DMM WG
Internet Engineering Task Force (IETF)                          P. Seite
Internet-Draft
Request for Comments: 8278                                        Orange
Intended status:
Category: Standards Track                                       A. Yegin
Expires: March 29, 2018
ISSN: 2070-1721                                                 Actility
                                                           S. Gundavelli
                                                                   Cisco
                                                      September 25,
                                                           November 2017

                      MAG

              Mobile Access Gateway (MAG) Multipath Binding Option
                 draft-ietf-dmm-mag-multihoming-07.txt

Abstract

   This specification defines extensions to the Proxy Mobile IPv6
   (PMIPv6) protocol for allowing that allow a mobile access gateway (MAG) to
   register more than one proxy care-of-address care-of address (pCoA) with the local
   mobility anchor (LMA) and to simultaneously establish multiple IP
   tunnels with the local mobility
   anchor. LMA.  This capability allows the mobile access gateway MAG to utilize all
   the available access networks for routing to route the mobile node's IP traffic.

Status of this This Memo

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

   Internet-Drafts are working documents an Internet Standards Track document.

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   Internet-Drafts are draft documents valid the IETF community.  It has
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   This Internet-Draft will expire on March 29, 2018.
   https://www.rfc-editor.org/info/rfc8278.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . .  3   2
   2.  Conventions and Terminology . . . . . . . . . . . . . . . . .   4
     2.1.  Conventions . . . . . . . . . . . . . . . . . . . . . . .  5   4
     2.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .  5   4
   3.  Overview  . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
     3.1.  Example Call Flow . . . . . . . . . . . . . . . . . . . .   5
     3.2.  Traffic distribution schemes . Distribution Schemes  . . . . . . . . . . . . . .  7   6
   4.  Protocol Extensions . . . . . . . . . . . . . . . . . . . . .  8   7
     4.1.  MAG Multipath-Binding Multipath Binding Option  . . . . . . . . . . . . . . .  8   7
     4.2.  MAG Identifier Option . . . . . . . . . . . . . . . . . . 10   9
     4.3.  New Status Code for Proxy Binding Acknowledgement . . . . 11  10
     4.4.  Signaling Considerations  . . . . . . . . . . . . . . . . .  11
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  12
   6.  Security Considerations . . . . . . . . . . . . . . . . . . . 13  12
   7.  Acknowledgements . .  References  . . . . . . . . . . . . . . . . . . . . . 13
   8.  References . . . .  12
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  12
     7.2.  Informative References  . . . . 13
     8.1.  Normative References . . . . . . . . . . . . .  14
   Acknowledgements  . . . . . . 13
     8.2.  Informative References . . . . . . . . . . . . . . . . . .  14
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 15  14

1.  Introduction

   Multihoming support on IP hosts can greatly improve the user
   experience.  With the simultaneoous simultaneous use of multiple access networks,
   multihoming brings better network connectivity, reliability reliability, and
   improved quality of communication.  Following  The following are some of the
   goals and benefits of multihoming support:

   o  Redundancy/Fault-Recovery

   o  Load balancing

   o  Load sharing

   o  Preferences  Preference settings

   According to [RFC4908], users of Small-Scale Networks small-scale networks can take benefit of multihoming
   from a mobile and fixed multihomed architecture using mobile IP
   [RFC6275] and Network Mobility (NEMO) [RFC3963] architecture in a mobile and fixed networking
   environment. [RFC3963].  This document is introducing the concept of
   describes multiple
   Care-of Addresses care-of addresses (CoAs) [RFC5648] that have been
   specified since
   then. RFC 4908 was published.

   The motivation for this work is to extend Proxy Mobile IPv6 the PMIPv6 protocol with
   multihoming extensions [RFC4908] for realizing the following
   capabilities:

   o  using  Using GRE as mobile tuneling, tunneling, possibly with its key extension
      [RFC5845] (a possible reason to use GRE is given on Section 3.2).
      [RFC5845].

   o  using  Using UDP encapsulation [RFC5844] in order to support NAT
      traversal in an IPv4 networking environment.

   o  Prefix Delegation  Using the prefix delegation mechanism [RFC7148].

   o  Using the vendor specific mobility option Vendor Specific Mobility Option [RFC5094], for example example,
      to allow the MAG and LMA to exchange information (e.g. (e.g., WAN
      interface QoS metrics) allowing to make metrics), which allows the appropriate traffic traffic-
      steering decision.

   Proxy Mobile IPv6 (PMIPv6) decisions to be made.

   PMIPv6 relies on two mobility entities: the
   mobile access gateway (MAG), MAG, which acts as the
   default gateway for the end-node end node, and the local mobility anchor (LMA), LMA, which acts as the
   topological anchor point.  Point-to-point links are established, established using
   IP-in-IP tunnels, tunnels between the MAG and the LMA.  Then, the MAG and LMA
   are distributing
   distribute traffic over these tunnels.  All PMIPv6 operations are
   performed on behalf of the end-node end node and its corespondent node, node.  Thus,
   it
   thus makes PMIPv6 well adapted to multihomed architecture as considered
   in [RFC4908].  Taking the LTE and WLAN networking environments as an example,
   examples, the PMIPv6 based PMIPv6-based multihomed architecture is depicted on in
   Figure 1.  Flow-1,2  Flow-1, -2 and 3 -3 are distributed either on Tunnel-1 (over
   LTE) or Tunnel-2 (over WLAN), while Flow-4 is spread on both Tunnel-1
   and 2. Tunnel-2.

     Flow-1
      |
      |Flow-2              _----_
      | |         CoA-1  _(      )_   Tunnel-1
      | |    .---=======(   LTE    )========\ Flow-1
      | |    |           (_      _)          \Flow-4
      | |    |             '----'             \
      | | +=====+                              \  +=====+    _----_
      | '-|     |                               \ |     |  _(      )_
      '---| MAG |                                 | LMA |-( Internet )--
      .---|     |                                 |     |  (_      _)
      | .-|     |                               / |     |    '----'
      | | +=====+                              /  +=====+
      | |    |             _----_             /
      | |    |    CoA-2  _(      )_ Tunnel-2 /
      | |    .---=======(   WLAN  )========/ Flow-2
      | |                (_     _)           Flow-3
      | |                  '----'
      |Flow-3
      |
     Flow0-4

             Figure 1: Multihomed MAG using Using Proxy Mobile IPv6

   The current version of Proxy Mobile IPv6 PMIPv6 does not allow a MAG to register more
   than one proxy Care-of-Adresse pCoA to the LMA.  In other words, only one MAG/LMA link, i.e.
   i.e., IP-in-IP tunnel, can be used at the same time.  This document
   overcomes this limitation by defining the multiple proxy Care-of Addresses (pCoAs) pCoAs extension
   for Proxy
   Mobile IPv6. PMIPv6.

2.  Conventions and Terminology

2.1.  Conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

2.2.  Terminology

   All mobility related mobility-related terms used in this document are to be
   interpreted as defined in [RFC5213], [RFC5844] [RFC5844], and [RFC7148].
   Additionally, this document uses the following terms: term:

   IP-in-IP
      IP-within-IP encapsulation [RFC2473], [RFC2473] [RFC4213]

3.  Overview

3.1.  Example Call Flow

   Figure 2 is the callflow call flow detailing multi-access support with PMIPv6.
   The MAG in this example scenario is equipped with both WLAN and LTE
   interfaces and is also configured with the multihoming functionality.
   The steps of the callflow call flow are as follows:

   Steps (1) and (2): the The MAG attaches to both WLAN and LTE networks; networks.
   Then, the MAG obtains respectively two different proxy care-of-addresses
   (pCoA). pCoAs, respectfully.

   Step (3): The MAG sends, over the WLAN access, a Proxy Binding Update
   (PBU) message, message with the new MAG Multipath Binding (MMB) and MAG
   Network Access Identifier (MAG-NAI) options to the LMA.  The request
   can be for a physical mobile node attached to the MAG, MAG or for a
   logical mobile node configured on the mobile node.  A logical mobile
   node is ALWAYS-
   ATTACHED a mobile node configuration that is always enabled on the
   MAG.  The mobility session that is created (i.e. (i.e., create a Binding
   Cache Entry) Entry (BCE)) on the LMA will be marked with multipath support.

   Step (4): the The LMA sends back a Proxy Binding Acknowledgement (PBA)
   including the HNP Home Network Prefix (HNP) and other session parameters
   allocated for that mobility session.

   Step (5): IP tunnel (IP-in-IP, GRE ...) GRE, etc.) is created over the WLAN
   access.

   Steps (6) to (8): The MAG repeats steps (3) to (5) on the LTE access.
   The MAG includes the HNP, received on step (4) in the PBU.  The LMA
   update
   updates its binding cache by creating a new mobility session for this
   MAG.

   Steps (9) and (10): The IP hosts MN_1 and MN_2 are assigned IP
   addresses from the mobile network prefix delegated by the MAG.

   +=====+ +=====+     +=====+      +=====+      +=====+         +=====+
   | MN_1| | MN_2|     | MAG |      | WLAN|      | LTE |         | LMA |
   +=====+ +=====+     +=====+      +=====+      +=====+         +=====+
      |       |           |            |            |               |
      |       |           |            |            |               |
      |       |           | (1) ATTACH |            |               |
      |       |           | <--------> |            |               |
      |       |           | (2) ATTACH              |               |
      |       |           | <---------------------->|               |
      |       |           | (3) PBU (MAG-NAI, MMB, ...)             |
      |       |           | ------------------------*-------------->|
      |       |           |                                         |
      |       |           |                                   Accept PBU
      |       |           |                               (allocate HNP,
      |       |           |                                  create BCE)
      |       |           | (4) PBA (MMB, ...)             |
      |       |           | <-----------------------*---------------|
      |       |           | (5) TUNNEL INTERFACE CREATION over WLAN |
      |       |           |-============== TUNNEL ==*==============-|
      |       |           |                                         |
      |       |           | (6) PBU (MAG-NAI, MMB, ...)             |
      |       |           | -----------*--------------------------->|
      |       |           |                                         |
      |       |           |                                   Accept PBU
      |       |           |                                 (update BCE)
      |       |           | (7) PBA (MMB, ...)             |
      |       |           | <----------*--------------------------- |
      |       |           | (8) TUNNEL INTERFACE CREATION over LTE  |
      |       |           |-===========*== TUNNEL =================-|
      |   (9) ATTACH      |                                         |
      | <---------------> |                                         |
      |       |(10) ATTACH|                                         |
      |       |<--------> |                                         |

      Figure 2: Functional Separation of the Control and User Plane Planes

3.2.  Traffic distribution schemes Distribution Schemes

   When the MAG has registered a multipath binding with the LMA, there
   will be multiple established overlay tunnels between them.  The MAG
   and the LMA can use any one, or more more, of the available tunnels tunnel paths
   for routing the mobile node's IP traffic.  This specification does
   not recommend, recommend or define any specific traffic distribution scheme,
   however scheme.
   However, it identifies two well-known approaches that implementations
   can potentially use.  These approaches are, Per-flow are per-flow and Per-packet
   Traffic per-packet
   traffic distribution schemes.

   Per-Flow Traffic Distribution:

   o  In this approach approach, the MAG and the LMA associate each of the IP
      flows (upstream and downstream) to with a specific tunnel path.  The
      packets in a given IP flow are always routed on the same overlay
      tunnel path; they are never split and routed concurrently on more
      than one tunnel path.  It is possible for a given flow may to be moved
      from one tunnel path to another, but the flow is never split.  The
      decision to bind a given IP flow to a specific tunnel path is
      based on the traffic distribution policy.  This traffic
      distribution policy is either statically configured on both the
      MAG and the
      LMA, LMA or dynamically negotiated over Proxy Mobile IPv6 PMIPv6 signaling.
      The Flow Binding extension [RFC6089] and Traffic Selectors for
      Flow Bindings [RFC6088] defines define the mechanism and the semantics for
      exchanging the traffic policy between two tunnel peers and peers; the same
      mechanism and the mobility options are used here.

   Per-Packet Traffic Distribution:

   o  In this approach, packets belonging to a given IP flow will be
      split and routed across more than one tunnel paths. path.  The exact
      approach for traffic distribution, distribution or the distribution weights is
      outside the scope of this specification.  In a very simplistic
      approach, assuming that the established tunnel paths have
      symmetric characteristics, the packets can be equally distributed
      on all the available tunnel paths.  In a different scenario scenario, when
      the links have different speeds, the chosen approach can be based
      on weighted distribution (Ex: (e.g., n:m ratio).  However, in any of
      these chosen approaches, implementations have to be sensitive to
      issues related to asymmetric link characteristics and the
      resulting issues such as re-ordering, buffering reordering, buffering, and the impact to the on
      application performance.  Care must be taken to ensure that there
      is no negative impact to on the application performance due to the
      use of this approach.

4.  Protocol Extensions

4.1.  MAG Multipath-Binding Multipath Binding Option

   The MAG Multipath-Binding Multipath Binding option is a new mobility header option
   defined for use with Proxy Binding Update PBU and Proxy Binding
   Acknowledgement PBA messages exchanged between the local mobility anchor LMA
   and the mobile access gateway. MAG.

   This mobility header option is used for requesting multipath support.
   It indicates that the mobile access gateway MAG is requesting that the local
   mobility anchor to LMA register the
   current care-of address CoA associated with the request as one of the many care-addresses CoAs
   through which the
   mobile access gateway MAG can be reached.  It is also used for carrying
   the information related to the access network associated with the care-of
   address.
   CoA.

   The MAG Multipath-Binding Multipath Binding option has an alignment requirement of
   8n+2.  Its format is as shown in Figure 3:

   0                   1                   2                   3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      Type     |   Length      |    If-ATT     |    If-Label   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Binding-Id  Binding ID   |B|O|             RESERVED             Reserved                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 3: MAG Multipath Binding Option

   Type

      <IANA-1> To be assigned by IANA.

      Type: MAG Multipath Binding (63)

   Length

      8-bit unsigned integer indicating the length of the option in
      octets, excluding the type Type and length Length fields.

   Interface Access-Technology Type (If-ATT)

      This 8-bit field identifies the Access-Technology type of the
      interface through which the mobile node is connected.  The
      permitted values for this are from the Access Technology Type
      registry <https://www.iana.org/assignments/mobility-parameters/>
      defined in [RFC5213].

   Interface Label (If-Label)

      This 8-bit unsigned integer represents the interface label.

      The interface label is an identifier configured on the WAN
      interface of the MAG.  All the WAN interfaces of the MAG that are
      used for sending PBU messages are configured with a label.  The
      labels merely identify the type of WAN interface and are primarily
      used in Application routing application-routing policies.  For example, a Wi-Fi
      interfaces
      interface can be configured with a label RED and a an LTE interface
      with a label BLUE.  Furthermore, the same label may be configured
      on two WAN interfaces of similar characteristics (Ex: Two (e.g., two
      Ethernet interfaces with the same label).

      Interfaces

      Interface labels are signaled from the MAG to the LMA in the PBU
      messages and both the LMA and MAG will be able to mark each of the
      dynamically created Binding/Tunnel with the associated label.
      These labels are used in generating consistent application routing application-routing
      rules on the both the LMA and the MAG.  For example, there can be
      a policy requiring HTTP packets to be routed over an interface
      that has Label RED, a RED label, and if any of the RED interfaces are not
      available, the traffic needs to be routed over the BLUE interface.
      The MAG and the LMA will be able to apply this Routing Rule routing rule with
      the exchange of Labels labels in PBU messages and by associating the
      application flows to tunnels with the matching labels.

   Binding-Identifier

   Binding Identifier (BID)

      This 8-bit unsigned integer is used for identifying the binding.
      The permitted values are 1 through 254.  The values, values 0 and 255 are
      reserved.

      The MAG identifies each of the mobile node's binding bindings with a
      unique identifier.  The MAG includes the identifier in the PBU message
      and
      message; when the PBU request is accepted by the LMA, the
      resulting
      Binding binding is associated with this binding identifier. BID.

   Bulk Re-registration Flag (B)

      This flag, if

      If set to a value of (1), is to notify this flag notifies the local
      mobility anchor LMA to consider
      this request as a request to update the binding lifetime of all the mobile
      node's bindings, bindings upon accepting this specific request.  This  The (B)
      flag MUST NOT be set to a value of (1), (1) if the value of the
      Registration Overwrite Flag (O) flag is set to a value of (1).

   Binding

   Registration Overwrite (O)

      This flag, if set to a value of (1), notifies the local mobility
      anchor LMA that upon
      accepting this request, it should replace all of the mobile node's
      existing bindings with this binding.  This flag MUST NOT be set to
      a value of (1), (1) if the value of the Bulk Re-
      registration Re-registration Flag (B)
      is set to a value of (1).  This flag MUST be set to a value of (0), (0)
      in de-registration De-Registration requests.

   Reserved

      This field is unused in this specification.  The value MUST be set
      to zero (0) by the sender and MUST be ignored by the receiver.

4.2.  MAG Identifier Option

   The MAG Identifier option is a new mobility header option defined for
   use with Proxy Binding Update PBU and Proxy Binding Acknowledgement PBA messages exchanged between the local mobility anchor LMA and the mobile
   access gateway. MAG.
   This mobility header option is used for conveying the MAG's identity.

   This option does not have any alignment requirements.

   0                   1                   2                   3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      Type     |   Length      |  Subtype      |  Reserved     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                           Identifier ...                      ~
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                      Figure 4: MAG Identifier Option

   Type

      <IANA-2> To be assigned by IANA.

      Type: MAG Identifier (64)

   Length

      8-bit unsigned integer indicating the length of the option in
      octets, excluding the type Type and length Length fields.

   Subtype

      One byte

      One-byte unsigned integer used for identifying the type of the
      Identifier field.  Accepted values for this field are the
      registered type values from the Mobile "Mobile Node Identifier Option
      Subtypes registry.
      Subtypes" registry <https://www.iana.org/assignments/mobility-
      parameters/>.

   Reserved

      This field is unused in this specification.  The value MUST be set
      to zero (0) by the sender and MUST be ignored by the receiver.

   Identifier

      A variable length variable-length identifier of the type indicated in the Subtype
      field.

4.3.  New Status Code for Proxy Binding Acknowledgement

   This document defines the following new Status Code value for use in
   Proxy Binding Acknowledgement message.
   PBA messages.

   The LMA SHOULD use this error code when rejecting a Proxy Binding
   Update PBU message from
   a MAG requesting a multipath binding.  Following  The following is the potential
   reason for rejecting the request:

   o  The LMA does not support multipath binding.

   CANNOT_SUPPORT_MULTIPATH_BINDING (Cannot Support Multipath Binding):
   <IANA-4>
   180

4.4.  Signaling Considerations

   o  The MAG MAG, when requesting multipath support support, MUST include the MAG
      Multipath Binding Option option (Section 4.1) in each of the PBU messages
      that it sends through the different WAN interfaces.  The inclusion
      of this option serves as a hint that the MAG is requesting
      Multipath
      multipath support.  Furthermore, the MAG Identifier option MUST
      also be present in the PBU message.

   o  If the MAG is aware that the LMA supports the multipath feature binding
      option defined in this specification and if it chooses to enable use
      multiple
      path feature, paths, then it can send the PBU packets for each of the
      paths, either sequentially, sequentially or concurrently.  However, if the MAG
      is not aware of the LMA capability, then it should SHOULD first discover
      the LMA capability by sending PBU packets with multipath on only
      one path first.  This will ensure that the LMA will not be over-writing
      overwriting the binding of one path with the other path.

   o  If the LMA supports multipath capability as defined in this
      specification and if it enables the same for a mobile node's' node's
      session per the MAG's request, then the LMA MUST include the
      Multipath Binding Option option (Section 4.1), 4.1) without the MAG NAI Option
      Section 4.2 MAG-NAI option
      (Section 4.2) in the corresponding PBA reply.

   o  If the LMA is a legacy LMA that does not support this
      specification, the LMA will skip the MAG Multipath Binding option
      (and MAG NAI MAG-NAI option) and process the rest of the message as
      specified in the base Proxy Mobile IPv6 PMIPv6 specification ([RFC5213]).
      Furthermore, the LMA will not include the MAG Multipath Binding
      option (or the MAG NAI Option)in MAG-NAI option) in the PBA message.  The MAG on MAG, upon
      receiving the PBA message without the MAG Multipath Binding option
      option, SHOULD disable Multipath multipath support for the mobile node.

   o  If the mobile node is not authorized for Multipath multipath support, then
      the LMA will reject the request by sending a PBA message with the
      Status field value set to CANNOT_SUPPORT_MULTIPATH_BINDING
      (Section 4.3).  The LMA will echo the MAG Multipath Binding option
      and the MAG NAI MAG-NAI option in the PBA message.  The MAG on MAG, upon
      receiving this message message, SHOULD disable Multipath multipath support for the
      mobile node.

   o  If the request for multipath support is accepted, then the LMA
      SHOULD enable multipath support for the mobile node and SHOULD
      also echo the MAG Multipath Binding option and the MAG NAI MAG-NAI option
      in the corresponding PBA message.

5.  IANA Considerations

   This document requires the following IANA actions.

   o  Action-1: This specification defines a new mobility option, option: the MAG Multipath-Binding Multipath
   Binding option.  The format of this option is described in
   Section 4.1.  The type value <IANA-1> 63 has been allocated for this mobility
   option needs to be allocated from the Mobility Options "Mobility Options" registry at
   <http://www.iana.org/assignments/mobility-parameters>.
      RFC Editor: Please replace <IANA-1> in Section 4.1 with the
      assigned value and update this section accordingly.

   o  Action-2:

   This specification defines a new mobility option, option: the MAG Identifier
   option.  The format of this option is described in Section 4.2.  The
   type value <IANA-2> 64 has been allocated for this mobility option
      needs to be allocated from the Mobility Options
   "Mobility Options" registry at
      <http://www.iana.org/assignments/mobility-parameters>.  RFC
      Editor: Please replace <IANA-2> in Section 4.2 with the assigned
      value and update this section accordingly.

   o  Action-3: <http://www.iana.org/assignments/
   mobility-parameters>.

   This document defines a new status value, value:
   CANNOT_SUPPORT_MULTIPATH_BINDING (<IANA-3>) (180) for use in Proxy
      Binding Acknowledgement message, PBA messages, as
   described in Section 4.3.  This value is to be has been assigned from the
   "Status Codes" registry at
      <http://www.iana.org/assignments/mobility-parameters>.  The
      allocated value has to be greater than 127.  RFC Editor: Please
      replace <IANA-3> in Section 4.3 with the assigned value and update
      this section accordingly. <http://www.iana.org/assignments/mobility-
   parameters>.

6.  Security Considerations

   This specification allows a mobile access gateway MAG to establish multiple Proxy Mobile IPv6 PMIPv6 tunnels
   with a local mobility anchor, an LMA by registering a care-of address CoA for each of its connected access
   networks.  This essentially allows the mobile node's IP traffic to be
   routed through any of the tunnel paths based on the negotiated flow
   policy.  This new capability has no impact on the protocol security.
   Furthermore, this specification defines two new mobility header
   options,
   options: the MAG Multipath-Binding Multipath Binding option and the MAG Identifier
   option.  These options are carried like any other mobility header
   option as specified in [RFC5213].  Therefore, it inherits security
   guidelines from [RFC5213].  Thus, this specification does not weaken
   the security of Proxy Mobile IPv6 Protocol, the PMIPv6 Protocol and does not introduce any new
   security vulnerabilities.

7.  Acknowledgements

   The authors of this draft would like to acknowledge the discussions
   and feedback on this topic from the members of the DMM working group.
   The authors would also like to thank Jouni Korhonen, Jong Hyouk Lee,
   Dirk Von-Hugo, Seil Jeon, Carlos Bernardos, Robert Sparks, Adam
   Roach, Kathleen Moriarty, Hilarie Orman, Ben Campbell, Warren Kumari,
   for their review feedback.  Special thanks to Mirja Kuehlewind for a
   very thorugh review and suggesting many text improvements.

8.  References

8.1.

7.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/
              RFC2119, 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC3963]  Devarapalli, V., Wakikawa, R., Petrescu, A., and P.
              Thubert, "Network Mobility (NEMO) Basic Support Protocol",
              RFC 3963, DOI 10.17487/RFC3963, January 2005,
              <https://www.rfc-editor.org/info/rfc3963>.

   [RFC5094]  Devarapalli, V., Patel, A., and K. Leung, "Mobile IPv6
              Vendor Specific Option", RFC 5094, DOI 10.17487/RFC5094,
              December 2007, <https://www.rfc-editor.org/info/rfc5094>.

   [RFC5213]  Gundavelli, S., Ed., Leung, K., Devarapalli, V.,
              Chowdhury, K., and B. Patil, "Proxy Mobile IPv6",
              RFC 5213, DOI 10.17487/RFC5213, August 2008,
              <https://www.rfc-editor.org/info/rfc5213>.

   [RFC5648]  Wakikawa, R., Ed., Devarapalli, V., Tsirtsis, G., Ernst,
              T., and K. Nagami, "Multiple Care-of Addresses
              Registration", RFC 5648, DOI 10.17487/RFC5648, October
              2009, <https://www.rfc-editor.org/info/rfc5648>.

   [RFC5844]  Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy
              Mobile IPv6", RFC 5844, DOI 10.17487/RFC5844, May 2010,
              <https://www.rfc-editor.org/info/rfc5844>.

   [RFC5845]  Muhanna, A., Khalil, M., Gundavelli, S., and K. Leung,
              "Generic Routing Encapsulation (GRE) Key Option for Proxy
              Mobile IPv6", RFC 5845, DOI 10.17487/RFC5845, June 2010,
              <https://www.rfc-editor.org/info/rfc5845>.

   [RFC6088]  Tsirtsis, G., Giarreta, G., Soliman, H., and N. Montavont,
              "Traffic Selectors for Flow Bindings", RFC 6088,
              DOI 10.17487/RFC6088, January 2011,
              <https://www.rfc-editor.org/info/rfc6088>.

   [RFC6089]  Tsirtsis, G., Soliman, H., Montavont, N., Giaretta, G.,
              and K. Kuladinithi, "Flow Bindings in Mobile IPv6 and
              Network Mobility (NEMO) Basic Support", RFC 6089,
              DOI 10.17487/RFC6089, January 2011,
              <https://www.rfc-editor.org/info/rfc6089>.

   [RFC6275]  Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility
              Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July
              2011, <https://www.rfc-editor.org/info/rfc6275>.

   [RFC7148]  Zhou, X., Korhonen, J., Williams, C., Gundavelli, S., and
              CJ. Bernardos, "Prefix Delegation Support for Proxy Mobile
              IPv6", RFC 7148, DOI 10.17487/RFC7148, March 2014,
              <https://www.rfc-editor.org/info/rfc7148>.

8.2.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

7.2.  Informative References

   [RFC2473]  Conta, A. and S. Deering, "Generic Packet Tunneling in
              IPv6 Specification", RFC 2473, DOI 10.17487/RFC2473,
              December 1998, <https://www.rfc-editor.org/info/rfc2473>.

   [RFC4213]  Nordmark, E. and R. Gilligan, "Basic Transition Mechanisms
              for IPv6 Hosts and Routers", RFC 4213,
              DOI 10.17487/
              RFC4213, 10.17487/RFC4213, October 2005,
              <https://www.rfc-editor.org/info/rfc4213>.

   [RFC4908]  Nagami, K., Uda, S., Ogashiwa, N., Esaki, H., Wakikawa,
              R., and H. Ohnishi, "Multi-homing for small scale fixed
              network Using Mobile IP and NEMO", RFC 4908,
              DOI 10.17487/
              RFC4908, 10.17487/RFC4908, June 2007,
              <https://www.rfc-editor.org/info/rfc4908>.

Acknowledgements

   The authors of this document would like to acknowledge the
   discussions and feedback on this topic from the members of the
   Distributed Mobility Management Working Group.  The authors would
   also like to thank Jouni Korhonen, Jong Hyouk Lee, Dirk Von-Hugo,
   Seil Jeon, Carlos Bernardos, Robert Sparks, Adam Roach, Kathleen
   Moriarty, Hilarie Orman, Ben Campbell, and Warren Kumari for their
   review feedback.  Special thanks to Mirja Kuehlewind for a very
   thorough review and suggesting many text improvements.

Authors' Addresses

   Pierrick Seite
   Orange
   4, rue du Clos Courtel, BP 91226
   Cesson-Sevigne  35512
   France

   Email: pierrick.seite@orange.com

   Alper Yegin
   Actility
   Turkey

   Email: alper.yegin@actility.com
   Sri Gundavelli
   Cisco
   170 West Tasman Drive
   San Jose, CA  95134
   USA
   United States of America

   Email: sgundave@cisco.com