Network Working Group                                            J. Park
Internet-Draft                                                    H. Kim
Intended status: Informational                                      ETRI
Expires: January 13, 2011                                  July 12, 2010


       Multihoming extension of PMIPv6 using 2-level Prefix Model
           draft-park-multihoming-ext-pmipv6-2level-prefix-01

Abstract

   This document discusses the use of multiple interfaces in mobile
   host.  Especially, Horizontal handover and flow handover in 2-level
   prefix model are resolved.

Status of this Memo

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

   Internet-Drafts are working documents of the Internet Engineering
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on January 13, 2011.

Copyright Notice

   Copyright (c) 2010 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
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   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.





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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Types of handover  . . . . . . . . . . . . . . . . . . . . . .  3
   3.  New 2-level prefix model . . . . . . . . . . . . . . . . . . .  6
   4.  New 2-level flow identifier model  . . . . . . . . . . . . . .  8
   5.  Usage scenarios for the 2-level prefix model . . . . . . . . .  8
     5.1.  Scenario 1 - simultaneous attachment . . . . . . . . . . .  8
       5.1.1.  Initial Stage in scenario 1  . . . . . . . . . . . . .  9
       5.1.2.  Second Stage in scenario 1 . . . . . . . . . . . . . . 10
     5.2.  Scenario 2 - Sequential attachment . . . . . . . . . . . . 14
       5.2.1.  Initial stage in scenario 2  . . . . . . . . . . . . . 14
       5.2.2.  Second stage in scenario 2 . . . . . . . . . . . . . . 15
       5.2.3.  Third stage in scenario 2  . . . . . . . . . . . . . . 16
   6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 16
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 16
   8.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
     8.1.  Normative References . . . . . . . . . . . . . . . . . . . 16
     8.2.  Informative References . . . . . . . . . . . . . . . . . . 16
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17































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1.  Introduction

   Proxy Mobile IPv6 (PMIPv6) is a network-based mobility management
   protocol.  In here, Mobile Host (MH) does not know the changes of
   network access caused by MH movement.  That is, Mobile Access
   Gateways (MAGs) and Local Mobility Anchors (LMAs) support the whole
   mobiltiy management.  However, they do not define the protocol
   procedures for supporting multiple interfaces and flow handover in
   MH.

   This document clarifies the types of handover. and describes the
   protocol procedures about multihoming extensin of PMIPv6 in 2-level
   prefix model.


2.  Types of handover

   Even though this classification is not common, this document
   describes the types of handover to understand the protocol procedures
   easily.

   o  Inter-access Handover (IAHO)

   o  Inter-interface Handover (IIHO)

   o  Partial Flow Handover (PFHO)

   o  Full Flow Handover (FFHO)

   First, Inter-access Handover (IAHO) occurs between MAGs.  That is,
   MN's interface is not changed.  The attached MAG is only changed.




















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       +----+                 +----+       LMA Binding Cache (Before)
       |LMA |                 |LMA |       -----------------------------
       +----+                 +----+       MN:if1[HNP_1,flow1] --> MAG1
        //\\                   //\\
  +----//--\\----+       +----//--\\----+  LMA Binding Cache (After)
 (    //    \\    )     (    //    \\    ) -----------------------------
 (   //      \\   )     (   //      \\   ) MN:if1[HNP_1,flow1] --> MAG2
  +-//--------\\-+       +-//--------\\-+
   //          \\         //          \\
  //            \\       //            \\
 +----+      +----+     +----+      +----+
 |MAG1|      |MAG2|     |MAG1|      |MAG2|
 +----+      +----+     +----+      +----+
   |                                  |
   |                                  |
   | if1     if2                      | if1     if2
   +----[MN]----                      +----[MN]----

                   Figure 1: Inter-access Handover(IAHO)

   Secondly, Inter-interface Handover (IIHO) considers the MH with
   multiple interfaces.  IIHO occurs among multiple interfaces in the
   same MH.  In this case, original interface will be broken by some
   reasons.  Therefore, all flow under control of original interface
   will be moved to the other interface.

   The IAHO and IIHO in LMA processing are same in case of the MH with
   logical interface.  That is, the HNP is assigned to logical interface
   only.  The MAC address of logical interface is informed to LMA.  LMA
   does not know the existence of multiple interfaces.





















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         +----+                 +----+       LMA Binding Cache (Before)
         |LMA |                 |LMA |       -------------------------
         +----+                 +----+       MN:if1 [HNP_1,flow1]-->MAG1
          //\\                   //\\
    +----//--\\----+       +----//--\\----+  LMA Binding Cache (After)
   (    //    \\    )     (    //    \\    ) -------------------------
   (   //      \\   )     (   //      \\   ) MN:if2 [HNP_1,flow1]-->MAG2
    +-//--------\\-+       +-//--------\\-+
     //          \\         //          \\
    //            \\       //            \\
   +----+      +----+     +----+      +----+
   |MAG1|      |MAG2|     |MAG1|      |MAG2|
   +----+      +----+     +----+      +----+
     |                                  |
     |                                  |
     |flow1                        flow1|
     +----[MN]----          ----[MN]----+
       if1     if2            if1   if2

                 Figure 2: Inter-interface Handover(IIHO)

   Lastly, Paritial and Full Flow Handover (PFHO/FFHO) are used in case
   of simulteneous attachment between MAGs in MH with multiple
   interfaces.  PFHO means partial transfer among application flows.
   FFHO means all flow transfer from one interface to the other.  The
   difference between IIHO and FFHO is the policy of keeping the
   mobility session on the original interface.  FFHO keeps the mobility
   session because of the possibility of reverse flow handover.  So,
   original information in LMA or MAG will be kept for some time with
   idle(I) flag.

   In this document, new prefix model will be used to support the flow
   handover.  The next section will describe in detailss.


















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      +----+                 +----+       LMA Binding Cache (Before)
      |LMA |                 |LMA |       -------------------------
      +----+                 +----+       MN:if1 [HNP_1,flow1]-->MAG1[A]
       //\\                   //\\        MN:if1 [HNP_1,flow2]-->MAG1[A]
 +----//--\\----+       +----//--\\----+  MN:if2 [HNP_2,flow3]-->MAG2[A]
(    //    \\    )     (    //    \\    )
(   //      \\   )     (   //      \\   ) LMA Binding Cache (After)
 +-//--------\\-+       +-//--------\\-+  -------------------------
  //          \\         //          \\   MN:if1 [HNP_1,flow1]-->MAG1[A]
 //            \\       //            \\  MN:if2 [HNP_1,flow2]-->MAG1[I]
+----+      +----+     +----+      +----+ MN:if2 [HNP_1,flow2]-->MAG2[A]
|MAG1|      |MAG2|     |MAG1|      |MAG2| MN:if2 [HNP_2,flow3]-->MAG2[A]
+----+      +----+     +----+      +----+
  |             |        |             |
  |flow1   flow3|        |flow1   flow3|
  |flow2        |        |        flow2|
  +----[MN]-----+        +----[MN]-----+
    if1    if2             if1    if2

                   Figure 3: Partial Flow Handover(PFHO)


      +----+                 +----+       LMA Binding Cache (Before)
      |LMA |                 |LMA |       -------------------------
      +----+                 +----+       MN:if1 [HNP_1,flow1]-->MAG1[A]
       //\\                   //\\        MN:if1 [HNP_1,flow2]-->MAG1[A]
 +----//--\\----+       +----//--\\----+  MN:if2 [HNP_2,flow3]-->MAG2[A]
(    //    \\    )     (    //    \\    )
(   //      \\   )     (   //      \\   ) LMA Binding Cache (After)
 +-//--------\\-+       +-//--------\\-+  -------------------------
  //          \\         //          \\   MN:if2 [HNP_1,flow1]-->MAG2[A]
 //            \\       //            \\  MN:if2 [HNP_1,flow2]-->MAG2[A]
+----+      +----+     +----+      +----+ MN:if2 [HNP_2,flow3]-->MAG2[A]
|MAG1|      |MAG2|     |MAG1|      |MAG2| MN:if2 [HNP_1,flow1]-->MAG1[I]
+----+      +----+     +----+      +----+ MN:if2 [HNP_1,flow2]-->MAG1[I]
  |flow1        |        |        flow1|  MN:if2 [HNP_2,flow3]-->MAG1[I]
  |flow2        |        |        flow2|
  |flow3        |        |        flow3|
  +----[MN]-----+        +----[MN]-----+
    if1    if2             if1    if2

                    Figure 4: Full Flow Handover (FFHO)


3.  New 2-level prefix model

   This document defines and uses 2-level prefix model like the
   following figure.  In here, pref_A1 and pref_B1 are called by level 1



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   prefix.  It is allocated and managed by LMA.  Especially, pref_A1 is
   a permanent prefix, which is indicated by flag(P).  It is used to
   support inter-interface and inter-access handover.  And logical
   interface will use the permanent prefix.

   On the other hand, pref_B1 is a temporal prefix, which is indicated
   by flag(T).  If the distinguished prefix ranges are assigned for
   permanet and temporal prefixes in each, these flags may be not
   required.  It is used to support flow handover. pref_B1 will be
   allocated by LMA to MAGs before initiation of mobility session.  Each
   MAG already knows the other's temporal prefixes.  And then, pref_01,
   called by level 2 prefix, will be allocated for MH.  Pref_01 will be
   allocated and managed by each MAG or LMA.  Basically MAG is better
   for distribution of load for flow management.

                   +---------+---------+---------+------+
                   | 2-level | For_LMA | For_MAG | Flag |
                   +=========+=========+=========+======+
                   | level 1 | pref_A1 |    x    |   P  |
                   +---------+---------+---------+------+
                   | level 1 | pref_B1 |    -    |   T  |
                   +---------+---------+---------+------+
                   | level 2 | pref_B1 | pref_01 |   T  |
                   +---------+---------+---------+------+

                      Figure 5: 2-level Prefix Model

   In the following section, HNP_x(P) and HNP_x_y(T) notation will be
   used.  In here, x means inteface identifer and y means level 2 prefix
   identifer and P/T is flag, which distinguishs the prefix.  As
   mensioned before, P means permanent prefix and T means temporal
   prefix.  The following examples will be used in this document.

   o  HNP_1(P) = pref_A1 (e.g., 2002:1:1:0::/64)

   o  HNP_2(P) = pref_A2 (e.g., 2002:1:2:0::/64)

   o  HNP_1(T) = pref_B1 (e.g., 2002:2:1:0::/64)

   o  HNP_2(T) = pref_B2 (e.g., 2002:2:2:0::/64)

   o

   o  HNP_1_1(T) = pref_B1 + pref_01 (e.g.,2002:2:1:1::/64)

   o  HNP_2_1(T) = pref_B2 + pref_01 (e.g.,2002:2:2:1::/64)

   In here, there are 2 types of prefixes: permanet and temporal.  The



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   permanent prefix without the part of level 2 prefix will be allocated
   to the logical interface in order to support inter-technology
   handover.  If we do not consider the logical interface concept, the
   type of services will be checked to use the proper prefix.  Even
   though the quality of service will be decreased during MH movement,
   we do not want to support the handover and flow mobility.  In that
   case, we will use the permanent prefixes.  In other case, we will use
   the temporal prefixes.


4.  New 2-level flow identifier model

   There are 2 types of flow identifier(FID).  These flow ids are
   managed separately in MN, MAG and LMA.  That is,the uniqueness of
   flow ids are satified just in each node.

   o  Input FID (IFID) = level-1 flow id(IFID1) + level-2 flow id(IFID2)
      or none

   o  output FID(OFID) = level-1 flow id(OFID1) + level-2 flow id(OFID2)
      or none

   After PBU and PBA exchange, level-1 input flow ids are exchanged
   between MAGs and LMA.  And then, level-2 flow ids are allocated
   according to emerging each data flow.  After the receiving RA
   messages, MH gets level-1 flow id from MAG.  On the other hand, MAG
   makes level-1 flow id after the recognizing L2 attachment or the
   first data receiving form MH.  And then level-2 flow ids are
   allocated during the data transmission.

   MH decides anf forwards the data from logical interface to physical
   interfaces by referring flow ids.  And then, MAG and LMA just decides
   and forwards the service flow by using ouput flow ids.


5.  Usage scenarios for the 2-level prefix model

   This document considers the MH with multiple interfaces, each
   interface of whose has multiple prefixes.  This section describes the
   simultaneous use and horizontal handover in 2-level prefix model.

5.1.  Scenario 1 - simultaneous attachment

   This scenario considers the nearly same attachment of multiple
   interfaces.






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5.1.1.  Initial Stage in scenario 1

   Initial attachment procedures of each interface are operated
   independently.  The following functions will be performed between MH
   and MAG or between MAG and LMA.

   o  The mobility session for all interfaces in MH

   o  Prefix allocation and maintenance in LMA and MAG

   o  Flow id generation and Distribution in LMA



                      LMA State
              +----+  ---------
              |LMA |  MH:if1 [HNP_1(P),flow1,flow2] --> MAG1
              +----+  MH:if2 [HNP_2(P),flow3]       --> MAG2
               //\\
    +---------//--\\-------------+
   (         //    \\             ) PMIPv6 domain
   (        //      \\            )
    +------//--------\\----------+
          //          \\
         //            \\
      +----+           +----+ MAG2 State
      |MAG1|           |MAG2| ----------
      +----+           +----+ MH: if2[HNP_2(P),flow3]-->MAG2
        |                 |   MH: if2[HNP_2(T)]      -->MAG2
        |                 |   MH: if2[HNP_2_1(T)]    -->MAG2
        |                 |
        |                 |   MAG1 State
        | if1         if2 |   ----------
        +-----+-----+-----+   MH: if1[HNP_1(P),flow1,flow2] -->MAG1
              |  MH |         MH: if1[HNP_1(T)]             -->MAG1
              +--+--+         MH: if1[HNP_1_1(T),HNP_1_2(T)]-->MAG1
                 |
                 |
                 |vi [HNP_1(P) or HNP_2(P)]


                   Figure 6: Scenario 1 - Initial Stage

   The initial attach procedures are following:

   1.  The if1 will be attached the network through MAG1.





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   2.  MAG1 sends the PBU to the LMA.  In here, HI option is 1 (initial
       attachment).

   3.  LMA allocates the HNP_1(P) for if1 of MH.  LMA sends PBA with
       HNP_1(P) option.

   4.  MAG1 sends RA message with HNP_1(P) and HNP_1_1(T).  In here,
       HNP_1(P) has been obtained from PBA message.  HNP_1_1(T) will be
       allocated by MAG1 using HNP_1(T) prefix, which had been
       distributed from LMA.

   5.  MH configures the HNP_1(P) and HNP_1_1(T) to the if1.

   6.  The if2 also does the above procedures.  After then, MH
       configures the HNP_2(P) and HNP_2_1(T) to the if2.

   7.  MH allocates HNP Address for logical Interface (LI).  HNP_1(P) or
       HNP_2(P) is randomly selected.  In here, we suppose that HNP_1(P)
       was selected.

   8.  Application services will be started.  For example, VoIP and web
       services have been started through if1.  IPTV service has been
       also started through if2.  In here, VoIP service has been
       assigned to flow1 by LMA.  The flow1 is flow identifier for VoIP
       service. flow2 for web service and flow3 for IPTV service is also
       assigned by LMA.

   9.  If we have the policy that only LI has the HNPs, the procedure 5
       and 6 are not required.  And the HNP assigend in LI is shown to
       all application services.

5.1.2.  Second Stage in scenario 1

   After initial stage, the following handover will be occured in
   according to network changes or user requirement.

   o  Inter-access Handover from MAG1 to MAG2

      *  MH: if1 is attached to network through the MAG2.

      *  MAG1: After receiving L2 hints, new tunnel may be configured
         between MAG1 and MAG2.  This tunnel is used to transfer the
         data, which are targeted to if1 through MAG1.

      *  MAG2: MAG2 sends PBU with HI(3) to the LMA.

      *  LMA: After receiving the PBU with HNP_1(P), all MAG1-related
         entries will be changed to the MAG22.  In addtion, LMA sends



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         the PBA to MAG2 with HNP_1(P).

      *  MAG2: After receiving the PBA, new BULE with if1 will be added.

   o  Inter-interface Handover from if1 and if2

      *  MH: No action.

      *  MAG1: After receiving L2 hints, new tunnel may be configured
         between MAG1 and MAG2.  This tunnel is used to transfer the
         data, which are targeted to if1 through MAG1.

      *  MAG2: MAG2 sends PBU with HI(2) to the LMA.

      *  LMA: After receiving the PBU with HNP_1(P) from MAG2, all MAG1-
         related entries will be changed to the MAG2.  LMA sends the PBA
         with HNP_1(P).

      *  MAG2: After receiving the PBA, new BULE with HNP_1(P) will be
         added.































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  LMA State (Before)
  ---------
  MH:if1 [HNP_1(P),HNP_1(T)]--> MAG1
  MH:if2 [HNP_2(P),HNP_2(T)]--> MAG2

  LMA State (After)
  ---------
  MH:if1 [HNP_1(P),HNP_1(T)]    --> MAG1
  MH:if1 [HNP_1_1(T),HNP_1_2(T)]--> MAG1
  MH:if2 [HNP_2(P),HNP_2(T)]    --> MAG2
  MH:if2 [HNP_2_1(T),HNP_2_2(T)]--> MAG2

             +----+
             |LMA |
             +----+
              //\\
   +---------//--\\-------------+
  (         //    \\             ) PMIPv6 domain
  (        //      \\            )
   +------//--------\\----------+
         //          \\
        //            \\     MAG2 State (Before)
     +----+           +----+ ----------
     |MAG1|           |MAG2| MH: if2[HNP_2(P)]  -->MAG2
     +----+           +----+ MH: if2[HNP_2_1(T)]-->MAG2
       |                 |
       |                 |   MAG2 State (After)
       |                 |   ----------
       |                 |   MH: if2[HNP_2(P)]  -->MAG2
       |                 |   MH: if2[HNP_2_1(T)]-->MAG2
       |                 |   MH: if2[HNP_1_2(T)]-->MAG2
       | if1         if2 |
       +-----+-----+-----+   MAG1 State (Before)
             |  MH |         ----------
             +--+--+         MH: if1[HNP_1(P)]             -->MAG1
                |            MH: if1[HNP_1_1(T),HNP_1_2(T)]-->MAG1
                |vi
                             MAG1 State (After)
                             ----------
                             MH: if1[HNP_1(P)]             -->MAG1
                             MH: if1[HNP_1_1(T)]           -->MAG1
                             MH: if1[HNP_1_2(T)]           -->MAG1[Idle]


                 Figure 7: Scenario 1 - Second Stage: PFHO






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   o  Partial Flow Handover using temporal prefixes

      *  MH: VoIP service is using HNP_1_1(T) as flow identifier.
         HNP_1_2(T) for Web service and HNP_2_1(T) for IPTV service are
         used.  In this scenario, Web service will be transfered from
         if1 and if2.

      *  MAG1: After receiving the L2 hints, MAG1 and MAG2 know the user
         requirement about the partial flow handover.

      *  MAG2: MAG2 sends the PBU with HI(5).  In addition, PBU has a
         HNP option.  In HNP option, HNP_1_2(T) will be included in
         order to inform the flow handover.

      *  LMA: After receiving the PBU(HI=5) with HNP option, LMA updates
         the BCE using HNP option.  That is, LMA knows the change of web
         service flow.

      *  MAG2: After receiving the PBA, MAG2's BULE will be changed.

   o  Full Flow Handover using temporal prefixes

      *  MH: HNP_1_1(T) for VoIP service, HNP_1_2(T) for Web service and
         HNP_2_1(T) for IPTV service are used as the flow identifier.
         In this scenario, all services from if1 will be transferred to
         if2.

      *  MAG1: After receiving the L2 hints, MAG1 and MAG2 maybe know
         the user requirement about the full flow handover.

      *  MAG2: MAG2 sends the PBU with HI(5).  In addition, PBU has the
         HNP options.  In HNP options, HNP_1_1(T) and HNP_1_2(T) will be
         included in order to inform the full flow handover.  In here,
         the aggregated HNP_1(T) for HNP_1_1(T) and HNP_1_2(T) will be
         included in PBU.

      *  LMA: After receiving the PBU(HI=5) with HNP options, LMA
         updates the BCE using HNP options.  That is, LMA knows the
         transfer of all service flows.  In this case, original mobility
         session for if1 will be kept in order to support the reverse
         partial or full flow handover.

      *  MAG2: After receiving the PBA, MAG2's BULE will be changed.








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5.2.  Scenario 2 - Sequential attachment

   This scenario considers the sequential attachment of multiple
   interfaces in MH.

5.2.1.  Initial stage in scenario 2

   A interface will be attached to the network.  The following functions
   will be performed between MH and MAG and LMA.

   o  The mobility session for one interface

   o  Prefix Allocation and Maintenance in LMA and MAG

   o  Flow id Generation and Distribution in LMA



                      LMA State
              +----+  ---------
              |LMA |  MH:if1 [HNP_1(P),flow1,flow2] --> MAG1
              +----+
               //
    +---------//-----------------+
   (         //                   ) PMIPv6 domain
   (        //                    )
    +------//--------------------+
          //
         //
       +----+           +----+  MAG2 State
       |MAG1|           |MAG2|  ----------
       +----+           +----+
         |                 |
         |                 |
         |                 |    MAG1 State
         | if1         if2 |    ----------
         +-----+-----+-----+    MH: if1 [HNP_1(P),flow1,flow2] --> MAG1
               |  MH |          MH: if1 [HNP_1(T)]             --> MAG1
               +--+--+          MH: if1 [HNP_1_1(T),HNP_1_2(T)]--> MAG1
                  |
                  |vi [HNP_1(P)]


                   Figure 8: Scenario 2 - Initial Stage

   TBD.





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5.2.2.  Second stage in scenario 2

   After initial stage, the other interfaces will be attached to the
   network.  The following functions will be performed between MH and
   MAG and LMA.

   o  Initial attachment of the other interface

   o  Inter-access Handover

   o  Partial Flow Handover

   o  Full Flow Handover



                                                    LMA State
                                                    ---------
                      MH:if1 [HNP_1(P),flow1,flow2]--> MAG1
              +----+  MH:if1 [HNP_1(T)]            --> MAG1
              |LMA |  MH:if2 [HNP_1(P),flow3]      --> MAG2
              +----+  MH:if2 [HNP_2(T)]            --> MAG2
               //\\
    +---------//--\\-------------+
   (         //    \\             ) PMIPv6 domain
   (        //      \\            )
    +------//--------\\----------+
          //          \\
         //            \\
      +----+           +----+  MAG2 State
      |MAG1|           |MAG2|  ----------
      +----+           +----+  MH: if2 [HNP_1(P),flow3]--> MAG2
        |                 |    MH: if2 [HNP_2(T)]      --> MAG2
        |                 |    MH: if2 [HNP_2_1(T)]    --> MAG2
        |                 |
        |                 |    MAG1 State
        | if1         if2 |    ----------
        +-----+-----+-----+    MH: if1 [HNP_1(P),flow1,flow2] --> MAG1
              |  MH |          MH: if1 [HNP_1(T)]             --> MAG1
              +--+--+          MH: if1 [HNP_1_1(T),HNP_1_2(T)]--> MAG1
                 |
                 |vi [HNP_1(P)]


                    Figure 9: Scenario 2 - Second Stage

   TBD.




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5.2.3.  Third stage in scenario 2

   After second stage, Inter-interface handover will be occurred
   generally.  The other functions will be same alike that of the second
   state.

   o  Inter-access Handover

   o  Inter-interface Handover

   o  Partial Flow Handover

   o  Full Flow Handover

   TBD.


6.  IANA Considerations

   IANA considerations are not required.


7.  Security Considerations

   TBD.


8.  References

8.1.  Normative References

   [1]   Perkins, C., "IP Mobility Support for IPv4", RFC 3344,
         August 2002.

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

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

8.2.  Informative References

   [4]   Devarapalli, V., "Multiple Interface Support with Proxy Mobile
         IPv6, draft-devarapalli-netlmm-multihoming-03 (work in
         progress)", August 2008.

   [5]   Jeyatharan, M. and C. Ng, "Multihoming Problem Statement in
         NetLMM, draft-jeyatharan-netext-multihoming-ps-01 (work in



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         progress)", March 2009.

   [6]   Krishnan, S., Yokota, H., Melia, T., and C. Bernardos, "Issues
         with network based inter-technology handovers,
         draft-krishnan-netext-intertech-ps-02 (work in progress)",
         July 2009.

   [7]   Tran, T. and Y. Hong, "Virtual interface for supporting
         multihoming and inter technology handover,
         draft-trung-netext-virtual-interface-01 (work in progress)",
         October 2009.

   [8]   Hong, Y. and J. Youn, "Virtual network interface model for
         multiple network interfaces in a host,
         draft-hong-netext-dynamic-hnp-00 (work in progress)",
         February 2010.

   [9]   Sarikaya, B. and F. Xia, "Local Mobility Anchor Initiated Flow
         Binding for Proxy Mobile IPv6,
         draft-sarikaya-netext-lma-init-flow-binding-00 (work in
         progress)", February 2010.

   [10]  Xia, F., "Flow Binding in Proxy Mobile
         IPv6,draft-xia-netext-flow-binding-00 (work in progress)",
         February 2009.

   [11]  Sarikaya, B. and F. Xia, "PMIPv6 Multihoming Support for Flow
         Mobility, draft-sarikaya-netext-fb-support-extensions-00 (work
         in progress)", February 2010.

   [12]  IEEE Std 802.11r-2008, "IEEE Std Part 11: Wireless LAN Medium
         Access Control (MAC) and Physical Layer (PHY) Specifications
         Amendment 2: Fast Basic Service Set (BSS) Transition",
         July 2008.


Authors' Addresses

   Jungsoo Park
   ETRI/SRC
   161 Gajeong-dong, Yuseong-gu
   Daejeon,   305-700
   Korea

   Phone: +82 42 860 6514
   Email: fnumber@gmail.com





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   HyeongJun Kim
   ETRI/SRC
   161 Gajeong-dong, Yuseong-gu
   Daejeon  305-350
   Korea

   Phone: +82 42 860 6576
   Email: khj@etri.re.kr











































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