Diameter Maintenance and                                J. Korhonen, Ed.
Extensions (DIME)                                            TeliaSonera                                 Nokia Siemens Networks
Internet-Draft                                              J. Bournelle
Intended status: Standards Track                             Orange Labs
Expires: May 22, July 13, 2009                                     H. Tschofenig
                                                  Nokia Siemens Networks
                                                              C. Perkins
                                                            K. Chowdhury
                                                        Starent Networks
                                                       November 18, 2008
                                                         January 9, 2009

  Diameter Mobile IPv6: Support for Network Access Server to Diameter
                           Server Interaction

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   A Mobile IPv6 node requires a home agent address, a home address, and
   a security association with its home agent before it can start
   utilizing Mobile IPv6.  RFC 3775 requires that some or all of these
   parameters are statically configured.  Mobile IPv6 bootstrapping work
   aims to make this information dynamically available to the Mobile
   Node.  An important aspect of the Mobile IPv6 bootstrapping solution
   is to support interworking with existing authentication,
   authorization and accounting infrastructure.  This document describes
   MIPv6 bootstrapping using the Diameter Network Access Server (NAS) to home
   Authentication, Authorization and Accounting server (HAAA) interface.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3  4
   2.  Terminology and Abbreviations  . . . . . . . . . . . . . . . .  3  4
   3.  Overview . . . . . . . . . . . . . . . . . . . . . . . . . . .  5  6
   4.  Commands, Attribute Value Pairs and Advertising
       Application Support  . . . . . . . . . . . . . . . . . . . . .  7
     4.1.  Advertising Application Support  . . . . . . . . . . . . .  7
     4.2.  Attribute Value Pair Definitions . . . . . . . . . . . . .  7
       4.2.1.  MIP6-Agent-Info  . . . . . . . . . . . . . . . . . . .  7
       4.2.2.  MIP-Home-Agent-Address AVP . . . . . . . . . . . . . .  8
       4.2.3.  MIP-Home-Agent-Host AVP  . . . . . . . . . . . . . . .  8
       4.2.4.  MIP6-Home-Link-Prefix AVP  . . . . . . . . . . . . . .  8  9
       4.2.5.  MIP6-Feature-Vector AVP  . . . . . . . . . . . . . . .  9
   5.  Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 11
     5.1.  Home Agent Assignment by the NAS . . . . . . . . . . . . . 10 11
     5.2.  Home Agent Assignment by the Diameter Server . . . . . . . 11 12
     5.3.  Home Agent Assignment by NAS or Diameter Server  . . . . . 12 13
   6.  Attribute Value Pair Occurrence Tables . . . . . . . . . . . . 13 14
   7.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 14
     7.1.  Registration of new AVPs . . . . . . . . . . . . . . . . . 14
     7.2.  New Registry: Mobility Capability  . . . . . . . . . . . . 14
   8.  Security Considerations  . . . . . . . . . . . . . . . . . . . 15
   9.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 15
   10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 16
     10.1. Normative References . . . . . . . . . . . . . . . . . . . 15 16
     10.2. Informative References . . . . . . . . . . . . . . . . . . 16
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17
   Intellectual Property and Copyright Statements . . . . . . . . . . 19

1.  Introduction

   The Mobile IPv6 (MIPv6) specification [RFC3775] requires a Mobile
   Node (MN) to perform registration with a home agent (HA) with
   information about its current point of attachment (care-of address).
   The HA creates and maintains the binding between the MN's Home
   Address and the MN's Care-of Address.

   In order to register with a HA, the MN needs to know some information
   such as the Home Link prefix, the HA address, the Home Address(es),
   the Home Link prefix length and security association related

   The aforementioned information may be statically configured.
   However, static provisioning becomes an administrative burden for an
   operator.  Moreover, it does not address load balancing, failover,
   opportunistic home link assignment or assignment of local HAs in
   close proximity to the MN.  Also the ability to react to sudden
   environmental or topological changes is minimal.  Static provisioning
   may not be desirable, in light of these limitations.

   Dynamic assignment of MIPv6 home registration information is a
   desirable feature for ease of deployment and network maintenance.
   For this purpose, the AAA infrastructure, which is used for access
   authentication, can be leveraged to assign some or all of the
   necessary parameters.  The Diameter server in the Access Service
   Provider's (ASP) or in the Mobility Service Provider's (MSP) network
   may return these parameters to the AAA client.  Regarding the
   bootstrapping procedures, the AAA client might either be the NAS, Network
   Access Server, in case of the integrated scenario, or the HA, in case
   of the split scenario [RFC5026].  The terms integrated and split are
   described in the terminology section and were introduced in [RFC4640]
   and [I-D.ietf-mext-aaa-ha-goals].

2.  Terminology and Abbreviations

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   document are to be interpreted as described in RFC2119 [RFC2119].

   General mobility terminology can be found in [RFC3753].  The
   following additional terms below are either borrowed from
   [RFC4640][RFC5026] or introduced in this document:

   Access Service Authorizer (ASA):

      A network operator that authenticates a MN and establishes the
      MN's authorization to receive Internet service.

   Access Service Provider (ASP):

      A network operator that provides direct IP packet forwarding to
      and from the MN.

   Mobility Service Authorizer (MSA):

      A service provider that authorizes MIPv6 service.

   Mobility Service Provider (MSP):

      A service provider that provides MIPv6 service.  In order to
      obtain such service, the MN must be authenticated and authorized
      to obtain the MIPv6 service.

   Split scenario:

      A scenario where the mobility service and the network access
      service are authorized by different entities.

   Integrated Scenario:

      A scenario where the mobility service and the network access
      service are authorized by the same entity.

   Network Access Server (NAS):

      A device that provides an access service for a user to a network.

   Home AAA (HAAA):

      An authentication, authorization and accounting server located in
      user's home network i.e., in the home realm.

   Local AAA (LAAA):

      An authentication, authorization and accounting proxy located in
      the local (ASP) network.

   Visited AAA (VAAA):

      An authentication, authorization and accounting proxy located in a
      visited network i.e., in the visited realm.  In a roaming case,
      the local Diameter proxy has the VAAA role (see Figure 1).

3.  Overview

   This document addresses the Authentication, Authorization and
   Accounting (AAA) functionality required for the MIPv6 bootstrapping
   solutions outlined in [RFC4640] and focuses on the Diameter based AAA
   functionality for the NAS to HAAA home AAA server (HAAA) communication.

   In the integrated scenario MIPv6 bootstrapping is provided as part of
   the network access authentication procedure.  Figure 1 shows the
   participating entities.

                      +---------------------------+  +-----------------+
                      |Access Service Provider    |  |ASA/MSA/(MSP)    |
                      |(Mobility Service Provider)|  |                 |
                      |                           |  |                 |
                      | +--------+                |  |    +--------+   |
                      | |Local   |      Diameter  |  |    |Home    |   |
                      | |Diameter|<---------------------->|Diameter|   |
                      | |Proxy   |         (*)    |  |    |Server  |   |
                      | +--------+                |  |    +--------+   |
                      |     ^ ^                   |  |        ^        |
                      |     | |                   |  |        |(+)     |
                      |     | |                   |  |        |        |
                      |   Diameter                |  |        v        |
                      |     | |(+)      +-------+ |  |    +-------+    |
                      |     | |         |Home   | |  |    |Home   |    |
                      |     | +-------->|Agent  | |  |    |Agent  |    |
                      |  (*)|           |in ASP | |  |    |in MSP |    |
                      |     v           +-------+ |  |    +-------+    |
   +-------+ IEEE     | +-----------+   +-------+ |  +-----------------+
   |Mobile | 802.1X   | |NAS/Relay  |   |DHCPv6 | |
   |Node   |------------|Diameter   |---|Server | |
   |       | PANA,    | |Client     |(+)|       | |
   +-------+ IKEv2,   | +-----------+   +-------+ |
             DHCP,... +---------------------------+

     (*): Functionality in scope of this specification
     (+): Extensions described in other documents.

      Figure 1: Mobile IPv6 Bootstrapping in the Integrated Scenario

   In a typical MIPv6 access scenario, a MN is attached to an ASP's
   network.  During the network attachment procedure, the MN interacts
   with the NAS/Diameter client.  Subsequently, the NAS/Diameter client
   interacts with the Diameter server over the NAS to HAAA interface.

   When the Diameter server performs the authentication and
   authorization for the network access it also determines whether the
   user is authorized to the MIPv6 service.  Based on the MIPv6 service
   authorization and user's policy profile, the Diameter server may
   return several MIPv6 bootstrapping related parameters to the NAS.
   The NAS to HAAA interface described in this document is not tied to
   DHCPv6 as the only mechanism to convey MIPv6 related configuration
   parameters from the NAS/Diameter client to the mobile node.

   While this specification addresses the bootstrapping of MIPv6 HA
   information and possibly the assignment of the home link prefix, it
   does not address how the Security Association (SA) between the MN and
   the HA for MIPv6 purposes is created.  The creation or the use of the
   SA between the MN and the HA takes places after the procedures
   described in this specification, and therefore are out of scope.

4.  Commands, Attribute Value Pairs and Advertising Application Support

4.1.  Advertising Application Support

   This document does not define a new application.  On the other hand
   it defines a number of AVPs used in the interface between NAS to HAAA
   for the integrated scenario of MIPv6 bootstrapping.  These AVPs can
   be used with any present and future Diameter applications, where
   permitted by the command ABNF.  The examples using existing
   applications and their commands in the following sections are for
   informational purposes only.  The examples in this document reuse the
   EAP [RFC4072] application and its respective commands.

4.2.  Attribute Value Pair Definitions

4.2.1.  MIP6-Agent-Info

   The MIP6-Agent-Info AVP (AVP code TBD) is type of Grouped and
   contains necessary information to assign a HA to the MN.  When the
   MIP6-Agent-Info AVP is present in a message, it MUST contain either
   the MIP-Home-Agent-Address AVP or the MIP-Home-Agent-Host AVP, or
   both AVPs.  The grouped AVP has the following ABNF (as defined in

   <MIP6-Agent-Info> ::= < AVP Header: TBD >
                       *2[ MIP-Home-Agent-Address ]
                         [ MIP-Home-Agent-Host ]
                         [ MIP6-Home-Link-Prefix ]
                       * [ AVP ]

   If both MIP-Home-Agent-Address and MIP-Home-Agent-Host APVs are
   present in the MIP6-Agent-Info, the MIP-Home-Agent-Address SHOULD
   have a precedence over the MIP-Home-Agent-Host.  The reason for this
   recommendation is that the MIP-Home-Agent-Address points to a
   specific home agent, where as the MIP-Home-Agent-Host may point to a
   group of HAs located at within the same realm.  A Diameter client or
   an agent may use the MIP-Home-Agent-Host AVP, for instance, to find
   out the realm where the HA is located.

   The ABNF allows returning up to two MIPv6 HA addresses.  This is an
   useful feature for deployments where the HA has both IPv6 and IPv4
   addresses, and particularly addresses Dual Stack Mobile IPv6
   (DSMIPv6) deployment scenarios [I-D.ietf-mext-nemo-v4traversal].

   This AVP MAY also be attached by the NAS or by intermediating
   Diameter proxies in a request message when sent to the Diameter
   server as a hint of a locally assigned HA.  This AVP MAY also be
   attached by the intermediating Diameter proxies in a reply message
   from the Diameter server, if locally assigned HAs are authorized by
   the Diameter server.  There MAY be multiple instances of the MIP6-
   Agent-Info AVPs in Diameter messages, for example in cases where the
   NAS receives a HA information from MN's home network and a locally
   allocated HA information from the visited network.  See Section 4.2.5
   for further discussion on possible scenarios.

4.2.2.  MIP-Home-Agent-Address AVP

   The MIP-Home-Agent-Address AVP (AVP Code 334 [RFC4004]) is of type
   Address and contains IPv6 or IPv4 address of the MIPv6 HA.  The
   Diameter server MAY decide to assign a HA to the MN that is in close
   proximity to the point of attachment (e.g., determined by the NAS-
   Identifier AVP).  There may be other reasons for dynamically
   assigning HAs to the MN, for example to share the traffic load.

4.2.3.  MIP-Home-Agent-Host AVP

   The MIP-Home-Agent-Host AVP (AVP Code 348 [RFC4004]) is of type
   Grouped and contains the identity of the assigned MIPv6 HA.  Both the
   Destination-Realm and the Destination-Host AVPs of the HA are
   included in the grouped AVP.  The usage of the MIP-Home-Agent-Host
   AVP is equivalent to the MIP-Home-Agent-Address AVP but offers an
   additional level of indirection by using the DNS infrastructure.  The
   Destination-Host AVP is used to identify a HA and the Destination-
   Realm AVP is used to identify the realm where the HA is located.

   Depending on the actual deployment and DNS configuration the
   Destination-Host AVP MAY represent one or more home agents.  It is
   RECOMMENDED that the Destination-Host AVP identifies exactly one HA.

   It is RECOMMENDED that the MIP-Home-Agent-Host AVP is always included
   in the MIP6-Agent-Info AVP.  In this way the HA IP address can be associated
   with the corresponding realm of the HA belongs to Diameter entity that added the
   MIP6-Agent-Info AVP using the Destination-Realm AVP included in the
   MIP-Home-Agent-Host AVP.

4.2.4.  MIP6-Home-Link-Prefix AVP

   The MIP6-Home-Link-Prefix AVP (AVP Code TBD) is of type OctetString
   and contains the Mobile IPv6 home network prefix information in a
   network byte order.  The home network prefix MUST be encoded as the
   8-bit prefix length information (one octet) followed by the 128-bit
   field (16 octets) for the available home network prefix.  The
   trailing bits of the IPv6 prefix after the prefix length bits MUST be
   set to zero (e.g., if the prefix length is 60, then the remaining 68
   bits MUST be set to zero).

   The HAAA MAY act as a central entity managing prefixes for MNs.  In
   this case, the HAAA returns to the NAS the prefix allocated for the MN and
   returns it to the NAS.
   MN.  The NAS/ASP uses then, for example, delivers then the home link prefix to the MN using
   e.g. mechanisms described in [I-D.ietf-mip6-bootstrapping-integrated-dhc]
   [I-D.ietf-mip6-bootstrapping-integrated-dhc].  The NAS/ASP MAY
   propose to deliver the home link HAAA a specific prefix to allocate to the MN. MN by
   including the MIP6-Home-Link-Prefix AVP in the request message.
   However, the HAAA MAY override the prefix allocation hint proposed by
   the NAS/ASP and return a different prefix in the response message.

4.2.5.  MIP6-Feature-Vector AVP

   The MIP6-Feature-Vector AVP (AVP Code TBD) is of type Unsigned64 and
   contains a 64 bit flags field of supported capabilities of the NAS/
   ASP.  Sending and receiving the MIP6-Feature-Vector AVP with value 0
   MUST be supported, although that does not provide much guidance about
   specific needs of bootstrapping.

   The NAS MAY include this AVP to indicate capabilities of the NAS/ASP
   to the Diameter server.  For example, the NAS may indicate that a
   local HA can be provided.  Similarly, the Diameter server MAY include
   this AVP to inform the NAS/ASP about which of the NAS/ASP indicated
   capabilities are supported or authorized by the ASA/MSA(/MSP).

   The following capabilities are defined in this document:

   MIP6_INTEGRATED (0x0000000000000001)

      When this flag is set by the NAS then it means that the Mobile
      IPv6 integrated scenario bootstrapping functionality is supported
      by the NAS.  When this flag is set by the Diameter server then the
      Mobile IPv6 integrated scenario bootstrapping is supported by the
      Diameter server.

   LOCAL_HOME_AGENT_ASSIGNMENT (0x0000000000000002)

      When this flag is set in the request message, a local home agent
      outside the home realm is requested and may be assigned to the MN.
      When this flag is set by the Diameter server in the answer
      message, then the assignment of local HAs is authorized by the
      Diameter server.

      A local HA may be assigned by the NAS, LAAA or VAAA depending on
      the network architecture and the deployment.

   The following examples show how the LOCAL_HOME_AGENT_ASSIGNMENT
   (referred as LOCAL-bit in the examples) capability and the MIP-Agent-
   Info AVP (referred as HA-Info in the examples) are used to assign
   HAs, either a local HA (L-HA) or a home network HA (H-HA).  Below is
   an example of a request message combinations as seen by the HAAA:

    LOCAL-bit  HA-Info  Meaning

      0          -      ASP or [LV]AAA is not able to assign a L-HA
      0         L-HA    Same as above. HA-Info must be ignored
      1          -      ASP or [LV]AAA can/wishes to assign a L-HA
      1         L-HA    Same as above but ASP or [LV]AAA also
                        provides a hint of the assigned L-HA

   Then the same as above for an answer message combinations as seen by
   the NAS:

    LOCAL-bit  HA-Info  Meaning

      0          -      No HA assignment allowed for HAAA or [LV]AAA
      0         H-HA    L-HA is not allowed. HAAA assigns a H-HA
      1          -      L-HA is allowed. No HAAA or [LV]AAA assigned HA
      1         L-HA    L-HA is allowed. [LV]AAA also assigns a L-HA
      1         H-HA    L-HA is allowed. HAAA also assigns a HA
      1         H-HA    L-HA is allowed. HAAA assigns a H-HA and
              + L-HA    [LV]AAA also assigns also a L-HA
   A NAS should expect to possible receive multiple of the MIP6-Agent-
   Info AVPs.

5.  Examples

5.1.  Home Agent Assignment by the NAS

   In this scenario we consider the case where the NAS wishes to
   allocate a local HA to the MN.  The NAS will also inform the Diameter
   server about the HA address it has assigned to the visiting MN (e.g.,
   2001:db8:1:c020::1).  The Diameter-EAP-Request message therefore has
   the MIP6-Feature-Vector with the LOCAL_HOME_AGENT_ASSIGNMENT and the
   MIP6_INTEGRATED set.  The MIP6-Agent-Info AVP contains the MIP-Home-
   Agent-Address AVP with the address of the proposed HA.

   NAS/VAAA                                                       Server
    |                                                                 |
    |  Diameter-EAP-Request                                           |
    |  MIP6-Feature-Vector=(LOCAL_HOME_AGENT_ASSIGNMENT               |
    |                       | MIP6_INTEGRATED)                        |
    |  MIP6-Agent-Info{                                               |
    |       MIP-Home-Agent-Address(2001:db8:1:c020::1)}               |
    |  }                                                              |
    |  Auth-Request-Type=AUTHORIZE_AUTHENTICATE                       |
    |  EAP-Payload(EAP Start)                                         |
    |                                                                 |
    |                                                                 |
    :              ...more EAP Request/Response pairs...              :
    |                                                                 |
    |                                                                 |
    |                                            Diameter-EAP-Answer  |
    |               MIP6-Feature-Vector=(LOCAL_HOME_AGENT_ASSIGNMENT  |
    |                                    | MIP6_INTEGRATED)           |
    |                                   Result-Code=DIAMETER_SUCCESS  |
    |                                       EAP-Payload(EAP Success)  |
    |                                         EAP-Master-Session-Key  |
    |                                           (authorization AVPs)  |
    |                                                           ...   |
    |                                                                 |

                  Figure 2: Home Agent Assignment by NAS

   Depending on the Diameter server configuration and user's
   subscription profile, the Diameter server either accepts or rejects
   the local HA allocated by the NAS.  In our example, the Diameter
   server accepts the proposal and the the MIP6-Feature-Vector AVP with
   flag) is set and returned to the NAS.

5.2.  Home Agent Assignment by the Diameter Server

   In this scenario we consider the case where the NAS supports the
   Diameter MIPv6 integrated scenario as defined in this document but
   does not offer local HA assignment.  Hence, the MIP6-Feature-Vector
   AVP only has the MIP6_INTEGRATED flag set.  The Diameter server
   allocates a HA to the mobile node and conveys the address in the MIP-
   Home-Agent-Address AVP that is encapsulated in the MIP6-Agent-Info
   AVP.  Additionally, the MIP6-Feature-Vector AVP has the
   MIP6_INTEGRATED flag set.

   NAS                                                            Server
    |                                                                 |
    |  Diameter-EAP-Request                                           |
    |  MIP6-Feature-Vector=(MIP6_INTEGRATED)                          |
    |  Auth-Request-Type=AUTHORIZE_AUTHENTICATE                       |
    |  EAP-Payload(EAP Start)                                         |
    |                                                                 |
    |                                                                 |
    :              ...more EAP Request/Response pairs...              :
    |                                                                 |
    |                                                                 |
    |                                            Diameter-EAP-Answer  |
    |                                               MIP6-Agent-Info{  |
    |            MIP-Home-Agent-Address(2001:db8:6000:302::1)         |
    |                                                              }  |
    |                          MIP6-Feature-Vector=(MIP6_INTEGRATED)  |
    |                                   Result-Code=DIAMETER_SUCCESS  |
    |                                       EAP-Payload(EAP Success)  |
    |                                         EAP-Master-Session-Key  |
    |                                           (authorization AVPs)  |
    |                                                           ...   |
    |                                                                 |

            Figure 3: Home Agent Assignment by Diameter Server

5.3.  Home Agent Assignment by NAS or Diameter Server

   This section shows another message flow for the MIPv6 integrated
   scenario bootstrapping where the NAS informs the Diameter server that
   it is able to locally assign a HA to the MN.  The Diameter server is
   able to provide a HA to the MN but also authorizes the assignment of
   local HA.  The Diameter server then replies to the NAS with HA
   related bootstrapping information.

   Whether the NAS/ASP then offers a locally assigned HA or the Diameter
   server assigned HA to the MN is, in this example, based on the local
   ASP policy.

   NAS/VAAA                                                       Server
    |                                                                 |
    |  Diameter-EAP-Request                                           |
    |  MIP6-Feature-Vector=(LOCAL_HOME_AGENT_ASSIGNMENT               |
    |                       | MIP6_INTEGRATED)                        |
    |  MIP6-Agent-Info{                                               |
    |       MIP-Home-Agent-Address(2001:db8:1:c020::1)}               |
    |  }                                                              |
    |  Auth-Request-Type=AUTHORIZE_AUTHENTICATE                       |
    |  EAP-Payload(EAP Start)                                         |
    |                                                                 |
    |                                                                 |
    :              ...more EAP Request/Response pairs...              :
    |                                                                 |
    |                                                                 |
    |                                            Diameter-EAP-Answer  |
    |                                               MIP6-Agent-Info{  |
    |                  MIP-Home-Agent-Address(2001:db8:6000:302::1)}  |
    |               MIP6-Feature-Vector=(LOCAL_HOME_AGENT_ASSIGNMENT  |
    |                                    | MIP6_INTEGRATED)           |
    |                                   Result-Code=DIAMETER_SUCCESS  |
    |                                       EAP-Payload(EAP Success)  |
    |                                         EAP-Master-Session-Key  |
    |                                           (authorization AVPs)  |
    |                                                           ...   |
    |                                                                 |

         Figure 4: Home Agent Assignment by NAS or Diameter Server

   If the Diameter server does not allow the MN to use a locally
   assigned HA, the Diameter returns the MIP6-Feature-Vector AVP with
   the LOCAL_HOME_AGENT_ASSIGNMENT bit unset and HA address it allocated
   to the MN.

6.  Attribute Value Pair Occurrence Tables

   Figure 5 lists the MIPv6 bootstrapping NAS to HAAA interface AVPs,
   along with a specification determining how many of each new AVP may
   be included in a Diameter command.  They may be present in any
   Diameter application request and answer commands, where permitted by
   the command ABNF.

                                     |  Command  |
      Attribute Name                 | Req | Ans |
      MIP6-Agent-Info                | 0+  | 0+  |
      MIP6-Feature-Vector            | 0-1 | 0-1 |
      MIP6-Home-Link-Prefix          | 0+  | 0+  |

          Figure 5: Generic Request and Answer Commands AVP Table

7.  IANA Considerations

7.1.  Registration of new AVPs

   This specification defines the following new AVPs to be allocated
   from a normal Diameter AVP Code space (values >= 256):

     MIP6-Agent-Info                is set to TBD

   The following new AVPs are to be allocated from RADIUS Type Code
   [RFC2865] space so that they are RADIUS backward compatible (AVP Code
   values between 0-255):

     MIP6-Feature-Vector            is set to TBD
     MIP6-Home-Link-Prefix          is set to TBD

7.2.  New Registry: Mobility Capability

   IANA is requested to create a new registry for the Mobility
   Capability as described in Section 4.2.5.

   Token                             | Value               | Description
   MIP6_INTEGRATED                   | 0x0000000000000001  | [RFC TBD]
   LOCAL_HOME_AGENT_ASSIGNMENT       | 0x0000000000000002  | [RFC TBD]
   Available for Assignment via IANA | 2^x                 |

   Allocation rule: Only numeric values that are 2^x (power of two,
   where x >= 2) are allowed based on the allocation policy described

   Following the example policies described in [RFC5226] new values for
   the MIP6-Feature-Vector AVP will be assigned based on the
   "Specification Required" policy.  No mechanism to mark entries as
   "deprecated" is envisioned.

8.  Security Considerations

   The security considerations for the Diameter interaction required to
   accomplish the integrated scenario are described in
   [I-D.ietf-mip6-bootstrapping-integrated-dhc].  Additionally, the
   security considerations of the Diameter base protocol [RFC3588],
   Diameter NASREQ application [RFC4005] / Diameter EAP [RFC4072]
   application (with respect to network access authentication and the
   transport of keying material) are applicable to this document.
   Developers should insure that special attention is paid to
   configuring the security associations protecting the messages that
   enables the global positioning and allocation of home agents, for
   instance, as outlined in section 5.

   Furthermore, the Diameter messages may be transported between the NAS
   and the RADIUS Diameter server via one or more AAA brokers or Diameter
   agents (such as proxies).  In this case the NAS to the Diameter
   server AAA communication rely on the security properties of the
   intermediate AAA brokers and Diameter agents.

9.  Acknowledgements

   This document is heavily based on the ongoing work for RADIUS MIPv6
   interaction.  Hence, credits go to respective authors for their work
   with draft-ietf-mip6-radius.  Furthermore, the author would like to
   thank the authors of draft-le-aaa-diameter-mobileipv6 (Franck Le,
   Basavaraj Patil, Charles E. Perkins, Stefano Faccin) for their work
   in context of MIPv6 Diameter interworking.  Their work influenced
   this document.  Jouni Korhonen would like to thank Academy of Finland
   and TEKES MERCoNe Project for providing funding to work on this
   document while he was with TeliaSonera.  Julien Bournelle would like
   to thank GET/INT since he began to work on this document while he was
   in their employ.  Authors would also like to acknowledge Raymond Hsu
   for his valuable feedback on local HA assignment and Wolfgang
   Fritsche for his thorough review.  Finally, we would like to Domagoj
   Premec for his review comments.

   We would like to thank Alper Yegin, Robert Marks, David Frascone for
   their comments at the second WGLC.

10.  References

10.1.  Normative References

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

   [RFC2685]  Fox, B. and B. Gleeson, "Virtual Private Networks

   [RFC2865]  Rigney, C., Willens, S., Rubens, A., and W. Simpson,
              "Remote Authentication Dial In User Service (RADIUS)",
              RFC 2685, September 1999. 2865, June 2000.

   [RFC3588]  Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J.
              Arkko, "Diameter Base Protocol", RFC 3588, September 2003.

   [RFC3775]  Johnson, D., Perkins, C., and J. Arkko, "Mobility Support
              in IPv6", RFC 3775, June 2004.

   [RFC4004]  Calhoun, P., Johansson, T., Perkins, C., Hiller, T., and
              P. McCann, "Diameter Mobile IPv4 Application", RFC 4004,
              August 2005.

   [RFC4005]  Calhoun, P., Zorn, G., Spence, D., and D. Mitton,
              "Diameter Network Access Server Application", RFC 4005,
              August 2005.

   [RFC4072]  Eronen, P., Hiller, T., and G. Zorn, "Diameter Extensible
              Authentication Protocol (EAP) Application", RFC 4072,
              August 2005.

10.2.  Informative References

              Giaretta, G., Guardini, I., Demaria, E., Bournelle, J.,
              and R. Lopez, "AAA Goals for Mobile IPv6",
              draft-ietf-mext-aaa-ha-goals-01 (work in progress),
              May 2008.

              Soliman, H., "Mobile IPv6 Support for Dual Stack Hosts and
              Routers", draft-ietf-mext-nemo-v4traversal-06
              Routers (DSMIPv6)", draft-ietf-mext-nemo-v4traversal-07
              (work in progress), November December 2008.

              Chowdhury, K. and A. Yegin, "MIP6-bootstrapping for the
              Integrated Scenario",
              draft-ietf-mip6-bootstrapping-integrated-dhc-06 (work in
              progress), April 2008.

   [RFC3753]  Manner, J. and M. Kojo, "Mobility Related Terminology",
              RFC 3753, June 2004.

   [RFC4640]  Patel, A. and G. Giaretta, "Problem Statement for
              bootstrapping Mobile IPv6 (MIPv6)", RFC 4640,
              September 2006.

   [RFC5026]  Giaretta, G., Kempf, J., and V. Devarapalli, "Mobile IPv6
              Bootstrapping in Split Scenario", RFC 5026, October 2007.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
              May 2008.

Authors' Addresses

   Jouni Korhonen (editor)
   Teollisuuskatu 13
   Sonera  FIN-00051
   Nokia Siemens Networks
   Linnoitustie 6
   Espoo  FIN-02600

   Email: jouni.nospam@gmail.com

   Julien Bournelle
   Orange Labs
   38-4O rue du general Leclerc
   Issy-Les-Moulineaux  92794

   Email: julien.bournelle@orange-ftgroup.com
   Hannes Tschofenig
   Nokia Siemens Networks
   Linnoitustie 6
   Espoo  02600

   Phone: +358 (50) 4871445

   Email: Hannes.Tschofenig@nsn.com
   URI:   http://www.tschofenig.priv.at

   Charles E. Perkins

   Phone: +1-650-496-4402

   Email: charliep@wichorus.com

   Kuntal Chowdhury
   Starent Networks
   30 International Place
   Tewksbury  MA  01876

   Phone: +1 214 550 1416

   Email: kchowdhury@starentnetworks.com

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