ENUM Working Group                                          R. Brandner
Internet Draft                                                  Siemens
                                                              L. Conroy
                                            Siemens Roke Manor Research
                                                             R. Stastny
                                                                  OeFEG
Expires: January 2005                                         July 2004


            IANA Registration for enumservices voice and video
                  <draft-brandner-enumservice-vovi-02.txt>

Status of this Memo

  By submitting this Internet-Draft, I certify that any applicable
  patent or other IPR claims of which I am aware have been disclosed,
  or will be disclosed, and any of which I become aware will be
  disclosed, in accordance with RFC 3668.

  Internet-Drafts are working documents of the Internet Engineering
  Task Force (IETF), its areas, and its working groups. Note that other
  groups may also distribute working documents as Internet-Drafts.

  Internet-Drafts are draft documents valid for a maximum of six months
  and may be updated, replaced, or obsoleted by other documents at any
  time.  It is inappropriate to use Internet-Drafts as reference
  material or to cite them other than a "work in progress."

  The list of current Internet-Drafts can be accessed at
  http://www.ietf.org/1id-abstracts.html

  The list of Internet-Draft Shadow Directories can be accessed at
  http://www.ietf.org/shadow.html

Copyright Notice

  Copyright (C) The Internet Society (2004).  All Rights Reserved.


Abstract

  This document registers the ENUMservices "voice" and "video" (each of
  which has a defined sub-type "tel"), as per the IANA registration
  process defined in the ENUM specification RFC3761[4]. These services
  are be used to indicate that the contact held in the generated URI
  can be used to initiate an interactive voice or video/audio call
  respectively.

Conventions used in this document

  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 [3].

1.  Introduction

   RFC3761 [4] (ENUM) describes a machanism to populate communication
   contacts within DNS [5] associated with an E.164 [6] number, using
   NAPTRs [7] that hold the DDDS [8][9] Application identifier "E2U".
   It defines a framework whereby the person controlling its population
   may indicate the kind of communication that can result from using
   the contact. This indication is called an ENUMservice, and there may
   be more than one ENUMservice associated with a single NAPTR, where
   the contact may be used to initiate more than one kind of
   communication.

   ENUMservices have a type and subtype. This latter is optional, as it
   may be implicit in the service type. The type defines the kind of
   communication session that can be initiated using the contact
   indicated by the URI generated by the enclosing NAPTR. The sub-type
   defines the subsystem that is to be used to initiate the
   communication session. Note that the sub-type definition includes
   the URI style that is to be used. Both the type and subtype (where
   present) must be supported for the NAPTR to be used by a potential
   correspondent.

   Whilst the protocol elements that make up ENUM are defined in the
   above documents and in this one, further examples of the use to
   which these may be put are given in other documents, for example in
   ETSI TS 102 172 [11].

   There are a number of DDDS Applications in addition to ENUM (for
   example, see [12] and [13]). However, an ENUMservice indication
   operates only within the context of the "E2U" (ENUM) DDDS
   Application.

   That context is specified in RFC3761, and requires a a standards
   track or experimental RFC to define the expectations for the
   ENUMservice, to be referred to in the IANA registry of ENUMservices.
   This document is the defining document for the ENUMservices "voice"
   and "video".


2.  ENUMservice for Interactive Voice

   ENUMservice Type:
      "Voice"

   The kind of communication indicated by this ENUMservice is
   "Interactive Voice". From a protocol perspective, this
   communication is expected to involve bidirectional media streams
   carrying audio data.

   A client may imply that the person controlling population of a
   NAPTR holding this ENUMservice indicates their capability to engage
   in an interactive voice session when contacted using the URI
   generated by this NAPTR.

2.1.  Defined Sub-types for Interactive Voice

2.1.1  ENUMservice "Voice" Sub-type "Tel"

   Sub-type:
      "tel"

   Generated URI scheme:
      "tel:" (defined in RFC2806 [10])

   This sub-type indicates that the person responsible for the NAPTR
   is accessible via the PSTN (Public Switched Telephone Network) or
   PLMN (Public Land Mobile Network) using the value of the generated
   URI.

   The kind of subsystem required to initiate a Voice ENUMservice with
   this sub-type is a "Dialler". This is a subsystem that either
   provides a local connection to the PSTN or PLMN, or that provides
   an indirect connection to those networks. The subsystem will use
   the telephone number held in the generated URI to place a voice
   call. The voice call is placed to a network that uses E.164 numbers
   to route calls to an appropriate destination.

   Note that the PLMN connection may be indirect. The end user
   receiving this NAPTR may have a relationship with a Communications
   Service Provider that accepts call initiation requests from that
   subsystem using an IP-based protocol such as SIP or H.323, and
   places the call to the PSTN using a remote gateway service. In this
   case the Provider may either accept requests using "tel:" URIs or
   has a defined mechanism to convert "tel:" URI values into a
   "protocol-native" form.

   The "tel:" URI value SHOULD be fully qualified (using the "global
   phone number" form of RFC2806 [10]). A "local phone number" [10]
   SHOULD NOT be used unless the controller of the zone in which the
   NAPTR appears is sure that it can be distinguished unambiguously by
   all clients that can access the resouce record and that a call from
   their network access points can be routed to that destination.

2.1.1.2  Security Considerations
   See main security considerations section of this document.

2.1.1.3.  Intended Usage of ENUMservice Voice
   COMMON

2.1.1.4.  Authors
   Rudolf Brandner, Lawrence Conroy, Richard Stastny
   (for author contact detail see section 9)

2.1.1.5.  Other Information Author Deems Interesting
   NONE


3.  ENUMservice for Interactive Video

   ENUMservice Type:
      "video"

   The kind of communication indicated by this ENUMservice is
   "Interactive Video and Voice". From a protocol perspective, this
   communication is expected to involve bidirectional media streams
   carrying video and audio data.

   A client may imply that the person controlling population of a
   NAPTR holding this ENUMservice indicates their capability to engage
   in an interactive video and voice session when contacted using the
   URI generated by this NAPTR.

3.1.  Defined Sub-types for Interactive Video

3.1.1. ENUMservice "Video" sub-type "Tel"

   Sub-type:
      "tel"

   Generated URI scheme:
      "tel:" (defined in RFC2806 [10])

   There are existing Video/Voice services provided over the telephone
   network, and this ENUMservice indicates that the destination has
   such a service. Specifically, this sub-type indicates that the
   person responsible for the NAPTR is accessible via the PSTN (Public
   Switched Telephone Network) or PLMN (Public Land Mobile Network)
   using the value of the generated URI.

   The kind of subsystem required to initiate a Voice ENUMservice with
   this sub-type is a "Dialler". This is a subsystem that either
   provides a local connection to the PSTN or PLMN, or that provides
   an indirect connection to those networks. The subsystem will use
   the telephone number held in the generated URI to place a call via
   the PSTN/PLMN network connection. See also section 2.1.1 above.

3.1.1.2  Security Considerations
   See main security considerations section of this document.

3.1.1.3.  Intended Usage of ENUMservice Voice
   COMMON

3.1.1.4.  Authors
   Rudolf Brandner, Lawrence Conroy, Richard Stastny
           (for author contact detail see section 9)

3.1.1.5.  Other Information Author Deems Interesting
   NONE


4.  Additional Information

    NONE


5.  Security Considerations

   DNS, as used by ENUM, is a global, distributed database. Thus any
   information stored there is visible to anyone anonymously. Whilst
   this is not qualitatively different from publication in a Telephone
   Directory, it does open the data subject to having "their"
   information collected automatically without any indication that this
   has been done or by whom.

   Such data harvesting by third parties is often used to generate
   lists of targets for unrequested information; in short, they are
   used to address "spam". Anyone who uses a Web-archived mailing list
   is aware that the volume of "spam" email they are sent increases
   when they post to the mailing list; publication of a telephone
   number in ENUM is no different, and may be used to send "junk faxes"
   or "junk SMS" for example.

   Many mailing list users have more than one email address and use
   "sacrificial" email accounts when posting to such lists to help
   filter out unrequested emails sent to them. This is not so easy with
   published telephone numbers; the PSTN E.164 number assignment
   process is much more involved and usually a single E.164 number (or
   a fixed range of numbers) is associated with each PSTN access. Thus
   providing a "sacrificial" phone number in any publication is not
   possible.

   Due to the implications of publishing data on a globally accessible
   database, as a principle the data subject MUST give their explicit
   informed consent to data being published in ENUM.

   In addition, they should be made aware that, due to storage of such
   data during harvesting by third parties, removal of the data from
   publication will not remove any copies that have been taken; in
   effect, any publication may be permanent.

   However, regulations in many regions will require that the data
   subject can at any time request that the data is removed from
   publication, and that their consent for its publication is
   explicitly confirmed at regular intervals.

   When placing a voice or video call via the PSTN or sending a message
   via the Public Land Mobile Network, the sender may be charged for
   this action. In both kinds of network, calling or messaging to some
   numbers is more expensive than sending to others; both networks have
   "premium rate" services that can charge considerably more than a
   "normal" call or message destination. As such, it is important that
   the end user be asked to confirm sending the message, and that the
   destination number be presented to them. It is the originating
   user's choice on whether or not to place a call to this destination
   number, but they SHOULD be shown the destination number so that they
   can make this decision

   Where voice or video terminals are configured to accept incoming
   calls, there SHOULD be an indication presented to the user that an
   incoming call is being offered. Particularly with some video
   systems, the terminal may be configured to "auto-accept" the call.
   In this case there MUST be an obvious indication presented to the
   called user that this has been done.

   Systems configured to auto-accept audio/video calls that are sent to
   a number published in a global public directory may be used by
   unexpected individuals to check for the presence or otherwise of
   people with a view to stealing property or other unwelcome acts.
   Whilst "security through obscurity" may have seemed acceptable when
   the access address was known to only a few, publication within ENUM
   removes the obscurity, so leaving (for example) a "WebCam" switched
   on after such publication is even less wise than in other
   situations.

   In addition to the specific security considerations given above, all
   security considerations given in RFC3761 apply.


6.  IANA Considerations

   This document requests that IANA adds entries to the Registry of
   ENUMservices set up as defined in the framework of RFC3761 for:
   -  ENUMservice type "voice" with sub-type "tel", and for
   -  ENUMservice type "video" with sub-type "tel".

   This document defines these ENUMservices and should be referred to
   in the Registry entries as their specification.


7.  Normative References:

  [1]  Bradner, S., "Intellectual Property Rights in IETF Technology",
       BCP 78, RFC3667, February 2004
  [2]  Bradner, S., "IETF Rights in Contributions", BCP 79, RFC3668,
       February 2004
  [3]  Bradner, S., "Key words for use in RFCs to Indicate Requirement
       Levels", BCP 14, RFC 2119, March 1997

  [4]  Faltstrom, P. and Mealling M., "The E.164 to Uniform Resource
       Identifiers (URI) Dynamic Delegation Discovery System (DDDS)
       Application (ENUM)", RFC 3761, April 2004.
  [5]  Mockapetris, P., "Domain Names - Concepts and Facilities", STD
       13, RFC 1034, November 1987
  [6]  ITU-T, "The International Public Telecommunication Number Plan",
       Recommendation E.164, May 1997
  [7]  Mealling, M., "Dynamic Delegation Discovery System (DDDS) Part
       Three: The Domain Name System (DNS) Database", RFC 3403, October
       2002.
  [8]  M. Mealling, RFC 3401,
       "Dynamic Delegation Discovery System (DDDS) Part One:
       The Comprehensive DDDS", October 2002
  [9]  M. Mealling, RFC 3402,
       "Dynamic Delegation Discovery System (DDDS) Part Two:
       The Algorithm", October 2002
  [10] A. Vaha-Sipila, RFC 2806, "URLs for Telephone Calls", April 2000


8.  Informative References:

  [11] ETSI TS 102 172,
      "Minimum Requirements for Interoperability of European ENUM
       Trials", July 2004
  [12] M. Mealling, RFC 3404,
      "Dynamic Delegation Discovery System (DDDS) Part Four:
       The Uniform Resource Identifiers (URI) Resolution
       Application", October 2002
  [13] M. Mealling, RFC 3405,
      "Dynamic Delegation Discovery System (DDDS) Part Five:
       URI.ARPA Assignment Procedures", October 2002


9.  Authors' Addresses

   Rudolf Brandner
    Siemens ICN
      Hofmannstrasse 51
      Munich
      Germany
      email: <mailto:rudolf.brandner@siemens.com>
      voice: <tel:+49-89-72251003>
      web:   <http://www.siemens.com>

   Lawrence Conroy
    Siemens Roke Manor Research
      Roke Manor
      Romsey
      U.K.
      email: <mailto:lwc@roke.co.uk>
      voice: <tel:+44-1794-833666>

   Richard Stastny
    OeFEG
      Postbox 147
      1103 Vienna
      Austria
      email: <mailto:richard.stastny@oefeg.at>
      voice: <tel:+43-664-420-4100>


10.  IPR and Full Copyright Statement

Disclaimer of validity:

  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.


Full Copyright Statement

  Copyright (C) The Internet Society (2004).  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.

Disclaimer of Warranty

  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 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.

Acknowledgement

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