RFC 4979






Network Working Group                                       A. Mayrhofer
Request for Comments: 4979                                       enum.at
Category: Standards Track                                    August 2007


                IANA Registration for Enumservice 'XMPP'

Status of This Memo



   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice



   Copyright (C) The IETF Trust (2007).

Abstract



   This document requests IANA registration of an Enumservice for XMPP,
   the Extensible Messaging and Presence Protocol.  This Enumservice
   specifically allows the use of 'xmpp' Uniform Resource Identifiers
   (URIs) in the context of E.164 Number Mapping (ENUM).

Table of Contents



   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 2
   3.  Enumservice Registration - XMPP . . . . . . . . . . . . . . . . 2
   4.  XMPP IRI/URI Considerations for ENUM  . . . . . . . . . . . . . 3
     4.1.  Authority Component . . . . . . . . . . . . . . . . . . . . 3
     4.2.  IRI-to-URI mapping  . . . . . . . . . . . . . . . . . . . . 3
   5.  Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
   6.  Security and Privacy Considerations . . . . . . . . . . . . . . 4
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 4
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 5
     9.1.  Normative References  . . . . . . . . . . . . . . . . . . . 5
     9.2.  Informative References  . . . . . . . . . . . . . . . . . . 5










Mayrhofer                   Standards Track                     [Page 1]

RFC 4979                    XMPP Enumservice                 August 2007


1.  Introduction



   E.164 Number Mapping (ENUM) [1] uses the Domain Name System (DNS) [6]
   to refer from E.164 numbers [7] to Uniform Resource Identifiers
   (URIs) [3].  Specific services to be used with ENUM must be
   registered with IANA.  Section 3 of RFC 3761 describes the process of
   such an Enumservice registration.

   The Extensible Messaging and Presence Protocol (XMPP) [9] provides
   means for streaming Extensible Markup Language (XML) [8] elements
   between endpoints in close to real time.  The XMPP framework is
   mainly used to provide instant messaging, presence, and streaming
   media services.

   RFC 4622 [5] registers a Uniform Resource Identifier (URI) scheme for
   identifying an XMPP entity as a URI or as an Internationalized
   Resource Identifier (IRI) [4].  The Enumservice specified in this
   document allows the provisioning of such "xmpp" URIs (and the URI
   representations of "xmpp" IRIs) in ENUM.

2.  Terminology



   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 RFC 2119 [2].

3.  Enumservice Registration - XMPP



   The following template contains information required for the IANA
   registrations of the 'XMPP' Enumservice, according to Section 3 of
   RFC 3761:

   Enumservice Name: "XMPP"

   Enumservice Type: "xmpp"

   Enumservice Subtype: n/a

   URI Schemes: "xmpp"

   Functional Specification:

      This Enumservice indicates that the resource identified is an XMPP
      entity.

   Security Considerations: see Section 6





Mayrhofer                   Standards Track                     [Page 2]

RFC 4979                    XMPP Enumservice                 August 2007


   Intended Usage: COMMON

   Author: Alexander Mayrhofer <alexander.mayrhofer@enum.at>

4.  XMPP IRI/URI Considerations for ENUM



4.1.  Authority Component



   XMPP IRIs/URIs optionally contain an "Authority Component" (see
   Section 2.3 of RFC 4622).  The presence of such an Authority
   Component in an IRI/URI signals the processing application to
   authenticate as the user indicated in the URI/IRI rather than using
   the preconfigured identity.

   In the context of this Enumservice, arbitrary clients may discover
   and use the XMPP URIs/IRIs associated to an E.164 number.  Hence, in
   most cases, those clients will not be able to authenticate as
   requested in the Authority Component.

   Therefore, URIs/IRIs that result from processing an XMPP Enumservice
   record SHOULD NOT contain an Authority Component.

4.2.  IRI-to-URI mapping



   While XMPP supports IRIs as well as 'plain' URIs, ENUM itself
   supports only the use of URIs for Enumservices.

   Therefore, XMPP IRIs MUST be mapped to URIs for use in an XMPP
   Enumservice record.  The mapping MUST follow the procedures outlined
   in Section 3.1 of RFC 3987.

5.  Example



   An example ENUM entry referencing to a XMPP URI could look like:

             $ORIGIN 6.9.4.0.6.9.4.5.1.1.4.4.e164.arpa.
             @  IN NAPTR  ( 100 10 "u"
                            "E2U+xmpp"
                            "!^.*$!xmpp:some-user@example.com!" .
                          )











Mayrhofer                   Standards Track                     [Page 3]

RFC 4979                    XMPP Enumservice                 August 2007


6.  Security and Privacy Considerations



   General security considerations of the protocols on which this
   Enumservice registration is based are addressed in Sections 3.1.3 and
   6 of RFC 3761 (ENUM) and Section 14 of RFC 3920 (XMPP).

   Since ENUM uses DNS -- a publicly available database -- any
   information contained in records provisioned in ENUM domains must be
   considered public as well.  Even after revoking the DNS entry and
   removing the referred resource, copies of the information could still
   be available.

   Information published in ENUM records could reveal associations
   between E.164 numbers and their owners -- especially if IRIs/URIs
   contain personal identifiers or domain names for which ownership
   information can be obtained easily.

   However, it is important to note that the ENUM record itself does not
   need to contain any personal information.  It just points to a
   location where access to personal information could be granted.

   ENUM records pointing to third-party resources can easily be
   provisioned on purpose by the ENUM domain owner -- so any assumption
   about the association between a number and an entity could therefore
   be completely bogus unless some kind of identity verification is in
   place.  This verification is out of scope for this memo.

7.  IANA Considerations



   This memo requests IANA to add a new "XMPP" Enumservice to the
   'Enumservice Registrations' registry, according to the definitions in
   this document and RFC 3761 [1].

   The required template is contained in Section 3.

8.  Acknowledgements



   Some text from RFC 4622 was used in the Introduction of this
   document.  Charles Clancy, Miguel Garcia, Andrew Newton, Jon
   Peterson, and Peter Saint-Andre provided extensive reviews and
   valuable feedback.










Mayrhofer                   Standards Track                     [Page 4]

RFC 4979                    XMPP Enumservice                 August 2007


9.  References



9.1.  Normative References



   [1]  Faltstrom, P. and M. Mealling, "The E.164 to Uniform Resource
        Identifiers (URI) Dynamic Delegation Discovery System (DDDS)
        Application (ENUM)", RFC 3761, April 2004.

   [2]  Bradner, S., "Key words for use in RFCs to Indicate Requirement
        Levels", BCP 14, RFC 2119, March 1997.

   [3]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
        Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986,
        January 2005.

   [4]  Duerst, M. and M. Suignard, "Internationalized Resource
        Identifiers (IRIs)", RFC 3987, January 2005.

   [5]  Saint-Andre, P., "Internationalized Resource Identifiers (IRIs)
        and Uniform Resource Identifiers (URIs) for the Extensible
        Messaging and Presence Protocol (XMPP)", RFC 4622, July 2006.

9.2.  Informative References



   [6]  Mockapetris, P., "Domain names - implementation and
        specification", STD 13, RFC 1035, November 1987.

   [7]  ITU-T, "The international public telecommunication numbering
        plan", Recommendation E.164 (02/05), Feb. 2005.

   [8]  Maler, E., Paoli, J., Bray, T., Yergeau, F., and C. Sperberg-
        McQueen, "Extensible Markup Language (XML) 1.0 (Third Edition)",
        World Wide Web Consortium FirstEdition REC-xml-20040204,
        February 2004, <http://www.w3.org/TR/2004/REC-xml-20040204>.

   [9]  Saint-Andre, P., Ed., "Extensible Messaging and Presence
        Protocol (XMPP): Core", RFC 3920, October 2004.














Mayrhofer                   Standards Track                     [Page 5]

RFC 4979                    XMPP Enumservice                 August 2007


Author's Address



   Alexander Mayrhofer
   enum.at GmbH
   Karlsplatz 1/2/9
   Wien  A-1010
   Austria

   Phone: +43 1 5056416 34
   EMail: alexander.mayrhofer@enum.at
   URI:   http://www.enum.at/








































Mayrhofer                   Standards Track                     [Page 6]

RFC 4979                    XMPP Enumservice                 August 2007


Full Copyright Statement



   Copyright (C) The IETF Trust (2007).

   This document is subject to the rights, licenses and restrictions
   contained in BCP 78, and except as set forth therein, the authors
   retain all their rights.

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
   THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
   THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Intellectual Property



   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at
   ietf-ipr@ietf.org.

Acknowledgement



   Funding for the RFC Editor function is currently provided by the
   Internet Society.







Mayrhofer                   Standards Track                     [Page 7]