Router(config-dial-peer)# destination-pattern 6789
     

    Specifies either the prefix or the full E.164 telephone number to be used for a dial peer.

     
    Step 6 session target {ipv4: destination-address | dns:[$s$. | $d$. | $e$. | $u$.] host-name | enum: table-num | loopback:rtp | ras | sip-server}


    Example:
    Router(config-dial-peer)# session target ipv4:172.29.129.123
     

    Designates a network-specific address to receive calls from the VoIP dial peer.

     
    Step 7 session protocol sipv2


    Example:
    Router(config-dial-peer)# session protocol sipv2
     

    (Optional) Specifies SIP as the session protocol for the VoIP dial peer.

    Note   

    Perform this step only if configuring a SIP call.

     
    Step 8 exit


    Example:
    Router(config-dial-peer)# exit
     

    Exits dial-peer configuration mode and returns to global configuration mode.

     

    Configuring a VoIP Call Setup Montioring Operation

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    ip sla operation-number

      4.    voip delay post-dial [detect-point {alert-ringing | connect-ok}] destination tag

      5.    history buckets-kept size

      6.    history distributions-of-statistics-kept size

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

      8.    history filter {none | all | overThreshold | failures}

      9.    frequency seconds

      10.    history hours-of-statistics-kept hours

      11.    history lives-kept lives

      12.    owner owner-id

      13.    history statistics-distribution-interval milliseconds

      14.    tag text

      15.    threshold milliseconds

      16.    timeout milliseconds

      17.    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 voip delay post-dial [detect-point {alert-ringing | connect-ok}] destination tag


      Example:
      Router(config-ip-sla)# voip delay post-dial detect-point alert-ringing destination 6789
       

      Enters IP SLA VoIP configuration mode and configures the operation as a VoIP call setup (post-dial delay) operation that will generate VoIP call setup response time measurements.

       
      Step 5 history buckets-kept size


      Example:
      Router(config-ip-sla-voip)# history buckets-kept 25
       

      (Optional) Sets the number of history buckets that are kept during the lifetime of an IP SLAs operation.

       
      Step 6 history distributions-of-statistics-kept size


      Example:
      Router(config-ip-sla-voip)# history distributions-of-statistics-kept 5
       

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

       
      Step 7 history enhanced [interval seconds] [buckets number-of-buckets]


      Example:
      Router(config-ip-sla-voip)# history enhanced interval 900 buckets 100
       

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

       
      Step 8 history filter {none | all | overThreshold | failures}


      Example:
      Router(config-ip-sla-voip)# history filter failures
       

      (Optional) Defines the type of information kept in the history table for an IP SLAs operation.

       
      Step 9 frequency seconds


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

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

       
      Step 10 history hours-of-statistics-kept hours


      Example:
      Router(config-ip-sla-voip)# history hours-of-statistics-kept 4
       

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

       
      Step 11 history lives-kept lives


      Example:
      Router(config-ip-sla-voip)# history lives-kept 5
       

      (Optional) Sets the number of lives maintained in the history table for an IP SLAs operation.

       
      Step 12 owner owner-id


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

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

       
      Step 13 history statistics-distribution-interval milliseconds


      Example:
      Router(config-ip-sla-voip)# history statistics-distribution-interval 10
       

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

       
      Step 14 tag text


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

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

       
      Step 15 threshold milliseconds


      Example:
      Router(config-ip-sla-voip)# threshold 10000
       

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

       
      Step 16 timeout milliseconds


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

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

       
      Step 17 end


      Example:
      Router(config-ip-sla-voip)# exit
       

      Exits to privileged EXEC mode.

       

      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 group 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.

         

        Enabling the IP SLAs VoIP Responder Application on the Destination Gateway


        Note


        The required configuration for setting up the dial peer will vary slightly depending on whether you are using H.323 or SIP.


        SUMMARY STEPS

          1.    enable

          2.    configure terminal

          3.    dial-peer voice tag voip

          4.    incoming called-number tag

          5.    application application-name

          6.    session protocol sipv2

          7.    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 dial-peer voice tag voip


          Example:
          Router(config)# dial-peer voice 6789 voip
           

          Defines a VoIP dial peer and enters dial-peer configuration mode.

           
          Step 4 incoming called-number tag


          Example:
          Router(config-dial-peer)# incoming called-number 6789
           

          Specifies a digit string to be matched by an incoming call to associate the call with a dial peer.

           
          Step 5 application application-name


          Example:
          Router(config-dial-peer)# application ipsla-responder
           

          Enables the Cisco IOS IP SLAs VoIP Responder application (ipsla-responder) on the dial peer to respond to incoming call setup messages.

           
          Step 6 session protocol sipv2


          Example:
          Router(config-dial-peer)# session protocol sipv2
           

          (Optional) Specifies SIP as the session protocol for the VoIP dial peer.

          Note   

          Perform this step only if configuring a SIP call.

           
          Step 7 end


          Example:
          Router(config-dial-peer)# exit
           

          Exits to privileged EXEC mode.

           

          Troubleshooting Tips

          • If the IP SLAs operation is not running and not 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 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 SLAs operation, see the “Configuring Proactive Threshold Monitoring” section.

          operation)

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

          Configuration Examples for VoIP Call Setup Monitoring

          Example VoIP Call Setup Configuration on the Source Gateway

          The following example shows the configuration on the source (originating) gateway to start the IP SLAs VoIP test-call application, set up the dial peer to route the test call, define the VoIP call setup operation, and schedule the VoIP call setup operation. In this example, test-call messages are generated using the Session Initiation Protocol (SIP).

          call application session start ipsla-testcall ipsla-testcall
          configure terminal
           dial-peer voice 6789 voip
            destination-pattern 6789
            session target ipv4:172.29.129.123
            session protocol sipv2
            exit
           ip sla 1
            voip delay post-dial detect-point alert-ringing destination 6789
            exit
           ip sla schedule 1 start-time now life forever

          Example VoIP Responder Application on Destination Gateway

          The following example shows the configuration for setting up the dial peer and enabling the IP SLAs VoIP Responder application to respond to the IP SLAs VoIP call setup test call. In this example, test-call messages are generated using the Session Initiation Protocol (SIP).

          configure terminal
           dial-peer voice 6789 voip
           incoming called-number 6789
           application ipsla-responder
           session protocol sipv2
           exit

          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 IP SLAs Configuration Guide.

          Standards

          Standard

          Title

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

          --

          MIBs

          MIB

          MIBs Link

          CISCO-RTTMON-MIB

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

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

          RFCs

          RFC

          Title

          No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.

          --

          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 VoIP Call Setup Monitoring

          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 www.cisco.com/​go/​cfn. An account on Cisco.com is not required.
          Table 1 Feature Information for VoIP Call Setup Monitoring

          Feature Name

          Releases

          Feature Information

          IP SLAs VoIP Call Setup (Post Dial Delay) Monitoring

          12.3(14)T

          The Cisco IOS IP SLAs Voice over IP (VoIP) call setup operation allows you to measure network response time for setting up a VoIP call.