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

 


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Internet Engineering Task Force (IETF)                            Y. Lee
Request for Comments: 8454                                        Huawei
Category: Informational                                       S. Belotti
ISSN: 2070-1721                                                    Nokia
                                                                D. Dhody
                                                                  Huawei
                                                           D. Ceccarelli
                                                                Ericsson
                                                                 B. Yoon
                                                                    ETRI
                                                          September 2018


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

Abstract

   This document provides an information model for Abstraction and
   Control of TE Networks (ACTN).

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Not all documents
   approved by the IESG are candidates for any level of Internet
   Standard; see Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   https://www.rfc-editor.org/info/rfc8454.

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Copyright Notice

   Copyright (c) 2018 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
   (https://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.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  ACTN Common Interfaces Information Model  . . . . . . . . . .   5
   3.  Virtual Network Primitives  . . . . . . . . . . . . . . . . .   6
     3.1.  VN Instantiate  . . . . . . . . . . . . . . . . . . . . .   7
     3.2.  VN Modify . . . . . . . . . . . . . . . . . . . . . . . .   7
     3.3.  VN Delete . . . . . . . . . . . . . . . . . . . . . . . .   7
     3.4.  VN Update . . . . . . . . . . . . . . . . . . . . . . . .   7
     3.5.  VN Compute  . . . . . . . . . . . . . . . . . . . . . . .   8
     3.6.  VN Query  . . . . . . . . . . . . . . . . . . . . . . . .   8
   4.  TE Primitives . . . . . . . . . . . . . . . . . . . . . . . .   8
     4.1.  TE Instantiate  . . . . . . . . . . . . . . . . . . . . .   9
     4.2.  TE Modify . . . . . . . . . . . . . . . . . . . . . . . .   9
     4.3.  TE Delete . . . . . . . . . . . . . . . . . . . . . . . .   9
     4.4.  TE Topology Update (for TE Resources) . . . . . . . . . .   9
     4.5.  Path Compute  . . . . . . . . . . . . . . . . . . . . . .  10
   5.  VN Objects  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     5.1.  VN Identifier . . . . . . . . . . . . . . . . . . . . . .  11
     5.2.  VN Service Characteristics  . . . . . . . . . . . . . . .  11
     5.3.  VN Endpoint . . . . . . . . . . . . . . . . . . . . . . .  13
     5.4.  VN Objective Function . . . . . . . . . . . . . . . . . .  14
     5.5.  VN Action Status  . . . . . . . . . . . . . . . . . . . .  14
     5.6.  VN Topology . . . . . . . . . . . . . . . . . . . . . . .  15
     5.7.  VN Member . . . . . . . . . . . . . . . . . . . . . . . .  15
       5.7.1.  VN Computed Path  . . . . . . . . . . . . . . . . . .  15
       5.7.2.  VN Service Preference . . . . . . . . . . . . . . . .  16
   6.  TE Objects  . . . . . . . . . . . . . . . . . . . . . . . . .  17
     6.1.  TE Tunnel Characteristics . . . . . . . . . . . . . . . .  17
   7.  Mapping of VN Primitives with VN Objects  . . . . . . . . . .  19
   8.  Mapping of TE Primitives with TE Objects  . . . . . . . . . .  20
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  20
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  21
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  21
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  21
     11.2.  Informative References . . . . . . . . . . . . . . . . .  21
   Contributors  . . . . . . . . . . . . . . . . . . . . . . . . . .  22
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  23

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1.  Introduction

   This document provides an information model for Abstraction and
   Control of TE Networks (ACTN).  The information model described in
   this document covers the interface requirements identified in the
   ACTN Framework document [RFC8453].

   The ACTN reference architecture [RFC8453] identifies a three-tier
   control hierarchy comprising the following as depicted in Figure 1:

      o Customer Network Controllers (CNCs)
      o Multi-Domain Service Coordinator (MDSC)
      o Provisioning Network Controllers (PNCs)

   +-------+                 +-------+                   +-------+
   | 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.  This
   document models these two interfaces and derivative interfaces
   thereof (e.g., MDSC-to-MDSC in a hierarchy of MDSCs) as a single
   common interface.

1.1.  Terminology

   The terms "Virtual Network (VN)" and "Virtual Network Service (VNS)"
   are defined in [RFC8453].  Other key terms and concepts, for example,
   "abstraction", can be found in [RFC7926].

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2.  ACTN Common Interfaces Information Model

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

   The standard interface is described between a client controller and a
   server controller.  A client-server relationship is recursive between
   a CNC and an MDSC and between an MDSC and a PNC.  In the CMI, the
   client is a CNC while the server is an MDSC.  In the MPI, the client
   is an MDSC and the server is a PNC.  There may also be MDSC-MDSC
   interfaces 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
   requests/queries, VN service requests, path computation and
   connection control, VN service policy negotiation, enforcement,
   routing options, etc.

   There are two different types of primitives depending on the type of
   interface:

   o  Virtual Network primitives at CMI
   o  Traffic Engineering primitives at MPI

   As well described in [RFC8453], at the CMI level, there is no need
   for detailed TE information since the basic functionality is to
   translate customer service information into VNS operation.

   At the MPI level, MDSC has the main scope for multi-domain
   coordination and creation of a single end-to-end (E2E) abstracted
   network view that is strictly related to TE information.

   As for topology, this document employs two types of topology.

   o  The first type is referred to as "virtual network topology" and is
      associated with a VN.  Virtual network topology is a customized
      topology for view and control by the customer.  See Section 3.1
      for details.

   o  The second type is referred to as "TE topology" and is associated
      with provider network operation on which we can apply policy to
      obtain the required level of abstraction to represent the
      underlying physical network topology.

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3.  Virtual Network Primitives

   This section provides a list of main VN primitives related to VNs and
   that are necessary to satisfy the ACTN requirements specified in
   [ACTN-REQ].

   The following VN Action primitives are supported:

   o  VN Instantiate

   o  VN Modify

   o  VN Delete

   o  VN Update

   o  VN Path Compute

   o  VN Query

   VN Action is an object describing the main VN primitives.

   VN Action can assume one of the mentioned above primitives values.

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

                   <VN Modify> |

                   <VN Delete> |

                   <VN Update> |

                   <VN Path Compute> |

                   <VN Query>

   All these actions will solely happen at CMI level between CNC and
   MDSC.

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3.1.  VN Instantiate

   VN Instantiate refers to an action from customers/applications to
   request the creation of VNs.  VN Instantiate is for CNC-to-MDSC
   communication.  Depending on the agreement between client and
   provider, VN instantiate can imply different VN operations.  There
   are two types of VN instantiation:

   VN Type 1:  VN is viewed as a set of edge-to-edge links (VN members).

   VN Type 2:  VN is viewed as a VN-topology comprising virtual nodes
               and virtual links.

   Please see [RFC8453] for full details regarding the types of VN.

3.2.  VN Modify

   VN Modify refers to an action issued from customers/applications to
   modify an existing VN (i.e., an instantiated VN).  VN Modify is for
   CNC-to-MDSC communication.

   VN Modify, depending of the type of VN instantiated, can be:

   1.  a modification of the characteristics of VN members (edge-to-edge
       links) in the case of VN Type 1, or

   2.  a modification of an existing virtual topology (e.g., adding/
       deleting virtual nodes/links) in the case of VN Type 2.

3.3.  VN Delete

   VN Delete refers to an action issued from customers/applications to
   delete an existing VN.  VN Delete is for CNC-to-MDSC communication.

3.4.  VN Update

   "VN Update" refers to any update to the VN that needs to be updated
   to the customers.  VN Update is MDSC-to-CNC communication.  VN Update
   fulfills a push model at the CMI level, making customers aware of any
   specific changes in the topology details related to the instantiated
   VN.

   VN Update, depending of the type of VN instantiated, can be:

   1.  an update of VN members (edge-to-edge links) in case of VN Type
       1, or

   2.  an update of virtual topology in case of VN Type 2.

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   The connection-related information (e.g., Label Switched Paths
   (LSPs)) update association with VNs will be part of the "translation"
   function that happens in MDSC to map/translate VN request into TE
   semantics.  This information will be provided in case the customer
   optionally wants to have more-detailed TE information associated with
   the instantiated VN.

3.5.  VN Compute

   VN Compute consists of a Request and Reply.  "VN Compute Request"
   refers to an action from customers/applications to request a VN
   computation.

   "VN Compute Reply" refers to the reply in response to VN Compute
   Request.

   A VN Compute Request/Reply is to be differentiated from a VN
   Instantiate.  The purpose of VN Compute is a priori exploration to
   compute network resources availability and getting a possible VN view
   in which path details can be specified matching customer/applications
   constraints.  This a priori exploration may not guarantee the
   availability of the computed network resources at the time of
   instantiation.

3.6.  VN Query

   "VN Query" refers to an inquiry pertaining to a VN that has already
   been instantiated.  VN Query fulfills a pull model that permits
   getting a topology view.

   "VN Query Reply" refers to the reply in response to a VN Query.  The
   topology view returned by a VN Query Reply would be consistent with
   the topology type instantiated for any specific VN.

4.  TE Primitives

   This section provides a list of the main TE primitives necessary to
   satisfy ACTN requirements specified in [ACTN-REQ] related to typical
   TE operations supported at the MPI level.

   The TE action primitives defined in this section should be supported
   at the MPI consistently with the type of topology defined at the CMI.

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   The following TE action primitives are supported:

   o  TE Instantiate/Modify/Delete

   o  TE Topology Update (see Section 4.4. for the description)

   o  Path Compute

   TE Action is an object describing the main TE primitives.

   TE Action can assume one of the mentioned above primitives values.

   <TE Action> ::= <TE Instantiate> |

                   <TE Modify> |

                   <TE Delete> |

                   <TE Topology Update> |
                   <Path Compute> |

   All these actions will solely happen at MPI level between MDSC and
   PNC.

4.1.  TE Instantiate

   "TE Instantiate" refers to an action issued from MDSC to PNC to
   instantiate new TE tunnels.

4.2.  TE Modify

   "TE Modify" refers to an action issued from MDSC to PNC to modify
   existing TE tunnels.

4.3.  TE Delete

   "TE Delete" refers to an action issued from MDSC to PNC to delete
   existing TE tunnels.

4.4.  TE Topology Update (for TE Resources)

   TE Topology Update is a primitive specifically related to MPI used to
   provide a TE resource update between any domain controller and MDSC
   regarding the entire content of any actual TE topology of a domain
   controller or an abstracted filtered view of TE topology depending on
   negotiated policy.

   See [TE-TOPO] for detailed YANG implementation of TE topology update.

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   <TE Topology Update> ::= <TE-topology-list>

   <TE-topology-list> ::= <TE-topology> [<TE-topology-list>]

   <TE-topology> ::= [<Abstraction>] <TE-Topology-identifier> <Node-
   list> <Link-list>
   <Node-list> ::= <Node>[<Node-list>]

   <Node> ::= <Node> <TE Termination Point-list>

   <TE Termination Point-list> ::= <TE Termination Point> [<TE-
   Termination Point-list>]

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

   Where

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

   TE-topology-identifier is an identifier that identifies a specific
   te-topology, e.g., te-types:te-topology-id [TE-TOPO].

   Node-list is detailed information related to a specific node
   belonging to a te-topology, e.g., te-node-attributes [TE-TOPO].

   Link-list is information related to the specific link related
   belonging to a te-topology, e.g., te-link-attributes [TE-TOPO].

   TE Termination Point-list is detailed information associated with the
   termination points of a te-link related to a specific node, e.g.,
   interface-switching-capability [TE-TOPO].

4.5.  Path Compute

   Path Compute consists of Request and Reply.  "Path Compute Request"
   refers to an action from MDSC to PNC to request a path computation.

   "Path Compute Reply" refers to the reply in response to the Path
   Compute Request.

   The context of Path Compute is described in [Path-Compute].

5.  VN Objects

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

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5.1.  VN Identifier

   A VN Identifier is a unique identifier of the VN.

5.2.  VN Service Characteristics

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

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

                                    <VN Directionality>

                                    (<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 types of services (e.g., P2P/P2MP, etc.),
   ACTN defines the "multi-destination" service that is a new P2P
   service where the endpoints are not fixed.  They can be chosen among
   a list of preconfigured endpoints or dynamically provided by the CNC.

   VN Directionality indicates if a VN is unidirectional or
   bidirectional.  This implies that each VN member that belongs to the
   VN has the same directionality as the VN.

   <VN Traffic Matrix> ::= <Bandwidth>

                           [<VN Constraints>]

   The VN Traffic Matrix represents the traffic matrix parameters for
   the required service connectivity.  Bandwidth is a mandatory
   parameter, and a number of optional constraints can be specified in
   the VN Constraints (e.g., diversity, cost).  They can include
   objective functions and TE metric bounds as specified in [RFC5541].

   Further details on the VN constraints are specified below:

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

                              ( <Metric> | <VN Objective Function> )

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      Where:

      Layer Protocol identifies the layer topology at which the VN
      service is requested.  It could be, for example, MPLS, Optical
      Data Unit (ODU), and Optical Channel (OCh).

      Diversity 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-Member-exclusion> (<VN-Member-id>...))

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

      As for VN Objective Function, see Section 5.4.

   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:

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

         o  Unprotected VN

         o  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].

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

                                       [<Domain Preference>]

                                       [<Push Allowed>]

                                       [<Incremental Update>]

         Where:

         Local Reroute Allowed is a delegation policy to the Server on
         whether or not to allow 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 an 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
         update.  Incremental update can be set as default unless
         otherwise specified.

5.3.  VN Endpoint

   VN End-Point Object describes the VN's customer endpoint
   characteristics.

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

                      [<Access Link Capability>]
                      [<Source Indicator>])...

      Where:

     Access Point Identifier represents a unique identifier of the
     client endpoint.  They are used by the customer to ask for the
     setup of a virtual network instantiation.  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 their own physical resources.

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

     Source Indicator indicates whether or not an endpoint is the
     source.

5.4.  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
   Section 4 of [RFC5541].

   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).

   o  MLP is the Minimum Load Path, meaning 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.

5.5.  VN Action Status

   VN Action Status is the status indicator whether or not the VN has
   been successfully instantiated, modified, or deleted in the server
   network 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 3.

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5.6.  VN Topology

   When a VN is seen by the customer as a topology, it is referred to as
   "VN topology".  This is associated with VN Type 2, which is composed
   of virtual nodes and virtual links.

   <VN Topology> ::= <Virtual node list> <Virtual link list>

   <Virtual node list> ::= <Virtual node> [<Virtual node list>]

   <Virtual link list> :: = <Virtual link>  [<Virtual link list>]

5.7.  VN Member

   VN Member describes details of a VN Member that is a list of a set of
   VN Members represented as VN_Member_List.

   <VN_Member_List> ::= <VN Member> [<VN_Member_List>]

   Where <VN Member> ::= <Ingress VN End-Point>

                         [<VN Associated LSP>]

                         <Egress VN End-Point>

   Ingress VN End-Point is the VN End-Point information for the ingress
   portion of the AP.  See Section 5.3 for VN End-Point details.

   Egress VN End-Point is the VN End-Point information for the egress
   portion of the AP.  See Section 5.3 for VN End-Point details.

   VN Associated LSP describes the instantiated LSPs in the Provider's
   network for the VN Type 1.  It describes the instantiated LSPs over
   the VN topology for VN Type 2.

5.7.1.  VN Computed Path

   The VN Computed Path is the list of paths obtained after the VN path
   computation request from a 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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5.7.2.  VN Service Preference

   This section provides the 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 (DCs)) 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 VNS
      that an application/client can enforce via CNC towards lower-level
      controllers.  For example, CNC can enforce client-specific
      preferences, e.g., selection of a destination DC from the set of
      candidate DCs based on some criteria in the context of Virtual
      Machine (VM) migration.  MSDC/PNC should then provide the DC
      interconnection that supports the Client-specific Preference.

      End-Point Dynamic Selection Preference describes if the endpoint
      (e.g., DC) 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.

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6.  TE Objects

6.1.  TE Tunnel Characteristics

   Tunnel Characteristics describes the parameters needed to configure
   TE tunnel.

   <TE Tunnel Characteristics> ::= [<Tunnel Type>]

                                   <Tunnel Id>

                                   [<Tunnel Layer>]

                                   [<Tunnel end-point>]

                                   [<Tunnel protection-restoration>]

                                   <Tunnel Constraints>

                                  [<Tunnel Optimization>]

   Where

   <Tunnel Type> ::= <P2P>|<P2MP>|<MP2MP>|<MP2P>

   The Tunnel Type identifies the type of required tunnel.  In this
   document, only the P2P model is provided.

   Tunnel Id is the TE tunnel identifier

   Tunnel Layer represents the layer technology of the LSPs supporting
   the tunnel

   <Tunnel End Points> ::= <Source> <Destination>

   <Tunnel protection-restoration> ::= <prot 0:1>|<prot 1+1>|<prot
   1:1>|<prot 1:N>|prot <M:N>|<restoration>
   Tunnel Constraints are the base tunnel configuration constraints
   parameters.

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   Where <Tunnel Constraints> ::= [<Topology Id>]

                                  [<Bandwidth>]

                                  [<Disjointness>]

                                  [<SRLG>]

                                  [<Priority>]

                                  [<Affinities>]

                                  [<Tunnel Optimization>]

                                  [<Objective Function>]

   Topology Id references the topology used to compute the tunnel path.

   Bandwidth is the bandwidth used as a parameter in path computation.

   <Disjointness> ::= <node> | <link> | <srlg>

   Disjointness provides the type of resources from which the tunnel has
   to be disjointed.

   Shared Risk Link Group (SRLG) is a group of physical resources
   impacted by the same risk from which an E2E tunnel is required to be
   disjointed.

   <Priority> ::= <Holding Priority> <Setup Priority>

   where

   Setup Priority indicates the level of priority for taking resources
   from another tunnel [RFC3209].

   Holding Priority indicates the level of priority to hold resources
   avoiding preemption from another tunnel [RFC3209].

   Affinities represents the structure to validate a link belonging to
   the path of the tunnel [RFC3209].

   <Tunnel Optimization> ::= <Metric> | <Objective Function>

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

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   <Objective Function> ::= <objective function type>

   <objective function type> ::= <MCP> | <MLP> | <MBP> | <MBC> | <MLL>
   | <MCC>

   See Section 5.4 for a description of objective function type.

7.  Mapping of VN Primitives with VN Objects

   This section describes the mapping of VN primitives with VN Objects
   based on Section 5.

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

                        <VN Member-List>

                        [<VN Service Preference>]

                        [<VN Topology>]

   <VN Modify> ::= <VN identifier>

                   <VN Service Characteristics>

                   <VN Member-List>

                   [<VN Service Preference>]

                   [<VN Topology>]

   <VN Delete> ::= <VN Identifier>

   <VN Update> :: = <VN Identifier>
                    [<VN Member-List>]

                    [<VN Topology>]

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

                                 <VN Member-List>

                                 [<VN Service Preference>]

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

   <VN Query> ::= <VN Identifier>

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

                        <VN Associated LSP>

                        [<TE Topology Reference>]

8.  Mapping of TE Primitives with TE Objects

   This section describes the mapping of TE primitives with TE Objects
   based on Section 6.

   <TE Instantiate> ::= <TE Tunnel Characteristics>

   <TE Modify> ::=  <TE Tunnel Characteristics>

   <TE Delete> ::= <Tunnel Id>
   <TE Topology Update> ::= <TE-topology-list>

   <Path Compute Request> ::= <TE Tunnel Characteristics>

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

                            <TE Tunnel Characteristics>

9.  Security Considerations

   The ACTN information model is not directly relevant when considering
   potential security issues.  Rather, it defines a set of interfaces
   for TE networks.  The underlying protocols, procedures, and
   implementations used to exchange the information model described in
   this document will need to secure the request and control of
   resources with proper authentication and authorization mechanisms.
   In addition, the data exchanged over the ACTN interfaces discussed in
   this document requires verification of data integrity.  Backup or
   redundancies should also be available to restore the affected data to
   its correct state.

   Implementations of the ACTN framework will have distributed
   functional components that will exchange an instantiation that
   adheres to this information model.  Implementations should encrypt
   data that flows between them, especially when they are implemented at
   remote nodes and irrespective of whether these data flows are on
   external or internal network interfaces.  The information model may
   contain customer, application, and network data that, for business or
   privacy reasons, may be considered sensitive.  It should be stored
   only in an encrypted data store.

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   The ACTN security discussion is further split into two specific
   interfaces:

   o  Interface between the CNC and MDSC, CNC-MDSC Interface (CMI)

   o  Interface between the MDSC and PNC, MDSC-PNC Interface (MPI).

   See the detailed discussion of the CMI and MPI in Sections 9.1 and
   9.2 (respectively) in [RFC8453].

   The conclusion is that all data models and protocols used to realize
   the ACTN information model should have rich security features, as
   discussed in this section.  Additional security risks may still
   exist.  Therefore, discussion and applicability of specific security
   functions and protocols will be better described in documents that
   are use case and environment specific.

10.  IANA Considerations

   This document has no IANA actions.

11.  References

11.1.  Normative References

   [RFC8453]  Ceccarelli, D., Ed. and Y. Lee, Ed., "Framework for
              Abstraction and Control of TE Networks (ACTN)", RFC 8453,
              DOI 10.17487/RFC8453, August 2018,
              <https://www.rfc-editor.org/info/rfc8453>.

11.2.  Informative References

   [ACTN-REQ]
              Lee, Y., Ceccarelli, D., Miyasaka, T., Shin, J., and K.
              Lee, "Requirements for Abstraction and Control of TE
              Networks", Work in Progress,
              draft-ietf-teas-actn-requirements-09, March 2018.

   [Path-Compute]
              Busi, I., Belotti, S., Lopezalvarez, V., Dios, O., Sharma,
              A., Shi, Y., Vilata, R., and K. Sethuraman, "Yang model
              for requesting Path Computation", Work in Progress,
              draft-ietf-teas-yang-path-computation-02, June 2018.

   [RFC3209]  Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
              and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
              Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
              <https://www.rfc-editor.org/info/rfc3209>.

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   [RFC3630]  Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
              (TE) Extensions to OSPF Version 2", RFC 3630,
              DOI 10.17487/RFC3630, September 2003,
              <https://www.rfc-editor.org/info/rfc3630>.

   [RFC4427]  Mannie, E., Ed. and D. Papadimitriou, Ed., "Recovery
              (Protection and Restoration) Terminology for Generalized
              Multi-Protocol Label Switching (GMPLS)", RFC 4427,
              DOI 10.17487/RFC4427, March 2006,
              <https://www.rfc-editor.org/info/rfc4427>.

   [RFC5541]  Le Roux, JL., Vasseur, JP., and Y. Lee, "Encoding of
              Objective Functions in the Path Computation Element
              Communication Protocol (PCEP)", RFC 5541,
              DOI 10.17487/RFC5541, June 2009,
              <https://www.rfc-editor.org/info/rfc5541>.

   [RFC7471]  Giacalone, S., Ward, D., Drake, J., Atlas, A., and S.
              Previdi, "OSPF Traffic Engineering (TE) Metric
              Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015,
              <https://www.rfc-editor.org/info/rfc7471>.

   [RFC7926]  Farrel, A., Ed., Drake, J., Bitar, N., Swallow, G.,
              Ceccarelli, D., and X. Zhang, "Problem Statement and
              Architecture for Information Exchange between
              Interconnected Traffic-Engineered Networks", BCP 206,
              RFC 7926, DOI 10.17487/RFC7926, July 2016,
              <https://www.rfc-editor.org/info/rfc7926>.

   [TE-TOPO]  Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and
              O. Dios, "YANG Data Model for Traffic Engineering (TE)
              Topologies", Work in Progress,
              draft-ietf-teas-yang-te-topo-18, June 2018.

Contributors

   Haomian Zheng
   Huawei Technologies
   Email: zhenghaomian@huawei.com

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

Top      ToC       Page 23 
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)
   Nokia
   Via Trento, 30
   Vimercate, Italy

   Email: sergio.belotti@nokia.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 Yeong Yoon
   ETRI

   Email: byyun@etri.re.kr