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Versions: 00 01

Network Working Group                                         I. Bryskin
Internet-Draft                                       Huawei Technologies
Intended status: Informational                                    X. Liu
Expires: September 2, 2018                                         Jabil
                                                           March 1, 2018


                    SF Aware TE Topology YANG Model
               draft-bryskin-teas-sf-aware-topo-model-01

Abstract

   This document describes a YANG data model for TE network topologies
   that are network service and function aware.

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 September 2, 2018.

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
   (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.





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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   3
     1.3.  Prefixes in Data Node Names . . . . . . . . . . . . . . .   3
   2.  Modeling Considerations . . . . . . . . . . . . . . . . . . .   3
   3.  Model Structure . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  YANG Modules  . . . . . . . . . . . . . . . . . . . . . . . .   6
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  13
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  14
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  14
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  14
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  15
   Appendix A.  Companion YANG Model for Non-NMDA Compliant
                Implementations  . . . . . . . . . . . . . . . . . .  16
     A.1.  SF Aware TE Topology State Module . . . . . . . . . . . .  16
   Appendix B.  Data Examples  . . . . . . . . . . . . . . . . . . .  18
     B.1.  A Topology with Multiple Connected Network Functions  . .  18
     B.2.  A Topology with an Encapsulated Network Service . . . . .  23
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  27

1.  Introduction

   Today a network offers to its clients far more services than just
   connectivity across the network.  Large variety of physical, logical
   and/or virtual service functions, network functions and transport
   functions (collectively named in this document as SFs) could be
   allocated for and assigned to a client.  As described in
   [I-D.bryskin-teas-use-cases-sf-aware-topo-model], there are some
   important use cases, in which the network needs to represent to the
   client SFs at the client's disposal as topological elements in
   relation to other elements of a topology (i.e. nodes, links, link and
   tunnel termination points) used by the network to describe itself to
   the client.  Not only would such information allow for the client to
   auto-discover the network's SFs available for the services
   provisioned for the client, it would also allow for the client
   selecting the SFs, duel-optimizing the selection on the SF location
   on the network and connectivity means (e.g.  TE tunnels) to inter-
   connect the SFs.  Consequently thus would give to both the network
   and the client powerful means for the service function chain (SFC
   [RFC7498] [RFC7665]) negotiation to achieve most efficient and cost
   effective (from the network point of view) and most optimal yet
   satisfying all necessary constraints of SFCs(from the client's point
   of view).

   This document defines a YANG data model that allows service functions
   to be represented along with TE topology elements.



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1.1.  Terminology

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

   The following terms are defined in [RFC7950] and are not redefined
   here:

   o  augment

   o  data model

   o  data node

1.2.  Tree Diagrams

   A simplified graphical representation of the data model is presented
   in this document, by using the tree format defined in
   [I-D.ietf-netmod-yang-tree-diagrams].

1.3.  Prefixes in Data Node Names

   In this document, names of data nodes, actions, and other data model
   objects are often used without a prefix, as long as it is clear from
   the context in which YANG module each name is defined.  Otherwise,
   names are prefixed using the standard prefix associated with the
   corresponding YANG module, as shown in Table 1.

     +--------+------------------+-----------------------------------+
     | Prefix | YANG module      | Reference                         |
     +--------+------------------+-----------------------------------+
     | inet   | ietf-inet-types  | [RFC6991]                         |
     | nw     | ietf-network     | [I-D.ietf-i2rs-yang-network-topo] |
     | nt     | ietf-network-    | [I-D.ietf-i2rs-yang-network-topo] |
     |        | topology         |                                   |
     | tet    | ietf-te-topology | [I-D.ietf-teas-yang-te-topo]      |
     +--------+------------------+-----------------------------------+

             Table 1: Prefixes and Corresponding YANG Modules

2.  Modeling Considerations

   The model introduced in this document is an augmentation of the TE
   Topology model defined in [I-D.ietf-teas-yang-te-topo].  SFs are
   modeled as child elements of a TE node similarly to how Link
   Termination Points (LTPs) and Tunnel Termination Points (TTPs) are



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   modeled in the TE Topology model.  The SFs are defined as opaque
   objects identified via topology unique service-function-id's.  Each
   SF has one or more Connection Points (CPs) identified via SF-unique
   sf-connection-point-id's, over which the SF could be connected to
   other SFs resided on the same TE node, as well as to other elements
   of the TE node, in particular, to the node's LTPs and/or TTPs.  An
   interested client may use service-function-id's to look up the SFs in
   TOSCA or YANG data store(s) defined by [ETSI-NFV-MAN] to retrieve the
   details of the SFs, for example, to understand the SF's mutual
   substitutability.

   The TE Topology model introduces a concept of Connectivity Matrix
   (CM), and uses the CM to describe which and at what costs a TE node's
   LTPs could be inter-connected internally across the TE node.  The
   model defined in this document heavily uses the same concept to
   describe the SF connectivity via introducing 3 additional CMs:

   1.  SF2SF CM.  This CM describes which pairs of SFs could be locally
       inter-connected, and, if yes, in which direction, via which CPs
       and at what costs.  In other words, the SF2SF CM describes how
       SFs residing on the same TE node could be inter-connected into
       local from the TE node's perspective SFCs;

   2.  SF2LTP CM.  This CM describes how, in which direction and at what
       costs the TE node's SFs could be connected to the TE node's LTPs
       and hence to SFs residing on neighboring TE nodes that are
       connected to LTPs at the remote ends of corresponding TE links;

   3.  SF2TTP CM.  This CM describes how, in which direction and at what
       costs the TE node's SFs could be connected to the TE node's TTPs
       and hence to SFs residing on other TE nodes on the topology that
       could be inter-connected with the TE node in question via TE
       tunnels terminated by the corresponding TTPs.

   In addition to SF2SF CM, the local SF chaining could be described
   with the help of ETSI models Virtual Links (VLs) [ETSI-NFV-MAN].
   This option is especially useful when the costs of the local chaining
   are negligible as compared to ones of the end-to-end SFCs said local
   SFCs are part of.

3.  Model Structure

   module: ietf-te-topology-sf
     augment /nw:networks/nw:network/nw:network-types/tet:te-topology:
       +--rw sf!
     augment /nw:networks/nw:network/nw:node/tet:te
   /tet:te-node-attributes:
       +--rw service-function



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          +--rw connectivity-matrices
          |  +--rw connectivity-matrix* [id]
          |     +--rw id                 uint32
          |     +--rw from
          |     |  +--rw service-function-id?      string
          |     |  +--rw sf-connection-point-id?   string
          |     +--rw to
          |     |  +--rw service-function-id?      string
          |     |  +--rw sf-connection-point-id?   string
          |     +--rw enabled?           boolean
          |     +--rw direction?         connectivity-direction
          |     +--rw virtual-link-id?   string
          +--rw link-terminations
             +--rw link-termination* [id]
                +--rw id           uint32
                +--rw from
                |  +--rw tp-ref?   -> ../../../../../../..
   /nt:termination-point/tp-id
                +--rw to
                |  +--rw service-function-id?      string
                |  +--rw sf-connection-point-id?   string
                +--rw enabled?     boolean
                +--rw direction?   connectivity-direction
     augment /nw:networks/nw:network/nw:node/tet:te
   /tet:information-source-entry:
       +--ro service-function
          +--ro connectivity-matrices
          |  +--ro connectivity-matrix* [id]
          |     +--ro id                 uint32
          |     +--ro from
          |     |  +--ro service-function-id?      string
          |     |  +--ro sf-connection-point-id?   string
          |     +--ro to
          |     |  +--ro service-function-id?      string
          |     |  +--ro sf-connection-point-id?   string
          |     +--ro enabled?           boolean
          |     +--ro direction?         connectivity-direction
          |     +--ro virtual-link-id?   string
          +--ro link-terminations
             +--ro link-termination* [id]
                +--ro id           uint32
                +--ro from
                +--ro to
                |  +--ro service-function-id?      string
                |  +--ro sf-connection-point-id?   string
                +--ro enabled?     boolean
                +--ro direction?   connectivity-direction
     augment /nw:networks/nw:network/nw:node/tet:te



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   /tet:tunnel-termination-point:
       +--rw service-function
          +--rw tunnel-terminations
             +--rw tunnel-termination* [id]
                +--rw id                        uint32
                +--rw service-function-id?      string
                +--rw sf-connection-point-id?   string
                +--rw enabled?                  boolean
                +--rw direction?                connectivity-direction


4.  YANG Modules


   <CODE BEGINS> file "ietf-te-topology-sf@2018-02-27.yang"
   module ietf-te-topology-sf {
     yang-version 1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-te-topology-sf";

     prefix "tet-sf";

     import ietf-network {
       prefix "nw";
     }

     import ietf-network-topology {
       prefix "nt";
     }

     import ietf-te-topology {
       prefix "tet";
     }

     organization
       "Traffic Engineering Architecture and Signaling (TEAS)
        Working Group";

     contact
       "WG Web:   <http://tools.ietf.org/wg/teas/>
        WG List:  <mailto:teas@ietf.org>

        Editors:  Igor Bryskin
                  <mailto:Igor.Bryskin@huawei.com>

                  Xufeng Liu
                  <mailto:Xufeng_Liu@jabil.com>";

     description



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       "Network service and function aware aware TE topology model.

        Copyright (c) 2018 IETF Trust and the persons identified as
        authors of the code.  All rights reserved.

        Redistribution and use in source and binary forms, with or
        without modification, is permitted pursuant to, and subject to
        the license terms contained in, the Simplified BSD License set
        forth in Section 4.c of the IETF Trust's Legal Provisions
        Relating to IETF Documents
        (http://trustee.ietf.org/license-info).";

     revision 2018-02-27 {
       description "Initial revision";
       reference "TBD";
     }

     /*
      * Typedefs
      */
     typedef connectivity-direction {
       type enumeration {
         enum "to" {
           description
           "The direction is uni-directional, towards the 'to'
            entity direction.";
         }
         enum "from" {
           description
           "The direction is uni-directional, from the 'to'
            entity direction.";
         }
         enum "bidir" {
           description
           "The direction is bi-directional.";
         }
       }
       description
         "A type used to indicates whether a connectivity is
          uni-directional, or bi-directional. If the relation is
          uni-directional, the value of this type indicates the
          direction.";
     } // connectivity-direction

     /*
      * Groupings
      */
     grouping service-function-node-augmentation {



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       description
         "Augmenting a TE node to be network service and function
          aware.";
       container service-function {
         description
           "Containing attributes related to network services and
            network functions";
         container connectivity-matrices {
           description
             "Connectivity relations between network services/functions
              on a TE node, which can be either abstract or physical.";
           reference
             "ETSI GS NFV-MAN 01: Network Functions Virtualisation
              (NFV); Management and Orchestration.
              RFC7665: Service Function Chaining (SFC) Architecture.";
           list connectivity-matrix {
             key "id";
             description
               "Represents the connectivity relations between network
                services/functions on a TE node.";
             leaf id {
               type uint32;
               description "Identifies the connectivity-matrix entry.";
             }

             container from {
               description
                 "Reference to the source network service or
                  network function.";
               leaf service-function-id {
                 type string;
                 description
                   "Reference to a network service or a network
                    function.";
               }
               leaf sf-connection-point-id {
                 type string;
                 description
                   "Reference to a connection point on a network
                    service or a network function.";
               }
             } // from
             container to {
               description
                 "Reference to the destination network service or
                  network function.";
               leaf service-function-id {
                 type string;



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                 description
                   "Reference to a network service or a network
                    function.";
                 }
               leaf sf-connection-point-id {
                 type string;
                 description
                   "Reference to a connection point on a network
                    service or a network function.";
               }
             } // to
             leaf enabled {
               type boolean;
               description
                 "'true' if this connectivity entry is enabled.";
             }
             leaf direction {
               type connectivity-direction;
               description
                 "Indicates whether this connectivity is
                  uni-directional, or bi-directional. If the
                  relation is uni-directional, the value of
                  this leaf indicates the direction.";
             }
             leaf virtual-link-id {
               type string;
               description
                 "Reference to a virtual link that models this
                  conectivity relation in the network function
                  model.";
             }
           } // connectivity-matrix
         } // connectivity-matrices

         container link-terminations {
           description
             "Connectivity relations between network services/functions
              and link termination points on a TE node, which can be
              either abstract or physical.";
           reference
             "ETSI GS NFV-MAN 01: Network Functions Virtualisation
              (NFV); Management and Orchestration.
              RFC7665: Service Function Chaining (SFC) Architecture.";
           list link-termination {
             key "id";
             description
               "Each entry of the list represents the connectivity
                relation between a network service/function and



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                a link termination point on a TE node.";
             leaf id {
               type uint32;
               description "Identifies the termination entry.";
             }

             container from {
               description
                 "Reference to the link termination point.";
             } // from
             container to {
               description
                 "Reference to the network service or network
                  function.";
               leaf service-function-id {
                 type string;
                 description
                   "Reference to a network service or a network
                    function.";
                 }
               leaf sf-connection-point-id {
                 type string;
                 description
                   "Reference to a connection point on a network
                    service or a network function.";
               }
             } // to
             leaf enabled {
               type boolean;
               description
                 "'true' if this connectivity entry is enabled.";
             }
             leaf direction {
               type connectivity-direction;
               description
                 "Indicates whether this connectivity is
                  uni-directional, or bi-directional. If the
                  relation is uni-directional, the value of
                  this leaf indicates the direction.";
             }
           } // link-termination
         }
       }
     } // service-function-node-augmentation

     grouping service-function-ttp-augmentation {
       description
         "Augmenting a tunnel termination point to be network service



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          aware.";
       container service-function {
         description
           "Containing attributes related to network services and
            network functions";
         container tunnel-terminations {
           description
             "Connectivity relations between network services/functions
              and tunnel termination points on a TE node, which can be
              either abstract or physical.";
           reference
             "ETSI GS NFV-MAN 01: Network Functions Virtualisation
              (NFV); Management and Orchestration.
              RFC7665: Service Function Chaining (SFC) Architecture.";
           list tunnel-termination {
             key "id";
             description
               "Each entry of the list represents the connectivity
                relation between a network service/function and
                a tunnel termination point on a TE node.";
             leaf id {
               type uint32;
               description "Identifies the termination entry.";
             }

             leaf service-function-id {
               type string;
               description
                 "Reference to a network service or a network
                  function.";
             }
             leaf sf-connection-point-id {
               type string;
               description
                 "Reference to a connection point on a network
                  service or a network function.";
             }
             leaf enabled {
               type boolean;
               description
                 "'true' if this connectivity entry is enabled.";
             }
             leaf direction {
               type connectivity-direction;
               description
                 "Indicates whether this connectivity is
                  uni-directional, or bi-directional. If the
                  relation is uni-directional, the value of



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                  this leaf indicates the direction.";
             }
           } // link-termination
         }
       }
     } // service-function-ttp-augmentation

     grouping sf-topology-type {
       description
         "Identifies the SF aware TE topology type.";
       container sf {
         presence "Indidates that the TE topology is SF aware.";
         description
           "Its presence identifies that the TE topology is SF aware.";
       }
     } // sf-topology-type

     /*
      * Augmentations
      */
     /* Augmentations to network-types/te-topology */
     augment "/nw:networks/nw:network/nw:network-types/"
       + "tet:te-topology" {
       description
         "Defines the SF aware TE topology type.";
       uses sf-topology-type;
     }

     /* Augmentations to te-node-attributes */
     augment "/nw:networks/nw:network/nw:node/tet:te/"
       + "tet:te-node-attributes" {
       description
         "Parameters for SF aware TE topology.";
       uses service-function-node-augmentation;
     }

     augment "/nw:networks/nw:network/nw:node/tet:te/"
           + "tet:information-source-entry" {
       description
         "Parameters for SF aware TE topology.";
       uses service-function-node-augmentation;
     }

     /* Augmentations to tunnel-termination-point */
     augment "/nw:networks/nw:network/nw:node/tet:te/"
       + "tet:tunnel-termination-point" {
       description
         "Parameters for SF aware TE topology.";



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       uses service-function-ttp-augmentation;
     }

     /* Augmentations to connectivity-matrix */
     augment "/nw:networks/nw:network/nw:node/tet:te/"
       + "tet:te-node-attributes/tet-sf:service-function/"
       + "tet-sf:link-terminations/tet-sf:link-termination/"
       + "tet-sf:from" {
       description
         "Add reference to the link termination point.
          This portion cannot be shared with the state module.";
       leaf tp-ref {
         type leafref {
           path "../../../../../../../nt:termination-point/"
             + "nt:tp-id";
         }
         description
           "Reference to the link termination point.";
       }
     }
   }
   <CODE ENDS>



5.  IANA Considerations

   RFC Ed.: In this section, replace all occurrences of 'XXXX' with the
   actual RFC number (and remove this note).

   This document registers the following namespace URIs in the IETF XML
   registry [RFC3688]:

   --------------------------------------------------------------------
   URI: urn:ietf:params:xml:ns:yang:ietf-te-topology-sf
   Registrant Contact: The IESG.
   XML: N/A, the requested URI is an XML namespace.
   --------------------------------------------------------------------

   --------------------------------------------------------------------
   URI: urn:ietf:params:xml:ns:yang:ietf-te-topology-sf-state
   Registrant Contact: The IESG.
   XML: N/A, the requested URI is an XML namespace.
   --------------------------------------------------------------------

   This document registers the following YANG modules in the YANG Module
   Names registry [RFC7950]:




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   --------------------------------------------------------------------
   name:         ietf-te-topology-sf
   namespace:    urn:ietf:params:xml:ns:yang:ietf-te-topology-packet
   prefix:       tet-sf
   reference:    RFC XXXX
   --------------------------------------------------------------------

   --------------------------------------------------------------------
   name:         ietf-te-topology-sf-state
   namespace:  urn:ietf:params:xml:ns:yang:ietf-te-topology-packet-state
   prefix:       tet-sf-s
   reference:    RFC XXXX
   --------------------------------------------------------------------

6.  Security Considerations

   The configuration, state, action and notification data defined in
   this document are designed to be accessed via the NETCONF protocol
   [RFC6241].  The data-model by itself does not create any security
   implications.  The security considerations for the NETCONF protocol
   are applicable.  The NETCONF protocol used for sending the data
   supports authentication and encryption.

7.  References

7.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997, <https://www.rfc-
              editor.org/info/rfc2119>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6991]  Schoenwaelder, J., Ed., "Common YANG Data Types",
              RFC 6991, DOI 10.17487/RFC6991, July 2013,
              <https://www.rfc-editor.org/info/rfc6991>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.







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   [ETSI-NFV-MAN]
              ETSI, "Network Functions Virtualisation (NFV); Management
              and Orchestration", ETSI GS NFV-MAN 001 V1.1.1, December
              2014.

   [I-D.bryskin-teas-use-cases-sf-aware-topo-model]
              Bryskin, I., Liu, X., Guichard, J., Lee, Y., Contreras,
              L., and D. Ceccarelli, "Use Cases for SF Aware Topology
              Models", draft-bryskin-teas-use-cases-sf-aware-topo-
              model-01 (work in progress), October 2017.

   [I-D.ietf-i2rs-yang-network-topo]
              Clemm, A., Medved, J., Varga, R., Bahadur, N.,
              Ananthakrishnan, H., and X. Liu, "A Data Model for Network
              Topologies", draft-ietf-i2rs-yang-network-topo-20 (work in
              progress), December 2017.

   [I-D.ietf-teas-yang-te-topo]
              Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and
              O. Dios, "YANG Data Model for Traffic Engineering (TE)
              Topologies", draft-ietf-teas-yang-te-topo-14 (work in
              progress), February 2018.

   [I-D.ietf-netmod-revised-datastores]
              Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore
              Architecture", draft-ietf-netmod-revised-datastores-10
              (work in progress), January 2018.

7.2.  Informative References

   [RFC7498]  Quinn, P., Ed. and T. Nadeau, Ed., "Problem Statement for
              Service Function Chaining", RFC 7498,
              DOI 10.17487/RFC7498, April 2015, <https://www.rfc-
              editor.org/info/rfc7498>.

   [RFC7665]  Halpern, J., Ed. and C. Pignataro, Ed., "Service Function
              Chaining (SFC) Architecture", RFC 7665,
              DOI 10.17487/RFC7665, October 2015, <https://www.rfc-
              editor.org/info/rfc7665>.

   [I-D.ietf-netmod-yang-tree-diagrams]
              Bjorklund, M. and L. Berger, "YANG Tree Diagrams", draft-
              ietf-netmod-yang-tree-diagrams-06 (work in progress),
              February 2018.






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Appendix A.  Companion YANG Model for Non-NMDA Compliant Implementations

   The YANG module ietf-te-topology-sf defined in this document is
   designed to be used in conjunction with implementations that support
   the Network Management Datastore Architecture (NMDA) defined in
   [I-D.ietf-netmod-revised-datastores].  In order to allow
   implementations to use the model even in cases when NMDA is not
   supported, the following companion module, ietf-te-topology-sf-state,
   is defined as state model, which mirrors the module ietf-te-topology-
   sf defined earlier in this document.  However, all data nodes in the
   companion module are non-configurable, to represent the applied
   configuration or the derived operational states.

   The companion module, ietf-te-topology-sf-state, is redundant and
   SHOULD NOT be supported by implementations that support NMDA.

   As the structure of the companion module mirrors that of the
   coorespinding NMDA model, the YANG tree of the companion module is
   not depicted separately.

A.1.  SF Aware TE Topology State Module


   <CODE BEGINS> file "ietf-te-topology-sf-state@2018-02-27.yang"
   module ietf-te-topology-sf-state {
     yang-version 1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-te-topology-sf-state";

     prefix "tet-sf-s";

     import ietf-te-topology-sf {
       prefix "tet-sf";
     }

     import ietf-network-state {
       prefix "nw-s";
     }

     import ietf-network-topology-state {
       prefix "nt-s";
     }

     import ietf-te-topology-state {
       prefix "tet-s";
     }

     organization
       "Traffic Engineering Architecture and Signaling (TEAS)



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        Working Group";

     contact
       "WG Web:   <http://tools.ietf.org/wg/teas/>
        WG List:  <mailto:teas@ietf.org>

        Editors:  Igor Bryskin
                  <mailto:Igor.Bryskin@huawei.com>

                  Xufeng Liu
                  <mailto:Xufeng_Liu@jabil.com>";

     description
       "Network service and function aware aware TE topology operational
        state model for non-NMDA compliant implementations.

        Copyright (c) 2018 IETF Trust and the persons identified as
        authors of the code.  All rights reserved.

        Redistribution and use in source and binary forms, with or
        without modification, is permitted pursuant to, and subject to
        the license terms contained in, the Simplified BSD License set
        forth in Section 4.c of the IETF Trust's Legal Provisions
        Relating to IETF Documents
        (http://trustee.ietf.org/license-info).";

     revision 2018-02-27 {
       description "Initial revision";
       reference "TBD";
     }

     /*
      * Augmentations
      */
     /* Augmentations to network-types/te-topology */
     augment "/nw-s:networks/nw-s:network/nw-s:network-types/"
       + "tet-s:te-topology" {
       description
         "Defines the SF aware TE topology type.";
       uses tet-sf:sf-topology-type;
     }

     /* Augmentations to connectivity-matrix */
     augment "/nw-s:networks/nw-s:network/nw-s:node/tet-s:te/"
       + "tet-s:te-node-attributes" {
       description
         "Parameters for SF aware TE topology.";
       uses tet-sf:service-function-node-augmentation;



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     }

     augment "/nw-s:networks/nw-s:network/nw-s:node/tet-s:te/"
           + "tet-s:information-source-entry" {
       description
         "Parameters for SF aware TE topology.";
       uses tet-sf:service-function-node-augmentation;
     }

     /* Augmentations to tunnel-termination-point */
     augment "/nw-s:networks/nw-s:network/nw-s:node/tet-s:te/"
       + "tet-s:tunnel-termination-point" {
       description
         "Parameters for SF aware TE topology.";
       uses tet-sf:service-function-ttp-augmentation;
     }

     /* Augmentations to connectivity-matrix */
     augment "/nw-s:networks/nw-s:network/nw-s:node/tet-s:te/"
       + "tet-s:te-node-attributes/tet-sf-s:service-function/"
       + "tet-sf-s:link-terminations/tet-sf-s:link-termination/"
       + "tet-sf-s:from" {
       description
         "Add reference to the link termination point.
          This portion cannot be shared with the state module.";
       leaf tp-ref {
         type leafref {
           path "../../../../../../../nt-s:termination-point/"
             + "nt-s:tp-id";
         }
         description
           "Reference to the link termination point.";
       }
     }
   }
   <CODE ENDS>



Appendix B.  Data Examples

B.1.  A Topology with Multiple Connected Network Functions









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                            Node-1
         +----o--o--------------------------o-------+
         |    |  |                          |       |
         |    \__/                          \__     |
         |    *\/ TTP-1   * * * * * * * * * *\/*    |
   LTP-4 |* * *         *                TTP-2  *   | LTP-1
         o------------*-----------------------------o
         |          *                             * |
   LTP-3 |* * * * *                                *| LTP-2
         o---                                  -----o
         |   \                                /     |
         |    \                              /      |
         |     \ CP01                   CP02/       |
         | +----o--------------------------o------+ |
         | | VL1|                       VL4|      | |
         | |    |CP11                      |CP33  | |
         | |  +-o--+        +----+       +-o--+   | |
         | |  |VNF1|        |VNF2|       |VNF3|   | |
         | |  +-o-o+  VL2   +--o-+  VL2  +-o-o+   | |
         | |CP12| |\----------/ \---------/| |CP32| |
         | |    | |CP13      CP21      CP31| |    | |
         | |    | |      VL2               | |    | |
         | |    | +------------------------+ |    | |
         | |    +----------------------------+    | |
         | |             VL3                      | |
         | |                  Network Service 1   | |
         | +--------------------------------------+ |
         +------------------------------------------+

   The configuration instance data for Node-1 in the above figure could
   be as follows:

   {
     "networks": {
       "network": [
         {
           "network-types": {
             "te-topology": {
               "sf": {}
             }
           },
           "network-id": "network-sf-aware",
           "provider-id": 201,
           "client-id": 300,
           "te-topology-id": "te-topology:network-sf-aware",
           "node": [
             {
               "node-id": "Node-1",



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               "te-node-id": "2.0.1.1",
               "te": {
                 "te-node-attributes": {
                   "domain-id": 1,
                   "is-abstract": [null],
                   "connectivity-matrices": {
                   },
                   "service-function": {
                     "connectivity-matrices": {
                       "connectivity-matrix": [
                         {
                           "id": 10,
                           "from": {
                             "service-function-id": "Network Service 1",
                             "sf-connection-point-id": "CP01"
                           },
                           "to": {
                             "service-function-id": "VNF1",
                             "sf-connection-point-id": "CP11"
                           }
                           "direction": "bidir",
                           "virtual-link-id": "VL1"
                         },
                         {
                           "id": 13,
                           "from": {
                             "service-function-id": "VNF1",
                             "sf-connection-point-id": "CP12"
                           },
                           "to": {
                             "service-function-id": "VNF3",
                             "sf-connection-point-id": "CP32"
                           }
                           "direction": "bidir",
                           "virtual-link-id": "VL3"
                         },
                         {
                           "id": 12,
                           "from": {
                             "service-function-id": "VNF1",
                             "sf-connection-point-id": "CP13"
                           },
                           "to": {
                             "service-function-id": "VNF2",
                             "sf-connection-point-id": "CP21"
                           }
                           "direction": "bidir",
                           "virtual-link-id": "VL2"



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                         },
                         {
                           "id": 23,
                           "from": {
                             "service-function-id": "VNF2",
                             "sf-connection-point-id": "CP21"
                           },
                           "to": {
                             "service-function-id": "VNF3"
                             "sf-connection-point-id": "CP31"
                           }
                           "direction": "bidir",
                           "virtual-link-id": "VL2"
                         },
                         {
                           "id": 30,
                           "from": {
                             "service-function-id": "Network Service 1",
                             "sf-connection-point-id": "CP02"
                           },
                           "to": {
                             "service-function-id": "VNF3",
                             "sf-connection-point-id": "CP33"
                           }
                           "direction": "bidir",
                           "virtual-link-id": "VL4"
                         }
                       ]
                     },
                     "link-terminations": {
                       "link-termination": [
                         {
                           "id": 2,
                           "from": {
                             "tp-ref": "LTP-2"
                           },
                           "to": {
                             "service-function-id": "Network Service 1",
                             "sf-connection-point-id": "CP02"
                           }
                           "direction": "bidir"
                         },
                         {
                           "id": 3,
                           "from": {
                             "tp-ref": "LTP-3"
                           },
                           "to": {



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                             "service-function-id": "Network Service 1",
                             "sf-connection-point-id": "CP01"
                           }
                           "direction": "bidir"
                         }
                       ]
                     }
                   }
                 }
                 "tunnel-termination-point": [
                   {
                     "tunnel-tp-id": 10001,
                     "name": "TTP-1",
                     "service-function-terminations": {
                     }
                   },
                   {
                     "tunnel-tp-id": 10002,
                     "name": "TTP-2",
                     "service-function-terminations": {
                     }
                   }
                 ]
               },
               "termination-point": [
                 {
                   "tp-id": "LTP-1",
                   "te-tp-id": 10001
                   "te": {
                     "interface-switching-capability": [
                       {
                         "switching-capability": "switching-l2sc",
                         "encoding": "lsp-encoding-ethernet"
                       }
                     ]
                   }
                 },
                 {
                   "tp-id": "LTP-2",
                   "te-tp-id": 10002
                   "te": {
                     "interface-switching-capability": [
                       {
                         "switching-capability": "switching-l2sc",
                         "encoding": "lsp-encoding-ethernet"
                       }
                     ]
                   }



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                 },
                 {
                   "tp-id": "LTP-3",
                   "te-tp-id": 10003
                   "te": {
                     "interface-switching-capability": [
                       {
                         "switching-capability": "switching-l2sc",
                         "encoding": "lsp-encoding-ethernet"
                       }
                     ]
                   }
                 },
                 {
                   "tp-id": "LTP-4",
                   "te-tp-id": 10004
                   "te": {
                     "interface-switching-capability": [
                       {
                         "switching-capability": "switching-l2sc",
                         "encoding": "lsp-encoding-ethernet"
                       }
                     ]
                   }
                 }
               ]
             }
           ]
         }
       ]
     }
   }


B.2.  A Topology with an Encapsulated Network Service

   In this example, a network service consists of several inter-
   connected network functions (NFs), and is represented by this model
   as an encapsulated opaque object without the details between its
   internals.











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                            Node-1
         +----o--o--------------------------o-------+
         |    |  |                          |       |
         |    \__/                          \__     |
         |    *\/ TTP-1   * * * * * * * * * *\/*    |
   LTP-4 |* * *         *                TTP-2  *   | LTP-1
         o------------*-----------------------------o
         |          *                             * |
   LTP-3 |* * * * *                                *| LTP-2
         o---                                  -----o
         |   \                                /     |
         |    \                              /      |
         |     \ CP01                   CP02/       |
         | +----o--------------------------o------+ |
         | |                                      | |
         | |                  Network Service 1   | |
         | +--------------------------------------+ |
         +------------------------------------------+

   The configuration instance data for Node-1 in the above figure could
   be as follows:

   {
     "networks": {
       "network": [
         {
           "network-types": {
             "te-topology": {
               "sf": {}
             }
           },
           "network-id": "network-sf-aware",
           "provider-id": 201,
           "client-id": 300,
           "te-topology-id": "te-topology:network-sf-aware",
           "node": [
             {
               "node-id": "Node-1",
               "te-node-id": "2.0.1.1",
               "te": {
                 "te-node-attributes": {
                   "domain-id": 1,
                   "is-abstract": [null],
                   "connectivity-matrices": {
                   },
                   "service-function": {
                     "connectivity-matrices": {
                     },



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                     "link-terminations": {
                       "link-termination": [
                         {
                           "id": 2,
                           "from": {
                             "tp-ref": "LTP-2"
                           },
                           "to": {
                             "service-function-id": "Network Service 1",
                             "sf-connection-point-id": "CP02"
                           }
                           "direction": "bidir"
                         },
                         {
                           "id": 3,
                           "from": {
                             "tp-ref": "LTP-3"
                           },
                           "to": {
                             "service-function-id": "Network Service 1",
                             "sf-connection-point-id": "CP01"
                           }
                           "direction": "bidir"
                         }
                       ]
                     }
                   }
                 }
                 "tunnel-termination-point": [
                   {
                     "tunnel-tp-id": 10001,
                     "name": "TTP-1",
                     "service-function-terminations": {
                     }
                   },
                   {
                     "tunnel-tp-id": 10002,
                     "name": "TTP-2",
                     "service-function-terminations": {
                     }
                   }
                 ]
               },
               "termination-point": [
                 {
                   "tp-id": "LTP-1",
                   "te-tp-id": 10001
                   "te": {



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                     "interface-switching-capability": [
                       {
                         "switching-capability": "switching-l2sc",
                         "encoding": "lsp-encoding-ethernet"
                       }
                     ]
                   }
                 },
                 {
                   "tp-id": "LTP-2",
                   "te-tp-id": 10002
                   "te": {
                     "interface-switching-capability": [
                       {
                         "switching-capability": "switching-l2sc",
                         "encoding": "lsp-encoding-ethernet"
                       }
                     ]
                   }
                 },
                 {
                   "tp-id": "LTP-3",
                   "te-tp-id": 10003
                   "te": {
                     "interface-switching-capability": [
                       {
                         "switching-capability": "switching-l2sc",
                         "encoding": "lsp-encoding-ethernet"
                       }
                     ]
                   }
                 },
                 {
                   "tp-id": "LTP-4",
                   "te-tp-id": 10004
                   "te": {
                     "interface-switching-capability": [
                       {
                         "switching-capability": "switching-l2sc",
                         "encoding": "lsp-encoding-ethernet"
                       }
                     ]
                   }
                 }
               ]
             }
           ]
         }



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       ]
     }
   }


Authors' Addresses

   Igor Bryskin
   Huawei Technologies

   EMail: Igor.Bryskin@huawei.com


   Xufeng Liu
   Jabil

   EMail: Xufeng_Liu@jabil.com


































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