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Versions: (draft-leebelotti-teas-actn-info) 00 01 02 03 04 05 06 07 08 09 10 RFC 8454

Teas Working Group                                            Young Lee
Internet Draft                                                   Huawei

Intended status: Informational                           Sergio Belotti
                                                                   Nokia
Expires: August 2017
                                                            Dhruv Dhody
                                                                 Huawei

                                                     Daniele Ceccarelli
                                                               Ericsson

                                                          Bin Young Yun
                                                                   ETRI

                                                       February 7, 2017



  Information Model for Abstraction and Control of TE Networks (ACTN)

                  draft-ietf-teas-actn-info-model-00.txt


Abstract

   This draft provides an information model for Abstraction and Control
   of Traffic Engineered (TE) networks (ACTN).



Status of this Memo

   This Internet-Draft is submitted to IETF in full conformance with
   the provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
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   reference material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt




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   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on August 7, 2017.

Copyright Notice

   Copyright (c) 2017 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
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   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
      1.1. Terminology...............................................4
   2. ACTN Common Interfaces Information Model.......................6
      2.1. VN Action Primitives......................................7
         2.1.1. VN Instantiate.......................................7
         2.1.2. VN Modify............................................7
         2.1.3. VN Delete............................................8
         2.1.4. VN Update............................................8
         2.1.5. VN Path Compute......................................8
         2.1.6. VN Query.............................................9
         2.1.7. TE Update (for TE resources).........................9
      2.2. VN Objects...............................................10
         2.2.1. VN Identifier.......................................10
         2.2.2. VN Service Characteristics..........................10
         2.2.3. VN End-Point........................................13
         2.2.4. VN Objective Function...............................13
         2.2.5. VN Action Status....................................14
         2.2.6. VN Associated LSP...................................14
         2.2.7. VN Computed Path....................................14
         2.2.8. VN Service Preference...............................15
      2.3. Mapping of VN Primitives with VN Objects.................15
   3. References....................................................17



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      3.1. Normative References.....................................17
      3.2. Informative References...................................17
   4. Contributors..................................................18
   Contributors' Addresses..........................................18
   Authors' Addresses...............................................18
   Appendix A: ACTN Applications....................................19
         A.1. Coordination of Multi-destination Service
         Requirement/Policy.........................................19
         A.2. Application Service Policy-aware Network Operation....21
         A.3. Network Function Virtualization Service Enabled
         Connectivity...............................................23
         A.4. Dynamic Service Control Policy Enforcement for
         Performance and Fault Management...........................25
         A.5. E2E VN Survivability and Multi-Layer (Packet-Optical)
         Coordination for Protection/Restoration....................26

1. Introduction

   This draft provides an information model for the requirements
   identified in the ACTN requirements [ACTN-Req] and the ACTN
   interfaces identified in the ACTN architecture and framework
   document [ACTN-Frame].

   The purpose of this draft is to put all information elements of ACTN
   in one place before proceeding to development work necessary for
   protocol extensions and data models.

   The ACTN reference architecture identified a three-tier control
   hierarchy as depicted in Figure 1:

   - Customer Network Controllers (CNC)
   - Multi-Domain Service Coordinator (MDSC)
   - Physical Network Controllers (PNC).
















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   +-------+                 +-------+                   +-------+
   | CNC-A |                 | CNC-B |                   | CNC-C |
   +-------+                 +-------+                   +-------+
         \___________            |             ____________ _/
          ----------             | CMI          ------------
                     \           |            /
                      +-----------------------+
                      |         MDSC          |
                      +-----------------------+
            _________/           |            \_________
            --------             | MPI          ------------____
           /                     |                          \
   +-------+                 +-------+                   +-------+
   |  PNC  |                 |  PNC  |                   |  PNC  |
   +-------+                 +-------+                   +-------+




               Figure 1: A Three-tier ACTN control hierarchy



   The two interfaces with respect to the MDSC, one north of the MDSC
   and the other south of the MDSC are referred to as CMI (CNC-MDSC
   Interface) and MPI (MDSC-PNC Interface), respectively. It is
   intended to model these two interfaces and derivative interfaces
   thereof (e.g., MDSC to MSDC in a hierarchy of MDSCs) with one common
   model.

   Appendix A provides some relevant ACTN use-cases extracted from
   [ACTN-Req]. Appendix A is information only and may help readers
   understand the context of key use-cases addressed in [ACTN-Req].

1.1. Terminology

     o A Virtual Network is a client view (typically a network slice)
        of the transport network.  It is presented by the provider as a
        set of physical and/or abstracted resources. Depending on the
        agreement between client and provider various VN operations and
        VN views are possible. There are three aspects related to VN:

            1) VN Creation: VN could be pre-configured and created via
              static negotiation between customer and provider. In
              other cases, VN could also be created dynamically based



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              on the request from the customer with given SLA
              attributes which satisfy the customer's objectives.

            2) Dynamic Operations: VN could be further modified and
              deleted based on customer request to request changes in
              the network resources reserved for the customer. The
              customer can further act upon the virtual network
              resources to perform E2E tunnel management (set-
              up/release/modify). These changes will incur subsequent
              LSP management on the operator's level.

            3)  VN View: (a) VN can be seen as an (or set of) e2e
              tunnel(s) from a customer point of view where an e2e
              tunnel is referred as a VN member. Each VN member (i.e.,
              e2e tunnel) can then be formed by recursive aggregation
              of lower level paths at a provider level. Such end to end
              tunnels may comprise of customer end points, access
              links, intra domain paths and inter-domain link. In this
              view VN is thus a list of VN members. (b) VN can also be
              seen as a terms of topology comprising of physical and
              abstracted nodes and links. The nodes in this case
              include physical customer end points, border nodes, and
              internal nodes as well as abstracted nodes. Similarly the
              links includes physical access, inter-domain and intra-
              domain links as well as abstracted links. The abstracted
              nodes and links in this view can be pre-negotiated or
              created dynamically.

     o A Virtual Network Service (VNS) is the creation and offering of
        a Virtual Network by a provider to a customer in accordance
        with SLA agreements reached between them (e.g., re satisfying
        the customer's objectives).

     o Abstraction is the process of applying policy to the available
        TE information within a domain, to produce selective
        information that represents the potential ability to connect
        across the domain.  Thus, abstraction does not necessarily
        offer all possible connectivity options, but it presents a
        general view of potential connectivity according to the
        policies that determine how the domain's administrator wants to
        allow the domain resources to be used [RFC7926].

     o Abstract topology:  Every lower controller in the provider
        network, when is representing its network topology to a higher
        layer, it may want to selective hide details of the actual
        network topology, as suggested for abstraction in [RFC7926]. In
        such case, an abstract topology may be used for this purpose.


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        Abstract topology enhances scalability for the MDSC to operate
        multi-domain networks.



2. ACTN Common Interfaces Information Model

   This section provides ACTN common interface information model to
   describe in terms of primitives, objects, their properties
   (represented as attributes), their relationships, and the resources
   for the service applications needed in the ACTN context.

   Basic primitives (messages) are required between the CNC-MDSC and
   MDSC-PNC controllers. These primitives can then be used to support
   different ACTN network control functions like network topology
   request/query, VN service request, path computation and connection
   control, VN service policy negotiation, enforcement, routing
   options, etc.

   The standard interface is described between a client controller and
   a server controller. A client-server relationship is recursive
   between a CNC and a MDSC and between a MDSC and a PNC. In the CMI,
   the client is a CNC while the server is a MDSC. In the MPI, the
   client is a MDSC and the server is a PNC. There may also be MDSC-
   MDSC interface(s) that need to be supported. This may arise in a
   hierarchy of MDSCs in which workloads may need to be partitioned to
   multiple MDSCs.

   Basic primitives (messages) are required between the CNC-MDSC and
   MDSC-PNC controllers. These primitives can then be used to support
   different ACTN network control functions like network topology
   request/query, VN service request, path computation and connection
   control, VN service policy negotiation, enforcement, routing
   options, etc.

   At a minimum, the following VN action primitives should be
   supported:

   - VN Instantiate (See Section 2.1.1. for the description)

   - VN Modify (See Section 2.1.2. for the description)

   - VN Delete (See Section 2.1.3. for the description)

   - VN Update ((See Section 2.1.4. for the description)

   - VN Path Compute (See Section 2.1.5. for the description)


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   - VN Query (See Section 2.1.6. for the description)

   In addition to VN action primitives, TE Update primitive should also
   be supported (See Section 2.1.7. for the description).

2.1. VN Action Primitives

   This section provides a list of main primitives necessary to satisfy
   ACTN requirements specified in [ACTN-REQ].

   <VN Action> describes main primitives. VN Action can be one of the
   following primitives: (i) VN Instantiate; (ii) VN Modify; (iii) VN
   Delete; (iv) VN Update; (v) VN Path Compute; (vi) VN Query.



   <VN Action> ::= <VN Instantiate> |

                   <VN Modify> |

                   <VN Delete> |

                   <VN Update> |

                   <VN Path Compute> |

                   <VN Query>



2.1.1. VN Instantiate

   <VN Instantiate> refers to an action from customers/applications to
   request their VNs. This primitive can also be applied from an MDSC
   to a PNC requesting a VN (if the domain the PNC supports can
   instantiate the entire VN) or a part of VN elements. Please see the
   definition of VN in the section 2.



2.1.2. VN Modify

   <VN Modify> refers to an action from customers/applications to
   modify an existing VN (i.e., instantiated VN). This primitive can
   also be applied from an MDSC to a PNC requesting a VN (if the domain
   the PNC supports can instantiate the entire VN) or a part of VN
   elements.


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2.1.3. VN Delete

   <VN Delete> refers to an action from customers/applications to
   delete an existing VN. This primitive can also be applied from an
   MDSC to a PNC requesting a VN (if the domain the PNC supports can
   instantiate the entire VN) or a part of VN elements.



2.1.4. VN Update

   <VN Update> refers to any update to the VN that need to be updated
   to the subscribers. VN Update fulfills a push model at CMI level, to
   make aware customers of any specific changes in the topology details
   related to VN instantiated.

   Note the VN Update means the connection-related information (e.g.,
   LSPs) update that has association with VNs.

2.1.5. VN Path Compute

   <VN Path Compute> consists of Request and Reply. Request refers to
   an action from customers/applications to request a VN path
   computation. This primitive can also be applied from an MDSC to a
   PNC requesting a VN (if the domain the PNC supports can instantiate
   the entire VN) or a part of VN elements.

   <VN Path Compute> Reply refers to the reply in response to <VN Path
   Compute> Request.

   <VN Path Compute> Request/Reply is to be differentiated from a VN
   Instantiate. The purpose of VN Path Compute is a priori exploration
   to estimate network resources availability and getting a list of
   possible paths matching customer/applications constraints. To make
   this type of request Customer/application controller can have a
   shared (with lower controller) view of an abstract network topology
   on which to get the constraints used as input in a Path Computation
   request. The list of paths obtained by the request can be used by
   customer/applications to give path constrains during VNS
   connectivity request and to compel the lower level controller (e.g.
   MDSC) to select the path that Client/application controller has
   chosen among the set of paths returned by the Path Computation
   primitives. The importance of this primitives is for example in a
   scenario like multi-domain in which the optimal path obtained by an
   orchestrator as sum of optimal paths for different domain controller


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   cannot be the optimal path in the Client/application controller
   prospective. This only applies between CNC and MDSC.

2.1.6. VN Query

   <VN Query> refers to any query pertaining to the VN that has been
   already instantiated. VN Query fulfills a pull model and permit to
   get topology view.

   <VN Query Reply> refers to the reply in response to <VN Query>.

2.1.7. TE Update (for TE resources)


    <TE Update> it is a primitives specifically related to MPI
   interface to provide TE resource update between any domain
   controller towards MDSC regarding the entire content of any "domain
   controller" TE topology or an abstracted filtered view of TE
   topology depending on negotiated policy.


   <TE Update> ::= [<Abstraction>]<TE-topology...>

   <TE-topology> ::= <TE-Topology-reference> <Node-list> <Link-list>

   <Node-list> ::= <Node>[<Node-list>]

   <Node> ::= <Node> <TE-Termination Points>

   <Link-list> ::= <Link>[<Link-list>]

   Where

   <Abstraction> provides information on level of abstraction (as
   determined a priori).

   <TE-topology-reference> ::= information related to the specific te-
   topology related to nodes and links present in this TE-topology.

   <Node-list> ::= detailed information related to a specific node
   belonging to a te-topology e.g. te-node-attributes [TE-TOPO].

   <Link-list> ::= information related to the specific link related
   belonging to a te-topology e.g. te-link-attributes [TE-TOPO].




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   <TE-Termination Points> ::= information details associated to the
   termination point of te-link related to a specific node e.g.
   interface-switching-capability [TE-TOPO].



2.2. VN Objects

   This section provides a list of objects associated to VN action
   primitives.

2.2.1. VN Identifier

   <VN Identifier> is a unique identifier of the VN.

2.2.2. VN Service Characteristics

   VN Service Characteristics describes the customer/application
   requirements against the VNs to be instantiated.

   <VN Service Characteristics> ::= <VN Connectivity Type>

                                    (<VN Traffic Matrix>...)

                                    <VN Survivability>

   Where

   <VN Connectivity Type> ::= <P2P>|<P2MP>|<MP2MP>|<MP2P>|<Multi-
   destination>

   The Connectivity Type identifies the type of required VN Service. In
   addition to the classical type of services (e.g. P2P/P2MP etc.),
   ACTN defines the "multi-destination" service that is a new P2P
   service where the end points are not fixed. They can be chosen among
   a list of pre-configured end points or dynamically provided by the
   CNC.

   <VN Traffic Matrix> ::= <Bandwidth>

                           [<VN Constraints>]

   The VN Traffic Matrix represents the traffic matrix parameters
   required against the service connectivity required and so the VN
   request instantiation between service related   Access Points [ACTN-
   Frame]. Bandwidth is a mandatory parameter and a number of optional
   constrains can be specified in the <VN Constrains> (e.g. diversity,


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   cost). They can include objective functions and TE metrics bounds as
   specified in [RFC5441].

   Further details on the VN constraints are specified below:

         <VN Constraints> ::= [<Layer Protocol>]

                              [<Diversity>]

                              [<Shared Risk>]

                              <Metric>

      Where:

      <Layer Protocol> Identifies the layer at which the VN service is
      requested. It could be for example MPLS, ODU, and OCh.

      <Diversity> This allows asking for diversity constraints for a VN
      Instantiate/Modify or a VN Path Compute. For example, a new VN or
      a path is requested in total diversity from an existing one (e.g.
      diversity exclusion).

            <Diversity> ::= <VN-exclusion> (<VN-id>...) |

                            <VN-E2E Tunnel-exclusion> (<Tunnel-id>...)

      <Shared Risk> Based on the realization of VN required, group of
      physical resources can be impacted by the same risk. An E2E
      tunnel can be impacted by this shared risk. This is used to get
      the SRLG associated with the different tunnels composing a VN.

      <Metric> can include all the Metrics (cost, delay, delay
      variation, latency), bandwidth utilization parameters defined and
      referenced by [RFC3630] and [RFC7471].

   <VN Survivability> describes all attributes related to the VN
   recovery level and its survivability policy enforced by the
   customers/applications.

         <VN Survivability> ::= <VN Recovery Level>

                              [<VN Tunnel Recovery Level>]

                              [<VN Survivability Policy>]

         Where:


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         <VN Recovery Level> It is a value representing the requested
         level of resiliency required against the VN. The following
         values are defined:

         . Unprotected VN
         . VN with per tunnel recovery: The recovery level is defined
            against the tunnels composing the VN and it is specified in
            the <VN Tunnel Recovery Level>.

         <VN Tunnel Recovery Level> ::= <0:1>|<1+1>|<1:1>|<1:N>|<M:N>|

                              <On the fly restoration>

         The VN Tunnel Recovery Level indicates the type of protection
         or restoration mechanism applied to the VN. It augments the
         recovery types defined in [RFC4427].

         <VN Survivability Policy> ::= [<Local Reroute Allowed>]

                                       [<Domain Preference>]

                                       [<Push Allowed>]

                                       [<Incremental Update>]





         Where:

          <Local Reroute Allowed> is a delegation policy to the Server
          to allow or not a local reroute fix upon a failure of the
          primary LSP.

          <Domain Preference> is only applied on the MPI where the MDSC
          (client) provides a domain preference to each PNC
          (server).e.g. when a inter-domain link fails, then PNC can
          choose the alternative peering with this info.

          <Push Allowed> is a policy that allows a server to trigger an
          updated VN topology upon failure without an explicit request
          from the client. Push action can be set as default unless
          otherwise specified.

          <Incremental Update> is another policy that triggers an
          incremental update from the server since the last period of


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          update. Incremental update can be set as default unless
          otherwise specified.

2.2.3. VN End-Point

   <VN End-Point> Object describes the VN's customer end-point
   characteristics.

   <VN End-Point> ::= (<Access Point Identifier>

                      [<Access Link Capability>]

                      [<Source Indicator>])...

      Where:

     <Access point identifier> It represents a unique identifier of the
     client end-point. They are used by the customer to ask for the
     setup of a virtual network creation. A <VN End-Point> is defined
     against each AP in the network and is shared between customer and
     provider. Both the customer and the provider will map it against
     his own physical resources.

     <Access Link Capability> An optional object that identifies the
     capabilities of the access link related to the given access point.
     (e.g., max-bandwidth, bandwidth availability, etc.)

    <Source Indicator> indicates if an End-point is source or not.





2.2.4. VN Objective Function

   The VN Objective Function applies to each VN member (i.e., each E2E
   tunnel) of a VN.

   The VN Objective Function can reuse objective functions defined in
   [RFC5541] section 4.

   For a single path computation, the following objective functions are
   defined:

          o MCP is the Minimum Cost Path with respect to a specific
             metric (e.g. shortest path).



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          o MLP is the Minimum Load Path, that means find a path
             composted by te-link least loaded.
          o MBP is the Maximum residual Bandwidth Path.


   For a concurrent path computation, the following objective functions
   are defined:

          o MBC is to Minimize aggregate Bandwidth Consumption.
          o MLL is to Minimize the Load of the most loaded Link.
          o MCC is to Minimize the Cumulative Cost of a set of paths.


2.2.5. VN Action Status

   <VN Action Status> is the status indicator whether the VN has been
   successfully instantiated, modified, or deleted in the server
   network or not in response to a particular VN action.

   Note that this action status object can be implicitly indicated and
   thus not included in any of the VN primitives discussed in Section
   2.3.



2.2.6. VN Associated LSP

   <VN Associated LSP> describes the instantiated LSPs that is
   associated with the VN. <VN Associated LSP> is used between each
   domain PNC and the MDSC as part of VN Update once the VN is
   instantiated in each domain network and when CNC want to have more
   details about the topology instantiated as consequence of a VN
   Instantiate.

   <VN Associated LSP> ::= <VN Identifier> (<LSP>...)

2.2.7. VN Computed Path

   The VN Computed Path is the list of paths obtained after the VN path
   computation request from higher controller. Note that the computed
   path is to be distinguished from the LSP. When the computed path is
   signaled in the network (and thus the resource is reserved for that
   path), it becomes an LSP.

   <VN Computed Path> ::= (<Path>...)




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2.2.8. VN Service Preference

   This section provides VN Service preference. VN Service is defined
   in Section 2.

   <VN Service Preference> ::= [<Location Service Preference >]

                           [<Client-specific Preference >]

                           [<End-Point Dynamic Selection Preference >]

   Where

      <Location Service Preference describes the End-Point Location's
      (e.g. Data Centers) support for certain Virtual Network Functions
      (VNFs) (e.g., security function, firewall capability, etc.)and is
      used to find the path that satisfies the VNF constraint.


      <Client-specific Preference> describes any preference related to
      Virtual Network Service (VNS) that application/client can enforce
      via CNC towards lower level controllers. For example, permission
      the correct selection from the network of the destination related
      to the indicated VNF It is e.g. the case of VM migration among
      data center and CNC can enforce specific policy that can permit
      MDSC/PNC to calculate the correct path for the connectivity
      supporting the data center interconnection required by
      application.

      <End-Point Dynamic Selection Preference> describes if the End-
      Point (e.g. Data Center) can support load balancing, disaster
      recovery or VM migration and so can be part of the selection by
      MDSC following service Preference enforcement by CNC.

2.3. Mapping of VN Primitives with VN Objects

   This section describes the mapping of VN Primitives with VN Objects
   based on Section 2.2.



   <VN Instantiate> ::= <VN Service Characteristics>

                        <VN Objective Function>

                        <VN End-Point>



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                        [<VN Service Preference>]



   <VN Modify> ::= <VN identifier>

                   <VN Service Characteristics>

                  [<VN Objective Function>]

                   <VN End-Point>

                  [<VN Service Preference>]



   <VN Delete> ::= <VN Identifier>



   <VN Update> :: = <VN Identifier>

                    <VN Associated LSP>



   <VN Path Compute Request> ::= <VN Service Characteristic>

                         <VN Objective Function>

                         <VN End-Point>





   <VN Path Compute Reply> ::= <VN Computed Path>



   <VN Query> ::= <VN Identifier>



   <VN Query Reply> ::= <VN Identifier>

                        <VN Associated LSP>


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3. References

3.1. Normative References



   [DRAFT-SER-AWARE] Dhruv Dhody, Qin Wu, Vishwas Manral, Zafar Ali,
             and Kenji Kumaki, "Extensions to the Path Computation
             Element Communication Protocol (PCEP) to compute service
             aware Label Switched Path (LSP).," June 2016, draft-ietf-
             pce-pcep-service-aware-10.

3.2. Informative References



   [TE-TOPO] Liu, X. et al., "YANG Data Model for TE Topologies",
             draft-ietf-teas-yang-te-topo, work in progress.Informative
             References

   [ACTN-Req] Y. Lee, et al., "Requirements for Abstraction and Control
             of Transport Networks", draft-lee-teas-actn-requirements,
             work in progress.

   [ACTN-Frame]   D. Ceccarelli, et al., "Framework for Abstraction and
             Control of Transport Networks", draft-ceccarelli-teas-
             actn-framework, work in progress.

   [Stateful-PCE] E. Crabbe, et al., "PCEP Extensions for Stateful
             PCE", draft-ietf-pce-stateful-pce, work in progress.

   [RFC5541] JL. Le Roux, JP. Vasseur and Y. Lee, "Encoding of
             Objective Functions in the Path Computation Element
             Communication Protocol (PCEP)", RFC 5541, June 2009.

   [RFC7926] A.Farrel, et al., "Problem Statement and Architecture for
             Information Exchange between Interconnected Traffic-
             Engineered Networks", RFC 7926, July 2016.





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4. Contributors

Contributors' Addresses

Authors' Addresses

   Young Lee (Editor)
   Huawei Technologies
   5340 Legacy Drive
   Plano, TX 75023, USA
   Phone: (469)277-5838
   Email: leeyoung@huawei.com

   Sergio Belotti (Editor)
   Alcatel Lucent
   Via Trento, 30
   Vimercate, Italy
   Email: sergio.belotti@alcatel-lucent.com

   Dhruv Dhody
   Huawei Technologies,
   Divyashree Technopark, Whitefield
   Bangalore, India
   Email: dhruv.ietf@gmail.com


   Daniele Ceccarelli
   Ericsson
   Torshamnsgatan,48
   Stockholm, Sweden
   Email: daniele.ceccarelli@ericsson.com


   Bin Young Yun
   ETRI
   Email: byyun@etri.re.kr

   Haomian Zheng
   Huawei Technologies
   Email: zhenghaomian@huawei.com

   Xian Zhang
   Huawei Technologies
   Email: zhang.xian@huawei.com



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Appendix A: ACTN Applications

A.1. Coordination of Multi-destination Service Requirement/Policy

                             +----------------+
                             |       CNC      |
                             |   (Global DC   |
                             |   Operation    |
                             |    Control)    |
                             +--------+-------+
                                      | |  Service Requirement/Policy:
                                      | |  - Endpoint/DC location info
                                      | |  - Endpoint/DC dynamic
                                      | |    selection policy
                                      | |    (for VM migration, DR, LB)
                                      | v
                            +---------+---------+
                            |  Multi-domain     | Service policy-driven
                            |Service Coordinator| dynamic DC selection
                            +-----+---+---+-----+
                                  |   |   |
                                  |   |   |
                 +----------------+   |   +----------------+
                 |                    |                    |
           +-----+-----+       +-----+------+      +------+-----+
           |   PNC for |       |  PNC for   |      |  PNC for   |
           | Transport |       | Transport  |      | Transport  |
           | Network A |       | Network B  |      | network C  |
           +-----------+       +------------+      +------------+
                 |                    |                   |
+---+      ------               ------              ------       +---+
|DC1|--////      \\\\       ////      \\\\      ////      \\\\---+DC5|
+---+ |              |     |              |    |              |  +---+
      |     TN A     +-----+     TN B     +----+      TN C    |
      /              |     |              |    |              |
     / \\\\      ////     / \\\\      ////      \\\\      ////
   +---+   ------        /      ------    \         ------ \
   |DC2|                /                  \                \+---+
   +---+               /                    \                |DC6|
                     +---+                   \ +---+         +---+
                     |DC3|                    \|DC4|
                     +---+                     +---+

                                                DR: Disaster Recovery
                                                LB: Load Balancing
            Figure A.1: Service Policy-driven Data Center Selection



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   Figure A.1 shows how VN service policies from the CNC are
   incorporated by the MDSC to support multi-destination applications.
   Multi-destination applications refer to applications in which the
   selection of the destination of a network path for a given source
   needs to be decided dynamically to support such applications.

   Data Center selection problems arise for VM mobility, disaster
   recovery and load balancing cases. VN's service policy plays an
   important role for virtual network operation. Service policy can be
   static or dynamic. Dynamic service policy for data center selection
   may be placed as a result of utilization of data center resources
   supporting VNs. The MDSC would then incorporate this information to
   meet the service objective of this application.




































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A.2. Application Service Policy-aware Network Operation

                           +----------------+
                           |       CNC      |
                           |   (Global DC   |
                           |   Operation    |
                           |    Control)    |
                           +--------+-------+
                                    | | Application Service Policy
                                    | | - VNF requirement (e.g.
                                    | |   security function, etc.)
                                    | | - Location profile for each VNF
                                    | v
                          +---------+---------+
                          |  Multi-domain     |  Dynamically select the
                          |Service Coordinator|  network destination to
                          +-----+---+---+-----+  meet VNF requirement.
                                |   |   |
                                |   |   |
                +---------------+   |   +----------------+
                |                   |                    |
         +------+-----+       +-----+------+      +------+-----+
         |   PNC for  |       |  PNC for   |      |  PNC for   |
         | Transport  |       | Transport  |      | Transport  |
         | Network A  |       | Network B  |      | network C  |
         |            |       |            |      |            |
         +------------+       +------------+      +------------+
                |                   |                    |
{VNF b}         |                   |                    |  {VNF b,c}
+---+      ------               ------              ------     +---+
|DC1|--////      \\\\       ////      \\\\      ////      \\\\-|DC5|
+---+ |              |     |              |    |              |+---+
     |      TN A      +---+     TN B       +--+      TN C      |
      /              |     |              |    |              |
     / \\\\      ////     / \\\\      ////      \\\\      ////
   +---+   ------        /      ------    \         ------ \
   |DC2|                /                  \                \\+---+
   +---+               /                    \                 |DC6|
    {VNF a}         +---+                    +---+            +---+
                    |DC3|                    |DC4|      {VNF a,b,c}
                    +---+                    +---+
            {VNF a, b}                      {VNF a, c}

        Figure A.2: Application Service Policy-aware Network Operation




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   This scenario is similar to the previous case in that the VN service
   policy for the application can be met by a set of multiple
   destinations that provide the required virtual network functions
   (VNF). Virtual network functions can be, for example, security
   functions required by the VN application. The VN service policy by
   the CNC would indicate the locations of a certain VNF that can be
   fulfilled. This policy information is critical in finding the
   optimal network path subject to this constraint. As VNFs can be
   dynamically moved across different DCs, this policy should be
   dynamically enforced from the CNC to the MDSC and the PNCs.







































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A.3. Network Function Virtualization Service Enabled Connectivity

                           +----------------+
                           |       CNC      |
                           |   (Global DC   |
                           |   Operation    |
                           |    Control)    |
                           +--------+-------+
                                    | | Service Policy related to VNF
                                    | | (e.g., firewall, traffic
                                    | | optimizer)
                                    | |
                                    | v
                          +---------+---------+
                          |  Multi-domain     | Select network
                          |Service Coordinator| connectivity subject to
                          +-----+---+---+-----+ meeting service policy
                                |   |   |
                                |   |   |
                +---------------+   |   +----------------+
                |                   |                    |
         +------+-----+       +-----+------+      +------+-----+
         |   PNC for  |       |  PNC for   |      |  PNC for   |
         | Transport  |       | Transport  |      | Transport  |
         | Network A  |       | Network B  |      | network C  |
         |            |       |            |      |            |
         +------------+       +------------+      +------------+
                |                   |                    |
                |                   |                    |
+---+      ------               ------              ------     +---+
|DC1|--////      \\\\       ////      \\\\      ////      \\\\-|DC5|
+---+ |              |     |              |    |              |+---+
     |      TN A      +---+     TN B       +--+      TN C      |
      /              |     |              |    |              |
     / \\\\      ////     / \\\\      ////      \\\\      ////
   +---+   ------        /      ------    \         ------ \
   |DC2|                /                  \                \\+---+
   +---+               /                    \                 |DC6|
                    +---+                    +---+            +---+
                    |DC3|                    |DC4|
                    +---+                    +---+


          Figure A.3: Network Function Virtualization Service Enabled
                                 Connectivity



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   Network Function Virtualization Services are usually setup between
   customers' premises and service provider premises and are provided
   mostly by cloud providers or content delivery providers. The context
   may include, but not limited to a security function like firewall, a
   traffic optimizer, the provisioning of storage or computation
   capacity where the customer does not care whether the service is
   implemented in a given data center or another. The customer has to
   provide (and CNC is providing this)the type of VNF he needs and the
   policy associated with it (e.g. metric like estimated delay to reach
   where VNF is located in the DC). The policy linked to VNF is
   requested as part of the VN instantiation. These services may be
   hosted virtually by the provider or physically part of the network.
   This allows the service provider to hide his own resources (both
   network and data centers) and divert customer requests where most
   suitable. This is also known as "end points mobility" case and
   introduces new concepts of traffic and service provisioning and
   resiliency (e.g., Virtual Machine mobility).
































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A.4. Dynamic Service Control Policy Enforcement for Performance and
   Fault Management

        +------------------------------------------------+
        |           Customer Network Controller          |
        +------------------------------------------------+
        1.Traffic|  /|\4.Traffic           | /|\
        Monitor& |   |  Monitor            |  | 8.Traffic
        Optimize |   |  Result   5.Service |  | modify &
        Policy   |   |             modify& |  | optimize
                \|/  |       optimize Req.\|/ | result
        +------------------------------------------------+
        |         Multi-domain Service Coordinator       |
        +------------------------------------------------+
        2. Path  |  /|\3.Traffic           | /|\
        Monitor  |   | Monitor             |  |7.Path
        Request  |   | Result     6.Path   |  | modify &
                 |   |            modify&  |  | optimize
                \|/  |       optimize Req.\|/ | result
        +------------------------------------------------+
        |          Physical Network Controller           |
        +------------------------------------------------+

        Figure A.4: Dynamic Service Control for Performance and Fault
                                 Management

   Figure A.4 shows the flow of dynamic service control policy
   enforcement for performance and fault management initiated by
   customer per VN. The feedback loop and filtering mechanism tailored
   for VNs performed by the MDSC differentiates this ACTN scope from
   traditional network management paradigm. VN level dynamic OAM data
   model is a building block to support this capability.

















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A.5. E2E VN Survivability and Multi-Layer (Packet-Optical) Coordination
for Protection/Restoration

                        +----------------+
                        |   Customer     |
                        |   Network      |
                        |   Controller   |
                        +--------*-------+
                                 *  |     E2E VN Survivability Req.
                                 *  |     - VN Protection/Restoration
                                 *  v        - 1+1, Restoration, etc.
                          +------*-----+   - End Point (EP) info.
                          |            |
                          |    MDSC    | MDSC enforces VN survivability
                          |            | requirement, determining the
                          |            | optimal combination of Packet/
                          +------*-----+ Optical protection/restoration
                                 *       Optical bypass, etc.
                                 *
                                 *
              **********************************************
              *               *             *              *
         +----*-----+    +----*----+   +----*-----+   +----*----+
         |PNC for   |    |PNC for  |   |PNC for   |   |PNC for  |
         |Access N. |    |Packet C.|   |Optical C.|   |Access N.|
         +----*-----+    +----*----+   +----*-----+   +---*-----+
              *             --*---          *             *
              *          ///      \\\       *             *
            --*---      |   Packet   |      *         ----*-
         ///      \\\   |    Core    +------+------///      \\\
        |  Access    +----\\      ///       *     |   Access   |
        |  Network   |      ---+--          *     |   Network  |  +---+
        |\\\      ///          |            *      \\\      ///---+EP6|
        |   +---+-  |          |       -----*         -+---+      +---+
      +-+-+     |   |          +----///      \\\       |   |
      |EP1|     |   +--------------+  Optical   |      |   |  +---+
      +---+     |                  |    Core    +------+   +--+EP5|
              +-+-+                 \\\      ///              +---+
              |EP2|                    ------ |
              +---+                     |     |
                                     +--++   ++--+
                                     |EP3|   |EP4|
                                     +---+   +---+

     Figure A.5: E2E VN Survivability and Multi-layer Coordination for
                        Protection and Restoration



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   Figure A.5 shows the need for E2E protection/restoration control
   coordination that involves CNC, MDSC and PNCs to meet the VN
   survivability requirement. VN survivability requirement and its
   policy need to be translated into multi-domain and multi-layer
   network protection and restoration scenarios across different
   controller types. After an E2E path is setup successfully, the MDSC
   has a unique role to enforce policy-based flexible VN survivability
   requirement by coordinating all PNC domains.

   As seen in Figure A.5, multi-layer (i.e., packet/optical)
   coordination is a subset of this E2E protection/restoration control
   operation. The MDSC has a role to play in determining an optimal
   protection/restoration level based on the customer's VN
   survivability requirement. For instance, the MDSC needs to interface
   the PNC for packet core as well as the PNC for optical core and
   enforce protection/restoration policy as part of the E2E
   protection/restoration. Neither the PNC for packet core nor the PNC
   for optical core is in a position to be aware of the E2E path and
   its protection/restoration situation. This role of the MDSC is
   unique for this reason. In some cases, the MDSC will have to
   determine and enforce optical bypass to find a feasible reroute path
   upon packet core network failure which cannot be resolved the packet
   core network itself.

   To coordinate this operation, the PNCs will need to update its
   domain level abstract topology upon resource changes due to a
   network failure or other factors. The MDSC will incorporate all
   these update to determine if an alternative E2E reroute path is
   necessary or not based on the changes reported from the PNCs. It
   will need to update the E2E abstract topology and the affected CN's
   VN topology in real-time. This refers to dynamic synchronization of
   topology from Physical topology to abstract topology to VN topology.

   MDSC will also need to perform the path restoration signaling to the
   affected PNCs whenever necessary.














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