V6OPS                                                       B. Carpenter
Internet-Draft                                         Univ. of Auckland
Intended status: Informational                                  S. Jiang
Expires: January 27, 2012                   Huawei Technologies Co., Ltd
                                                            V. Kuarsingh
                                                   Rogers Communications
                                                           July 26, 2011

             Framework for IP Version Transition Scenarios


   This document sets out a framework agreed by the V6OPS WG for the
   presentation of scenarios and recommendations for a variety of
   approaches to the transition from IPv4 to IPv6, given the necessity
   for a long period of co-existence of the two protocols.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
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   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on January 27, 2012.

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Document Topics . . . . . . . . . . . . . . . . . . . . . . . . 4
   3.  Security Considerations . . . . . . . . . . . . . . . . . . . . 5
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
   5.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 5
   6.  Change log  . . . . . . . . . . . . . . . . . . . . . . . . . . 5
   7.  Informative References  . . . . . . . . . . . . . . . . . . . . 6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 6

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1.  Introduction

   This document sets out a framework for the presentation of scenarios
   and recommendations for a variety of approaches to the transition
   from IPv4 to IPv6, given the necessity for a long period of co-
   existence of the two protocols.  A general "call to arms" for
   transition is found in [RFC5211], and a recommendation for four
   principal scenarios is given in [RFC6180].  A report on experience
   and plans of various Internet Service Providers (ISPs) is given in
   [RFC6036].  However, it is clear that operators require more detailed
   technical recommendations than are available so far.  Unfortunately,
   the number of different combinations of existing IPv4 deployment
   models, customer profiles and requirements, and possible coexistence
   and transition models, is enormous, so it is quite impracticable to
   produce either a set of recommendations for each case, or a
   recommended "one size fits all" model.  That is why this document
   proposes a set of topics or dimensions, as a framework for a
   reasonable number of recommendation documents.

   The reader is assumed to be familiar with IPv6.  The IETF's view of
   core IPv6 requirements is to be found in [RFC4294] (currently being
   updated as [I-D.ietf-6man-node-req-bis]).  However, this does not
   give a complete view of mechanisms an ISP may need to deploy, since
   it considers the requirements for an individual node, not for a
   network or service infrastructure as a whole.

   [RFC4029] discussed scenarios for introducing IPv6 into ISP networks,
   as the problem was viewed some years ago.  Its end goal was simply a
   dual-stack ISP backbone.  Today's view is that this is insufficient,
   as it does not allow for prolonged interworking between IPv6-only and
   legacy (IPv4-only) hosts.  Indeed, the end goal today might be an
   IPv6-only ISP backbone, with some form of legacy IPv4 support

   Although the basic IPv6 standards are stable, considerable work
   continues in several IETF working groups, on issues such as
   multihoming, tunneling, and IP layer interworking between IPv6-only
   and IPv4-only hosts.  However, operators faced with IPv4 address
   exhaustion in the coming few years need immediate guidance.  These
   operators cannot avoid the need for general skills acquisition, or
   the need to write their own detailed deployment plan, but they also
   need guidance for generic scenarios similar to their actual
   situation.  They cannot obtain such guidance from individual protocol
   specifications developed by the IETF, so there is a need for
   additional documents.

   This draft is maintained as a "living document" of the V6OPS WG,
   because it is not considered necessary to archive it as an RFC.

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2.  Document Topics

   On the assumption that a series of documents are produced describing
   and recommending transition scenarios, there are two basic
   1.  The documents will not be primary protocol specifications,
       because those are the outcome of IETF working groups chartered to
       work on specific protocol mechanisms.
   2.  The documents are addressed to service providers who have taken
       the decision to support IPv6, have acquired basic knowledge and
       skills, have determined how they will obtain upstream IPv6
       connectivity, and are ready to write their operational plan for

   The documents should describe scenarios for real transition to IPv6,
   not life extensions to IPv4 or other matters best handled in other
   working groups.  They should each cover some or all of the following
   aspects or dimensions:
   o  For the convenience of readers, each document should briefly
      describe its network model in the Abstract (or Introduction) for
      quick reference.
   o  The documents should explain how certain technology components fit
      together in a given transition and co-existence scenario.
   o  They will present major generic network models, and their subsets,
      which exist (or are firmly planned) today, including network
      topologies and/or architectures.
   o  They should specify their scope: the range of technologies that
      they do or do not apply to (e.g. specific access network
      technologies, core network technologies and topologies, mobile vs
      fixed hosts, business vs private customers, etc.).
   o  They should develop analysis criteria on how to recognize
      appropriate transition technologies for existing provider networks
      within their scope.  This should include information related to
      deployed protocols and functions which may assist or hinder
      various transition technologies from being deployed.
   o  If multiple transition technologies are needed for provider
      environments where access networks differ and have various
      capabilities, the documents should show how these technologies can
      be deployed simultaneously.
   o  They should describe how multiple technologies can co-exist, if
      necessary, during all stages of migration (e.g., moving from IPv4
      Only to Dual-Stack to DS-Lite to NAT64).
   o  They should cover considerations for legacy operation while moving
      to IPv6 and its transition technologies.  Many operators will have
      large quantities of IPv4-only equipment which cannot feasibly be
      upgraded until the end of its economic life, or which is under
      customer control.

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   o  They should cover considerations which apply when retro-fitting
      various technologies to existing networks.  Included in this would
      be impacts on ancillary protocols, routing platforms/systems,
      security policies, provisioning systems, network services (i.e.
      DHCP, DNS etc), law enforcement procedures and more.
   o  They should quantify scaling characteristics of deployment modes
      for each technology model and intersections during co-existence
      (e.g. if some of the Network is DS-Lite and some is classical Dual
      Stack; peak load on NAT64; etc.).
   o  The documents should include security considerations for their
      specific transition scenario(s).

   A desirable outcome would be a set of Best Current Practice (BCP) or
   advisory (Informational) documents for a range of generic deployment
   models and how they fit into a network, including key services such
   as subscriber authentication, DHCP, and DNS.  However, it must not be
   forgotten that every service provider is different and such documents
   can never replace specific deployment plans drawn up by each
   individual service provider.

3.  Security Considerations

   Service providers will insist on having security for IPv6 services,
   and for all transition technologies, that is at least as good as for
   IPv4 services in all respects.  Particular attention must be paid to
   security exposures that are specific to transition and coexistence
   mechanisms.  Thus, all recommendations for transition scenarios must
   include any security aspects that are specific to that scenario.

4.  IANA Considerations

   This document makes no request of the IANA.

5.  Acknowledgements

   Useful comments and contributions were made by Randy Bush and other
   members of the V6OPS WG.

   This document was produced using the xml2rfc tool [RFC2629].

6.  Change log

   draft-ietf-v6ops-v4v6tran-framework-02: updated as living document
   for WG, 2011-07-26

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   draft-ietf-v6ops-v4v6tran-framework-01: small addition following
   WGLC, 2011-02-02

   draft-ietf-v6ops-v4v6tran-framework-00: adopted by WG at IETF 79,

   draft-carpenter-v4v6tran-framework-00: original version, 2010-08-18

7.  Informative References

              Jankiewicz, E., Loughney, J., and T. Narten, "IPv6 Node
              Requirements", draft-ietf-6man-node-req-bis-11 (work in
              progress), May 2011.

   [RFC2629]  Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
              June 1999.

   [RFC4029]  Lind, M., Ksinant, V., Park, S., Baudot, A., and P.
              Savola, "Scenarios and Analysis for Introducing IPv6 into
              ISP Networks", RFC 4029, March 2005.

   [RFC4294]  Loughney, J., "IPv6 Node Requirements", RFC 4294,
              April 2006.

   [RFC5211]  Curran, J., "An Internet Transition Plan", RFC 5211,
              July 2008.

   [RFC6036]  Carpenter, B. and S. Jiang, "Emerging Service Provider
              Scenarios for IPv6 Deployment", RFC 6036, October 2010.

   [RFC6180]  Arkko, J. and F. Baker, "Guidelines for Using IPv6
              Transition Mechanisms during IPv6 Deployment", RFC 6180,
              May 2011.

Authors' Addresses

   Brian Carpenter
   Department of Computer Science
   University of Auckland
   PB 92019
   Auckland,   1142
   New Zealand

   Email: brian.e.carpenter@gmail.com

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   Sheng Jiang
   Huawei Technologies Co., Ltd
   Huawei Building, No.3 Xinxi Rd.,
   Shang-Di Information Industry Base, Hai-Dian District, Beijing
   P.R. China

   Email: jiangsheng@huawei.com

   Victor Kuarsingh
   Rogers Communications

   Email: Victor.Kuarsingh@rci.rogers.com

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