Internet Engineering Task Force (IETF)                     M. Westerlund
Request for Comments: 6336                                      Ericsson
Updates: 5245                                                 C. Perkins
Category: Standards Track                          University of Glasgow
ISSN: 2070-1721                                                July 2011


 IANA Registry for Interactive Connectivity Establishment (ICE) Options

Abstract

   It has been identified that "Interactive Connectivity Establishment
   (ICE): A Protocol for Network Address Translator (NAT) Traversal for
   Offer/Answer Protocols" (RFC 5245) is missing a registry for ICE
   options.  This document defines this missing IANA registry and
   updates RFC 5245.

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/rfc6336.

Copyright Notice

   Copyright (c) 2011 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 ....................................................2
   2. Requirements Language ...........................................2
   3. IANA Considerations .............................................3
      3.1. ICE Options ................................................3
   4. Security Considerations .........................................3
   5. Acknowledgements ................................................4
   6. References ......................................................4
      6.1. Normative References .......................................4
      6.2. Informative References .....................................4

1.  Introduction

   "Interactive Connectivity Establishment (ICE): A Protocol for Network
   Address Translator (NAT) Traversal for Offer/Answer Protocols"
   [RFC5245] defines a concept of ICE options.  However, the ICE RFC
   fails to create an IANA registry for ICE options.  As one ICE option
   is under specification in [ECN-FOR-RTP], there is now a need to
   create the registry.

   RFC 5245 says: "ICE provides for extensibility by allowing an offer
   or answer to contain a series of tokens that identify the ICE
   extensions used by that agent.  If an agent supports an ICE
   extension, it MUST include the token defined for that extension in
   the ice-options attribute".

   Thus, as future extensions are defined, these ICE options need to be
   registered with IANA to ensure non-conflicting identification.  The
   ICE option identifiers are used in signalling between the ICE
   endpoints to negotiate extension support.  RFC 5245 defines one
   method of signalling these ICE options, using the Session Description
   Protocol (SDP) with Offer/Answer [RFC3264].

   This document updates the ICE specification [RFC5245] to define the
   "Interactive Connectivity Establishment (ICE) Options" registry.

2.  Requirements 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 RFC 2119 [RFC2119].

3.  IANA Considerations

   This document defines a registry "Interactive Connectivity
   Establishment (ICE) Options" for ICE options that can be used in the
   SDP "ice-options" attribute or other signalling parameters carrying
   the ICE options.

3.1.  ICE Options

   An ICE option identifier MUST fulfill the ABNF [RFC5234] syntax for
   "ice-option-tag" as specified in [RFC5245].  This syntax is
   reproduced here for simplicity, but the authoritative definition is
   in the ICE RFC:

   ice-option-tag        = 1*ice-char
   ice-char              = ALPHA / DIGIT / "+" / "/"

   ICE options are of unlimited length according to the syntax; however,
   they are RECOMMENDED to be no longer than 20 characters.  This is to
   reduce message sizes and allow for efficient parsing.

   Registration of an ICE option in the "Interactive Connectivity
   Establishment (ICE) Options" registry is done using the Specification
   Required policy as defined in "Guidelines for Writing an IANA
   Considerations Section in RFCs" [RFC5226].

   A registration request MUST include the following information:

   o  The ICE option identifier to be registered

   o  Name, Email, and Address of a contact person for the registration

   o  Organization or individuals having the change control

   o  Short description of the ICE extension to which the option relates

   o  Reference(s) to the specification defining the ICE option and the
      related extensions

   This document registers no ICE option.

4.  Security Considerations

   As this document defines an IANA registry for an already existing
   concept, there are no new security considerations.

5.  Acknowledgements

   The authors would like to thank the people who reviewed the document
   and provided feedback: Flemming Andreasen, Mykyta Yevstifeyev, Amanda
   Baber, and Brian Carpenter.

6.  References

6.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
              May 2008.

   [RFC5234]  Crocker, D., Ed., and P. Overell, "Augmented BNF for
              Syntax Specifications: ABNF", STD 68, RFC 5234,
              January 2008.

   [RFC5245]  Rosenberg, J., "Interactive Connectivity Establishment
              (ICE): A Protocol for Network Address Translator (NAT)
              Traversal for Offer/Answer Protocols", RFC 5245,
              April 2010.

6.2.  Informative References

   [ECN-FOR-RTP]
              Westerlund, M., Johansson, I., Perkins, C., O'Hanlon, P.,
              and K. Carlberg, "Explicit Congestion Notification (ECN)
              for RTP over UDP", Work in Progress, July 2011.

   [RFC3264]  Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model
              with Session Description Protocol (SDP)", RFC 3264,
              June 2002.

Authors' Addresses

   Magnus Westerlund
   Ericsson
   Farogatan 6
   SE-164 80 Kista
   Sweden

   Phone: +46 10 714 82 87
   EMail: magnus.westerlund@ericsson.com


   Colin Perkins
   University of Glasgow
   School of Computing Science
   Glasgow  G12 8QQ
   United Kingdom

   EMail: csp@csperkins.org