[Docs] [txt|pdf] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-krishnan-netext-update-notifications) 00 01 02 03 04 05 06 07 08 09 10 11 12 RFC 7077

NETEXT WG                                                    S. Krishnan
Internet-Draft                                                  Ericsson
Intended status: Standards Track                           S. Gundavelli
Expires: April 11, 2014                                            Cisco
                                                              M. Liebsch
                                                                     NEC
                                                               H. Yokota
                                                                    KDDI
                                                             J. Korhonen
                                                          Renesas Mobile
                                                         October 8, 2013


               Update Notifications for Proxy Mobile IPv6
               draft-ietf-netext-update-notifications-12

Abstract

   This document specifies protocol enhancements for allowing the local
   mobility anchor in a Proxy Mobile IPv6 domain to asynchronously
   notify the mobile access gateway about changes related to a mobility
   session.  These update notification messages are exchanged using a
   new Mobility Header message type specifically designed for this
   purpose.

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
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on April 11, 2014.

Copyright Notice

   Copyright (c) 2013 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



Krishnan, et al.         Expires April 11, 2014                 [Page 1]

Internet-Draft            Update Notifications              October 2013


   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 and Terminology  . . . . . . . . . . . . . . . . .  4
     2.1.  Conventions  . . . . . . . . . . . . . . . . . . . . . . .  4
     2.2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . .  4
   3.  Notification Message - Usage Examples  . . . . . . . . . . . .  4
   4.  Message Formats  . . . . . . . . . . . . . . . . . . . . . . .  5
     4.1.  Update Notification(UPN) . . . . . . . . . . . . . . . . .  5
     4.2.  Update Notification Acknowledgement(UPA) . . . . . . . . .  7
   5.  LMA Considerations . . . . . . . . . . . . . . . . . . . . . .  9
     5.1.  Constructing the Update Notification Message . . . . . . . 10
     5.2.  Receiving the Update Notification Acknowledgement
           Message  . . . . . . . . . . . . . . . . . . . . . . . . . 11
   6.  MAG Considerations . . . . . . . . . . . . . . . . . . . . . . 12
     6.1.  Receiving the Update Notification Message  . . . . . . . . 12
     6.2.  Constructing the Update Notification Acknowledgement
           Message  . . . . . . . . . . . . . . . . . . . . . . . . . 14
   7.  Protocol Configuration Variables . . . . . . . . . . . . . . . 15
   8.  Security Considerations  . . . . . . . . . . . . . . . . . . . 15
   9.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16
   10. IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 16
   11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
     11.1. Normative References . . . . . . . . . . . . . . . . . . . 18
     11.2. Informative References . . . . . . . . . . . . . . . . . . 19
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19















Krishnan, et al.         Expires April 11, 2014                 [Page 2]

Internet-Draft            Update Notifications              October 2013


1.  Introduction

   In some situations, there is a need for the local mobility anchor to
   send asynchronous notification messages to the mobile access gateway
   in the course of a mobility session.  These situations include
   changes to mobility session parameters and policy parameters.  In
   this context, 'Asynchronous messages' is used to mean messages that
   are not synchronous with the Proxy Binding Update and Proxy Binding
   Acknowledgement messages of the base Proxy Mobile IPv6 specification
   [RFC5213].  The base Proxy Mobile IPv6 specification does not have a
   provision for sending unsolicited update notifications messages from
   the local mobility anchor to the mobile access gateway.

   Proxy Mobile IPv6 [RFC5213] is a network-based mobility management
   protocol.  It is designed for providing IP mobility management
   support to a mobile node, without requiring the participation of the
   mobile node in any IP mobility related signaling.  The protocol
   defines two mobility management entities, local mobility anchor (LMA)
   and mobile access gateway (MAG).  These entities are responsible for
   managing IP mobility management support for a mobile node in a Proxy
   Mobile IPv6 domain.  The setup of the mobility session is initiated
   by the mobile access gateway by sending a Proxy Binding Update
   message and acknowledged by the local mobility anchor in the Proxy
   Binding Acknowledgement message.  Once the mobility session is set
   up, currently there is no mechanism for the local mobility anchor to
   inform the mobile access gateway about changes to the mobility
   session or any parameters related to the mobility session.  However,
   there are mechanisms in the Proxy Mobile IPv6 protocol which allows a
   local mobility anchor to send signaling messages to the mobile access
   gateway asynchronously, as defined in Proxy Mobile IPv6 Heartbeat
   message [RFC5847], or in the Binding Revocation message [RFC5846],
   but, these signaling messages are designed for a very specific
   purpose and are not sufficient for supporting a notification
   framework.

   One such scenario where such a mechanism is needed is when the local
   mobility anchor wants to inform the mobile access gateway that it
   needs to re-register the mobility session for a mobile node.  It is
   possible to achieve a similar effect by using a short lifetime for
   the mobility sessions but in several networks this results in an
   unacceptable, and mostly unnecessary, increase in the signaling load
   and overhead.  More suitable is to enable a demand-based signaling
   from the local mobility anchor to one or more mobile access gateways.
   Another example is when there is change in QoS policy
   [I-D.ietf-netext-pmip6-qos], or a change in IP Flow mobility policy
   [I-D.ietf-netext-pmipv6-flowmob], or a IPv4 Traffic Offload Policy
   [RFC6909], for a mobility session, the local mobility anchor wants to
   request the mobile access gateway to perform re-registration of the



Krishnan, et al.         Expires April 11, 2014                 [Page 3]

Internet-Draft            Update Notifications              October 2013


   mobility session and so in order to update the policies associated
   with the mobility session of a mobile node.

   This document defines a new mobility header message for allowing the
   local mobility anchor to send notification messages to the mobile
   access gateway and a corresponding mobility header message for the
   mobile access gateway to acknowledge the notification message.  The
   purpose of the notification message is two-fold: (1) enable the local
   mobility anchor to notify the mobile access gateway about the updated
   session parameters, (2) enable the local mobility anchor to request
   the mobile access gateway to re-negotiate the session parameters.


2.  Conventions and Terminology

2.1.  Conventions

   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 RFC 2119 [RFC2119].

2.2.  Terminology

   All the mobility related terms used in this document are to be
   interpreted as defined in the base Proxy Mobile IPv6 specifications
   [RFC5213] and [RFC5844].


3.  Notification Message - Usage Examples

   Use Case 1: Consider a use case where the local mobility anchor wants
   the mobile access gateway to re-register a specific mobility session.

   MN     MAG       LMA
   |------>|        |    1.  Mobile Node Attach
   |       |------->|    2.  Proxy Binding Update
   |       |<-------|    3.  Proxy Binding Acknowledgement
   |       |========|    4.  Tunnel/Route Setup
   |       |        |
   |       |<-------|    5.  Update Notification (FORCE-REREGISTRATION)
   |       |------->|    6.  Update Notification Acknowledgement
   |       |        |
   |       |------->|    7.  Proxy Binding Update
   |       |<-------|    8.  Proxy Binding Acknowledgement
   |       |        |

           Figure 1: Update Notification - Force ReRegistration




Krishnan, et al.         Expires April 11, 2014                 [Page 4]

Internet-Draft            Update Notifications              October 2013


   Use Case 2: Consider a use case where the local mobility anchor wants
   to notify the updated session parameters to the mobile access
   gateway, for example, an updated QoS profile, or an updated IPv4
   Offload Policy.

   MN     MAG     LMA
   |------>|        |    1.  Mobile Node Attach
   |       |------->|    2.  Proxy Binding Update
   |       |<-------|    3.  Proxy Binding Acknowledgement
   |       |========|    4.  Tunnel/Route Setup
   |       |        |
   |       |<-------|    5.  Update Notification
   |       |------->|    6.  Update Notification Acknowledgement
   |       +        |    7.  MAG applies the new policy option
   |       |        |

       Figure 2: Update Notification - Notifying Session Parameters


4.  Message Formats

4.1.  Update Notification(UPN)

   The Update Notification is a mobility header message that has an MH
   Type value of <IANA-1>.  It is used by the local mobility anchor to
   notify the mobile access gateway that some parameters related to the
   mobility session have changed.

   The format of the Update Notification message is as follows:


   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 #          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Notification Reason        |A|D|          Reserved         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   .                                                               .
   .                        Mobility options                       .
   .                                                               .
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



                   Figure 3: Update Notification Message



Krishnan, et al.         Expires April 11, 2014                 [Page 5]

Internet-Draft            Update Notifications              October 2013


   Sequence Number
      A 16-bit unsigned integer used by the local mobility anchor to
      match the received Update Notification Acknowledgement message
      with this Update Notification message.  This sequence number could
      be a random number and can be managed under the same variable used
      in Proxy Mobile IPv6 signaling messages [RFC5213].  At any time,
      implementations MUST ensure there is no collision between the
      sequence numbers of all outstanding Update Notification messages.
   Notification Reason
      This 16-bit unsigned integer indicates the Notification reason
      code.  This code corresponding to the reason that caused the local
      mobility anchor to send the Update Notification to the mobile
      access gateway.  This field does not contain any structure and
      MUST be treated as an enumeration.  The reason code can indicate
      vendor specific reason in case the semantics of the Update
      Notification message get clear from the attached options, not
      solely from the reason code.  These attached options can be
      deployment specific and are not specified in this document.  The
      following Notification Reason values are currently defined:

      (0) -   Reserved
         This value is currently reserved and cannot be used

      (1) -   FORCE-REREGISTRATION
         Request to re-register the session by sending a Proxy Binding
         Update for the mobility session

      (2) -   UPDATE-SESSION-PARAMETERS
         Request to apply the updated session parameters obtained from
         the message on the mobility session

      (3) -   VENDOR-SPECIFIC-REASON
         The Notification reason is for vendor-specific use.  The
         processing rules are to based on the Vendor-specific mobility
         option(s) [RFC5094] present in the message

      (4) -   ANI-PARAMS-REQUESTED
         Request to send currently known ANI [RFC6757] parameters for
         the mobility session

      (255) -   Reserved
         This value is currently reserved and cannot be used

   Acknowledgement Requested Flag ('A' Flag)
      When this flag is set to a value of (1), it is an indication that
      the local mobility anchor is requesting the mobile access gateway
      to send a Update Notification Acknowledgement message.  When this
      flag is set to a value of (0), it is an indication that the local



Krishnan, et al.         Expires April 11, 2014                 [Page 6]

Internet-Draft            Update Notifications              October 2013


      mobility anchor is not requesting any Update Notification
      Acknowledgement message.
   Re-Transmitted Request Flag ('D' Flag)
      When this flag is set to a value of (1), it is an indication that
      the message is a re-transmitted message and has the same Sequence
      Number and other message contents as in the previously sent
      message.  The 'D' flag is set for retransmitted request messages,
      to aid the reliable detection of duplicate requests at the
      received of the request message.  It is set when originating
      requests that have not yet been acknowledged, as an indication of
      a possible duplicate due to a retransmission.  This flag MUST be
      cleared when sending a request for the first time for a given
      Sequence Number; otherwise, the sender MUST set this flag.
   Reserved
      This field is unused for now.  The value MUST be initialized to 0
      by the sender and MUST be ignored by the receiver.
   Mobility Options
      A variable-length field of such length that the complete Mobility
      Header is an integer multiple of 8 octets long;Pad1 [RFC6275] and
      PadN [RFC6275] options can be used for padding.  This field
      contains zero or more TLV-encoded mobility options.  Any of the
      mobility header options including vendor-specific mobility options
      [RFC5094] can be included here.  The receiver MUST ignore and skip
      any options that it does not understand.  These mobility options
      are used by the mobile access gateway to identify the specific
      binding for which the Update Notification message is sent.

4.2.  Update Notification Acknowledgement(UPA)

   The Update Notification Acknowledgement is a mobility header message
   that has an MH Type value of <IANA-2>.  The mobile access gateway
   sends this message in order to acknowledge that it has received an
   Update Notification message with the A-flag set and to indicate the
   status after processing the message.

   The format of the Update Notification Acknowledgement message is as
   follows:














Krishnan, et al.         Expires April 11, 2014                 [Page 7]

Internet-Draft            Update Notifications              October 2013


   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 #          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Status Code |                   Reserved                    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   .                                                               .
   .                        Mobility options                       .
   .                                                               .
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



           Figure 4: Update Notification Acknowledgement Message

   Sequence Number
      A 16-bit unsigned integer copied from the Update Notification
      message.  This is used for matching the Update Notification
      Acknowledgement message with the Update Notification message.
   Status Code
      This 8-bit unsigned integer indicates the status code.  Specifies
      the result of the processing of the update notification message.
      The status codes between 0 and 127 signify successful processing
      of the Update Notification message and codes between 128 and 255
      signify that an error occurred during processing of the update
      notification message.  The following Status Code values are
      currently defined:

      (0) -   SUCCESS
         The mobile access gateway successfully processed the received
         Update Notification Message.

      (128) -   FAILED-TO-UPDATE-SESSION-PARAMETERS
         The mobile access gateway was not able to apply the session
         parameters sent by the local mobility anchor in the Update
         Notification Message.

      (129) -   MISSING-VENDOR-SPECIFIC-OPTION
         The received Update Notification Message does not have the
         required vendor-specific mobility option(s) needed for handling
         the message.







Krishnan, et al.         Expires April 11, 2014                 [Page 8]

Internet-Draft            Update Notifications              October 2013


   Reserved
      This field is unused for now.  The value MUST be initialized to 0
      by the sender and MUST be ignored by the receiver.
   Mobility Options
      A variable-length field of such length that the complete Mobility
      Header is an integer multiple of 8 octets long;Pad1 [RFC6275] and
      PadN [RFC6275] options can be used for padding.  This field
      contains zero or more TLV-encoded mobility options.  Any of the
      mobility header options including vendor-specific mobility options
      [RFC5094] can be included here.  The receiver MUST ignore and skip
      any options that it does not understand.  These mobility options
      are used by the mobile access gateway to identify the specific
      binding for which the Update Notification Acknowledgement message
      is sent.


5.  LMA Considerations

   o  The local mobility anchor sends the Update Notification message in
      response to a condition that is specified in the Notification
      Reason field.  The Notification Reason field in the Update
      Notification message MUST be set to a specific value that
      identifies the reason for which the Update Notification message is
      being sent.  The Notification Reason based on the chosen value,
      may require a specific Action that the mobile access gateway needs
      to perform (Ex: Requiring Re-registration of a mobility session).
   o  The Update Notification message MUST include either the Mobile
      Node Identifier option [RFC4283], or the Mobile Node Group
      Identifier Option [RFC6602].
      *  If the Mobile Node Identifier option is present, it indicates
         that the Update Notification message is sent for that specific
         mobility session.
      *  If the Mobile Node Group Identifier option is present, it
         indicates that the Update Notification message is sent for the
         set of mobility sessions identified by the Group Identifier.
         The Group Identifier is negotiated as part of the initial
         PMIPv6 signaling.  If the Group Identifier is not negotiated in
         the initial Proxy Mobile IPv6 signaling, a value of (1) for the
         Group Identifier can always be used.  The Group Identifier
         value of (1) identifies the all the mobility sessions
         established between that local mobility anchor and the mobile
         access gateway.
   o  The Update Notification message MAY contain a modified session
      parameters in the form of a mobility options (e.g.,: IPv4 Traffic
      Offload option, or a QoS option), so the mobile access gateway can
      apply them on the identified mobility session.





Krishnan, et al.         Expires April 11, 2014                 [Page 9]

Internet-Draft            Update Notifications              October 2013


5.1.  Constructing the Update Notification Message

   The local mobility anchor when sending the Update Notification
   message to the mobile access gateway has to construct the message as
   specified below:

   o  For requesting an Acknowledgement message and an indication about
      the result of processing the message from the mobile access
      gateway for the Update Notification message, the "A" flag in the
      Update Notification message MUST be set to a value of (1),
      otherwise it MUST be set to a value of (0).  However, if the
      Notification Reason is set to a value of (1) "FORCE-
      REREGISTRATION", or (4) "ANI-PARAMS-REQUESTED", then it is
      RECOMMENDED to have the "A" flag set to a value of (0).  For
      certain general notifications of informational in nature, the
      local mobility anchor may choose not request Acknowledgement for
      the Update Notification message.
   o  The Sequence Number field of the message MUST be initialized to a
      random number and increased monotonically for subsequent messages.
      Once the sequence number hits the maximum value, it should be
      wrapped around to 0.  Furthermore, if the message is a re-
      transmission of a previously sent message, then the sequence
      number value is not changed.
   o  When using IPv4 transport, the source address in the IPv4 header
      MUST be set to local mobility anchor's IPv4 address (IPv4-LMAA)
      and the destination address in the IPv4 header MUST be set to
      IPv4-Proxy-CoA of the mobile access gateway.  The Mobility Header
      (without the IPv6 header) containing the Update Notification
      message is encapsulated in UDP header with the destination port of
      5436 [RFC5844].  If IPsec ESP is used to protect signaling, the
      packet is processed using transport mode ESP.
   o  The format of the Update Notification message sent over IPv4 and
      protected using ESP is shown below:


       IPv4 header (src=IPv4-LMAA, dst=IPv4-Proxy-CoA)
         ESP header (in transport mode)
           UDP header (sport=5436, dport=5436)
             Mobility Header (Update Notification)
               (One or more Mobile Header Options)


   o  When using IPv6 transport, the source address in the IPv6 header
      MUST be set to local mobility anchor's IPv6 address (LMAA).  The
      destination address in the IPv6 header MUST be set to Proxy-CoA of
      the mobile access gateway.  The Mobility Header is part of the
      IPv6 headers.




Krishnan, et al.         Expires April 11, 2014                [Page 10]

Internet-Draft            Update Notifications              October 2013


   o  The format of the Update Notification message sent over IPv6 and
      protected using ESP is shown below:


       IPv6 header (src=Proxy-CoA, dst=LMAA)
         Mobility Header (Update Notification)
         ESP header (in transport mode)
           (One or more Mobile Header Options)


5.2.  Receiving the Update Notification Acknowledgement Message

   o  If the local mobility anchor does not receive an Update
      Notification Acknowledgement message from the mobile access
      gateway for the Update Notification message with the A-flag set,
      then the local mobility anchor MUST retransmit the message.
      Following are the related considerations:
      *  When retransmitting an Update Notification message, the
         sequence number value and other message contents MUST be the
         same as in the original message.  The "D" flag in the message
         MUST be set to a value of (1).
      *  There MUST be a minimum delay of,
         MIN_DELAY_BETWEEN_UPDATE_NOTIFICATION_REPLAY (Section 7), with
         a default value of 1000 milli-seconds, between two retransmit
         messages.
      *  The message MUST be retransmitted up to number of times defined
         by the configuration variable,
         MAX_UPDATE_NOTIFICATION_RETRANSMIT_COUNT (Section 7), with a
         default value of (1).  If there is no Update Notification
         Acknowledgement message after retransmission count reaches the
         value defined by the configuration variable,
         MAX_UPDATE_NOTIFICATION_RETRANSMIT_COUNT, then the message MUST
         be discarded and the event SHOULD be logged.
   o  If the local mobility anchor receives a Binding Error message with
      the Status field set to 2 as described in [RFC6275], then it is an
      indication that the mobile access gateway does not support the
      Update Notification Mobility Header message and hence the local
      mobility anchor MUST NOT send any further Update Notification
      messages to that mobile access gateway unless an administrative
      action is taken.
   o  When receiving a Update Notification Acknowledgement message, the
      local mobility anchor MUST verify the Mobility Header as described
      in Section 9.2. of [RFC6275].  If the packet is dropped due to
      failing of any of the Mobility Header test checks, the local
      mobility anchor MUST follow the processing rules as in Section 9.2
      of [RFC6275].





Krishnan, et al.         Expires April 11, 2014                [Page 11]

Internet-Draft            Update Notifications              October 2013


   o  Upon receiving the Update Notification Acknowledgement message,
      the local mobility anchor MUST verify that the received message is
      protected by the security association that is being used to
      protect the other signaling messages between those two peers.  For
      example, if the Proxy Binding Update and Proxy Binding
      Acknowledgement messages are protected using IPsec Security
      Association, then the Update Notification Acknowledgement message
      MUST have the IPsec protection with the currently established
      IPsec security association that is being used for protecting the
      other Proxy Mobile IPv6 signaling messages.
   o  If the local mobility anchor receives an Update Notification
      Acknowledgement message with a failure Status and the value of 128
      or greater, then it SHOULD log an error.
   o  If the sequence number in the received Update Notification
      Acknowledgement message does not match any of the Update
      Notification messages that the local mobility anchor sent, then
      the message MUST be discarded and the message should be logged.
   o  If the local mobility anchor receives an Update Notification
      Acknowledgement message from the mobile access gateway for the
      Update Notification message, which did not have the A-flag set,
      the local mobility anchor MUST process the received message in the
      same way as a requested acknowledgement.


6.  MAG Considerations

6.1.  Receiving the Update Notification Message

   o  When receiving a Update Notification message, the mobile access
      gateway MUST verify the Mobility Header as described in Section
      9.2. of [RFC6275].  If the packet is dropped due to failing of any
      of the Mobility Header test checks, the mobile access gateway MUST
      follow the processing rules as in Section 9.2 of [RFC6275].
   o  Upon receiving the Update Notification message, the mobile access
      gateway MUST verify that the received packet is protected by the
      security association that is being used to protect the other
      signaling messages between those two peers.  For example, if the
      Proxy Binding Update and Proxy Binding Acknowledgement messages
      are protected using IPsec Security Association, then the Update
      Notification message MUST have the IPsec protection with the
      currently established IPsec security association that is being
      used for protecting the other Proxy Mobile IPv6 signaling
      messages.
   o  If the received Update Notification message is a re-transmission
      of a previously received message, identified by the Sequence
      Number, then the mobile access gateway MUST NOT handle the message
      as a new request.  The 'D' flag is used as an indication of a
      retransmitted request, e.g., due to lost messages or the local



Krishnan, et al.         Expires April 11, 2014                [Page 12]

Internet-Draft            Update Notifications              October 2013


      mobility anchor not seeing the requested update actions.  If the
      mobile access gateway has not seen the (potentially lost) initial
      request message, it MUST treat the received Update Notification
      message (with the 'D' flag set) as receiving the initial request
      and continue processing based on that.  If the mobile access
      gateway detects that the request is a retransmission based on the
      'D' flag and the Sequence Number, then it SHOULD redo the
      requested update action e.g., when the acknowledgement 'A' flag is
      not set.  The mobile access gateway MUST always respond to the
      retransmitted request if the 'A' flag is set.
   o  Upon accepting the Update Notification message, the mobile access
      gateway MUST process the message and perform the actions based on
      the Notification Reason.
      *  If the (A) flag in the message is set to a value of (1), the
         mobile access gateway MUST send an Update Notification
         Acknowledgement message with the status code field set based on
         the result of processing the Update Notification message.
      *  If the Notification Reason is set to a value of (1) "FORCE-
         REREGISTRATION", then the mobile access gateway MUST send a
         Proxy Binding Update message to the local mobility anchor and
         obtain the updated session parameters for that mobility
         session.
      *  If the Notification Reason is set to a value of (2) "UPDATE-
         SESSION-PARAMETERS", then the mobile access gateway MUST apply
         the session parameters that are obtained from the Update
         Notification message in the form of mobility options.  However,
         if the mobile access gateway is unable to apply the notified
         session parameters, then the mobile access gateway MUST apply
         the following considerations.
         +  If the received Update Notification message has the (A) flag
            in the message set to a value of (0), then the mobile access
            gateway MUST drop the received Update Notification message
            and log the error.
         +  If the received Update Notification message has the (A) flag
            in the message set to a value of (1), then the mobile access
            gateway MUST send an Update Notification Acknowledgement
            message with the Status Code value of 128 (FAILED-TO-UPDATE-
            SESSION-PARAMETERS).
      *  If the Notification Reason is set to a value of (3) "VENDOR-
         SPECIFIC-REASON", then the mobile access gateway MUST apply the
         considerations related to handling of the Vendor-specific
         option [RFC5094] that is carried in the Update Notification
         message.  However, if there is no Vendor-specific option
         present in the message, the mobile access gateway MUST apply
         the following considerations.
         +  If the received Update Notification message has the (A) flag
            in the message set to a value of (0), then the mobile access
            gateway MUST drop the received Update Notification message



Krishnan, et al.         Expires April 11, 2014                [Page 13]

Internet-Draft            Update Notifications              October 2013


            and log the error.
         +  If the received Update Notification message has the (A) flag
            in the message set to a value of (1), then the mobile access
            gateway MUST send an Update Notification Acknowledgement
            message with the Status Code value of 129 (MISSING-VENDOR-
            SPECIFIC-OPTION).
      *  If the Notification Reason is set to a value of (4) "ANI-
         PARAMS-REQUESTED", then the mobile access gateway MUST send a
         Proxy Binding Update message to the local mobility anchor with
         the Access Network Identifier Option [RFC6757].  The Access
         Network Identifier option MUST reflect the current access
         network parameters for that mobility session as known to the
         mobile access gateway at the time of sending the Proxy Binding
         Update message.
      *  For other Notification Reasons that are not reserved by this
         document, the processing required on the mobile access gateway
         is out of the scope for this document and will be specified for
         each Notification reason in the respective document.

6.2.  Constructing the Update Notification Acknowledgement Message

   The mobile access gateway when sending the Update Notification
   Acknowledgement message to the local mobility anchor has to construct
   the message as specified below:

   o  The Sequence Number MUST be the same as the sequence Number from
      the received Update Notification message.
   o  The status field of the Update Notification message MUST be set to
      a value that reflects the status of the processing of the Update
      Notification request.  The value of 0 (success), indicates that
      the handling of the Update Notification message was successful.
   o  The Update Notification Acknowledgement message MUST contain
      either the Mobile Node Identifier option, or the Mobile Node Group
      Identifier option, copied from the Update Notification message.
      Furthermore, the mobile access gateway MAY include other mobility
      header options.
   o  The source address in the IP header of the Update Notification
      Acknowledgement message MUST be set to the destination IP address
      of the received Update Notification message.
   o  The destination address in the IP header MUST be set to the source
      address of the received Update Notification message.
   o  If IPsec ESP is used to protect signaling, the packet is processed
      using transport mode ESP.
   o  The format of the Update Notification Acknowledgement message sent
      over IPv4 and protected using ESP is shown below:






Krishnan, et al.         Expires April 11, 2014                [Page 14]

Internet-Draft            Update Notifications              October 2013


       IPv4 header (src=IPv4-Proxy-CoA, dst=IPv4-LMAA)
         ESP header (in transport mode)
           UDP header (sport=5436, dport=5436)
             Mobility Header (Update Notification Acknowledgement)
               (One or more Mobile Header Options)


   o  The format of the Update Notification Acknowledgement message sent
      over IPv6 and protected using ESP is shown below:


       IPv6 header (src=LMAA, dst=Proxy-CoA )
         Mobility Header (Update Notification Acknowledgement)
         ESP header (in transport mode)
           (One or more Mobile Header Options)



7.  Protocol Configuration Variables

   This specification defines the following configuration variables that
   controls the Update Notification feature.

   The mobility entities, local mobility anchor, and the mobile access
   gateway have to allow these variables to be configured by the system
   management.  The configured values for these protocol variables have
   to survive server reboots and service restarts.

   MAX_UPDATE_NOTIFICATION_RETRANSMIT_COUNT

      This variable specifies the maximum number of times a local
      mobility anchor can retransmit a Update Notification message
      before it receives an Update Notification Acknowledgement message.
      The default value for this parameter is 1.  The suggested range
      for this variable is to keep the configured value between 0 and 5.

   MIN_DELAY_BETWEEN_UPDATE_NOTIFICATION_REPLAY

      This variable specifies the minimum delay in seconds before an
      Update Notification message is retransmitted.  The default value
      for this parameter is 1000 milli-seconds.  The suggested range for
      this varaible is to keep the configured value between 500 and 5000
      milli-seconds.


8.  Security Considerations

   The Update Notification protocol described in this specification is



Krishnan, et al.         Expires April 11, 2014                [Page 15]

Internet-Draft            Update Notifications              October 2013


   for use between local mobility anchor and mobile access gateway.
   This specification defines two new mobility header messages, Update
   Notification and the Update Notification Acknowledgement messages.
   These mobility header messages are to be protected using the same
   security mechanism that is used for protecting the Proxy Mobile IPv6
   signaling messages exchanged between a given local mobility anchor
   and mobile access gateway.

   If IPsec is used, the IPsec security association that is used for
   protecting the Proxy Binding Update and Proxy Binding
   Acknowledgement, also needs to be used for protecting Update
   Notification and the Update Notification Acknowledgement messages.  A
   Proxy Mobile IPv6 implementation and the IPsec layer are typically
   able to communicate with each other through an implementation
   specific interface, for example, to exchange configuration and
   notification information.

   The traffic selectors associated with the Security Policy Database
   (SPD) entry for protecting Proxy Binding Update and Proxy Binding
   Acknowledgement messages (section 4.2, [RFC5213]) have to be extended
   to include the mobility header type values, <IANA-1> and <IANA-2>,
   allocated for Update Notification and Update Notification
   Acknowledgement messages.  Furthermore, any time there is rekeying of
   the IPsec security association between the mobile access gateway and
   the local mobility anchor, the newly established IPsec security
   association will be used for protecting the Update Notification and
   the Update Notification Acknowledgement messages.


9.  Acknowledgements

   The authors would like to thank Basavaraj Patil, Rajeev Koodli,
   Lionel Morand, Itsuma Tanaka, Rajesh Pazhyannur, Carlos Jesus
   Bernardos Cano, John Kaippallimalil, Brian Haberman and other members
   of the NETEXT working group for all the comments and discussions on
   the draft.

   The authors would like to thank Barry Leiba, Robert Sparks, Carlos
   Pignataro, Benoit Claise, Stephen Farrell and Jari Arkko for their
   inputs to the document as part of the IESG review proccess.


10.  IANA Considerations

   This document requires the following IANA actions.






Krishnan, et al.         Expires April 11, 2014                [Page 16]

Internet-Draft            Update Notifications              October 2013


   o  Action-1: This specification defines a new Mobility Header Type
      message, Update Notification.  This mobility header message is
      described in Section 4.1.  The type value <IANA-1> for this
      message needs to be allocated from the Mobility Header Types
      registry at http://www.iana.org/assignments/mobility-parameters.
      RFC Editor: Please replace <IANA-1> in Section 4.1 and Section 8
      with the assigned value, and update this section accordingly.
   o  Action-2: This specification defines a new Mobility Header Type
      message, Update Notification Acknowledgement.  This mobility
      header message is described in Section 4.2.  The type value
      <IANA-2> for this message needs to be allocated from the Mobility
      Header Types registry at
      http://www.iana.org/assignments/mobility-parameters.  RFC Editor:
      Please replace <IANA-2> in Section 4.2 and Section 8 with the
      assigned value, and update this section accordingly.
   o  Action-3: This specification defines a new registry for
      Notification Reasons.  It is called, "Update Notification Reasons
      Registry".  This registry should be created under "Mobile IPv6
      Parameters" registry at
      http://www.iana.org/assignments/mobility-parameters.  The
      Notification Reason is a field in the Update Notification message
      Section 4.1.  The number space for the Notification Reason field
      needs to be managed by IANA, under the Registry, Update
      Notification Reason Registry.  This specification reserves the
      following type values.  The allocation policy for this field is,
      "specification required".



   +=====+===========================+=======================+
   |Value|       Description         |     Reference         |
   +=====+===========================+=======================+
   | 0   | Reserved                  | <this draft>          |
   +=====+===================================================+
   | 1   | FORCE-REREGISTRATION      | <this draft>          |
   +=====+===================================================+
   | 2   | UPDATE-SESSION-PARAMETERS | <this draft>          |
   +=====+===================================================+
   | 3   | VENDOR-SPECIFIC-REASON    | <this draft>          |
   +=====+===================================================+
   | 4   | ANI-PARAMS-REQUESTED      | <this draft>          |
   +=====+===================================================+
   |255  | Reserved                  | <this draft>          |
   +=====+===================================================+







Krishnan, et al.         Expires April 11, 2014                [Page 17]

Internet-Draft            Update Notifications              October 2013


   o  Action-4: This specification defines a new registry for Status.
      It is called, "Update Notification Acknowledgement Status
      Registry".  This registry should be created under "Mobile IPv6
      Parameters" registry at
      http://www.iana.org/assignments/mobility-parameters.  The status
      is a field in the Update Notification Acknowledgement message
      Section 4.2.  The number space for the status field needs to be
      managed by IANA, under the Registry, Update Notification Status
      Registry.  This specification reserves the following type values.
      The allocation policy for this field is, "specification required".
      The status codes between 0 and 127 signify successful processing
      of the Update Notification message and codes between 128 and 255
      signify that an error occurred during processing of the Update
      Notification message.


   +=====+=====================================+=============+
   |Value|       Description                   |  Reference  |
   +=====+=====================================+=============+
   | 0   | SUCCESS                             | <this draft>|
   +=====+=====================================+=============+
   |128  | FAILED-TO-UPDATE-SESSION-PARAMETERS | <this draft>|
   +=====+=====================================+=============+
   |129  | MISSING-VENDOR-SPECIFIC-OPTION      | <this draft>|
   +=====+=====================================+=============+




11.  References

11.1.  Normative References

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

   [RFC4283]  Patel, A., Leung, K., Khalil, M., Akhtar, H., and K.
              Chowdhury, "Mobile Node Identifier Option for Mobile IPv6
              (MIPv6)", RFC 4283, November 2005.

   [RFC5094]  Devarapalli, V., Patel, A., and K. Leung, "Mobile IPv6
              Vendor Specific Option", RFC 5094, December 2007.

   [RFC5213]  Gundavelli, S., 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.



Krishnan, et al.         Expires April 11, 2014                [Page 18]

Internet-Draft            Update Notifications              October 2013


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

   [RFC6602]  Abinader, F., Gundavelli, S., Leung, K., Krishnan, S., and
              D. Premec, "Bulk Binding Update Support for Proxy Mobile
              IPv6", RFC 6602, May 2012.

11.2.  Informative References

   [I-D.ietf-netext-pmip6-qos]
              Liebsch, M., Seite, P., Yokota, H., Korhonen, J., and S.
              Gundavelli, "Quality of Service Option for Proxy Mobile
              IPv6", draft-ietf-netext-pmip6-qos-03 (work in progress),
              July 2013.

   [I-D.ietf-netext-pmipv6-flowmob]
              Bernardos, C., "Proxy Mobile IPv6 Extensions to Support
              Flow Mobility", draft-ietf-netext-pmipv6-flowmob-07 (work
              in progress), August 2013.

   [RFC5846]  Muhanna, A., Khalil, M., Gundavelli, S., Chowdhury, K.,
              and P. Yegani, "Binding Revocation for IPv6 Mobility",
              RFC 5846, June 2010.

   [RFC5847]  Devarapalli, V., Koodli, R., Lim, H., Kant, N., Krishnan,
              S., and J. Laganier, "Heartbeat Mechanism for Proxy Mobile
              IPv6", RFC 5847, June 2010.

   [RFC6757]  Gundavelli, S., Korhonen, J., Grayson, M., Leung, K., and
              R. Pazhyannur, "Access Network Identifier (ANI) Option for
              Proxy Mobile IPv6", RFC 6757, October 2012.

   [RFC6909]  Gundavelli, S., Zhou, X., Korhonen, J., Feige, G., and R.
              Koodli, "IPv4 Traffic Offload Selector Option for Proxy
              Mobile IPv6", RFC 6909, April 2013.


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




Krishnan, et al.         Expires April 11, 2014                [Page 19]

Internet-Draft            Update Notifications              October 2013


   Sri Gundavelli
   Cisco
   170 West Tasman Drive
   San Jose, CA  95134
   USA

   Email: sgundave@cisco.com


   Marco Liebsch
   NEC
   Kurfuersten-Anlage 36
   D-69115 Heidelberg
   Germany

   Email: marco.liebsch@neclab.eu


   Hidetoshi Yokota
   KDDI

   Email: yokota@kddilabs.jp


   Jouni Korhonen
   Renesas Mobile
   Porkkalankatu 24
   Helsinki  FIN-00180
   Finland

   Email: jouni.nospam@gmail.com




















Krishnan, et al.         Expires April 11, 2014                [Page 20]


Html markup produced by rfcmarkup 1.107, available from http://tools.ietf.org/tools/rfcmarkup/