DMM Working Group                                             M. Liebsch
Internet-Draft                                                       NEC
Intended status: Standards Track                           S. Matsushima
Expires: November 7, 2015                               Softbank Telecom
                                                           S. Gundavelli
                                                                   Cisco
                                                                D. Moses
                                                       Intel Corporation
                                                             May 6, 2015


       Protocol for Forwarding Policy Configuration (FPC) in DMM
                     draft-ietf-dmm-fpc-cpdp-00.txt

Abstract

   The specification as per this document supports the separation of the
   Control-Plane for mobility- and session management from the actual
   Data-Plane.  The protocol semantics abstract from the actual details
   for the configuration of Data-Plane nodes and apply between a Client
   function, which is used by an application of the mobility Control-
   Plane, and an Agent function, which is associated with the
   configuration of Data-Plane nodes according to the policies issued by
   the mobility Control-Plane.  The scope of the policies comprises
   forwarding rules and treatment of packets in terms of encapsulation,
   IP address re-writing and QoS.  Additional protocol semantics are
   described to support the maintenance of the Data-Plane path.

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 November 7, 2015.







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Copyright Notice

   Copyright (c) 2015 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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions and Terminology . . . . . . . . . . . . . . . . .   3
   3.  Model for Policy-based DMM Network Control  . . . . . . . . .   3
     3.1.  Reference Architecture for DMM Forwarding Policy
           Configuration . . . . . . . . . . . . . . . . . . . . . .   3
     3.2.  Generalized Rules on the Client-Agent-Interface . . . . .   6
     3.3.  Role of the DMM FPC Client Function . . . . . . . . . . .   6
     3.4.  Role of the DMM FPC Agent Function  . . . . . . . . . . .   7
   4.  Protocol Messages and Semantics . . . . . . . . . . . . . . .   7
     4.1.  Protocol Messages . . . . . . . . . . . . . . . . . . . .   7
     4.2.  Protocol Attributes . . . . . . . . . . . . . . . . . . .   8
     4.3.  Protocol Operation  . . . . . . . . . . . . . . . . . . .  10
   5.  Conceptual Data Structures  . . . . . . . . . . . . . . . . .  15
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  16
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  16
   8.  Work Team Participants  . . . . . . . . . . . . . . . . . . .  16
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  16
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  16
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  16
   Appendix A.  YANG Data Model for the FPC Protocol . . . . . . . .  17
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  25

1.  Introduction

   One objective of the Distributed Mobility Management (DMM) WG is the
   separation of the mobility management Control- and Data-Plane to
   enable flexible deployment, such as decentralized provisioning of
   Data-Plane nodes (DPN).  Data-Plane nodes can be configured to
   function as anchor for a registered Mobile Node's (MN) traffic,
   others can be configured to function as Mobile Access Gateway (MAG)
   as per the Proxy Mobile IPv6 protocol [RFC5213] or a Foreign Agent



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   (FA) as per the Mobile IPv4 protocol [RFC3344].  Requirements for DMM
   have been described in [RFC7333], whereas best current practices for
   DMM are documented in [RFC7429].

   The Data-Plane must provide a set of functions to the Mobility
   Control-Plane, such as support for encapsulation, IP address re-
   writing, QoS differentiation and traffic shaping.  In addition, the
   configuration of forwarding rules must be provided.  These
   requirements are met by various transport network components, such as
   IP switches and routers, though configuration semantics differs
   between them.

   Forwarding Policy Configuration (FPC) as per this document enables
   the configuration of any Data-Plane node and type by the abstraction
   of configuration details and the use of common configuration
   semantics.  The protocol using the FPC semantics is deployed between
   a Client function, which is associated with the Mobility Management
   Control-Plane, and an Agent function.  The Agent function enforces
   the Data-Plane configuration and can be present on a transport
   network controller or co-located with a Data-Plane node.  The Agent
   applies the generalized configuration semantics to configuration,
   which is specific to the Data-Plane node and type.  The Mobility
   Control-Plane can select one or multiple DPNs which suit the MN's
   mobility management without the need to handle each node's routing-
   or switching tables and local interface configurations for
   potentially many routers serving the Data-Plane, but enforce the
   policies for traffic treatment and forwarding through the FPC Client
   and the FPC Agent functions.

2.  Conventions and Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

3.  Model for Policy-based DMM Network Control

3.1.  Reference Architecture for DMM Forwarding Policy Configuration

   The DMM Forwarding Policy Configuration (FPC) protocol enables DMM
   use cases in deployments with separated Control-/Data-Plane and is
   used by applications of the Mobility Control-Plane to enforce rules
   for forwarding and traffic treatment in the Data-Plane.  Figure 1
   depicts an exemplary use case where downlink traffic from a
   Correspondent Node (CN) towards a Mobile Node (MN) traverses multiple
   DPNs, each applying policies as per the Control-Plane's request.
   Policies in the one or multiple DPNs can result in traffic steering
   according to a host-route, packet scheduling and marking according to



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   a subscriber's QoS profile, or forwarding rules (e.g. encapsulation
   within GRE or GTP-U tunnel).


                           +--------------------------+
                           |     Mobility Control     |
                           +--------------------------+
                            |             |         |
                            |             |         |
                            |             |         |
                     \ /    V             V         V
            +--+     -o-  +---+         +---+     +---+   +--+
            |MN| ---- |---|DPN|<========|DPN|<----|DPN|<--|CN|
            +--+      |   +---+         +---+     +---+   +--+
                          Rules:       Rules:     Rules:
                          Decap,       Encap,     host-route
                          Forward      Forward,
                                       qos


      Figure 1: Exemplary illustration of a use case for DMM traffic
         steering and policy enforcement at Data Plane Nodes (DPN)

   Mobility Control-Plane functions have the following roles in common:

   o  Tracking an MN's location

   o  Accept requests to set up and maintain mobility-related Data-Plane
      path between DPNs, taking QoS attributes into account.  Such
      requests can be issued through mobility protocols, such as Proxy
      Mobile IPv6, and the associated operation with remote Mobility
      Control-Plane functions.

   o  Become aware of different DPNs that provide the required Data-
      plane functions to the Mobility Control-Plane and can be used for
      mobility traffic forwarding and treatment

   o  Monitor the DPNs' operation and handle exceptions, e.g. the
      detection of a partial DPN failure and the diversion of traffic
      through a different DPN

   o  Maintain consistency between multiple DPNs which enforce policy
      rules for an MN

   Mobility Data-Plane functions have the following roles in common:

   o  Forward and treat traffic according to the policies and directives
      sent by the Mobility Control-Plane



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   o  Provide status (e.g. load, health, statistics and traffic volume)
      information on request

   o  Participate in the process for topology acquisition, e.g. by
      exposing relevant topological and capability information, such as
      support for QoS differentiation and supported encapsulation
      protocols

   The protocol for DMM FPC applies to the interface between an FPC
   Client function and an FPC Agent function, as depicted in Figure 2.
   The FPC Client function is associated with an application function of
   the mobility management Control-Plane, e.g. a Local Mobility Anchor
   Control-Plane function as per the Proxy Mobile IPv6 protocol.  The
   FPC Agent function processes the FPC protocol semantics and
   translates them into configuration commands as per the DPN's
   technology.  In one example, an FPC Agent can be co-located with a
   Transport Network Controller, which enforces forwarding rules on a
   set of SDN switches.  In another example, the Agent can be co-located
   with a single router to directly interact with interface management
   and the router's RIB Manager.  The mapping of the common FPC
   semantics and policy description as per this specification to the
   configuration commands of a particular DPN is specific to the DPN's
   technology and the Agent's implementation.


                              +-------------------------+
                              | Mobility Control-Plane  |
                              |                         |
                              |+--------[API]----------+|
                              ||  FPC Client Function  ||
                              |+----------^------------+|
                              +-----------|-------------+
                                          |
                                          | DMM FPC protocol
                                          |
                              +-----------|-------------+
                              |+----------v------------+|
                              ||  FPC Agent Function   ||
                              |+-----------------------+|
                              |                         |
                              |  DPN Configuration API  |
                              +-------------------------+


    Figure 2: Illustration of the functional reference architecture for
                 DMM Forwarding Policy Configuration (FPC)





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3.2.  Generalized Rules on the Client-Agent-Interface

   To abstract configuration details of an IP switch or IP router on the
   FPC protocol interface, this specification adopts the model of
   logical gates (Ports) to bind certain properties, such as a QoS
   policy.  Additional properties can be bound to the same logical Port,
   e.g. encapsulation of packets, being directed to that logical Port,
   in a GRE tunnel.  The remote tunnel endpoint is configured as part of
   the property bound to that logical Port.  All traffic, which has a
   forwarding rule in common and should be forwarded according to the
   properties bound to a particular Port, can be referred to that Port
   by configuration of a forwarding rule.  Multiple IP flows or even
   aggregated traffic being destined to a given IP prefix can be
   directed to that logical Port and experiences the same treatment
   according to the configured properties and forwarding
   characteristics.  Aggregated or per-Host/per-Flow traffic can be
   identified by a longest prefix match or a Traffic Selector
   respectively.

   Figure 3 illustrates the generic policy configuration model as used
   between an FPC Client function and an FPC Agent function.


    <prefix 1>     <IP flow 1>  <host src IP 1>    +-------------------+
  <host dst IP 1>  <IP flow 2>   <prefix 2>        |     Bind 1..M     |
         |         <IP flow 3>       |             | traffic templates |
         |             |             |             |  to each logical  |
         |             |             |             |        port       |
         |             |             |             +-------------------+
         v             v             v
      <PORT_1>------<PORT_2>------<PORT_3>--- ...  [logical ports space]
         |             |             |
         +--PROP_1.1   +--PROP_2.1   +--PROP_3.1   +-------------------+
         |                           |             |     Bind 1..N     |
         +--PROP_1.2                 +--PROP_3.2   |     properties    |
         |                                         |  to each logical  |
         +--PROP_1.3                               |        port       |
                                                   +-------------------+

                Figure 3: Illustration of generalized rules

3.3.  Role of the DMM FPC Client Function

   The DMM FPC Client function includes the following tasks:

   o  Per mobility management transaction or relevant event, build one
      or multiple Control messages/attributes to control policies on one
      or multiple DPA(s) according to the application's directives



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   o  Treat a DPN's policy rules (encapsulation, address re-write, QoS,
      traffic monitoring) on the basis of properties being bound to
      logical ports (similar to the bearer concept in cellular networks)

   o  Build, modify or delete logical ports as needed

   o  Bind associated policy rules as one or multiple properties to a
      logical port

   o  Treat forwarding rules (e.g. per-IP flow, per-MN, per-IP, per-
      prefix) on the basis of logical ports

   o  Send each generated message to the DMM FPC Agent associated with
      the identified DPN

   o  Keep record of the policy rules/port information and the
      associated DPN and FPC Agent Function

   o  Process received Response, Notification and Query messages issued
      by a DMM FPC Agent Function and notify the application

3.4.  Role of the DMM FPC Agent Function

   The DMM FPC Agent function includes the following tasks:

   o  Process the received Control messages issued by a DMM FPC Client
      Function

   o  Unambiguously match each logical port with an associated physical
      port or interface at the identified DPN

   o  Apply the received properties to local configuration (e.g.
      encapsulation, NA(P)T, traffic prioritization and scheduling) on
      the identified DPN according to the DPN's technology

   o  Monitor scheduled events (e.g. failure or missing rule) and issue
      an associated message to the FPC Client Function (NOTIFICATION,
      QUERY)

4.  Protocol Messages and Semantics

4.1.  Protocol Messages









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 +---------------------------------------------------------------------+
 |     Message     |                    Description                    |
 +=====================================================================+
 |               Messages issued by the FPC Client                     |
 +---------------------------------------------------------------------+
 |    PRT_ADD      | Add a logical port                                |
 +---------------------------------------------------------------------+
 |    PRT_DEL      | Delete an existing logical port                   |
 +---------------------------------------------------------------------+
 |    PROP_ADD     | Add a property to a logical port                  |
 +---------------------------------------------------------------------+
 |    PROP_MOD     | Modify a property of a logical port               |
 +---------------------------------------------------------------------+
 |    PROP_DEL     | Remove and delete a property from a logical port  |
 +---------------------------------------------------------------------+
 |    RULE_ADD     | Add forwarding rule by binding traffic descriptor |
 |                 | to a logical port                                 |
 +---------------------------------------------------------------------+
 |    RULE_MOD     | Modify existing forwarding rule by changing the   |
 |                 | traffic descriptor bound to a logical port        |
 +---------------------------------------------------------------------+
 |    RULE_DEL     | Delete a forwarding rule                          |
 +---------------------------------------------------------------------+
 |   EVENT_REG     | Register an event at an Agent, which is to be     |
 |                 | monitored by the Agent and to be reported         |
 +---------------------------------------------------------------------+
 |     PROBE       | Probe the status of a registered event            |
 +---------------------------------------------------------------------+
 |                 Messages issued by the FPC Agent                    |
 +---------------------------------------------------------------------+
 |                 | Notify the Client about the status of a           |
 |    NOTIFY       | monitored attribute at any event kind             |
 |                 | (periodic / event trigger / probed)               |
 +---------------------------------------------------------------------+
 |     QUERY       | Query the Client about missing rules/states       |
 +---------------------------------------------------------------------+


                        Figure 4: Protocol Messages

4.2.  Protocol Attributes

   Protocol messages as per Section 4.1 carry attributes to identify an
   FPC Client- or Agent function, as well as a DPN, logical ports and
   configuration data.  Furthermore, attributes are carried to manage
   logical ports and describe properties associated with a logical port,
   as well as to describe per-host-, aggregate or IP flow traffic and
   refer to a logical port as forwarding information.



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   This document specifies attributes from the following categories:

   o  Identifier attributes

   o  Properties

   o  Property-specific attributes

   o  Traffic descriptors

   Note on the list of attributes: The list of attributes is not yet
   complete.

   Note on Format Clarification: Meant to provide a first idea on the
   format and number space and indicates length (bit) and semantics of
   key information fields.

 +---------------------------------------------------------------------+
 |   Attribute    | Format Clarification |         Description         |
 +=====================================================================+
 |                            Identifiers                              |
 +---------------------------------------------------------------------+
 |    PRT_ID      | [16,PTR_ID]          | Identifies a logical Port   |
 +---------------------------------------------------------------------+
 |  PRT_PROP_ID   | [16,PRT_ID]          | Identifies a logical Port   |
 |                | [8,PROP_ID]          | and one of its properties   |
 +---------------------------------------------------------------------+
 |    CLI_ID      | [8, Carrier ID]      | Identifies an               |
 |                | [8, Network ID]      | FPC Client function         |
 |                | [16, Client ID]      |                             |
 +---------------------------------------------------------------------+
 |    AGT_ID      | [8, Carrier ID]      | Identifies an               |
 |                | [8, Network ID]      | FPC Agent function          |
 |                | [16, Agent ID]       |                             |
 +---------------------------------------------------------------------+
 |    DPN_ID      | [8, Carrier ID]      | Identifies a Data Plane     |
 |                | [8, Network ID]      | Node (DPN)                  |
 |                | [16, DPN ID]         |                             |
 +---------------------------------------------------------------------+
 |   EVENT_ID     | [16, Event ID]       |Identifies a registered event|
 +---------------------------------------------------------------------+

                Figure 5: Protocol Attributes: Identifiers








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 +---------------------------------------------------------------------+
 |   Attribute    | Format Clarification |         Description         |
 +=====================================================================+
 |                              Properties                             |
 +---------------------------------------------------------------------+
 |   PROP_TUN     | [type][src][dst]     | Property Encapsulation,     |
 |                |                      | indicates type GRE, IP, GTP |
 +---------------------------------------------------------------------+
 |   PROP_REWR    |        TBD           | Property NAT                |
 +---------------------------------------------------------------------+
 |   PROP_QOS     |        TBD           | Property QoS                |
 +---------------------------------------------------------------------+
 |   PROP_GW      | [ip address next hop]| Property Next Hop           |
 +---------------------------------------------------------------------+

                 Figure 6: Protocol Attributes: Properties

 +---------------------------------------------------------------------+
 |   Attribute    | Format Clarification |         Description         |
 +=====================================================================+
 |                           Property-specific                         |
 +---------------------------------------------------------------------+
 |   IPIP_CONF    |                      | IP-encapsulation            |
 |                |                      | configuration attribute     |
 +---------------------------------------------------------------------+
 |   GRE_CONF     | [prototype][seq-#]   | GRE_encapsulation           |
 |                | [key]..              | configuration attribute     |
 +---------------------------------------------------------------------+
 |   GTP_CONF     | [TEID_local]         | GTP-U encapsulation         |
 |                | [TEID_remote]        | configuration attribute     |
 |                | [seq-#]..            |                             |
 +---------------------------------------------------------------------+

             Figure 7: Protocol Attributes: Property-specific

4.3.  Protocol Operation

   The following list comprises a more detailed description of each
   message's semantic.

   o  PRT_ADD - Issued by a Client to add a new logical port at an
      Agent, to which traffic can be directed.  An Agent receiving the
      PRT_ADD message should identify the new logical port according to
      the included port identifier (PRT_ID).  In case the DPN holds
      already a registration for a logical port with the same
      identifier, the Agent should throw an error message to the Client.
      Otherwise the Agent should add a new logical port into its
      conceptual data structures using the port identifier as key.



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   o  PRT_DEL - Used by a Client to delete an existing logical port.  An
      Agent receiving such message should delete all properties
      associated with the identified port.

   o  PROP_ADD - Used by the Client to add a new property to an existing
      logical port.  The property is unambiguously identified through a
      property identifier (PRT_PROP_ID).  All traffic, which is directed
      to this logical port, experiences the existing and newly added
      property.

   o  PROP_MOD - Used by a Client to modify an existing property.  For
      example, a tunnel property can be changed to direct traffic to a
      different tunnel endpoint in case of an MN's handover

   o  PROP_DEL - Used by a Client to delete one or multiple properties,
      each being identified by a property identifier.

   o  RULE_ADD - Used by a Client to add a forwarding rule and direct
      traffic towards a logical port.  The rule add command must
      unambiguously identify aggregated traffic (longest prefix), per
      host IP traffic or per-flow traffic in the RULE_ADD command and
      bind the identified traffic to a logical port.  An Agent receiving
      a RULE_ADD command must add the rule to its local conceptual data
      structures and apply commands for local configuration to add the
      new forwarding rule on the DPN.  Multiple forwarding rules, each
      identifying different traffic, can direct traffic to the same
      logical port.  All traffic being directed to this logical port
      will then experience the same properties.

   o  RULE_MOD - Used by a Client to modify an existing forwarding rule.
      An Agent receiving such message should apply commands for local
      configuration to update the forwarding rule on the DPN.

   o  RULE_DEL - Used to delete an existing forwarding rule on a DPN.
      The Agent receiving such message should delete the rules from its
      local conceptual data structures and apply commands for local
      configuration to remove the forwarding rule on the DPN.

   o  EVENT_REG - Used by a Client to register an attribute, which is to
      be monitored, at an Agent.  The EVENT_REG provides an attribute to
      the Agent as well as a reporting kind.  The Agent should register
      the event and an event identifier in the local conceptual data
      structures.  The Agent should start monitoring the registered
      attribute (e.g. load) and notify the Client about the status
      according to the registered reporting kind (periodic, event
      trigger, probed).  In case of a periodic reporting kind, the Agent
      should report the status of the attribute each configured interval
      using a NOTIFY message.  The reporting interval is provided with



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      the EVENT_REG message.  In case of an event triggered reporting
      kind, the Agent should report the status of the attribute in case
      of a triggered event, e.g. the monitored attribute's value exceeds
      a given threshold.  The threshold is provided with the EVENT_REG
      message.  In case of probed reporting, the Agent receives a PROBE
      message and should report the status of a monitored attributes to
      the Client by means of a NOTIFY message.

   o  PROBE - Used by a Client to retrieve information about a
      previously registered event.  The PROBE message should identify
      one or more events by means of including the associated event
      identifier.  An Agent receiving a PROBE message should send the
      requested information for each event in a single or multiple
      NOTIFY messages.

   o  NOTIFY - Used by an Agent to report the status of an event to a
      Client.

   o  QUERY - Used by an Agent to request an update of logical port
      properties via a Client.

   Figure 8 illustrates an exemplary session life-cycle based on Proxy
   Mobile IPv6 registration via MAG Control-Plane function 1 (MAG-C1)
   and handover to MAG Control-Plane function 2 (MAG-C2).  Edge DPN1
   represents the Proxy CoA after attachment, whereas Edge DPN2 serves
   as Proxy CoA after handover.

























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                                                 +-------Router--------+
                         +-----------+           |+-------+ +---------+|
 +------+ +------+     +-----+ FPC   |            | FPC   | |  Anchor |
 |MAG-C1| |MAG-C2|     |LMA-C| Client|            | Agent | |   DPN   |
 +------+ +------+     +-----+-------+            +-------+ +---------+
 [MN attach]  |            |                          |           |
    |-------------PBU----->|                          |           |
    |         |            |----(1)-PRT_ADD---------->|           |
    |         |            |        [PRT_ID]          |           |
    |         |            |                          |           |
    |         |            |--(2)---PROP_ADD--------->|           |
    |         |            |   [PROP_ID,PROP_TUN]     |--tun1 up->|
    |         |            |                          |           |
    |         |            |--(3)---PROP_ADD--------->|           |
    |         |            |    [PROP_ID,PROP_QOS]    |--tc qos-->|
    |<------------PBA------|--(4)----RULE_ADD-------->|           |
    | +----+  |            |       [HNP,PRT_ID]       |-route add>|
    | |Edge|  |            |                          |           |
    | |DPN1|  |            |                          |           |
    | +----+  |            |                          |           |
    |   |                                                         |
    |   |-=======================================================-|
    |                      |                          |           |
    |   [MN handover]      |                          |           |
    |         |---PBU ---->|                          |           |
    |         |            |--(5)---PROP_MOD--------->|           |
    |         |<--PBA------|   [PROP_ID,PROP_TUN]     |-tun1 mod->|
    |         |            |                          |           |
    |         |  +----+    |                          |           |
    |         |  |Edge|    |                          |           |
    |         |  |DPN2|    |                          |           |
    |         |  +----+    |                          |           |
    |         |    |       |                          |           |
    |         |    |-============================================-|
    |         |            |                          |           |


    Figure 8: Exemplary Message Sequence (focus on FPC reference point)

   After reception of the Proxy Binding Update (PBU) at the LMA Control-
   Plane function (LMA_C), the LMA-C selects a suitable DPN, which
   serves as Data-Plane anchor to the MN's traffic.  The LMA-C adds a
   new logical port to the DPN to treat the MN's traffic (1) and
   includes a Port Identifier (PRT_ID) to the PRT_ADD command.  The
   LMA-C identifies the selected Anchor DPN by including the associated
   DPN identifier.





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   Subsequently, the LMA-C adds properties to the new logical port.  One
   property is added (2) to specify the forwarding tunnel type and
   endpoints (Anchor DPN, Edge DPN1).  Another property is added (3) to
   specify the QoS differentiation, which the MN's traffic should
   experience.  At reception of the properties, the FPC Agent calls
   local router commands to enforce the tunnel configuration (tun1) as
   well as the traffic control (tc) for QoS differentiation.  After
   configuration of port properties have been completed, the LMA can
   configure the enforcement of the MN's traffic by adding a rule
   (RULE_ADD) to forward traffic destined to the MN's HNP to the new
   logical port (4).  At the reception of the forwarding rule, the Agent
   applies a new route to forward all traffic destined to the MN's HNP
   to the configured tunnel interface (tun1).

   During handover, the LMA-C receives an updating PBU from the handover
   target MAG-C2.  The PBU refers to a new Data-Plane node (Edge DPN2)
   to represent the new tunnel endpoint.  The LMA-C sends a PROP_MOD
   message (5) to the Agent to modify the existing tunnel property of
   the existing logical port and to update the tunnel endpoint from Edge
   DPN1 to Edge DPN2.  At reception of the PROP_MOD message, the Agent
   applies local configuration commands to modify the tunnel.

   To reduce the number of protocol handshakes between the LMA-C and the
   DPN, the LMA-C can append property (PROP_TUN, PROP_QOS) and rules
   (prefix info HNP) attributes to the PRT_ADD message, as illustrated
   in Figure 9

























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                         +-----------+             +-------+ +---------+
 +------+ +------+     +-----+ FPC   |             | FPC   | |  Anchor |
 |MAG-C1| |MAG-C2|     |LMA-C| Client|             | Agent | |   DPN   |
 +------+ +------+     +-----+-------+             +-------+ +---------+
 [MN attach]  |            |                           |           |
    |-------------PBU----->|                           |           |
    |         |            |----(1)-PRT_ADD----------->|           |
    |         |            | [PRT_ID,PROP_ID,PROP_TUN, |--tun1 up->|
    |<------------PBA------|         PROP_ID,PROP_QOS, |--tc qos-->|
    |         |            |         HNP]              |-route add>|
    | [Edge]-=====================================================-|
    | [DPN1|  |            |                           |           |
    |         |            |                           |           |
    |   [MN handover]      |                           |           |
    |         |---PBU ---->|                           |           |
    |         |            |---------PROP_MOD--------->|           |
    |         |<--PBA------|     [PROP_ID,PROP_TUN]    |-tun1 mod->|
    |         |            |                           |           |
    |         | [Edge]-===========================================-|
    |         | [DPN2]     |                           |           |


     Figure 9: Example: Sequence for Message Aggregation (focus on FPC
                             reference point)

5.  Conceptual Data Structures

   An FPC Client must keep record about the logical ports, each port's
   properties as well as configured rules as per the Mobility Control-
   Plane function's request.  Such information must be maintained for
   each Agent, with which the Client communicates.  In case the Mobility
   Control-Plane function identifies a particular DPN at which the
   policies should be enforced, the Client must associate the DPN
   identifier with the logical port configuration.

   According to the FPC Agent's role, the Agent translates the
   generalized model for policy configuration and forwarding rules into
   semantics and commands for local configuration, which is specific to
   a DPN.  Keeping a local record of DPN configuration attributes/values
   is implementation specific and out of scope of this document.

   Description of detailed data structures and information to be
   recorded and maintained by an FPC Client and an FPC Agent are TBD and
   will be added to a revision of this initial document.







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6.  Security Considerations

   Detailed protocol implementations for DMM Forwarding Policy
   Configuration must ensure integrity of the information exchanged
   between an FPC Client and an FPC Agent.  Required Security
   Associations may be derived from co-located functions, which utilize
   the FPC Client and FPC Agent respectively.

7.  IANA Considerations

   This document provides an information model for DMM Forwarding Policy
   Configuration.  Detailed protocol specifications for DMM Forwarding
   Policy Configuration will follow the information model as per this
   document and can be based on, for example, ReST-like or binary
   protocol formats.  Such protocol-specific details will be described
   in separate documents and may require IANA actions.

8.  Work Team Participants

   Participants in the FPSM work team discussion include Satoru
   Matsushima, Danny Moses, Sri Gundavelli, Marco Liebsch, Pierrick
   Seite, Alper Yegin, Carlos Bernardos, Charles Perkins and Fred
   Templin.

9.  References

9.1.  Normative References

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

   [RFC7333]  Chan, H., Liu, D., Seite, P., Yokota, H., and J. Korhonen,
              "Requirements for Distributed Mobility Management", RFC
              7333, August 2014.

   [RFC7429]  Liu, D., Zuniga, JC., Seite, P., Chan, H., and CJ.
              Bernardos, "Distributed Mobility Management: Current
              Practices and Gap Analysis", RFC 7429, January 2015.

9.2.  Informative References

   [RFC3344]  Perkins, C., "IP Mobility Support for IPv4", RFC 3344,
              August 2002.

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





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Appendix A.  YANG Data Model for the FPC Protocol

   This appendix provides (so far experimental) formating of some FPC
   protocol components adopting YANG data modeling.  The current FPC
   information model as per this initial draft version will experience
   extensions, as it is not yet complete, and may experience changes
   that need to be reflected in the data model.  Whether a detailed data
   model will be included in this document or solely an information
   model will be adopted by this document and a detailed data model will
   be part of a separate document is currently being discussed.


   module ietf-dmm-fpcp {
       namespace "urn:ietf:params:xml:ns:yang:dmm-fpcp";
       prefix fpcp;

       import ietf-inet-types { prefix inet; }

       description
       "This module contains YANG definition for
        Forwarding Policy Configuration Protocol.(FPCP)";

       revision 2015-03-09 {}

       typedef fpcp-port-id {
           description "PRT_ID";
           type uint16;
       }

       typedef fpcp-property-id {
           description "PROP_ID";
           type uint8;
       }

       identity tunnel-type {
           description
           "Base identity from which specific use of
            tunnels are derived.";
       }

       identity fpcp-tunnel-type {
           base "tunnel-type";
           description
           "Base identity from which specific tunnel
            types in FPCP uses are derived.";
       }

       identity ip-in-ip {



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           base "fpcp-tunnel-type";
           description "IP-in-IP tunnel";
       }

       identity gtp {
           base "fpcp-tunnel-type";
           description "GTP-U tunnel";
       }

       identity gre {
           base "fpcp-tunnel-type";
           description "GRE tunnel";
       }

       identity ip-protocol {
           description
           "Base identity from which specific
            IP protocol types are derived.";
       }

       identity qos-type {
           description
           "Base identity from which specific
            uses of QoS types are derived.";
       }

       identity fpcp-qos-type {
           base "qos-type";
           description
           "Base identity from which specific
            QoS types in FPCP uses are derived.";
       }

       identity fpcp-qos-type-high {
           base "fpcp-qos-type";
           description
           "An example FPCP QoS Type for high quality class.
            FPCP supported QoS classes are TBD.";
       }

       identity fpcp-qos-type-middle {
           base "fpcp-qos-type";
           description
           "An example FPCP QoS Type for middle quality class.
            FPCP supported QoS classes are TBD.";
       }

       identity fpcp-qos-type-low {



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           base "fpcp-qos-type";
           description
           "An example FPCP QoS Type for low quality class.
            FPCP supported QoS classes are TBD.";
       }

       grouping fpcp-client {
           description "CLI_ID to identify FPCP Client";
           leaf carrier-id {
               type uint8;
           }
           leaf network-id {
               type uint8;
           }
           leaf client-id {
               type uint16;
               mandatory true;
           }
       }

       grouping fpcp-agent {
           description "AGT_ID to identify FPCP Agent";
           leaf carrier-id {
               type uint8;
           }
           leaf network-id {
               type uint8;
           }
           leaf agent-id {
               type uint16;
               mandatory true;
           }
       }

       grouping dpn {
           description "DPN_ID to identify Data-Plane Node";
           leaf carrier-id {
               type uint8;
           }
           leaf network-id {
               type uint8;
           }
           leaf dpn-id {
               type uint16;
               mandatory true;
           }
       }




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       grouping port-property-id {
           description "PRT_PROP_ID";
           leaf port-id {
               mandatory true;
               type fpcp-port-id;
           }
           leaf property-id {
               type fpcp-property-id;
               mandatory true;
           }
       }

       grouping tunnel-endpoints {
           description
           "PROP_TUN property as a set of tunnel endpoints";
           leaf tunnel-type {
               type identityref {
                   base "fpcp-tunnel-type";
               }
           }
           leaf remote-address {
               type inet:ip-address;
           }
           leaf local-address {
               type inet:ip-address;
           }
       }

       grouping gtp-attributes {
           description
           "GTP_CONF as GTP tunnel specific attributes";
           leaf remote-teid {
               type uint32;
           }
           leaf local-teid {
               type uint32;
           }
       }

       grouping gre-attributes {
           description
           "GRE_CONF as GRE tunnel specific attribute";
           leaf key {
               type uint32;
           }
       }

       grouping fpcp-identifier-attributes {



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           description
           "Identifiers of protocol attributes";
           leaf port-id {
               type fpcp-port-id;
           }
           container client {
               uses fpcp-client;
           }
           container agent {
               uses fpcp-agent;
           }
           list nodes {
               key dpn-id;
               uses dpn;
           }
       }

       grouping fpcp-traffic-descriptor {
           description
           "Traffic descriptor group collects parameters to
            identify target traffic flow and apply QoS policy";
           leaf destination-ip {
               type inet:ip-prefix;
           }
           leaf source-ip {
               type inet:ip-prefix;
           }
           leaf protocol {
               type identityref {
                   base "ip-protocol";
               }
           }
           leaf destination-port {
               type inet:port-number;
           }
           leaf source-port {
               type inet:port-number;
           }
           leaf qos {
               type identityref {
                   base "fpcp-qos-type";
               }
           }
       }

       grouping fpcp-port-properties {
           description
           "A set of port property attributes";



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           leaf property-id {
               type fpcp-property-id;
           }
           list next-hops {
               container endpoints {
                   uses tunnel-endpoints;
               }
               choice tunnel {
                   case gtp-u {
                       when "tunnel-type = 'gtp'";
                       uses gtp-attributes;
                   }
                   case gre {
                       when "tunnel-type = 'gre'";
                       uses gre-attributes;
                   }
               }
           }
       }


       // Port Entries

       container port-entries {
           description
           "This container binds set of traffic-descriptor and
            port properties to a port and lists them as a port entry.";
           list port-entry {
               key port-id;
               container identifier {
                   uses fpcp-identifier-attributes;
               }
               container trafic-descriptor {
                   uses fpcp-traffic-descriptor;
               }
               list properties {
                   uses fpcp-port-properties;
               }
           }
       }

       // PRT_ADD

       rpc port_add {
           description "PRT_ADD";
           output {
               list fpcp-port-entry {
                   uses fpcp-identifier-attributes;



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               }
           }
       }

       // PRT_DEL

       rpc port_delete {
           description "PRT_DEL";
           input {
               leaf deleting-port {
                   type fpcp-port-id;
               }
           }
       }

       // PROP_ADD

       rpc port_property_add {
           description "PROP_ADD";
           input {
               leaf target-port {
                   type fpcp-port-id;
                   mandatory true;
               }
               container port-properties {
                   uses fpcp-port-properties;
               }
           }
       }

       // PROP_MOD

       rpc port_property_modify {
           description "PROP_MOD";
           input {
               leaf target-port {
                   type fpcp-port-id;
                   mandatory true;
               }
               container port-properties {
                   uses fpcp-port-properties;
               }
           }
       }

       // PROP_DEL

       rpc port_property_delete {



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           description "PROP_DEL";
           input {
               container deleting-property {
                   uses port-property-id;
               }
           }
       }

       // RULE_ADD

       rpc rule_add {
           description
           "TBD for input parameters of which RULE_ADD includes
            but now just traffic-descriptor.";
           input {
               leaf target-port {
                   type fpcp-port-id;
                   mandatory true;
               }
               container port-properties {
                   uses fpcp-traffic-descriptor;
               }
           }
       }

       // RULE_MOD

       rpc rule_modify {
           description
           "TBD for input parameters of which RULE_MOD includes
            but now just traffic-descriptor.";
           input {
               leaf target-port {
                   type fpcp-port-id;
                   mandatory true;
               }
               container port-properties {
                   uses fpcp-traffic-descriptor;
               }
           }
       }

       // RULE_DEL

       rpc rule_delete {
           description
           "TBD for input parameters of which RULE_DEL includes
            but now just traffic-descriptor.";



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           input {
               leaf target-port {
                   type fpcp-port-id;
                   mandatory true;
               }
               container port-properties {
                   uses fpcp-traffic-descriptor;
               }
           }
       }

       // EVENT_REG

       rpc event_register {
           description
           "TBD for registered parameters included in EVENT_REG.";
       }

       // PROBE

       rpc probe {
           description
           "TBD for retrieved parameters included in PROBE.";
       }

       // NOTIFY

       notification notify {
           description
           "TBD for which status and event are reported to client.";
       }
   }



                      Figure 10: FPC YANG Data Model

Authors' Addresses

   Marco Liebsch
   NEC Laboratories Europe
   NEC Europe Ltd.
   Kurfuersten-Anlage 36
   D-69115 Heidelberg
   Germany

   Phone: +49 6221 4342146
   Email: liebsch@neclab.eu



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   Satoru Matsushima
   Softbank Telecom
   1-9-1,Higashi-Shimbashi,Minato-Ku
   Tokyo  105-7322
   Japan

   Email: satoru.matsushima@g.softbank.co.jp


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

   Email: sgundave@cisco.com


   Danny Moses

   Email: danny.moses@intel.com






























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