Network Working Group                                          Seil Jeon
Internet-Draft                                              Younghan Kim
Intended status: Standards Track              Soongsil University, Korea
Expires: January 11, 2012                                  July 11, 2011





                    NEMO Problem Statement in PMIPv6
                draft-sijeon-netext-nemo-ps-pmip6-01.txt

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Abstract

   This document summarizes the problem statement for network mobility
   support in the Proxy Mobile IPv6 (PMIPv6) domain. Especially, when
   applying the NEMO basic support protocol (NEMO-BSP) in PMIPv6 domain,
   the applicability of NEMO support is examined. Then, problems and
   requirements are also described.



Table of Contents

   1. Introduction.....................................................4
   2. Terminology......................................................4
   3. Appllication of the NEMO-BSP into PMIPv6 domain..................5
   4. Considerations for NEMO support in the PMIPv6....................6
     4.1. Basic operation requirements.................................6
     4.2. Requirements for performance improvement.....................7
   5. IANA Considerations..............................................8
   6. Security Considerations..........................................8
   7. References.......................................................8
     7.1. Normative References.........................................8
   Authors' Addresses..................................................9






















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1. Introduction

   The recent rapid propagation of Wi-Fi handheld devices and increasing
   demand for Internet access everywhere, even within moving vehicles,
   have made network mobility (NEMO) technology much noticeable.

   To provide NEMO support, the NEMO basic support protocol (NEMO-BSP)
   has been specified [RFC3963]. The NEMO-BSP defines a mobile router
   (MR), which is based on the Mobile IPv6 (MIPv6) client protocol, so
   the MR needs to perform binding update to the home agent (HA)
   [RFC6275].

   With the advent of Proxy Mobile IPv6 (PMIPv6) providing network-based
   IP mobility management and new attempts on PMIPv6 enhancement, the
   research on NEMO support is being tried [NEMO-PPS]. PMIPv6
   specification defines only host mobility case [RFC5213]. To
   facilitate NEMO support within the PMIPv6 domain, as a first
   approach, we need to check the applicability of NEMO-BSP as
   representative well-known group mobility protocol into PMIPv6 domain
   and confirm the issues and problem according to the applications.

   Through checking the application of NEMO-BSP into PMIPv6, we then
   describe issues and problems. In addition, we discuss requirements
   for basic operation and performance improvement.

2. Terminology and Functional Components

   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.

   o  Mobile Network Node (MNN) - The node that has an address
      containing the MNP, as defined in [RFC3963].

   o  Mobile Router (MR) - It is extended from Mobile IPv6 client
      protocol and in charge of mobility management on behalf of MNN
      within a mobile network, as defined in [RFC3963].

   o  Mobile Network Prefix (MNP): An IPv6 prefix delegated to a moving
      router and advertised in the mobile network.





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3. Application of the NEMO-BSP into PMIPv6 domain

   In NEMO-BSP, the HA is used as anchor node to provide IP session
   continuity for MNNs within mobile network while the LMA is used in
   PMIPv6. To support NEMO in PMIPv6, two anchor nodes, e.g., HA and
   LMA, are needed. Therefore, we describe two cases applicable where HA
   is separated with LMA or collocated with it. Through the
   applications, we check the issues and problems introduced from each
   scenario.

                                               |
    +--------+              +--------------+   |  +--------------+
    |        |              |              |   |  |              |
    | Mobile |              |    PMIPv6    |   |  |    PMIPv6    |
    |  IPv6  |  +--------+  |    Domain    |   |  |    Domain    |
    | Network|  |        |  |              |   |  |              |
    | +----+ |==|Internet|==|    +-----+   |   |  |   +------+   |
    | | HA | |  |        |  |    | LMA |   |   |  |   |HA+LMA|   |
    | +----+ |  +--------+  |    +-----+   |   |  |   +------+   |
    |        |              |     // \\    |   |  |     // \\    |
    +--------+              |    //   \\   |   |  |    //   \\   |
                            |   //     \\  |   |  |   //     \\  |
                            | +---+  +---+ |   |  | +---+  +---+ |
                            | |MAG|  |MAG| |   |  | |MAG|  |MAG| |
                            | +---+  +---+ |   |  | +---+  +---+ |
                            |              |   |  |              |
                            +--------------+   |  +--------------+
                                               |
                                               |
                                               |
                                +-----+        |      +-----+
                            +---|  MR |----+   |  +---|  MR |----+
                            |   +-----+    |   |  |   +-----+    |
                            |              |   |  |              |
                            | MNN1, MNN2,..|   |  | MNN1, MNN2,..|
                            |              |   |  |              |
                            +--------------+   |  +--------------+
                                               |

         (a) Separated HA with LMA           (b) Collocated HA with LMA

             Figure 1. Applications of NEMO-BSP into PMIPv6 Domain



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   In former case, HA and LMA are separated in different networks but
   they are connected through Internet. In perspective of MR entering
   PMIPv6 domain, a MAG is regarded as one of access routers placed in
   foreign networks therefore there is no need to extend or modify
   PMIPv6 entities.

   In latter case, the LMA needs to have HA function therefore
   processing MR's BU signaling, performing double look-up processing,
   and making IP tunnel header for the MR. Protocol operation is same as
   the former case where LMA separated with HA.

   Protocol operation is as follows. When a MR approaches to PMIPv6
   domain, a MAG detects MR's movement, sends PBU message to LMA, and
   receives a PBA message including HNP of MR from LMA. Then, it
   delivers assigned HNP to the MR through router advertisement. The MR
   newly configures its CoA (MR-CoA) based on assigned HNP then performs
   binding update message to the its HA. The HA binds received MR-CoA
   with MR-HoA and sends back binding acknowledgment message to the MR.

   If the MR moves to another MAG within the same PMIPv6 domain,
   reconfiguration of MR-CoA and additional BU signaling are not
   required due to home emulation provided by the MAG.

   The PMIPv6 supports only per-MN prefix model in [RFC5213] but all
   MNNs share the MR's HNP assigned by the LMA. When a MNN enters or
   goes out to/from mobile network, it receives a new HNP it used
   therefore it SHOULD configure a new IP address based on received HNP.
   Eventually, IP session continuity becomes broken and disrupted.


4. Considerations for NEMO support in the PMIPv6

   This section presents considerations for NEMO support within the
   PMIPv6 domain. It consists of two parts: the requirements for basic
   operation and performance improvement.

4.1. Basic operation requirements

   1) Prefix delegation support for an MNN: Within mobile network, a MNN
      receives the MNP from MR but the method can be varied for
      effective and secure delivery. As one possible way, a DHCPv6
      prefix delegation method MAY be used [DHCPv6-PD].



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   2) No host stack involvement: a NEMO SHOULD provide IP mobility
      management of MR and MNNs without host stack involvement.

   3) Node mobility support: as the NEMO scenario described in Section
      3, the mobile network advertises its MNP to MNNs but the MNP is
      different from the HNP assigned from LMA. A NEMO solution SHOULD
      support IP session continuity for freely roaming MNN between a
      mobile network and the fixed access of PMIPv6 domain.

4.2. Requirements for performance improvement

   1) Resource-efficient handoff management: when a mobile network moves
      to another MAG within the same PMIPv6 domain, network resources in
      wired/wireless SHOULD be saved for location/handoff management.

   2) Minimal packet overhead: to deliver data packet to a MNN, it may
      need one or more IP packet tunneling to pass network entities in
      charge of node anchoring. As the number of IP tunnel increases, it
      makes packet overhead more severe per data packet. Ultimately, it
      leads to energy-efficiency issue.

   3) Minimal packet loss during handoff: packet loss caused by a
      handoff event during a change in the attachment point SHOULD be
      minimal.

   4) Minimal end-to-end delay: IP tunneling is caused by anchoring
      points as the number of encapsulated tunnel headers. Depending on
      the location of anchor points, it may make data route much longer,
      therefore it leads to increase end-to-end packet delay. This delay
      SHOULD be minimized.















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5. IANA Considerations

   TBD.


6. Security Considerations

   TBD.


7. References

7.1. Normative References

   [RFC3963]  V. Devarapalli, R.Wakikawa, A. Petrescu, and P. Thubert,
               "Network Mobility (NEMO) Basic Support Protocol," IETF
               RFC 3963, January, 2005.

   [RFC6275]  C. Perkins, D. Johnson, and J. Arkko, "Mobility support in
               IPv6," IETF RFC 6275, July 2011.

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

   [NEMO-PPS]  CJ. Bernardos, M. Calderon, and I. Soto, "PMIPv6 and
               Network Mobility Problem Statement," draft-bernardos-
               netext-pmipv6-nemo-ps-01.txt, October 2009.

   [DHCPv6-PD] R. Droms, P. Thubert, F. Dupont, W. Haddad, and CJ.
               Bernardos, "DHCPv6 Prefix Delegation for NEMO," draft-
               ietf-mext-nemo-pd-07.txt, December 2010.













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Authors' Addresses

   Seil Jeon
   Soongsil University
   4F Hyungnam Engineering Bldg. 424,
   (156-743) 511 Sangdo-Dong, Dongjak-Gu, Seoul, Korea
   Phone: +82-2-820-0841
   E-mail: sijeon@dcn.ssu.ac.kr

   Younghan Kim
   Soongsil University
   11F Hyungnam Engineering Bldg. 1107,
   (156-743) 511 Sangdo-Dong, Dongjak-Gu, Seoul, Korea
   Phone: +82-2-820-0904
   E-mail: younghak@ssu.ac.kr






























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