Cisco Unified Border Element (Enterprise) SIP Support Configuration Guide, Cisco IOS XE Release 3S
Configuring Support for Dynamic REFER Handling on the Cisco UBE
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Contents

Configuring Support for Dynamic REFER Handling on the Cisco UBE

The Dynamic REFER Handling on the Cisco UBE feature provides a REFER handling mechanism for call transfers on the Cisco Unified Border Element (UBE). You can configure the Cisco UBE to either pass across or consume the REFER message. When an endpoint invokes a supplementary service such as a call transfer, the endpoint generates and sends an in-dialog REFER request towards the Cisco UBE. To enable REFER handling on the Cisco UBE, use the supplementary-service sip refer command in voice service voip configuration mode.

Finding Feature Information

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 "Cisco Unified Border Element Features Roadmap" section on page 3 .

Use Cisco Feature Navigator to find information about platform support and Cisco IOS XE 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 Configuring Support for Dynamic REFER Handling on the Cisco UBE

  • Transcoding configuration is required on the Cisco UBE for midcall transcoder insertion, deletion, or modification during call transfers.

Cisco Unified Border Element

  • Cisco IOS Release 15.2(1)T or a later release must be installed and running on your Cisco Unified Border Element.

Cisco Unified Border Element (Enterprise)

  • Cisco IOS XE Release 3.7S or a later release must be installed and running on your Cisco ASR 1000 Series Router.

Restrictions for Configuring Support for Dynamic REFER Handling on the Cisco UBE

  • The Dynamic REFER Handling on the Cisco UBE feature supports only Session Initiation Protocol (SIP)-to-SIP call transfers.
  • Call escalation and de-escalation are not supported in REFER consumption mode on the Cisco UBE.
  • Video transcoding is not supported in REFER consumption mode on the Cisco UBE.
  • Session Description Protocol (SDP) pass-through is not supported in REFER consumption mode on the Cisco UBE.

How to Configure Support for Dynamic REFER Handling on Cisco UBE

Configuring REFER Pass-Through on the Cisco UBE

In REFER pass-through mode, the Cisco UBE passes the REFER message from the in-leg to the out-leg. To enable REFER pass-through on the Cisco UBE, use the supplementary-service sip refer command at the global or dial peer configuration level. If the referto-passing command is configured, the Cisco UBE does not perform dial peer lookup while passing the REFER message and passes the Refer-To header without any modification, even if address hiding is enabled.

This section contains the following tasks:

Configuring REFER Pass-Through on the Cisco UBE at the Global Level

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    voice service voip

    4.    supplementary-service sip refer

    5.    sip

    6.    referto-passing

    7.    exit

    8.    exit


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 voice service voip


    Example:
    Device(config)# voice service voip
     

    Enters voice service voip configuration mode.

     
    Step 4 supplementary-service sip refer


    Example:
    Device(conf-voi-serv)# supplementary-service sip refer
     

    Enables SIP supplementary services for REFER pass-through.

     
    Step 5sip


    Example:
    Device(conf-voi-serv)# sip
     

    Enters voice service voip SIP configuration mode.

     
    Step 6referto-passing


    Example:
    Device(conf-serv-sip)# referto-passing
     

    Disables the dial peer lookup and modification of the Refer-To header when the Cisco UBE passes across the REFER message during a call transfer.

     
    Step 7exit


    Example:
    Device(conf-serv-sip)# exit
     

    Exits voice service voip SIP configuration mode.

     
    Step 8exit


    Example:
    Device(conf-voi-serv)# exit
     

    Exits voice service voip configuration mode.

     

    Configuring REFER Pass-Through on the Cisco UBE at the Dial Peer Level

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    dial-peer voice number voip

      4.    voice-class sip referto-passing system

      5.    exit


    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 dial-peer voice number voip


      Example:
      Device(config)# dial-peer voice 22 voip
       

      Enters dial peer voice configuration mode for the specified dial peer.

       
      Step 4 voice-class sip referto-passing system


      Example:
      Device(config-dial-peer)# voice-class sip referto-passing
       

      Enables pass-through mode on the specified dial peer.

      • In the pass-through mode, the Cisco UBE passes across the Refer-To header during a call transfer.
       
      Step 5exit


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

      Exits dial peer voice configuration mode.

       

      Configuring REFER Consumption on the Cisco UBE

      In REFER consumption mode, the Cisco UBE consumes the REFER message and performs a dial peer lookup based on the Refer-To header. The Cisco UBE uses the properties of the matching dial peer and sends a triggered INVITE to the call-transfer target. To enable REFER consumption on the Cisco UBE, use the no supplementary-service sip refer command at the global or dial peer configuration level. The dial peer configuration takes precedence over the global configuration.

      Following are the benefits of the Dynamic REFER Handling on the Cisco UBE feature in REFER consumption mode:

      • Midcall codec changes are supported.
      • Both normal and high density (optimized) transcoding are supported.
      • End-to-end media renegotiation is supported during call transfer. To enable midcall media renegotiation, use the supplementary-service media-renegotiate command.
      • Secure Real-time Transport Protocol (SRTP) to RTP conversion is supported.
      • Media flow-through and flow-around are supported for transferred calls.
      • Uniform Resource Identifier (URI)-based routing (dial-peer lookup based on domain name) is supported for the triggered INVITE.

      This section contains the following tasks:

      Configuring REFER Consumption on the Cisco UBE at the Global Level

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    voice service voip

        4.    no supplementary-service sip refer

        5.    supplementary-service media-renegotiate

        6.    exit


      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 voice service voip


        Example:
        Device(config)# voice service voip
         

        Enters voice service voip configuration mode.

         
        Step 4 no supplementary-service sip refer


        Example:
        Device(conf-voi-serv)# no supplementary-service sip refer
         

        Enables SIP supplementary services for REFER consumption.

         
        Step 5supplementary-service media-renegotiate


        Example:
        Device(conf-voi-serv)# supplementary-service media-renegotiate
         

        Enables end-to-end media renegotiation during the call transfer in REFER consumption mode.

         
        Step 6exit


        Example:
        Device(conf-voi-serv)# exit
         

        Exits voice service voip configuration mode.

         

        Configuring REFER Consumption on the Cisco UBE at the Dial Peer Level

        The REFER consumption behavior on the Cisco UBE can be configured for every dial peer.

        SUMMARY STEPS

          1.    enable

          2.    configure terminal

          3.    dial-peer voice number voip

          4.    no supplementary-service sip refer

          5.    exit


        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 dial-peer voice number voip


          Example:
          Device(config)# dial-peer voice 22 voip
           

          Enters dial peer voice configuration mode for the specified dial peer.

           
          Step 4 no supplementary-service sip refer


          Example:
          Device(config-dial-peer)# no supplementary-service sip refer
           

          Enables SIP supplementary services for REFER consumption.

           
          Step 5exit


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

          Exits dial peer voice configuration mode.

           

          Troubleshooting Tips for Configuring Support for Dynamic REFER Handling on the Cisco UBE

          Use any of the following debug commands as appropriate on the Cisco UBE:

          • debug ccsip all 
            Device# debug ccsip all
All SIP Call tracing is enabled
          • debug voip ccapi inout 
            Device# debug voip ccapi input
voip ccapi inout debugging is on
          • debug sccp messages 
            Device# debug sccp messages
Skinny Client Control Protocol messages debugging is on
          • debug voip application supplementary-service 
            Device# debug voip application supplementary-service
voip application supplementary service debugging is on
          • debug voip application media negotiation 
            Device# debug voip application media negotiation
voip application medianeg debugging is on

          Feature History and Information for Configuring Support for Dynamic REFER Handling on the Cisco UBE

          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 History and Information for Configuring Support for Dynamic REFER Handling on the Cisco UBE

          Feature Name

          Releases

          Feature Information

          Dynamic REFER Handling on the Cisco UBE

          15.2(1)T

          The Dynamic REFER Handling on the Cisco UBE feature provides REFER message handling support on the Cisco UBE. You can configure the Cisco UBE for REFER pass-through or REFER consumption.

          The following commands were introduced or modified: referto-passing, voice-class sip referto-passing.

          Dynamic REFER Handling on the Cisco UBE

          Cisco IOS XE Release 3.7S

          The Dynamic REFER Handling on the Cisco UBE feature provides REFER message handling support on the Cisco UBE. You can configure the Cisco UBE for REFER pass-through or REFER consumption.

          The following commands were introduced or modified: referto-passing, voice-class sip referto-passing.