Internet DRAFT - draft-ietf-netext-rfc5149bis

draft-ietf-netext-rfc5149bis






Network-Based Mobility Extensions                            J. Korhonen
(Netext)                                          Nokia Siemens Networks
Internet-Draft                                                U. Nilsson
Obsoletes: 5149 (if approved)                                TeliaSonera
Updates: 5213 (if approved)                               V. Devarapalli
Intended status: Standards Track                          August 2, 2012
Expires: February 3, 2013


        Service Selection for Mobile IPv6 and Proxy Mobile IPv6
                  draft-ietf-netext-rfc5149bis-02.txt

Abstract

   In some Mobile IPv6 deployments, identifying the mobile node or the
   mobility service subscriber is not enough to distinguish between
   multiple services possibly provisioned to the mobile node and its
   mobility service subscription.  A capability to specify different
   services in addition to the mobile node identity can be leveraged to
   provide flexibility for mobility service providers on provisioning
   multiple services to one mobility service subscription.  This
   document describes a Service Selection Mobility Option for both
   conventional Mobile IPv6 and Proxy Mobile IPv6 that is intended to
   assist home agents and local mobility agents to make a specific
   service selection for the mobility service subscription during the
   binding registration procedure.  This specification updates RFC5213
   and obsoletes RFC5149.

Requirements

   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].

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."



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   This Internet-Draft will expire on February 3, 2013.

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
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   described in the Simplified BSD License.



































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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2.  Service Selection Mobility Option  . . . . . . . . . . . . . .  5
   3.  Processing Considerations  . . . . . . . . . . . . . . . . . .  6
     3.1.  Binding Cache Entry Lookup Considerations  . . . . . . . .  6
     3.2.  Mobile Node Considerations . . . . . . . . . . . . . . . .  7
     3.3.  Home Agent and Local Mobility Agent Considerations . . . .  7
     3.4.  Correspondent Node Considerations  . . . . . . . . . . . .  8
   4.  Configuration Objects  . . . . . . . . . . . . . . . . . . . .  9
   5.  Security Considerations  . . . . . . . . . . . . . . . . . . .  9
   6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  9
   7.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
     7.1.  Normative references . . . . . . . . . . . . . . . . . . . 10
     7.2.  Informative references . . . . . . . . . . . . . . . . . . 10
   Appendix A.  Changes from RFC5149  . . . . . . . . . . . . . . . . 11
     A.1.  Service Selection option in a PBA  . . . . . . . . . . . . 11
     A.2.  Service Selection Identifier encoding  . . . . . . . . . . 11
     A.3.  Using Service Selection as a BCE lookup key  . . . . . . . 11
     A.4.  Addition of a new Status Code  . . . . . . . . . . . . . . 11
     A.5.  Change of the document category from Informational to
           Standards Track  . . . . . . . . . . . . . . . . . . . . . 11
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12




























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1.  Introduction

   Mobile IPv6 [RFC6275] can identify mobile nodes in various ways,
   including home addresses, Network Access Identifiers (NAIs)
   [RFC4282][RFC4283], and credentials suitable for the Internet Key
   Exchange Protocol version 2 (IKEv2) [RFC4877].  Proxy Mobile IPv6
   [RFC5213] uses Home Network Prefix (HNP) and/or Mobile Node
   Identifier [RFC4283].  In some Mobile IPv6 deployments, identifying
   the mobile node or the mobility service subscriber via a Proxy Mobile
   IPv6 client [RFC5213] (hereafter, the mobile node and the Proxy
   Mobile IPv6 client are used interchangeably) is not enough to
   distinguish between multiple services possibly provisioned to the
   mobile node .

   The capability to specify different services in addition to the
   mobile node identity can be leveraged to provide flexibility for
   mobility service providers to provide multiple services within the
   same mobility service subscription.  For example:

   o  Provide an enterprise data access for which the mobility service
      provider hosts connectivity and mobility services on behalf of the
      enterprise.

   o  Provide access to service domains that are otherwise not
      accessible from public networks because of some mobility service
      provider's business reasons.

   o  Provide simultaneous access to different service domains that are
      separated based on policies of the mobility service provider.

   o  Enable easier policy and quality of service assignment for
      mobility service providers based on the subscribed services.

   o  In the absence of a specifically indicated service, the home agent
      MUST act as if the default service, plain Internet access, had
      been requested.  There is no absolute requirement that this
      default service be allowed to all subscribers, but it is highly
      RECOMMENDED in order to avoid having normal subscribers employ
      operator-specific configuration values in order to get basic
      service.

   This document describes a Service Selection Mobility Option for
   (Proxy) Mobile IPv6 that is intended to assist home agents or local
   mobility agents to make specific service selections for the mobility
   service subscription during the binding registration procedure.  The
   service selection may affect home agent or local mobility agent
   routing decisions, Home Address or Home Network Prefix assignment
   policies, firewall settings, charging and security policies among



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   others.  The Service Selection option should be used in every (Proxy)
   Binding Update or Acknowledgement message.

   Some of the potential use-cases were listed earlier in this section.
   The general aim is better manageability of services and service
   provisioning from the point of view of both operators and service
   providers.  However, it should be understood that there are potential
   deployment possibilities where selecting a certain service may
   restrict simultaneous access to other services from a user's point of
   view.  For example, services may be located in different
   administrative domains or external customer networks that practice
   excessive filtering of inbound and outbound traffic.

   There are existing deployments using the Service Selection option.
   3GPP PMIPv6-based Evolved Packet Core (EPC) [RFC6459] deployments use
   the Service Selection option to carry the Access Point Name (APN)
   [TS.23003].  Recently, service provider Wi-Fi services over
   residential architectures [I-D.gundavelli-v6ops-community-wifi-svcs]
   that intend to integrate into e.g., 3GPP EPC using PMIPv6, need
   Service Selection option again to carry the APN information for
   identifying a particular routing domain.


2.  Service Selection Mobility Option

   At most one Service Selection Mobility option SHOULD be included in
   any (Proxy) Binding Update message.  If and only if the (Proxy)
   Binding Update message included the Service Selection Option, then
   the corresponding (Proxy) Binding Acknowledgement message SHOULD also
   contain the Service Selection option with the service name in the
   Identifier.

   If the (Proxy) Binding Update message includes any authorization-
   related options (such as the Binding Authorization Data option
   [RFC6275]) or authentication related options (such as the Mobility
   Message Authentication option [RFC4285]), then the Service Selection
   option MUST appear before any mobility message authorization- or
   authentication-related options.

   The Service Selection option SHOULD NOT be sent to a correspondent
   node.  The mobile node cannot assume that the correspondent node has
   any knowledge about a specific service selection made between the
   mobile node and the home agent.

   The Service Selection option has no alignment requirement as such.






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    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 = 20    |   Length      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Identifier...                                                 ~
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                Figure 1: Service Selection Mobility Option

   o  Type: 8-bit identifier set to 20 of the type of the skipable
      mobility option.

   o  Length: 8-bit unsigned integer, representing the length of the
      Service Selection Mobility Option in octets, excluding the Option
      Type and Option Length fields.  A value of zero (0) is not
      allowed.

   o  Identifier: A variable-length encoded service identifier string
      used to identify the requested service.  The identifier string
      length is between 1 and 255 octets.  This specification allows
      international identifier strings that are based on the use of
      Unicode characters, encoded as UTF-8 [RFC3269], and formatted
      using Normalization Form KC (NFKC) as specified in [NFKC].

      Alternatively, based on the local configuration, the identifier
      string can be encoded using the domain name style encoding
      described in Section 3.1 of [RFC1035].  However, the terminating
      length of zero octet (i.e. the '\0' octet) is not included into
      the encoded identifier since the option length implicitly tells
      when the identifier string ends [TS.23003].  The selection of the
      encoding is controlled by the ServiceSelectionMobilityOptionFormat
      configuration object, see Section 4.

      'ims', 'voip', and 'voip.companyxyz.example.com' are valid
      examples of Service Selection option Identifiers.  At minimum, the
      Identifier MUST be unique among the home agents to which the
      mobile node is authorized to register.



3.  Processing Considerations

3.1.  Binding Cache Entry Lookup Considerations

   Section 5.4.1 of [RFC5213] describes various Binding Cache Entry
   (BCE) lookup variations in the local mobility agent.  Some existing
   Proxy Mobile IPv6 deployments have added the Service Selection option



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   as one of the used BCE lookup keys.  This implies that the Service
   Selection option SHOULD be included in all Proxy Binding Update
   messages, especially when the Home Network Prefix is not readily
   available.

3.2.  Mobile Node Considerations

   A mobile node or a Proxy Mobile IPv6 client MAY include, at most, one
   Service Selection Mobility Option into a (Proxy) Binding Update
   message.  The option is used to identify the service to be associated
   with the binding registration and SHOULD only be included into the
   initial Binding Update message sent to a home agent.  If the mobile
   node wishes to change the selected service, it is RECOMMENDED that
   the mobile node de-register the existing binding with the home agent
   before proceeding with a binding registration for a different
   service.  The provisioning of the service identifiers to the mobile
   node or to the Proxy Mobile IPv6 client is out of the scope of this
   specification.

   The placement of the Service Selection option is as follows: when
   present, this option MUST appear after the Mobile Node-Network Access
   Identifier (MN-NAI) option, if the MN-NAI option is present, and
   before any authorization- and authentication-related options.  The
   Service Selection option can be used with any mobile node
   identification method such as a home address, an MN-NAI, and
   credentials suitable for IKEv2.

   If the mobile node receives a (Proxy) Binding Acknowledgement with a
   Status Code set to SERVICE_AUTHORIZATION_FAILED and the mobile node
   has an existing binding with the Home Address or the Home Network
   Prefix used in the failed (Proxy) Binding Update message, the mobile
   node MUST delete the existing binding.  If there is no existing
   binding, the mobile node proceeds as with any failed initial binding
   registration.

   If the mobile node receives a (Proxy) Binding Acknowledgement with a
   Status Code set to MISSING_OR_UNKNOWN_SERVICE the mobile node
   proceeds as with any failed initial binding registration.  The mobile
   node SHOULD log the event as it is usually an indication of a
   configuration error.

3.3.  Home Agent and Local Mobility Agent Considerations

   Upon receiving a (Proxy) Binding Update message with a Service
   Selection option, the home agent or the local mobility agent
   authenticates and authorizes the mobile node.  If the home agent or
   the local mobility anchor supports the Service Selection and the
   Service Selection is required by the local policy, the home agent or



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   the local mobility anchor MUST also verify that the mobile node is
   authorized for the service it included in the Service Selection
   option.  The services the mobile node is authorized for SHOULD be
   part of the general mobile node subscription profile.  If the mobile
   node is not authorized for the service, the home agent or the local
   mobility agent MUST deny the registration and send a (Proxy) Binding
   Acknowledgement with a Status Code set to
   SERVICE_AUTHORIZATION_FAILED (151).  If the (Proxy) Binding Update
   does not contain the Service Selection option or the indicated
   service is unknown, the home agent or the local mobility agent SHOULD
   deny the registration and send a (Proxy) Binding Acknowledgement with
   a Status Code set to MISSING_OR_UNKNOWN_SERVICE (TBD).

   If binding registration was successful in the home agent or the local
   mobility agent, then the (Proxy) Binding Acknowledgement SHOULD
   contain the Service Selection option with the service name in the
   Identifier.

   The Service Selection option is used to assist the authorization and
   identifies a specific service that is to be authorized.  The Service
   Selection option MAY also affect the Home Address or the Home Network
   Prefix allocation when, for example, used with the MN-NAI option.
   For example, for the same NAI there MAY be different Home Addresses
   or Home Network Prefixes depending on the identified service.
   Furthermore, the Service Selection option MAY also affect the routing
   of the outbound IP packets in the home agent or the local mobility
   agent depending on the selected service.  The home agent MAY also
   apply different policy or quality of service treatment to traffic
   flows based on the selected service.

   If the newly arrived (Proxy) Binding Update message with a Service
   Selection option indicates a change in the selected service, then the
   home agent MUST re-authorize the mobile node.  Depending on the home
   agent or the local mobility agent policies, the services policies,
   Home Address or Home Network Prefix allocation policies, and the
   subscription policies, the home agent may or may not be able to
   authorize the mobile node to the new service.  For example, the
   existing service and the new service could require different Home
   Network Prefixes.  If the authorization fails, then the home agent or
   the local mobility agent MUST deny the registration, delete any
   binding with the existing Home Address or Home Network Prefix, and
   send a (Proxy) Binding Acknowledgement with a Status Code set to
   SERVICE_AUTHORIZATION_FAILED (151).

3.4.  Correspondent Node Considerations

   Unless the correspondent node and the home agent share the same
   knowledge about mobility services, the Service Selection option is



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   more or less useless information to the correspondent node.  The
   correspondent node SHOULD silently ignore the Service Selection
   option in this case.

   There are deployment cases where the home agent and a correspondent
   node, for example, belong to the same administrative domain.  In this
   case, it is possible that the correspondent node shares the same
   knowledge of the services as the home agent.  Therefore, the
   correspondent node is, for example, able to provide service-based
   traffic handling to mobile nodes.


4.  Configuration Objects

   This specification defines one configuration object that controls the
   encoding of the service identifier string.

   ServiceSelectionMobilityOptionFormat

      This configuration object is available in both a MAG and in a LMA.
      When set to 'label', the PMIPv6 node encodes the service
      identifier string using [RFC1035] domain name encoding.  When set
      to 'dotted', the PMIPv6 node encodes the service identifier string
      as any UTF-8 string.


5.  Security Considerations

   The protection for the Service Selection Mobility Option depends on
   the service that is being identified and eventually selected.  If the
   service selection information should not be revealed on the wire,
   (Proxy) Binding Updates and (Proxy) Binding Acknowledgements should
   use Encapsulating Security Payload (ESP) [RFC4303] in transport mode
   with a non-null encryption transform to provide message
   confidentiality.


6.  IANA Considerations

   A Mobile IPv6 Mobility Option type has been assigned for the
   following new mobility option from [RFC6275] "Mobility Options"
   registry.  The mobility option is defined in Section 2:

      Service Selection Mobility Option       is set to 20

   A Mobile IPv6 registration denied by home agent Status Code has been
   assigned.  The Status Code was allocated from the range 128-255:




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      SERVICE_AUTHORIZATION_FAILED            is set to 151
      MISSING_OR_UNKNOWN_SERVICE              is set to TBD


7.  References

7.1.  Normative references

   [NFKC]     Davis, M. and M. Durst, "Unicode Standard Annex #15;
              Unicode Normalization Forms", Unicode 5.0.0, October 2006.

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

   [RFC5213]  Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K.,
              and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008.

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

7.2.  Informative references

   [I-D.gundavelli-v6ops-community-wifi-svcs]
              Gundavelli, S., Grayson, M., Seite, P., and Y. Lee,
              "Service Provider Wi-Fi Services Over Residential
              Architectures",
              draft-gundavelli-v6ops-community-wifi-svcs-04 (work in
              progress), April 2012.

   [RFC1035]  Mockapetris, P., "Domain names - implementation and
              specification", STD 13, RFC 1035, November 1987.

   [RFC3269]  Kermode, R. and L. Vicisano, "Author Guidelines for
              Reliable Multicast Transport (RMT) Building Blocks and
              Protocol Instantiation documents", RFC 3269, April 2002.

   [RFC4282]  Aboba, B., Beadles, M., Arkko, J., and P. Eronen, "The
              Network Access Identifier", RFC 4282, December 2005.

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

   [RFC4285]  Patel, A., Leung, K., Khalil, M., Akhtar, H., and K.
              Chowdhury, "Authentication Protocol for Mobile IPv6",
              RFC 4285, January 2006.

   [RFC4303]  Kent, S., "IP Encapsulating Security Payload (ESP)",



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              RFC 4303, December 2005.

   [RFC4877]  Devarapalli, V. and F. Dupont, "Mobile IPv6 Operation with
              IKEv2 and the Revised IPsec Architecture", RFC 4877,
              April 2007.

   [RFC6459]  Korhonen, J., Soininen, J., Patil, B., Savolainen, T.,
              Bajko, G., and K. Iisakkila, "IPv6 in 3rd Generation
              Partnership Project (3GPP) Evolved Packet System (EPS)",
              RFC 6459, January 2012.

   [TS.23003]
              3GPP, "Numbering, addressing and identification", 3GPP
              TS 23.003 10.2.0, June 2011.


Appendix A.  Changes from RFC5149

A.1.  Service Selection option in a PBA

   3GPP EPC PMIPv6-based interfaces echo the Service Selection option
   always back in Proxy Binding Acknowledgements.  This is clarified
   from the RFC5149, which did not say anything about the Service
   Selection option in Proxy Binding Acknowledgement messages.

A.2.  Service Selection Identifier encoding

   3GPP EPC decided to encode their Service Selection Identifiers using
   the [RFC1035] domain name style encoding [TS.23003].  Implementations
   has to take this into account when they intend to interoperate with
   3GPP EPC.

A.3.  Using Service Selection as a BCE lookup key

   3GPP EPC use the Service Selection option as one of the BCE lookup
   keys.  This is additional to RFC5213 defined set of BCE lookup keys.

A.4.  Addition of a new Status Code

   RFC5149 did not make a difference between a service authorization
   failure (SERVICE_AUTHORIZATION_FAILED) and a service not being
   provisioned in a home agent/local mobility agent or otherwise unknown
   (MISSING_OR_UNKNOWN_SERVICE).

A.5.  Change of the document category from Informational to Standards
      Track

   RFC5149 has implementations by multiple vendors and there are several



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   deployments.  Furthermore, RFC5149 is not specific to 3GPP networks
   anymore.


Authors' Addresses

   Jouni Korhonen
   Nokia Siemens Networks
   Linnoitustie 6
   FIN-02600 Espoo
   Finland

   Email: jouni.nospam@gmail.com


   Ulf Nilsson
   TeliaSonera Corporation
   Marbackagatan 11
   S-123 86 Farsta
   SWEDEN

   Email: ulf.s.nilsson@teliasonera.com


   Vijay Devarapalli

   Email: dvijay@gmail.com
























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