One document matched: draft-wu-netext-pmipv6-ipv4-ro-ps-00.txt


Network Working Group                                            Q.Wu
Internet Draft                                                 Huawei
Intended status: Standard Track                          May 21, 2009
Expires: November 2009



       Problem Statement of IPv4 Support for PMIPv6 Localized Routing
                 draft-wu-netext-pmipv6-ipv4-ro-ps-00.txt


Status of this Memo

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

   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 as "work in progress."

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

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

   This Internet-Draft will expire on November 21, 2009.

Copyright Notice

   Copyright (c) 2009 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 in effect on the date of
   publication of this document (http://trustee.ietf.org/license-info).
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.







Wu                   Expires November 21, 2009               [Page 1]

Internet-Draft  PS of IPv4 Support for PMIPv6 local routing    May 2009


Abstract

   [ID-PMIP6-RO-PS] describes the problem space of localized routing
   which allows end-to-end user traffic forwarding between MN and CN
   directly without involving Local Mobility Anchor (LMA) in a single
   Proxy Mobile IPv6 [RFC5213] domain. However, localized routing with
   IPv4 support which allows IPv4 transport between MAG and LMA and/or
   IPv4 enabled user traffic between MN and CN is not considered. This
   document introduces the scenarios and problem statement for localized
   routing with IPv4 support.



Table of Contents


   1. Introduction.................................................3
   2. Conventions used in this document............................3
   3. Scenarios and Problem Statement..............................4
   4. Security Considerations......................................6
   5. References...................................................6
      5.1. Normative References....................................6
      5.2. Informative References..................................7
   6. Acknowledgments..............................................7
























Wu                   Expires November 21, 2009               [Page 2]

Internet-Draft  PS of IPv4 Support for PMIPv6 local routing    May 2009




1. Introduction

   In Proxy Mobile IPv6 [RFC5213], Local Mobility Anchor (LMA) is
   responsible for forwarding the user traffic from the correspondent
   node to the current location of registered mobile nodes. To reduce
   latency and backhaul load, optimized routing path without involving
   LMA in path is expected. [ID-PMIP6-RO-PS] has outlined some possible
   problems during setting up an optimized routing path. However, the
   IPv4 support for the scenarios and problems of routing optimization
   for PMIP6 [ID-PMIP6-IPv4] are not specified.

   As [ID-PMIP6-IPv4] described, PMIPv6 with IPv4 support contains two
   basic features: IPv4 transport support and IPv4 HoA support. This
   document describes these scenarios and its relevant problems during
   setting up an optimized routing path.

2. 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 [RFC2119].

   This document uses the terminology of [RFC5213].  The following terms
   are used in the context of this problem statement:

   o Routing Optimization (RO): referred as the general processing or
      operation that makes end-to-end user traffic between the MN and
      the CN go through an optimized routing path in a single PMIPv6
      domain.

   o Routing Optimization Path (ROP): referred as that the end-to-end
      direct path between both the MN and the CN attached MAG(s) without
      involving both the MN and the CN registered LMA(s) where the user
      traffic is transported.

   o Routing Optimization States (ROS): referred as RO information that
      is generally stored in the corresponding LMA(s) and MAG(s). Such
      information includes RO policies and tunnel ID of ROP, etc.

   o Routing Optimization Control (ROC): referred as ROP setting up and
      ROS maintaining by the involved network entities.






Wu                   Expires November 21, 2009               [Page 3]

Internet-Draft  PS of IPv4 Support for PMIPv6 local routing    May 2009


3. Scenarios and Problem Statement

   Fig.1 shows a generic IPv4 support architecture. In this architecture,
   the end-to-end user traffic routing is allowed between MN and CN (CN1,
   CN2 or CN3). To make the description simple, we have the following
   general assumptions of this architecture.

   -  LMA1 and LMA2 which MN and CN are respectively registering to may
   be the same LMA or different LMA in a single PMIPv6 domain.

   -  With IPv4 user traffic support, MN and CN both are IPv4-only
   enabled node or dual stack node.

   -  With IPv4 transport support, we assume IPv4 network is deployed
   between LMA1 and MAG1. However, the transport network between LMA2
   and MAG2, MAG1 and MAG2 is not limited to IPv4 network.

                            +---------+
                ============|LMA1/LMA2|============
               //           +---------+            \\
               ||                                  ||
             +-----+                               ||
             | NAT |                          +-----------+
          +--+-----+--+                       | IPv4/IPv6 |
          |   IPv4    |                       |  Network  |
          |  Network  |                       +-----------+
          +-----------+                            ||
               ||                                  ||
               ||           +-----------+          ||
            +------+        |IPv4/IPv6 +---+     +------+
            | MAG1 |===================|NAT|=====| MAG2 |
            +------+        | Network  +---+     +------+
              |  |          +-----------+          |  |
        +-----+  +-----+                     +-----+  +-----+
        |              |                     |              |
      +----+        +-----+               +-----+         +-----+
      | MN |        | CN1 |               | CN2 |         | CN3 |
      +----+        +-----+               +-----+         +-----+

      {IPv4-MN-HoA1} {IPv4-CN1-HoA2}   {IPv4-CN2-HoA3} {IPv6-CN3-HoA4}
      {IPv6-MN-HoA1}                   {IPv6-CN2-HoA3}

                        Fig.1 IPv4 support architecture

   Based on the assumption mentioned above, we have the following three
   use cases on IPv4 support for PMIPv6 localized routing.



Wu                   Expires November 21, 2009               [Page 4]

Internet-Draft  PS of IPv4 Support for PMIPv6 local routing    May 2009


   Case 1: both MN and CN are IPv4 enabled nodes

   In this case, the end-to-end user traffic between MN and CN belongs
   to the IPv4 application. MN and CN may be attached to the same or
   different MAG. Furthermore, MN and CN attached MAGs communicate with
   the LMAs using IPv4 or IPv6 transport.

   Case 2: both MN and CN attached MAGs are using IPv4 transport

   In this case, the PMIPv6 signaling between MAGs and LMAs for MN and
   CN is carried over IPv4 network. The end-to-end user traffic between
   MN and CN can be IPv4 or IPv6 application.

   Case 3: MN and CN attached MAGs are using IPv4 transport and IPv6
   transport respectively

   In this case, the PMIPv6 signaling between MAG1 and LMA1 for MN is
   carried over IPv4 network while the PMIP6 signaling between MAG2 and
   LMA2 for CN is carried over IPv6 network. The end-to-end user traffic
   between MN and CN can be IPv4 or IPv6 application.


   On the basis of the above use cases, we have several problems of IPv4
   Support for PMIPv6 localized routing to be considered below.

   o P1: NAT Detection

   For IPv4 transport support, when the IPv4 network is deployed between
   both MAG(s) in an optimized routing path, NAT [RFC3022] device may be
   located. In general, [ID-DSMIP6] for detecting the on-path NAT device
   may be applicable for ROP setup. However, if there existing NAT
   between the MAGs associated with the MN and CN and the MAG is not
   aware of it, the NAT may automatically drop the user traffic between
   the MN and CN and prevent setting up localized routing path.

   o P2: Encapsulation Mode Negotiation

   There may be some situations where both MN and CN are located in the
   different MAG respectively and the MAG supports different transport
   (e.g., IPv4 over IPv6 transport, IPv6 over IPv4 transport), In such
   cases, there are various encapsulation modes existed between MAG1 and
   MAG2 for choice. Therefore, it is expected to negotiate and determine
   the appropriate encapsulation mode for end-to-end user traffic
   routing between MN and CN during ROC processing.


   o P3: IPv4 address space overlapping


Wu                   Expires November 21, 2009               [Page 5]

Internet-Draft  PS of IPv4 Support for PMIPv6 local routing    May 2009


   There may be some situations where mobile nodes from different
   operators may be assigned the same IPv4 HoA from overlapping private
   address space. In PMIPv6 domain, the MAG and the LMA can distinguish
   each mobile node flow based on the GRE key encapsulated within the
   tunneled packet [ID-PMIP-GREKEY]. However, when the traffic destined
   for the CNs with same HoA does not pass through the LMA and go
   directly to the path between the MAGs, the MAG attached by the CN can
   not identify the right CN and forward the user traffic to the right
   CN.


   o P4: IP Protocol Version Switch

   There may be some situations where the IPv4 network is deployed
   between both MAG(s) in an optimized routing path and the IPv6 network
   is deployed between the MAG and the LMA, in such cases, once the
   local routing is allowed between both MAG(s) and the traffic from the
   MN or CN is sent directly to the corresponding MAG, the dual stack
   MAG needs to switch the transport from IPv6 version to the IPv4
   version ,i.e., change the destination address of the packet from
   IPv6-Proxy-CoA to IPv4-Proxy-CoA. This change should be considered
   during ROC processing.

   o P5: ROS Maintaining

   For IPv4 support, the ROS should include the additional source/
   destination IPv4 address or the transport IPv4 address (e.g. IPv4-
   Proxy-CoA), etc. Further more, RO policy (e.g. whether per-MN based
   RO is enabled or disabled) may be downloaded from AAA or DHCPv4
   server as an attribute of ROS and maintained locally in the ROS.


4. Security Considerations

   The scenarios and problems specified in this document can use the
   security association between the LMA and the MAG to create security
   association between MAGs associated with the MN and CN in
   communication.

5. References

5.1. Normative References

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




Wu                   Expires November 21, 2009               [Page 6]

Internet-Draft  PS of IPv4 Support for PMIPv6 local routing    May 2009


   [RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K.,
             and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008.

   [RFC3022] Srisuresh, P. and K. Egevang, "Traditional IP Network
             Address Translator (Traditional NAT)", RFC 3022, January
             2001.

   [ID-PMIP6-RO-PS] Liebsch, M., "PMIPv6 Localized Routing Problem
             Statement", draft-liebsch-netext-pmip6-ro-ps-00, February
             2009.

5.2. Informative References

   [RFC3775] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support
             in IPv6", RFC 3775, June 2004.

   [ID-PMIP6-IPv4] Wakikawa, R. and S.Gundavelli, "IPv4 Support for
             Proxy Mobile IPv6", draft-ietf-netlmm-pmip6-ipv4-support-12
             (work in progress), April 2009.

   [ID-PMIP-GREKEY] Muhanna, A., Khalil, M., S.Gundavelli and K. Leung,
             "GRE Key Option for Proxy Mobile IPv6", draft-ietf-netlmm-
             grekey-option-09, May 2009



6. Acknowledgments

   Many thanks to NetExt members for their comments.



















Wu                   Expires November 21, 2009               [Page 7]

Internet-Draft  PS of IPv4 Support for PMIPv6 local routing    May 2009


Authors' Addresses

   Qin Wu
   Huawei Technologies Co.,Ltd.
   Floor 10, HuiHong Mansion, No.91 BaiXia Rd.
   Nanjing, Jiangsu, 210001
   P.R.China

   Email: sunseawq@huawei.com

   Yungui Wang
   Huawei Technologies Co.,Ltd.
   Floor 10, HuiHong Mansion, No.91 BaiXia Rd.
   Nanjing, Jiangsu, 210001
   P.R.China

   Email: w52006@huawei.com































Wu                   Expires November 21, 2009               [Page 8]


PAFTECH AB 2003-20262026-04-23 21:19:19