DISPATCH                                                  H. Schulzrinne
Internet-Draft                                                       FCC
Intended status: Standards Track                      September 30, 2016
Expires: April 3, 2017


                 A SIP Response Code for Unwanted Calls
             draft-schulzrinne-dispatch-status-unwanted-00

Abstract

   This document defines the 666 (Unwanted) SIP response code, allowing
   called parties to indicate that the call was unwanted.  The
   terminating SIP entity may use this information to adjust future call
   handling behavior for this called party or more broadly.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on April 3, 2017.

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   document authors.  All rights reserved.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Normative Language  . . . . . . . . . . . . . . . . . . . . .   2
   3.  Motivation  . . . . . . . . . . . . . . . . . . . . . . . . .   2
   4.  Behavior of SIP Entities  . . . . . . . . . . . . . . . . . .   3
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   3
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   3
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   3
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   4
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   4

1.  Introduction

   In many countries, an increasing number of calls are unwanted
   [RFC5039], as they might be fraudulent, illegal telemarketing or the
   receiving party does not want to be disturbed by, say, surveys or
   solicitation by charities.  Carriers and other service providers may
   want to help their subscribers avoid receiving such calls, using a
   variety of global or user-specific filtering algorithms.  One input
   into such algorithms is user feedback.  User feedback may be offered
   through smartphone apps, APIs or within the context of a SIP-
   initiated call.  This document addresses only the last mode, where
   the called party either rejects the SIP INVITE request as unwanted or
   terminates the call with a BYE request after answering the call.  To
   allow the called party to express that the call was unwanted, this
   document defines the 666 (Unwanted) response code.

2.  Normative Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in BCP 14, RFC 2119
   [RFC2119].

3.  Motivation

   None of the existing 4xx, 5xx or 6xx response codes allow the called
   party to convey that they not only reject this call, e.g., using 480
   (Temporarily Unavailable), 486 (Busy Here), 600 (Busy Everywhere),
   603 (Decline) or 606 (Not Acceptable), but that the caller is
   unwanted.  The particular response code number was chosen to reflect
   the distaste felt by many upon receiving such calls.






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4.  Behavior of SIP Entities

   The SIP entities receiving this response code are not obligated to
   take any particular action.  The service provider delivering calls to
   the user issuing the response MAY, for example, add the calling party
   to a personal blacklist, or MAY use the information as input when
   computing the likelihood that the calling party is placing unwanted
   calls ("crowd sourcing").

   The response code MAY also be used in Reason header fields [RFC3326],
   typically when the UAS issues a BYE request terminating an incoming
   call.

5.  IANA Considerations

   This document register a new SIP response code.  This response code
   is defined by the following information, which is to be added to the
   method and response-code sub-registry under
   http://www.iana.org/assignments/sip-parameters.

   Response Code Number  666

   Default Reason Phrase  Unwanted

   Reference  [this RFC]

6.  Security Considerations

   If the calling party number is spoofed, users may report the number
   as placing unwanted calls, possibly leading to the blocking of calls
   from the legitimate user of the number in addition to the unwanted
   caller.  Thus, it is RECOMMENDED that the response code is used for
   creating call filters only if the calling party number has been
   authenticated using [I-D.ietf-stir-rfc4474bis].

7.  Acknowledgements

   TBD.

8.  References

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.




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   [RFC3261]  Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
              A., Peterson, J., Sparks, R., Handley, M., and E.
              Schooler, "SIP: Session Initiation Protocol", RFC 3261,
              DOI 10.17487/RFC3261, June 2002,
              <http://www.rfc-editor.org/info/rfc3261>.

   [RFC3326]  Schulzrinne, H., Oran, D., and G. Camarillo, "The Reason
              Header Field for the Session Initiation Protocol (SIP)",
              RFC 3326, DOI 10.17487/RFC3326, December 2002,
              <http://www.rfc-editor.org/info/rfc3326>.

8.2.  Informative References

   [I-D.ietf-stir-rfc4474bis]
              Peterson, J., Jennings, C., Rescorla, E., and C. Wendt,
              "Authenticated Identity Management in the Session
              Initiation Protocol (SIP)", draft-ietf-stir-rfc4474bis-13
              (work in progress), September 2016.

   [RFC5039]  Rosenberg, J. and C. Jennings, "The Session Initiation
              Protocol (SIP) and Spam", RFC 5039, DOI 10.17487/RFC5039,
              January 2008, <http://www.rfc-editor.org/info/rfc5039>.

Author's Address

   Henning Schulzrinne
   FCC
   450 12th Street SW
   Washington, DC  20554
   US

   Email: henning.schulzrinne@fcc.gov



















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