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RFC 7222

Proposed STD
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Quality-of-Service Option for Proxy Mobile IPv6

Part 1 of 3, p. 1 to 12
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Internet Engineering Task Force (IETF)                        M. Liebsch
Request for Comments: 7222                                           NEC
Category: Standards Track                                       P. Seite
ISSN: 2070-1721                                                   Orange
                                                               H. Yokota
                                                                KDDI Lab
                                                             J. Korhonen
                                                 Broadcom Communications
                                                           S. Gundavelli
                                                                   Cisco
                                                                May 2014


            Quality-of-Service Option for Proxy Mobile IPv6

Abstract

   This specification defines a new mobility option, the Quality-of-
   Service (QoS) option, for Proxy Mobile IPv6.  This option can be used
   by the local mobility anchor and the mobile access gateway for
   negotiating Quality-of-Service parameters for a mobile node's IP
   flows.  The negotiated QoS parameters can be used for QoS policing
   and marking of packets to enforce QoS differentiation on the path
   between the local mobility anchor and the mobile access gateway.
   Furthermore, making QoS parameters available on the mobile access
   gateway enables mapping of these parameters to QoS rules that are
   specific to the access technology and allows those rules to be
   enforced on the access network using access-technology-specific
   approaches.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc7222.

Page 2 
Copyright Notice

   Copyright (c) 2014 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1. Introduction ....................................................3
   2. Conventions and Terminology .....................................4
      2.1. Conventions ................................................4
      2.2. Terminology ................................................5
   3. Overview of QoS Support in Proxy Mobile IPv6 ....................7
      3.1. Quality-of-Service Option -- Usage Examples ................9
      3.2. Quality-of-Service Attributes -- Usage Examples ...........11
   4. Protocol Messaging Extensions ..................................12
      4.1. Quality-of-Service Option .................................12
      4.2. Quality-of-Service Attributes .............................14
           4.2.1. Per-Mobile-Node Aggregate Maximum Downlink
                  Bit Rate ...........................................16
           4.2.2. Per-Mobile-Node Aggregate Maximum Uplink Bit Rate ..17
           4.2.3. Per-Mobility-Session Aggregate Maximum
                  Downlink Bit Rate ..................................18
           4.2.4. Per-Mobility-Session Aggregate Maximum
                  Uplink Bit Rate ....................................20
           4.2.5. Allocation and Retention Priority ..................22
           4.2.6. Aggregate Maximum Downlink Bit Rate ................23
           4.2.7. Aggregate Maximum Uplink Bit Rate ..................25
           4.2.8. Guaranteed Downlink Bit Rate .......................26
           4.2.9. Guaranteed Uplink Bit Rate .........................27
           4.2.10. QoS Traffic Selector ..............................28
           4.2.11. QoS Vendor-Specific Attribute .....................29
      4.3. New Status Code for Proxy Binding Acknowledgement .........30
      4.4. New Notification Reason for Update Notification Message ...30
      4.5. New Status Code for Update Notification
           Acknowledgement Message ...................................31
   5. Protocol Considerations ........................................31
      5.1. Local Mobility Anchor Considerations ......................31
      5.2. Mobile Access Gateway Considerations ......................35

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   6. QoS Services in Integrated WLAN-3GPP Networks ..................39
      6.1. Technical Scope and Procedure .............................39
      6.2. Relevant QoS Attributes ...................................41
   7. IANA Considerations ............................................42
   8. Security Considerations ........................................44
   9. Acknowledgements ...............................................44
   10. References ....................................................44
      10.1. Normative References .....................................44
      10.2. Informative References ...................................45
   Appendix A.  Information When Implementing 3GPP QoS in IP
                Transport Network ....................................47
     A.1.  Mapping Tables ............................................47
     A.2.  Use Cases and Protocol Operations .........................48
       A.2.1.  Handover of Existing QoS Rules ........................48
       A.2.2.  Establishment of QoS Rules ............................50
       A.2.3.  Dynamic Update to QoS Policy ..........................52
   Appendix B.  Information When Implementing PMIP-Based QoS Support
                with IEEE 802.11e ....................................53
   Appendix C.  Information When Implementing with a Broadband
                Network Gateway ......................................57

1.  Introduction

   Mobile operators deploy Proxy Mobile IPv6 (PMIPv6) [RFC5213] to
   enable network-based mobility management for mobile nodes (MNs).
   Users can access IP-based services from their mobile device by using
   various radio access technologies.  The currently supported mobile
   standards have adequate support for QoS-based service differentiation
   for subscriber traffic in cellular radio access networks.  QoS
   policies are typically controlled by a policy control function,
   whereas the policies are enforced by one or more gateways in the
   infrastructure, such as the local mobility anchor (LMA) and the
   mobile access gateway (MAG), as well as by access network elements.
   Policy control and in-band QoS differentiation for access to the
   mobile operator network through alternative non-cellular access
   technologies are not supported in the currently specified standards.
   Although support for IP session handovers and IP flow mobility across
   access technologies already exists in cellular standards [TS23.402],
   QoS policy handovers across access technologies has not received much
   attention so far.

   Based on the deployment trends, Wireless LAN (WLAN) can be considered
   as the dominant alternative access technology to complement cellular
   radio access.  Since the 802.11e extension [IEEE802.11e-2005]
   provides QoS extensions to WLAN, it is beneficial to apply QoS
   policies to WLAN access, which enables QoS classification of downlink
   as well as uplink traffic between a mobile node and its local

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   mobility anchor.  For realizing this capability, this specification
   identifies three functional operations:

      (a) Maintaining QoS classification during a handover between
      cellular radio access and WLAN access by means of establishing QoS
      policies in the handover target access network,

      (b) mapping of QoS classes and associated policies between
      different access systems, and

      (c) establishment of QoS policies for new data sessions/flows,
      which are initiated while using WLAN access.

   This document specifies an extension to the PMIPv6 protocol [RFC5213]
   to establish QoS policies for a mobile node's data traffic on the
   local mobility anchor and the mobile access gateway.  QoS policies
   are conveyed in-band with PMIPv6 signaling using the specified QoS
   option and are enforced on the local mobility anchor for downlink
   traffic and on the mobile access gateway and its access network for
   the uplink traffic.  The specified option allows association between
   IP session classification characteristics, such as a Differentiated
   Services Code Point (DSCP) [RFC2474], and the expected QoS class for
   the IP session.  This document specifies fundamental QoS attributes
   that apply on a per-mobile-node, per-mobility-session, or per-flow
   basis.  The specified attributes are not specific to any access
   technology but are compatible with the Third Generation Partnership
   Project (3GPP) and IEEE 802.11 Wireless LAN QoS specifications
   [IEEE802.11-2012].

   Additional QoS attributes can be specified and used with the QoS
   option, e.g., to represent more specific descriptions of latency
   constraints or jitter bounds.  The specification of such additional
   QoS attributes as well as the handling of QoS policies between the
   mobile access gateway and the access network are out of the scope of
   this specification.

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].

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2.2.  Terminology

   All the mobility-related terms used in this document are to be
   interpreted as defined in the Proxy Mobile IPv6 specifications
   [RFC5213], [RFC5844], and [RFC7077].  Additionally, this document
   uses the following abbreviations:

   Aggregate Maximum Bit Rate (AMBR)

      AMBR defines the upper limit on the bit rate that can be provided
      by the network for a set of IP flows.  IP packets within the flows
      exceeding the AMBR limit may be discarded by the rate-shaping
      function where the AMBR parameter is enforced.  Variants of the
      "AMBR" term can be defined by restricting the target set of IP
      flows on which the AMBR is applied to a mobile node, mobility
      session, or flow direction.  For example, Per-Mobile-Node
      Aggregate Maximum Downlink Bit Rate, Per-Mobile-Node Aggregate
      Maximum Uplink Bit Rate, Per-Mobility-Session Aggregate Maximum
      Downlink Bit Rate, and Per-Mobility-Session Aggregate Maximum
      Uplink Bit Rate are used in this document.

   Allocation and Retention Priority (AARP)

      AARP is used in congestion situations when there are insufficient
      resources for meeting all Service Requests.  It is used primarily
      by the Admission Control function to determine whether a
      particular Service Request must be rejected due to lack of
      resources or honored by preempting an existing low-priority
      service.

   Differentiated Services Code Point (DSCP)

      In the Differentiated Services Architecture [RFC2474], packets are
      classified and marked to receive a particular per-hop forwarding
      behavior on nodes along their path based on the marking present on
      the packet.  This marking on IPv4 and IPv6 packets that defines a
      specific per-hop behavior is known as DSCP.  Refer to [RFC2474],
      [RFC2475], [RFC4594], and [RFC2983] for a complete explanation.

   Downlink (DL) Traffic

      The mobile node's IP packets that the mobile access gateway
      receives from the local mobility anchor are referred to as the
      Downlink traffic.  The "Downlink" term used in the QoS attribute
      definition is always from the reference point of the mobile node,
      and it implies traffic heading towards the mobile node.

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   Guaranteed Bit Rate (GBR)

      GBR denotes the assured bit rate that will be provided by the
      network for a set of IP flows.  It is assumed that the network
      reserves the resources for supporting the GBR parameter.  Variants
      of the "GBR" term can be defined by limiting the scope of the
      target IP flows on which the GBR is applied to a mobile node,
      mobility session, or flow direction.  For example, Guaranteed
      Downlink Bit Rate and Guaranteed Uplink Bit Rate are used in this
      document.

   Mobility Session

      The term "mobility session" is defined in [RFC5213].  It refers to
      the creation or existence of state associated with the mobile
      node's mobility binding on the local mobility anchor and on the
      mobile access gateway.

   QoS Service Request

      A QoS Service Request is a set of QoS parameters that are defined
      to be enforced on one or more mobile node's IP flows.  The
      parameters at the minimum include a DSCP marking and additionally
      may include Guaranteed Bit Rate or Aggregate Maximum Bit Rate.
      The Quality-of-Service option defined in this document represents
      a QoS Service Request.

   Service Identifier

      In some mobility architectures, multiple services within the same
      mobility service subscription are offered to a mobile node.  Each
      of those services provide a specific service (for example,
      Internet Service and Voice Over IP Service) and has an identifier
      called "Service Identifier". 3GPP APN (Access Point Name) is an
      example of a Service Identifier.  Refer to [RFC5149] for the
      definition of the Service Identifier and the mobility option used
      for carrying the Service Identifier.

   Uplink (UL) Traffic

      The mobile node's IP packets that the mobile access gateway
      forwards to the local mobility anchor are referred to as the
      Uplink traffic.  The "Uplink" term used in the QoS attribute
      definitions is based on the reference point of the mobile node,
      and it implies traffic originating from the mobile node.

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3.  Overview of QoS Support in Proxy Mobile IPv6

   The Quality-of-Service support in Proxy Mobile IPv6 specified in this
   document is based on the Differentiated Services Architecture
   ([RFC2474] and [RFC2475]).  The access and the home network in the
   Proxy Mobile IPv6 domain are assumed to be DiffServ-enabled, with
   every network node in the forwarding path for the mobile node's IP
   traffic being DiffServ-compliant.  The per-hop behavior for providing
   differential treatment based on the DiffServ marking in the packet is
   assumed to be supported in the Proxy Mobile IPv6 domain.

   The local mobility anchor in the home network and the mobile access
   gateway in the access network define the network boundary between the
   access and the home network.  As the tunnel entry and exit points for
   the mobile node's IP traffic, these entities are the logical choice
   for being chosen as the QoS enforcement points.  The basic QoS
   functions such as marking, metering, policing, and rate-shaping on
   the mobile node's IP flows can be enforced at these nodes.

   The local mobility anchor and the mobile access gateway can negotiate
   the Quality-of-Service parameters for a mobile node's IP flows based
   on the signaling extensions defined in this document.  The QoS
   services that can be enabled for a mobile node are for meeting both
   the quantitative performance requirements (such as Guaranteed Bit
   Rate) as well as for realizing relative performance treatment by way
   of class-based differentiation.  The subscriber's policy and the
   charging profile (for example, [TS22.115]) are key considerations for
   the mobility entities in the QoS service negotiation.  The decision
   on the type of QoS services that are to be enabled for a mobile node
   is based on the subscriber profile and based on available network
   resources.  The negotiated QoS parameters are used for providing QoS
   differentiation on the path between the local mobility anchor and the
   mobile access gateway.  The signaling related to QoS services is
   strictly between the mobility entities and does not result in per-
   flow state or signaling to any other node in the network.

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     +=======+
     |  MN-1 |
     +=======+
       | | |                                                    Flow-6
       Flow-1<--(GBR: 64 Kbps)                                       |
       |                                                      Flow-4 |
         Flow-2                                                  | | |
       | |                                                  Flow-1 | |
         | Flow-3                                                | | |
       |_|_|                                            DSCP-X   | | |
      (     )<--(Per-Session-AMBR: 1 Mbps)                   :   | | |
       | | |                                          DSCP-Z :   | | |
         | |                                               : :   | | |
       | | |             +=====+                        +==:=v+  | | |
         | '- -- - - - --|     |                        |  : o|--' | |
       | '- - ---  - -  -|     |           __           |  v o|----' |
       '- - - - -  - -  -|     |       _--'  '--_       |  o--|------'
                         |     |      (          )      |     |
                         | MAG |=====( IP Network )=====| LMA |
                         |     |      (          )      |     |
       ,- - - - - - - - -|     |        '--__--'        |    o|-- - -,
         ,- - -- - -- - -|     |                        |    o|--- , |
       | | ,- -  - - -- -|     |                        |    o|--, | |
         | |             +=====+                        +====^+  | | |
       |_|_|                                                 :   | | |
      ( _ _ )<--(Per-Session-AMBR: 2 Mbps)                   :   | | |
       | | |                                            DSCP-Y   | | |
         | |                                                     | | |
       | | |                                                     | | |
         | Flow-6                                           Flow-2 | |
       | |                                                         | |
         Flow-5 (MBR: 100 Kbps)                               Flow-3 |
       |                                                             |
       Flow-4  (GBR: 64 Kbps)                                   Flow-5
       | | |
     +=======+
     |  MN-2 |
     +=======+

                           Figure 1: QoS Support

   Figure 1 illustrates the support of QoS services in a Proxy Mobile
   IPv6 domain.  The local mobility anchor and the mobile access gateway
   have negotiated QoS parameters for the mobility sessions belonging to
   MN-1 and MN-2.  The negotiated QoS parameters include a Per-Session-
   AMBR of 1 Mbps and 2 Mbps for MN-1 and MN-2 respectively.
   Furthermore, different IP flows from MN-1 and MN-2 are given

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   different QoS service treatment, for example, a GBR of 64 Kbps for
   Flow-1 and Flow-4 is assured, a DSCP marking enforcement of "Z" on
   Flow-6, and an MBR of 100 Kbps on Flow-5.

3.1.  Quality-of-Service Option -- Usage Examples

   Use Case 1: Figure 2 illustrates a scenario where a local mobility
   anchor initiates a QoS Service Request to a mobile access gateway.

      +-----+            +-----+              +-----+
      | MN  |            | MAG |              | LMA |
      +-----+            +-----+              +-----+
         |                   |                   |
   1)    |---- MN Attach ----|                   |
   2)    |                   |------ PBU ------->|
   3)    |                   |<----- PBA --------|
         |                   |                   |
   4)    |                   |o=================o|
         |                   |   PMIPv6 Tunnel   |
         |                   |                   |
         |  (LMA initiates QoS Service Request)  |
   5)    |                   |<----- UPN (QoS)---|
         |                   |                   |
         |  (MAG proposes a revised QoS Request) |
   6)    |                   |------ UPA (QoS')->|
         |                   |                   |
   7)    |                   |<----- UPN (QoS')--|
   8)    |                   |------ UPA (QoS')->|
         |  QoS Rules     ---|                   |
   9)    | Established <-|   |  QoS Rules     ---|
   10)   |                ---| Established <-|   |
         |                   |                ---|
   11)   |<----------------->|                   |

      Figure 2: LMA-Initiated QoS Service Request

   o  (1) to (4): MAG detects the mobile node's attachment to the access
      link and initiates the signaling with the local mobility anchor.
      Upon completing the signaling, the LMA and MAG establish the
      mobility session and the forwarding state.

   o  (5) to (8): The LMA initiates a QoS Service Request to the mobile
      access gateway.  The trigger for this service can be based on a
      trigger from a policy function, and the specific details of that
      trigger are outside the scope of this document.  The LMA sends an
      Update Notification (UPN) message [RFC7077] to the MAG.  The
      message includes the QoS option (Section 4.1), which includes a
      set of QoS parameters.  On determining that it cannot support the

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      requested QoS Service Request for that mobile, the MAG sends an
      Update Notification Acknowledgement (UPA) message.  The message
      contains a revised QoS option with an updated set of QoS
      attributes.  The LMA accepts the revised QoS Service Request by
      sending a new Update Notification message including the updated
      QoS option.

   o  (9) to (11): Upon successfully negotiating a QoS Service Request,
      the MAG and the LMA install the QoS rules for that Service
      Request.  Furthermore, the MAG (using access-technology-specific
      mechanisms) installs the QoS rules on the access network.

   Use Case 2: Figure 3 illustrates a scenario where a mobile access
   gateway initiates a QoS Service Request to a local mobility anchor.

      +-----+            +-----+              +-----+
      | MN  |            | MAG |              | LMA |
      +-----+            +-----+              +-----+
         |                   |                   |
   1)    |---- MN Attach ----|                   |
   2)    |                   |------ PBU ------->|
   3)    |                   |<----- PBA --------|
         |                   |                   |
   4)    |                   |o=================o|
         |                   |   PMIPv6 Tunnel   |
         |                   |                   |
         |  (MAG initiates QoS Service Request)  |
   5)    |                   |------ PBU (QoS)-->|
   6)    |                   |<----- PBA (QoS)---|
         |  QoS Rules     ---|                   |
   7)    | Established <-|   |  QoS Rules     ---|
   8)    |                ---| Established <-|   |
         |                   |                ---|
   9)    |<----------------->|                   |

       Figure 3: MAG-Initiated QoS Service Request

   o  (1) to (4): MAG detects the mobile node's attachment to the access
      link and initiates the signaling with the local mobility anchor.
      Upon completing the signaling, the LMA and MAG establish the
      mobility session and the forwarding state.

   o  (5) to (6): The MAG initiates a QoS Service Request to the local
      mobility anchor.  The trigger for this service can be based on a
      trigger from the mobile node using access-technology-specific
      mechanisms.  The specific details of that trigger are outside the
      scope of this document.  The MAG sends a Proxy Binding Update
      (PBU) message [RFC5213] to the LMA.  The message includes the QoS

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      option (Section 4.1), which includes a set of QoS parameters.  The
      LMA agrees to the proposed QoS Service Request by sending a Proxy
      Binding Acknowledgement (PBA) message.

   o  (7) to (9): Upon successfully negotiating a QoS Service Request,
      the MAG and the LMA install the QoS rules for that Service
      Request.  Furthermore, the MAG using access-technology-specific
      mechanisms installs the QoS rules on the access network.

3.2.  Quality-of-Service Attributes -- Usage Examples

   This section identifies the use cases where the Quality-of-Service
   option (Section 4.1) and its attributes (Section 4.2) defined in this
   document are relevant.

   o  The subscription policy offered to a mobile subscriber requires
      the service provider to enforce Aggregate Maximum Bit Rate (AMBR)
      limits on the subscriber's IP traffic.  The local mobility anchor
      and the mobile access gateway negotiate the uplink and the
      downlink AMBR values for the mobility session and enforce them in
      the access and the home network.  The QoS option (Section 4.1)
      with the QoS attributes Per-Session-Agg-Max-DL-Bit-Rate
      (Section 4.2.3) and Per-Session-Agg-Max-UL-Bit-Rate
      (Section 4.2.4) is used for this purpose.

   o  In Community Wi-Fi deployments, the residential gateway
      participating in the Wi-Fi service is shared between the home user
      and the community Wi-Fi users.  In order to ensure the home user's
      Wi-Fi service is not impacted because of the community Wi-Fi
      service, the service provider enables Guaranteed Bit Rate (GBR)
      for the home user's traffic.  The QoS option (Section 4.1) with
      the QoS attributes Guaranteed-DL-Bit-Rate (Section 4.2.8) and
      Guaranteed-UL-Bit-Rate (Section 4.2.9) is used for this purpose.

   o  A mobile user using the service provider's Voice over IP
      infrastructure establishes a VoIP call with some other user in the
      network.  The negotiated call parameters for the VoIP call require
      a dedicated bandwidth of certain fixed value for the media flows
      associated with that VoIP session.  The application function in
      the VoIP infrastructure notifies the local mobility anchor to
      enforce the GBR limits on that IP flow identified by the flow
      definition.  The QoS option (Section 4.1) with the QoS attributes
      Guaranteed-DL-Bit-Rate (Section 4.2.8), Guaranteed-UL-Bit-Rate
      (Section 4.2.9), and QoS-Traffic-Selector (Section 4.2.10) is used
      for this purpose.

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   o  An emergency service may require network resources in conditions
      when the network resources have been fully allocated to other
      users and the network may be experiencing severe congestion.  In
      such cases, the service provider may want to revoke resources that
      have been allocated and reassign them to emergency services.  The
      local mobility anchor and the mobile access gateway negotiate
      Allocation and Retention Priority (AARP) values for the IP
      sessions associated with the emergency applications.  The QoS
      option (Section 4.1) with the QoS attribute Allocation-Retention-
      Priority (Section 4.2.5) is used for this purpose.



(page 12 continued on part 2)

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