GENWiki

Premier IT Outsourcing and Support Services within the UK

User Tools

Site Tools

Problem, Formatting or Query -  Send Feedback

Was this page helpful?-10+1


rfc:rfc6705

Internet Engineering Task Force (IETF) S. Krishnan Request for Comments: 6705 Ericsson Category: Standards Track R. Koodli ISSN: 2070-1721 Cisco Systems

                                                           P. Loureiro
                                                                   NEC
                                                                 Q. Wu
                                                                Huawei
                                                              A. Dutta
                                                                NIKSUN
                                                        September 2012
              Localized Routing for Proxy Mobile IPv6

Abstract

 Proxy Mobile IPv6 (PMIPv6) is a network based mobility management
 protocol that enables IP mobility for a host without requiring its
 participation in any mobility-related signaling.  PMIPv6 requires all
 communications to go through the local mobility anchor.  As this can
 be suboptimal, Localized Routing (LR) allows Mobile Nodes (MNs)
 attached to the same or different Mobile Access Gateways (MAGs) to
 route traffic by using localized forwarding or a direct tunnel
 between the gateways.  This document proposes initiation,
 utilization, and termination mechanisms for localized routing between
 mobile access gateways within a proxy mobile IPv6 domain.  It defines
 two new signaling messages, Localized Routing Initiation (LRI) and
 Local Routing Acknowledgment (LRA), that are used to realize this
 mechanism.

Status of This Memo

 This is an Internet Standards Track document.
 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by
 the Internet Engineering Steering Group (IESG).  Further
 information on Internet Standards is available in Section 2 of
 RFC 5741.
 Information about the current status of this document, any
 errata, and how to provide feedback on it may be obtained at
 http://www.rfc-editor.org/info/rfc6705.

Krishnan, et al. Standards Track [Page 1] RFC 6705 PMIPv6 Localized Routing September 2012

Copyright Notice

 Copyright (c) 2012 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
 carefully, as they describe your rights and restrictions with respect
 to this document.  Code Components extracted from this document must
 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.

Table of Contents

 1. Introduction ....................................................3
 2. Conventions Used in This Document ...............................3
 3. Initiation of Localized Routing .................................3
    3.1. MAG Behavior ...............................................4
    3.2. LMA Behavior ...............................................4
 4. Teardown of Localized Routing ...................................4
 5. Scenario A11: Two MNs Attached to the Same MAG and LMA ..........4
    5.1. Handover Considerations ....................................6
 6. Scenario A21: Two MNs Attached to Different MAGs but the
    Same LMA ........................................................7
    6.1. Handover Considerations ....................................9
    6.2. Tunneling between the MAGs .................................9
 7. Scenario A12: Two MNs Attached to the Same MAG with
    Different LMAs .................................................10
    7.1. Handover Considerations ...................................12
 8. Scenario A22: Two MNs Attached to Different MAGs with
    Different LMAs .................................................13
 9. IPv4 Support in Localized Routing ..............................13
 10. Message Formats ...............................................13
    10.1. Localized Routing Initiation (LRI) .......................14
    10.2. Localized Routing Acknowledgment (LRA) ...................15
 11. New Mobility Option ...........................................16
    11.1. MAG IPv6 Address .........................................16
 12. Configuration Variables .......................................17
 13. Security Considerations .......................................17
 14. IANA Considerations ...........................................17
 15. Contributors ..................................................18
 16. Acknowledgments ...............................................18
 17. References ....................................................19
    17.1. Normative References .....................................19
    17.2. Informative References ...................................19

Krishnan, et al. Standards Track [Page 2] RFC 6705 PMIPv6 Localized Routing September 2012

1. Introduction

 Proxy Mobile IPv6 [RFC5213] describes the protocol operations to
 maintain reachability and session persistence for a Mobile Node (MN)
 without the explicit participation from the MN in signaling
 operations at the Internet Protocol (IP) layer.  In order to
 facilitate such network-based mobility, the PMIPv6 protocol defines a
 Mobile Access Gateway (MAG), which acts as a proxy for the Mobile
 IPv6 [RFC6275] signaling, and the Local Mobility Anchor (LMA), which
 acts similar to a Home Agent.  The LMA and the MAG establish a
 bidirectional tunnel for forwarding all data traffic belonging to the
 Mobile Nodes.  In the case where both endpoints are located in the
 same PMIPv6 domain, this can be suboptimal and result in increased
 delay and congestion in the network.  Moreover, it increases
 transport costs and traffic load at the LMA.
 To overcome these issues, localized routing can be used to allow
 nodes attached to the same or different MAGs to directly exchange
 traffic by using localized forwarding or a direct tunnel between the
 gateways.  [RFC6279] defines the problem statement for PMIPv6
 localized routing.  This document describes a solution for PMIPv6
 localized routing between two MNs in the same PMIPv6 domain.  The
 protocol specified here assumes that each MN is attached to a MAG and
 that each MN's MAG has established a binding for the attached MN at
 its selected LMA according to [RFC5213].  The protocol builds on the
 scenarios defined in [RFC6279].

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 also uses the terminology defined in Section 2 of
 [RFC6279].

3. Initiation of Localized Routing

 Since the traffic to be localized passes through both the LMA and the
 MAGs, it is possible, at least in some scenarios, for either of them
 to initiate Localized Routing (LR).  In order to eliminate ambiguity,
 the protocol described in this document selects the initiator of LR
 based on the rules below.

Krishnan, et al. Standards Track [Page 3] RFC 6705 PMIPv6 Localized Routing September 2012

3.1. MAG Behavior

 The MAG MUST initiate LR if both of the communicating MNs are
 attached to it and the MNs are anchored at different LMAs.  The MAG
 MUST NOT initiate LR in any other case.

3.2. LMA Behavior

 The LMA MUST initiate LR if both of the communicating MNs are
 anchored to it.  The LMA MUST NOT initiate LR in any other case.

4. Teardown of Localized Routing

 The use of localized routing is not persistent.  Localized routing
 has a defined lifetime as specified by the initiator; upon expiry,
 the forwarding MUST revert to using bidirectional tunneling.  When
 localized routing ceases, the corresponding Localized Routing Entries
 (LREs) MUST be removed.
 If the initiator of LR wishes to terminate localized routing before
 the expiry of the lifetime specified in the LRI message, it MUST do
 so by sending a new LRI message with the lifetime set to zero.

5. Scenario A11: Two MNs Attached to the Same MAG and LMA

 In this scenario, the two Mobile Nodes involved in communication are
 attached to a single MAG and both are anchored at the same LMA as
 shown in Figure 1.
                               Internet
                                  :
                                  |
                                  |
                               +-----+
                               | LMA |
                               +-----+
                                  |
                                  |
                                  |
                               +-----+
                               | MAG |
                               +-----+
                                :   :
                             +---+ +---+
                             |MN1| |MN2|
                             +---+ +---+
                               Figure 1

Krishnan, et al. Standards Track [Page 4] RFC 6705 PMIPv6 Localized Routing September 2012

 The LMA initiates a localized routing session by detecting traffic
 between two MNs attached to the same MAG.  The exact traffic
 identification mechanism is not specified in this document and is
 left open for implementations and specific deployments.  An example
 trigger could be that an application-layer signaling entity detects
 the possibility of localized routing and notifies the LMA about the
 two endpoints, and the LMA determines that the two endpoints are
 attached to the same MAG.  Such a trigger mechanism offers localized
 routing at the granularity of an individual application session,
 providing flexibility in usage.  It is also possible that one of the
 mobility entities (LMA or MAG) could decide to initiate localized
 routing based on configured policy.  Please note that a MAG
 implementing the protocol specified in this document will not
 dynamically initiate LR in the same LMA case (i.e., by sending an
 LRI), but can statically initiate LR based on the
 EnableMAGLocalRouting configuration variable specified in [RFC5213].
    +----+      +----+      +----+          +----+
    |MN1 |      |MN2 |      |MAG1|          |LMA |
    +----+      +----+      +----+          +----+
      |           |           |               |
      |         data          |     data      |
      |<--------------------->|<------------->|
      |           |           |               |
      |           |    data   |     data      |
      |           |<--------->|<------------->|
      |           |           |          LR decision
      |           |           |  LRI(Opt1)    |
      |           |           |<--------------|
      |           |           |               |
      |           |           |  LRA(Opt2)    |
      |           |           |-------------->|
      |           |           |               |
      |        data           |               |
      |<--------------------->|               |
      |           |           |               |
      |           |   data    |               |
      |           |<--------->|               |
      |           |           |               |
      |           |           |               |
    Opt1: MN1-ID,MN1-HNP,MN2-ID,MN2-HNP
    Opt2: U=0,MN1-ID,MN1-HNP,MN2-ID,MN2-HNP
    where U is the flag defined in Section 10.2.
                               Figure 2

Krishnan, et al. Standards Track [Page 5] RFC 6705 PMIPv6 Localized Routing September 2012

 After detecting a possibility for localized routing, the LMA SHOULD
 construct an LRI message that is used to signal the intent to
 initiate localized routing and to convey parameters for the same.
 This is a Mobility Header message and it MUST contain the MN-
 Identifier (MN-ID) and the Home Network Prefix (HNP) (as Mobility
 Header options) for each of the MNs involved.  The LMA MUST then send
 the LRI message to the MAG (MAG1) where the two MNs are attached.
 The initiation of the LR procedure is shown in Figure 2.
 The MAG (MAG1) MUST verify the attachment status of the two MNs
 locally by checking the binding cache.  The MAG MUST then verify if
 the EnableMAGLocalRouting flag is set to 1.  If it is not, the MAG
 has not been configured to allow localized routing, and it MUST
 reject the LRI and MUST send an LRA with Status code "Localized
 Routing Not Allowed".  Please note that this does not update behavior
 specified in [RFC5213] but merely implements the LMA enforcement
 specified in Section 6.10.3 of [RFC5213].  If the MAG is configured
 to allow localized routing, it MUST then create LREs for each
 direction of the communication between the two MNs.  The exact form
 of the forwarding entries is left for the implementations to decide;
 however, they SHOULD contain the HNP corresponding to the destination
 IP address and a next-hop identifier (e.g., the layer-2 address of
 the next hop).  These LREs MUST override the Binding Update List
 (BUL) entries for the specific HNPs identified in the LRI message.
 Hence, all traffic matching the HNPs is forwarded locally.
 If the MAG is unable to deliver packets using the LREs, it is
 possible that one of the MNs is no longer attached to the MAG.
 Hence, the MAG MUST fall back to using the BUL entry, and the LMA
 MUST forward the received packets using its Binding Cache Entry
 (BCE).
 After processing the LRI message, the MAG MUST respond with a Local
 Routing Acknowledgment (LRA) message.  This Mobility Header message
 MUST also include the MN-ID and the HNP for each of the communicating
 MNs, as well as an appropriate Status code indicating the outcome of
 LRI processing.  Status code 0 indicates localized routing was
 successfully offered by the MAG.  Any other value for Status code
 indicates the reason for the failure to offer localized routing
 service.  When Status code is 0, the LMA sets a flag in the BCE
 corresponding to the HNPs to record that localized routing is in
 progress for that HNP.

5.1. Handover Considerations

 If one of the MNs, say MN1, detaches from the MAG and attaches to
 another MAG (say nMAG), the localized routing state needs to be
 re-established. When the LMA receives the PBU from nMAG for MN1, it

Krishnan, et al. Standards Track [Page 6] RFC 6705 PMIPv6 Localized Routing September 2012

 will see that localized routing is active for MN1.  The LMA MUST
 hence initiate LR at nMAG and update the LR state of pMAG.  After the
 handover completes, LR will resemble Scenario A21.  The pMAG MUST
 follow the forwarding rules described in Section 6.10.5 of [RFC5213]
 and decide that it will no longer perform LR for MN1.

6. Scenario A21: Two MNs Attached to Different MAGs but the Same LMA

 The LMA may choose to support local forwarding to Mobile Nodes
 attached to two different MAGs within a single PMIPv6 domain.
                               Internet
                                  :
                                  |
                                  |
                               +-----+
                               | LMA |
                               +-----+
                                  |
                                  |
                             +----+-----+
                             |          |
                          +----+     +----+
                          |MAG1|     |MAG2|
                          +----+     +----+
                            :           :
                          +---+       +---+
                          |MN1|       |MN2|
                          +---+       +---+
                               Figure 3
 As earlier, the LMA initiates LR as a response to some trigger
 mechanism.  In this case, however, it MUST send two separate LRI
 messages to the two MAGs.  In addition to the MN-ID and the HNP
 options, each LRI message MUST contain the IP address of the
 counterpart MAG.  When the MAG IP address option is present, each MAG
 MUST create a local forwarding entry such that the packets for the MN
 attached to the remote MAG are sent over a tunnel associated with
 that remote MAG.  The tunnel between the MAGs is assumed to be
 established following the considerations mentioned in Section 6.2.

Krishnan, et al. Standards Track [Page 7] RFC 6705 PMIPv6 Localized Routing September 2012

    +----+      +----+      +----+      +----+        +----+
    |MN1 |      |MN2 |      |MAG1|      |MAG2|        |LMA |
    +----+      +----+      +----+      +----+        +----+
      |           |           |           |             |
      |        data           |          data           |
      |<--------------------->|<----------------------->|
      |           |           |           |             |
      |           |         data          |    data     |
      |           |<--------------------->|<----------->|
      |           |           |           |             |
      |           |           |           |             |
      |           |           |       LRI(Opt1)         |
      |           |           |<------------------------|
      |           |           |           |             |
      |           |           |           |  LRI(Opt2)  |
      |           |           |           |<------------|
      |           |           |           |             |
      |           |           |        LRA(Opt3)        |
      |           |           |------------------------>|
      |           |           |           |             |
      |           |           |           |   LRA(Opt4) |
      |           |           |           |------------>|
      |           |           |           |             |
      |           |           |           |             |
      |           |           |           |             |
      |        data           |    data   |             |
      |<--------------------->|<--------->|             |
      |           |           |           |             |
      |           |         data          |             |
      |           |<--------------------->|             |
      |           |           |           |             |
      |           |           |           |             |
    Opt1: MN1-ID,MN1-HNP,MAG2-IPv6-Address
    Opt2: MN2-ID,MN2-HNP,MAG1-IPv6-Address
    Opt3: U=0,MN1-ID,MN1-HNP,MAG2-IPv6-Address
    Opt4: U=0,MN2-ID,MN2-HNP,MAG1-IPv6-Address
    where U is the flag defined in Section 10.2.
                               Figure 4
 In this case, each MAG responds to the LRI with an LRA message.  All
 subsequent packets are routed between the MAGs locally, without
 traversing the LMA.  If one of the MAGs (say MAG1) responds with a
 successful LRA (Status value is zero) and the other (say MAG2)

Krishnan, et al. Standards Track [Page 8] RFC 6705 PMIPv6 Localized Routing September 2012

 responds with an error (Status value is non-zero), LR will still be
 performed in one direction (MN1->MAG1->MAG2->MN2), but the packets
 flowing the other way will take the LMA path
 (MN2->MAG2->LMA->MAG1->MN1).
 The protocol does not require any synchronization between the MAGs
 before local forwarding begins.  Each MAG begins its local forwarding
 independent of the other.
 No synchronization between the MAGs is required because each MAG
 initiates LR in one direction.  After the LMA instructs MAG1 to
 initiate LR, packets from MN1 to MN2 will take the path
 MN1->MAG1->MAG2->MN2 while those from MN2 to MN1 will take the path
 MN2->MAG2->LMA->MAG1->MN1 until the LMA instructs MAG2 to initiate LR
 as well.  A MAG will forward a packet towards either another MAG or
 its own LMA; therefore, there would be no duplication of packets.

6.1. Handover Considerations

 If one of the MNs, say MN1, detaches from its current MAG (in this
 case MAG1) and attaches to another MAG (say nMAG1), the localized
 routing state needs to be re-established.  When the LMA receives the
 PBU from nMAG1 for MN1, it will see that localized routing is active
 for MN1.  The LMA MUST then initiate LR at nMAG1 and update the LR
 state of MAG2 to use nMAG1 instead of MAG1.

6.2. Tunneling between the MAGs

 In order to support localized routing, both MAGs SHOULD support the
 following encapsulation modes for the user packets, which are also
 defined for the tunnel between the LMA and MAG:
 o  IPv4-or-IPv6-over-IPv6 [RFC5844]
 o  IPv4-or-IPv6-over-IPv4 [RFC5844]
 o  IPv4-or-IPv6-over-IPv4-UDP [RFC5844]
 o  TLV-header UDP tunneling [RFC5845]
 o  Generic Routing Encapsulation (GRE) tunneling with or without GRE
    key(s) [RFC5845]
 MAG1 and MAG2 MUST use the same tunneling mechanism for the data
 traffic tunneled between them.  The encapsulation mode to be employed
 SHOULD be configurable.  It is RECOMMENDED that:

Krishnan, et al. Standards Track [Page 9] RFC 6705 PMIPv6 Localized Routing September 2012

 1.  As the default behavior, the inter-MAG tunnel uses the same
     encapsulation mechanism as that being used for the PMIPv6 tunnel
     between the LMA and the MAGs.  MAG1 and MAG2 automatically start
     using the same encapsulation mechanism without a need for a
     special configuration on the MAGs or a dynamic tunneling
     mechanism negotiation between them.
 2.  Configuration on the MAGs can override the default mechanism
     specified in Option 1 above.  MAG1 and MAG2 MUST be configured
     with the same mechanism, and this configuration is most likely to
     be uniform throughout the PMIPv6 domain.  If the packets on the
     PMIPv6 tunnel cannot be uniquely mapped onto the configured
     inter-MAG tunnel, this scenario is not applicable, and Option 3
     below SHOULD directly be applied.
 3.  An implicit or explicit tunnel negotiation mechanism between the
     MAGs can override the default mechanism specified in Option 1
     above.  The employed tunnel negotiation mechanism is outside the
     scope of this document.

7. Scenario A12: Two MNs Attached to the Same MAG with Different LMAs

 In this scenario, both the MNs are attached to the same MAG, but are
 anchored at two different LMAs.  MN1 is anchored at LMA1, and MN2 is
 anchored at LMA2.  Note that the two LMAs are part of the same
 Provider Domain.
                               Internet
                         :                  :
                         +------------------+
                         |                  |
                      +----+              +----+
                      |LMA1|              |LMA2|
                      +----+              +----+
                         |                  |
                         |                  |
                         +------------------+
                                  |
                                  |
                                  |
                               +-----+
                               | MAG |
                               +-----+
                                :   :
                             +---+ +---+
                             |MN1| |MN2|
                             +---+ +---+
                               Figure 5

Krishnan, et al. Standards Track [Page 10] RFC 6705 PMIPv6 Localized Routing September 2012

 Hence, neither LMA has a means to determine that the two Mobile Nodes
 are attached to the same MAG.  Only the MAG can possibly determine
 that the two Mobile Nodes involved in communication are attached to
 it.  Therefore, localized routing MUST be initiated by the MAG.
 The MAG sends an LRI message containing the MN-ID, HNP, and the
 counterpart LMA address to each LMA.  Each LMA makes a decision to
 support local forwarding independently based on configured policy for
 the corresponding LMA.  Each LMA MUST respond to the LRI message with
 an LRA message.  If the initiation of LR on the LMA was successful,
 the Status value in the received LRA would be set to zero.  After the
 MAG receives both the LRA messages, each with the Status value set to
 zero (success) from the two different LMAs, the MAG will conclude
 that it can provide local forwarding support for the two Mobile
 Nodes.

Krishnan, et al. Standards Track [Page 11] RFC 6705 PMIPv6 Localized Routing September 2012

    +----+      +----+      +----+      +----+        +----+
    |MN1 |      |MN2 |      |MAG |      |LMA1|        |LMA2|
    +----+      +----+      +----+      +----+        +----+
      |           |           |           |             |
      |        data           |   data    |    data     |
      |<--------------------->|<--------->|<----------->|
      |           |           |           |             |
      |           |   data    |          data           |
      |           |<--------->|<----------------------->|
      |           |           |           |             |
      |           |           |           |             |
      |           |           | LRI(Opt1) |             |
      |           |           |---------->|             |
      |           |           |           |             |
      |           |           |        LRI(Opt2)        |
      |           |           |------------------------>|
      |           |           |           |             |
      |           |           | LRA(Opt3) |             |
      |           |           |<----------|             |
      |           |           |           |             |
      |           |           |        LRA(Opt4)        |
      |           |           |<------------------------|
      |           |           |           |             |
      |           |           |           |             |
      |           |           |           |             |
      |        data           |           |             |
      |<--------------------->|           |             |
      |           |           |           |             |
      |           |    data   |           |             |
      |           |<--------->|           |             |
      |           |           |           |             |
      |           |           |           |             |
    Opt1: MN1-ID,MN1-HNP
    Opt2: MN2-ID,MN2-HNP
    Opt3: U=0,MN1-ID,MN1-HNP
    Opt4: U=0,MN2-ID,MN2-HNP
    where U is the flag defined in Section 10.2.
                               Figure 6

7.1. Handover Considerations

 If one of the MNs, say MN1, detaches from its current MAG (in this
 case MAG1) and attaches to another MAG (say nMAG1), the current MAG
 MUST immediately stop using the LRE and MUST send all packets
 originated by the other MN (MN2) towards its LMA (in this case LMA2).

Krishnan, et al. Standards Track [Page 12] RFC 6705 PMIPv6 Localized Routing September 2012

8. Scenario A22: Two MNs Attached to Different MAGs with Different LMAs

 This scenario will not be covered in this document since PMIPv6 does
 not define any form of inter-LMA communication.  When a supported
 scenario, such as Scenario A12, morphs into Scenario A22, the node
 that initiated the localized routing session MUST tear it down in
 order to prevent lasting packet loss.  This can result in transient
 packet loss when routing switches between the localized path into the
 normal path through the LMAs.  In applications that are loss
 sensitive, this can lead to observable service disruptions.  In
 deployments where Scenario A22 is possible, the use of localized
 routing is NOT RECOMMENDED when packet-loss-sensitive applications
 are in use.

9. IPv4 Support in Localized Routing

 PMIPv6 MNs can use an IPv4 Home Address (HoA) as described in
 [RFC5844].  In order to support the setup and maintenance of
 localized routes for these IPv4 HoAs in PMIPv6, the MAGs MUST add the
 IPv4 HoAs into their LREs.  The MAGs MUST also support encapsulation
 of IPv4 packets as described in [RFC5844].  The localized routing
 protocol messages MUST include an IPv4 HoA option in their signaling
 messages in order to support IPv4 addresses for localized routing.
 If the transport network between the PMIPv6 entities involved in
 localized routing is IPv4-only, the LRI and LRA messages MUST be
 encapsulated similar to the PBU/PBA messages as specified in
 [RFC5844].  The encapsulation mode used SHOULD be identical to the
 one used to transport PBU and PBA messages.

10. Message Formats

 The localized routing messages use two new Mobility Header types (17
 and 18).  The LRI message requests creation or deletion of the
 localized routing state, and the LRA message acknowledges the
 creation or deletion of such localized routing state.

Krishnan, et al. Standards Track [Page 13] RFC 6705 PMIPv6 Localized Routing September 2012

10.1. Localized Routing Initiation (LRI)

 The LRI messages use a new Mobility Header type (17).  The LMA sends
 an LRI message to a MAG to request local forwarding for a pair of
 MNs.  The MAG may also send this message to request the two LMAs for
 offering local forwarding as described in Section 7.
   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
                                  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                  |           Sequence #          |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |         Reserved              |           Lifetime            |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                                                               |
  .                                                               .
  .                        Mobility options                       .
  .                                                               .
  |                                                               |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    Sequence Number: A monotonically increasing integer.  Set by a
    sending node in a request message and used to match a reply to the
    request.
    Reserved: This field is unused and MUST be set to zero.
    Lifetime: The requested time, in seconds, for which the sender
    wishes to have local forwarding.  A value of 0xffff (all ones)
    indicates an infinite lifetime.  When set to 0, indicates a
    request to stop localized routing.
    Mobility Options: MUST contain two separate MN-ID options,
    followed by one or more HNPs for each of the MNs.  For instance,
    for Mobile Nodes MN1 and MN2 with identifiers MN1-ID and MN2-ID,
    and Home Network Prefixes MN1-HNP and MN2-HNP, the following tuple
    MUST be present in the following order: [MN1-ID, MN1-HNP],
    [MN2-ID, MN2-HNP].  The MN-ID and HNP options are the same as in
    [RFC5213].  The LRI MAY contain the remote MAG IPv6 address
    option, which is formatted identically to the HNP option, except
    that it uses a different Type code and the Prefix Length is always
    equal to 128 bits (see Section 10.1).
 The LRI message SHOULD be re-transmitted if a corresponding LRA
 message is not received within LRA_WAIT_TIME time units, up to a
 maximum of LRI_RETRIES, each separated by LRA_WAIT_TIME time units.

Krishnan, et al. Standards Track [Page 14] RFC 6705 PMIPv6 Localized Routing September 2012

10.2. Localized Routing Acknowledgment (LRA)

 The LRA messages use a new Mobility Header type (18).  A MAG sends an
 LRA message to the LMA as a response to the LRI message.  An LMA may
 also send this message to a MAG as a response to the LRI message as
 described in Section 7.
   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
                                  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                  |           Sequence #          |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |U|  Reserved   |   Status      |           Lifetime            |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                                                               |
  .                                                               .
  .                        Mobility options                       .
  .                                                               .
  |                                                               |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    Sequence Number: Copied from the sequence number field of the LRI
    message being responded to.
     'U' flag: When set to 1, the LRA message is sent unsolicited.
     The Lifetime field indicates a new requested value.  The MAG MUST
     wait for the regular LRI message to confirm that the request is
     acceptable to the LMA.
     Reserved: This field is unused and MUST be set zero.
     Status: 8-bit unsigned integer indicating the result of
     processing the Localized Routing Acknowledgment message.  Values
     of the Status field less than 128 indicate that the Localized
     Routing Acknowledgment was processed successfully by the mobility
     entities(LMA or MAG).  Values greater than or equal to 128
     indicate that the Localized Routing Acknowledgment was rejected
     by the mobility entities.  The following Status values are
     currently defined:
        0: Success
        128: Localized Routing Not Allowed
        129: MN Not Attached
     Lifetime: The time, in seconds, for which local forwarding is
     supported.  It is typically copied from the corresponding field
     in the LRI message.

Krishnan, et al. Standards Track [Page 15] RFC 6705 PMIPv6 Localized Routing September 2012

     Mobility Options: When Status code is 0, MUST contain the
     [MN-ID, HNP] tuples in the same order as in the LRI message.
     When Status code is not 0, MUST contain only those [MN-ID, HNP]
     tuples for which local forwarding is supported.  The MN-ID and
     HNP options are the same as those described in [RFC5213].

11. New Mobility Option

11.1. MAG IPv6 Address

 The MAG IPv6 address mobility option contains the IPv6 address of a
 MAG involved in localized routing.  The MAG IPv6 address option has
 an alignment requirement of 8n+4.
   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      |   Reserved    | Address Length|
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                                                               |
  +                                                               +
  |                                                               |
  +                       MAG IPv6 Address                        +
  |                                                               |
  +                                                               +
  |                                                               |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      Type
          51
      Length
          8-bit unsigned integer indicating the length of the option
          in octets, excluding the type and length fields.  This field
          MUST be set to 18.
      Reserved (R)
          This 8-bit field is unused.  The value MUST be initialized
          to 0 by the sender and MUST be ignored by the receiver.
      Address Length
          This field MUST be set to 128.

Krishnan, et al. Standards Track [Page 16] RFC 6705 PMIPv6 Localized Routing September 2012

      MAG IPv6 Address
          A 16-byte field containing the MAG's IPv6 address.

12. Configuration Variables

 The LMA and the MAG must allow the following variables to be
 configurable:
 LRA_WAIT_TIME:  This variable is used to set the time interval, in
    seconds, between successive retransmissions of an LRI message.
    The default value is 3 seconds.
 LRI_RETRIES:  This variable indicates the maximum number of times the
    initiator retransmits an LRI message before stopping.  The default
    value for this variable is 3.

13. Security Considerations

 The protocol inherits the threats to [RFC5213] that are identified in
 [RFC4832].  The protocol specified in this document uses the same
 security association as defined in [RFC5213] for use between the LMA
 and the MAG to protect the LRI and LRA messages.  This document also
 assumes the preexistence of a MAG-MAG security association if LR
 needs to be supported between them.  Support for integrity protection
 using IPsec is REQUIRED, but support for confidentiality is OPTIONAL.
 The MAGs MUST perform ingress filtering on the MN-sourced packets
 before encapsulating them into MAG-MAG tunnels in order to prevent
 address spoofing.

14. IANA Considerations

 The Localized Routing Initiation (described in Section  10.1) and the
 Localized Routing Acknowledgment (described in Section 10.2) have
 each been assigned a Mobility Header type (17 and 18, respectively)
 from the "Mobility Header Types - for the MH Type field in the
 Mobility Header" registry at
 http://www.iana.org/assignments/mobility-parameters.
 The MAG IPv6 Address has been assigned a Mobility Option type (51)
 from the "Mobility Options" registry at
 http://www.iana.org/assignments/mobility-parameters.

Krishnan, et al. Standards Track [Page 17] RFC 6705 PMIPv6 Localized Routing September 2012

15. Contributors

 This document merges ideas from five different draft documents
 addressing the PMIP localized routing problem.  The authors of these
 drafts are listed below (in alphabetical order).
 Kuntal Chowdhury <kchowdhury@starentnetworks.com>
 Ashutosh Dutta <adutta@niksun.com>
 Rajeev Koodli <rkoodli@starentnetworks.com>
 Suresh Krishnan <suresh.krishnan@ericsson.com>
 Marco Liebsch <marco.liebsch@nw.neclab.eu>
 Paulo Loureiro <loureiro@neclab.eu>
 Desire Oulai <desire.oulai@videotron.com>
 Behcet Sarikaya <sarikaya@ieee.org>
 Qin Wu <sunseawq@huawei.com>
 Hidetoshi Yokota <yokota@kddilabs.jp>

16. Acknowledgments

 The authors would like to thank Sri Gundavelli, Julien Abeille, Tom
 Taylor, Kent Leung, Mohana Jeyatharan, Jouni Korhonen, Glen Zorn,
 Ahmad Muhanna, Zoltan Turanyi, Dirk von Hugo, Pete McCann, Xiansong
 Cui, Carlos Bernardos, Basavaraj Patil, Jari Arkko, Mary Barnes, Les
 Ginsberg, Russ Housley, Carl Wallace, Ralph Droms, Adrian Farrel, and
 Stephen Farrell for their comments and suggestions.

Krishnan, et al. Standards Track [Page 18] RFC 6705 PMIPv6 Localized Routing September 2012

17. References

17.1. Normative References

 [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
            Requirement Levels", BCP 14, RFC 2119, March 1997.
 [RFC5213]  Gundavelli, S., Ed., Leung, K., Devarapalli, V.,
            Chowdhury, K., and B. Patil, "Proxy Mobile IPv6", RFC
            5213, August 2008.
 [RFC5844]  Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy
            Mobile IPv6", RFC 5844, May 2010.
 [RFC5845]  Muhanna, A., Khalil, M., Gundavelli, S., and K. Leung,
            "Generic Routing Encapsulation (GRE) Key Option for Proxy
            Mobile IPv6", RFC 5845, June 2010.
 [RFC6275]  Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility
            Support in IPv6", RFC 6275, July 2011.

17.2. Informative References

 [RFC4832]  Vogt, C. and J. Kempf, "Security Threats to Network-Based
            Localized Mobility Management (NETLMM)", RFC 4832, April
            2007.
 [RFC6279]  Liebsch, M., Ed., Jeong, S., and Q. Wu, "Proxy Mobile IPv6
            (PMIPv6) Localized Routing Problem Statement", RFC 6279,
            June 2011.

Krishnan, et al. Standards Track [Page 19] RFC 6705 PMIPv6 Localized Routing September 2012

Authors' Addresses

 Suresh Krishnan
 Ericsson
 8400 Blvd Decarie
 Town of Mount Royal, Quebec
 Canada
 Phone: +1 514 345 7900 x42871
 EMail: suresh.krishnan@ericsson.com
 Rajeev Koodli
 Cisco Systems
 EMail: rkoodli@cisco.com
 Paulo Loureiro
 NEC Laboratories Europe
 NEC Europe Ltd.
 Kurfuersten-Anlage 36
 69115 Heidelberg
 Germany
 EMail: loureiro@neclab.eu
 Qin Wu
 Huawei Technologies Co., Ltd.
 101 Software Avenue, Yuhua District
 Nanjing, Jiangsu  21001
 China
 Phone: +86-25-56623633
 EMail: sunseawq@huawei.com
 Ashutosh Dutta
 NIKSUN
 EMail: adutta@niksun.com

Krishnan, et al. Standards Track [Page 20]

/data/webs/external/dokuwiki/data/pages/rfc/rfc6705.txt · Last modified: 2012/09/20 00:08 (external edit)