Completion of Calls for the Session Initiation Protocol (SIP)
RFC 6910

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions
• 14
• 15
• 16
• 17
• 18
• 19

Internet Engineering Task Force (IETF)                         D. Worley
Request for Comments: 6910               Ariadne Internet Services, Inc.
Category: Standards Track                                  M. Huelsemann
ISSN: 2070-1721                                                R. Jesske
                                                        Deutsche Telekom
                                                           D. Alexeitsev
                                                               TeleFLASH
                                                              April 2013

     Completion of Calls for the Session Initiation Protocol (SIP)

Abstract

   The "completion of calls" feature defined in this specification
   allows the caller of a failed call to be notified when the callee
   becomes available to receive a call.

   For the realization of a basic solution without queuing, this
   document references the usage of the dialog event package (RFC 4235)
   that is described as 'Automatic Redial' in "Session Initiation
   Protocol Service Examples" (RFC 5359).

   For the realization of a more comprehensive solution with queuing,
   this document introduces an architecture for implementing these
   features in the Session Initiation Protocol where "completion of
   calls" implementations associated with the caller's and callee's
   endpoints cooperate to place the caller's request for completion of
   calls into a queue at the callee's endpoint; when a caller's request
   is ready to be serviced, re-attempt of the original, failed call is
   then made.

   The architecture is designed to interoperate well with existing
   completion of calls solutions in other networks.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6910.

Worley, et al.               Standards Track                    [Page 1]
RFC 6910                   Completion of Calls                April 2013

Copyright Notice

   Copyright (c) 2013 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
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1. Introduction ....................................................3
   2. Requirements Terminology ........................................4
   3. Terminology .....................................................4
   4. Solution ........................................................6
      4.1. CC Architecture ............................................6
      4.2. CC Procedures ..............................................8
      4.3. Automatic Redial as a Fallback ............................11
      4.4. Differences from SS7 ......................................11
   5. CC Queue Model .................................................12
   6. Caller's Agent Behavior ........................................13
      6.1. Receiving the CC Possible Indication ......................13
      6.2. Subscribing to CC .........................................13
      6.3. Receiving a CC Recall Notification ........................14
      6.4. Initiating a CC Call ......................................15
      6.5. Suspending CC .............................................15
      6.6. Resuming CC ...............................................15
   7. Callee's Monitor Behavior ......................................16
      7.1. Sending the CC Possible Indication ........................16
      7.2. Receiving a CC Subscription ...............................17
      7.3. Sending a CC Notification .................................18
      7.4. Receiving a CC Call .......................................19
      7.5. Receiving a CC Suspension .................................19
      7.6. Receiving a CC Resumption .................................20
   8. Examples .......................................................20
   9. 'call-completion' Event Package ................................24
      9.1. Event Package Name ........................................24