Configuring Support for Dynamic REFER Handling on Cisco UBE

Configuring Support for Dynamic REFER Handling on the Cisco UBE

Last Updated: September 23, 2012

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

  • To enable the Dynamic REFER Handling on the Cisco UBE feature, you must have Cisco IOS Release 15.2(1)T or a later release installed and running on your Cisco gateway.

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

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:

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
voice service voip


Example:

Router(config)# voice service voip

 

Enters voice service voip configuration mode.

 
Step 4
supplementary-service sip refer


Example:

Router(conf-voi-serv)# supplementary-service sip refer

 

Enables SIP supplementary services for REFER pass-through.

 
Step 5
sip


Example:

Router(conf-voi-serv)# sip

 

Enters voice service voip SIP configuration mode.

 
Step 6
referto-passing


Example:

Router(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 7
exit


Example:

Router(conf-serv-sip)# exit

 

Exits voice service voip SIP configuration mode.

 
Step 8
exit


Example:

Router(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:

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 number voip


Example:

Router(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:

Router(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 5
exit


Example:

Router(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:

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
voice service voip


Example:

Router(config)# voice service voip

 

Enters voice service voip configuration mode.

 
Step 4
no supplementary-service sip refer


Example:

Router(conf-voi-serv)# no supplementary-service sip refer

 

Enables SIP supplementary services for REFER consumption.

 
Step 5
supplementary-service media-renegotiate


Example:

Router(conf-voi-serv)# supplementary-service media-renegotiate

 

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

 
Step 6
exit


Example:

Router(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:

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 number voip


Example:

Router(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:

Router(config-dial-peer)# no supplementary-service sip refer

 

Enables SIP supplementary services for REFER consumption.

 
Step 5
exit


Example:

Router(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

    Router# debug ccsip all
    All SIP Call tracing is enabled
  • debug voip ccapi inout

    Router# debug voip ccapi input
    voip ccapi inout debugging is on
  • debug sccp messages

    Router# debug sccp messages
    Skinny Client Control Protocol messages debugging is on
  • debug voip application supplementary-service

    Router# debug voip application supplementary-service
    voip application supplementary service debugging is on
  • debug voip application media negotiation

    Router# 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 1Feature 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.

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