Session Initiation Protocol (SIP) Call Control - Transfer
RFC 5589
Document | Type |
RFC - Best Current Practice
(June 2009; Errata)
Also known as BCP 149
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Last updated | 2015-10-14 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized with errata bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 5589 (Best Current Practice) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Cullen Jennings | ||
Send notices to | (None) |
Network Working Group R. Sparks Request for Comments: 5589 Tekelec BCP: 149 A. Johnston, Ed. Category: Best Current Practice Avaya D. Petrie SIPez LLC June 2009 Session Initiation Protocol (SIP) Call Control - Transfer Status of This Memo This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. Distribution of this memo is unlimited. Copyright Notice Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English. Abstract This document describes providing Call Transfer capabilities in the Session Initiation Protocol (SIP). SIP extensions such as REFER and Replaces are used to provide a number of transfer services including blind transfer, consultative transfer, and attended transfer. This work is part of the SIP multiparty call control framework. Sparks, et al. Best Current Practice [Page 1] RFC 5589 SIP CC Transfer June 2009 Table of Contents 1. Overview ........................................................3 2. Actors and Roles ................................................3 3. Terminology .....................................................4 4. Requirements ....................................................4 5. Using REFER to Achieve Call Transfer ............................5 6. Basic Transfer ..................................................6 6.1. Successful Transfer ........................................8 6.2. Transfer with Dialog Reuse ................................11 6.3. Failed Transfer ...........................................15 6.3.1. Target Busy ........................................16 6.3.2. Transfer Target Does Not Answer ....................17 7. Transfer with Consultation Hold ................................18 7.1. Exposing Transfer Target ..................................18 7.2. Protecting Transfer Target ................................19 7.3. Attended Transfer .........................................24 7.4. Recovery When One Party Does Not Support REFER ............28 7.5. Attended Transfer When Contact URI Is Not Known to Route to a User Agent .....................................29 7.6. Semi-Attended Transfer ....................................37 7.7. Attended Transfer Fallback to Basic Transfer ..............42 8. Transfer with Referred-By ......................................45 9. Transfer as an Ad Hoc Conference ...............................49 10. Transfer with Multiple Parties ................................52 11. Gateway Transfer Issues .......................................54 11.1. Coerce Gateway Hairpins to the Same Gateway ..............54 11.2. Consultative Turned Blind Gateway Glare ..................55 12. Security Considerations .......................................55 13. Acknowledgments ...............................................56 14. References ....................................................56 14.1. Normative References .....................................56 14.2. Informative References ...................................57 Sparks, et al. Best Current Practice [Page 2] RFC 5589 SIP CC Transfer June 2009 1. Overview This document describes providing Call Transfer capabilities andShow full document text