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Versions: 00 01

TEAS Working Group                                           Italo Busi
Internet Draft                                            Haomian Zheng
Intended status: Standard Track                                  Huawei

Expires: April 2020                                    October 11, 2019


 YANG Data Models for Multiprotocol Label Switching - Transport Profile

                draft-busizheng-teas-mpls-tp-yang-01.txt



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

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   This Internet-Draft will expire on September 11, 2019.

Copyright Notice

   Copyright (c) 2019 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
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   (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




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   Section 4.e of the Trust Legal Provisions and are provided without
   warranty as described in the Simplified BSD License.

Abstract

   Multi-protocol Label Switching - Transport Profile (MPLS-TP) is a
   profile of the MPLS protocol that is used in packet switched
   transport networks and operated in a similar manner to other
   existing transport technologies (e.g., OTN), as described in
   RFC5921. This document specifies YANG models for MPLS-TP, which have
   not been covered by existing models so far. The gap analysis with
   current relevant traffic-engineering (TE) and MPLS models is also
   included.


Table of Contents


   1. Introduction...................................................2
   2. Considerations on the Augmentation.............................3
      2.1. Modules Relationship......................................3
      2.2. Prefixs in Model Names....................................4
   3. Gap Analysis for MPLS-TP topology..............................4
      3.1. TE Bandwidth Augmentations................................5
      3.2. TE Label Augmentations....................................6
   4. Gap Analysis for MPLS-TP Tunnel Configuration..................6
      4.1. TE Bandwidth Augmentation.................................7
      4.2. TE Label Augmentation.....................................7
   5. Related YANG Code..............................................8
      5.1. YANG Code for MPLS-TP Topology Augmentation...............8
      5.2. YANG Code for MPLS-TP Tunnel Augmentation................11
      5.3. MPLS-TP Specific YANG Types..............................13
   6. Open Issues...................................................15
   7. Security......................................................16
   8. Acknowledgements..............................................16
   9. References....................................................16
      9.1. Normative References.....................................16
      9.2. Informative References...................................17
   Authors' Addresses...............................................17

1. Introduction

   Multi-protocol Label Switching - Transport Profile (MPLS-TP) is a
   packet switching technology intended operated in a similar manner to
   other existing transport technologies (e.g., OTN), as described in
   [RFC5921], which includes Traffic Engineering (TE) features.



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   Generic TE models, including the TE topology and tunnel, have been
   defined in [TE-Topology] and [TE-Tunnel] using the YANG data
   modeling language and are applicable to any TE technologies
   including MPLS-TE and OTN and therefore also to MPLS-TP.

   The YANG models for MPLS with TE features (MPLS-TE), are provided in
   [TE-MPLS] as a technology-specific augmentations of the generic TE
   models. However, technology-specific augmentations for TE label, and
   TE bandwidth of TE Topology and Tunnel models, have not been covered
   yet.

   This document defines YANG data models for MPLS-TP topologies and
   tunnels, providing the minimum set of attributes that are required
   and not yet available in existing TE and MPLS YANG models. See
   section 3 and 4 for more detailed gap analysis.

   The proposed MPLS-TP YANG models can be used as an input to enhance
   the current MPLS-TE YANG models.

2. Considerations on the Augmentation

2.1. Modules Relationship

   In this draft two models are proposed: one MPLS-TP
   technology-specific topology model that augments the ietf-te-
   topology YANG module, defined in [TE-Topology], and another MPLS-TP
   technology-specific tunnel model that augments the ietf-te YANG
   module, defined in [TE-Tunnel].

   The following common fundamental models are imported:

      o  ietf-routing-types defined in [RFC8294]

    TE generic  +------------------+       +------------+    o: augment
    module      | ietf-te-topology |       |  ietf-te   |
                +------------------+       +------------+
                      o                           o
                      |                           |
                      |                           |
                      |                           |
            +----------------------+   +-------------------------+
    MPLS-TP | ietf-te-mpls-tp-topo |   | ietf-te-mpls-tp-tunnel  |
            +----------------------+   +-------------------------+

   Figure 1: Relationship of MPLS-TP topology and tunnel module with TE
   generic TE topology and tunnel YANG modules



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2.2. Prefixs in Model Names

   In this document, names of data nodes and other data model objects
   are prefixed using the standard prefix associated with the
   corresponding YANG imported modules, as shown in Table 1.

   +---------------+----------------------+--------------------------+
   | Prefix        | YANG module          | Reference                |
   +---------------+----------------------+--------------------------+
   | yang          | ietf-yang-types      | [RFC6991]                |
   | inet          | ietf-inet-types      | [RFC6991]                |
   | rt-types      | ietf-routing-types   | [RFC8294]                |
   | tet           | ietf-te-topology     | [TE-Topology]            |
   | te            | ietf-te              | [TE-Tunnel]              |
   | te-mpls       | ietf-te-mpls         | [TE-MPLS]                |
   | mpls-tp-topo  | ietf- mpls-tp-topo   | This document            |
   | mpls-tp-tunnel|ietf- mpls-tp-tunnel  | This document            |
   +---------------+----------------------+--------------------------+

                Table 1: Prefixes and corresponding YANG modules

3. Gap Analysis for MPLS-TP topology

   There are no YANG models that provide MPLS-TE technology-specific
   augmentations of the generic TE Topology model defined in
   [TE-Topology].

   This section analyses the minimum set of attributes that are
   required to be specified in an MPLS-TP technology-specific
   augmentation.

   Additional attributes that may be required to support a broader set
   of MPLS-TP and/or MPLS-TE functions are for further study.

   Given the guidance for augmentation in [TE-Topology], the following
   technology-specific augmentations need to be provided:

   - A network-type to indicate that the TE topology is an MPLS-TP
     Topology, as follow:

    augment /nw:networks/nw:network/nw:network-types/tet-te-topology:
     +-- rw mpls-tp-topology!

   - TE Bandwidth Augmentations a described in section 3.1;



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   - TE Label Augmentations as described in section 3.2;

3.1. TE Bandwidth Augmentations

   Following TE Bandwidth attributes are needed to be augmented to the
   module ietf-te-topology in [TE-Topology]:


   - Augmentations for te-bandwidth in the max-link-bandwidth, max-
     resv-link-bandwidth and unreserved-bandwidth attributes of MPLS-TP
     TE Links are necessary for te-link-attributes and listed as
     follow. It is worth noting that for te-bandwidth in other places,
     this augment is not necessary.

     augment /nw:networks/nw:network/nt:link/tet:te/tet:te-link-
     attributes/tet:max-link-bandwidth/tet:te-bandwidth/tet:technology:
        +--:(mpls-tp)
           +--rw mpls-tp-bandwidth?   uint64

     augment /nw:networks/nw:network/nt:link/tet:te/tet:te-link-
     attributes/tet:max-resv-link-bandwidth/tet:te-
     bandwidth/tet:technology:
        +--:(mpls-tp)
           +--rw mpls-tp-bandwidth?   uint64

     augment /nw:networks/nw:network/nt:link/tet:te/tet:te-link-
     attributes/tet:unreserved-bandwidth/tet:te-
     bandwidth/tet:technology:
        +--:(mpls-tp)

         +--rw mpls-tp-bandwidth?   uint64

   - Augmentations for the max-lsp-bandwidth attribute are necessary
     for MPLS-TP TE Links and TTPs and listed as following. It is worth
     noting that for the other 'max-lsp-bandwidth', this augmentation
     is not necessary.

     augment /nw:networks/nw:network/nt:link/tet:te/tet:te-link-
     attributes/tet:interface-switching-capability/tet:max-lsp-
     bandwidth/tet:te-bandwidth/tet:technology:
        +--:(mpls-tp)
           +--rw bandwidth-profile-name?   string
           +--rw bandwidth-profile-type?   identityref
           +--rw CIR?                      uint64
           +--rw EIR?                      uint64



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           +--rw CBS?                      uint64
           +--rw EBS?                      uint64

     augment /nw:networks/nw:network/nw:node/nt:termination-
     point/tet:te/tet:interface-switching-capability/tet:max-lsp-
     bandwidth/tet:te-bandwidth/tet:technology:
        +--:(mpls-tp)
           +--rw bandwidth-profile-name?   string
           +--rw bandwidth-profile-type?   identityref
           +--rw CIR?                      uint64
           +--rw EIR?                      uint64
           +--rw CBS?                      uint64
           +--rw EBS?                      uint64


3.2. TE Label Augmentations

   In MPLS-TP, the label allocation is done by NE, information about
   label values availability is not necessary to be provided to the
   controller. Moreover, MPLS-TP tunnels are currently established
   within a single domain.

   Therefore this document does not define any MPLS-TP
   technology-specific augmentations, of the TE Topology model, for the
   TE label since no TE label related attributes should be instantiated
   for MPLS-TP Topologies.

4. Gap Analysis for MPLS-TP Tunnel Configuration

   MPLS-TE technology-specific augmentations of the generic TE Tunnel
   model defined in [TE-MPLS].

   This section analyses the minimum set of attributes that are
   required to be specified in an MPLS-TP technology-specific
   augmentation and not yet available in [TE-MPLS].

   Additional attributes that may be required to support a broader set
   of MPLS-TP and/or MPLS-TE functions are for further study.

   Although there are no guidance for augmentation in [TE-Tunnel], the
   following technology-specific augmentations need to be provided:

   - TE Bandwidth Augmentations as described in section 4.1

   - TE Label Augmentations as described in section 4.2




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4.1. TE Bandwidth Augmentation

   Following TE Bandwidth attributes are needed to be augmented for
   MPLS-TP to the to the module ietf-te in [TE-Tunnel], but are not yet
   defined in [TE-MPLS]:

   - Augmentations for the te-bandwdith attribute of TE Tunnels under
     te/globals/tunnels are listed as follow. It is worth noting that
     for te-bandwidth in other places, this augmentation is not
     necessary.

     augment /te:te/te:tunnels/te:tunnel/te:te-bandwidth/te:technology:
        +--:(mpls-tp)
           +--rw bandwidth-profile-name?   string
           +--rw bandwidth-profile-type?   identityref
           +--rw CIR?                      uint64
           +--rw EIR?                      uint64
           +--rw CBS?                      uint64
           +--rw EBS?                      uint64



4.2. TE Label Augmentation

   Following TE Label attributes are needed to be augmented for MPLS-TP
   to the to the module ietf-te in [TE-Tunnel], but are not yet defined
   in [TE-MPLS]:

   - Augmentations for the te-label attribute of MPLS-TP label hops are
     used to report the computed primary and secondary paths of MPLS-TP
     TE Tunnels as well as the route and the path of the MPLS-TP LSPs
     of the primary and secondary paths of MPLS-TP TE Tunnels. These
     augmentations are listed as follow, and it is worth noting for te-
     label in other places, there is no need to do the augmentation.

     augment /te:te/te:tunnels/te:tunnel/te:p2p-primary-paths/te:p2p-
     primary-path/te:computed-paths-properties/te:computed-path-
     properties/te:path-properties/te:path-route-objects/te:path-
     computed-route-object/te:type/te:label/te:label-hop/te:te-
     label/te:technology:
        +--:(mpls-tp)
           +--ro mpls-label?   rt-types:mpls-label

     augment /te:te/te:tunnels/te:tunnel/te:p2p-primary-paths/te:p2p-
     primary-path/te:lsps/te:lsp/te:path-properties/te:path-route-
     objects/te:path-computed-route-object/te:type/te:label/te:label-
     hop/te:te-label/te:technology:


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        +--:(mpls-tp)
           +--ro mpls-label?   rt-types:mpls-label

     augment /te:te/te:tunnels/te:tunnel/te:p2p-secondary-paths/te:p2p-
     secondary-path/te:computed-paths-properties/te:computed-path-
     properties/te:path-properties/te:path-route-objects/te:path-
     computed-route-object/te:type/te:label/te:label-hop/te:te-
     label/te:technology:
        +--:(mpls-tp)
           +--ro mpls-label?   rt-types:mpls-label

     augment /te:te/te:tunnels/te:tunnel/te:p2p-secondary-paths/te:p2p-
     secondary-path/te:lsps/te:lsp/te:path-properties/te:path-route-
     objects/te:path-computed-route-object/te:type/te:label/te:label-
     hop/te:te-label/te:technology:
        +--:(mpls-tp)
           +--ro mpls-label?   rt-types:mpls-label

5. Related YANG Code

5.1. YANG Code for MPLS-TP Topology Augmentation

   <CODE BEGINS>file "ietf-mpls-tp-topology@2019-03-11.yang"
     module ietf-mpls-tp-topology {
       //yang-version 1.1;

       namespace "urn:ietf:params:xml:ns:yang:ietf-mpls-tp-topology";
       prefix "mpls-tp-topo";

       import ietf-network {
         prefix "nw";
       }

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

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

       import ietf-mpls-tp-types {
         prefix "mpls-tp-types";
       }

       organization



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         "Internet Engineering Task Force (IETF) TEAS WG";
       contact
         "
           WG List: <mailto:teas@ietf.org>

           ID-draft editor:
             Italo Busi (italo.busi@huawei.com);
             Haomian Zheng (zhenghaomian@huawei.com);
         ";

       description
         "This module defines technology-specific MPLS-TP topology
          data model.";

       revision 2019-03-11 {
         description
           "version -00 as an I-D";
         reference
           "draft-busizheng-teas-mpls-tp-yang";
       }

       augment "/nw:networks/nw:network/nw:network-types/"
             + "tet:te-topology" {
         container mpls-tp-topology {
           presence "indicates a topology type of MPLS-TP layer.";
           description "mpls-tp te topology type";
         }
         description "augment network types to include mpls-tp
     newtork";
       }

       augment "/nw:networks/nw:network/nt:link/tet:te/"
             + "tet:te-link-attributes/"
             + "tet:interface-switching-capability/tet:max-lsp-
     bandwidth/"
             + "tet:te-bandwidth/tet:technology" {
         when "../../../../../../../nw:network-types/tet:te-topology/"
            + "mpls-tp-topo:mpls-tp-topology" {
           description "MPLS-TP TE bandwidth.";
         }
         description "MPLS-TP bandwidth.";
         case mpls-tp {
           uses mpls-tp-types:mpls-tp-path-bandwidth;
         }
       }




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       augment "/nw:networks/nw:network/nw:node/nt:termination-point/"
             + "tet:te/tet:interface-switching-capability/"
             + "tet:max-lsp-bandwidth/tet:te-bandwidth/tet:technology"
     {
         when "../../../../../../../nw:network-types/tet:te-topology/"
            + "mpls-tp-topo:mpls-tp-topology" {
           description "Augment MPLS-TP TE bandwidth";
         }
         description "MPLS-TP bandwidth.";
         case mpls-tp {
           uses mpls-tp-types:mpls-tp-path-bandwidth;
         }
       }

       augment "/nw:networks/nw:network/nt:link/tet:te/"
             + "tet:te-link-attributes/tet:max-link-bandwidth/"
             + "tet:te-bandwidth/tet:technology" {
         when "../../../../../../nw:network-types/tet:te-topology/"
            + "mpls-tp-topo:mpls-tp-topology" {
           description "MPLS-TP TE bandwidth.";
         }
         description "MPLS-TP bandwidth.";
         case mpls-tp {
           uses mpls-tp-types:mpls-tp-bandwidth;
         }
       }

       augment "/nw:networks/nw:network/nt:link/tet:te/"
             + "tet:te-link-attributes/tet:max-resv-link-bandwidth/"
             + "tet:te-bandwidth/tet:technology" {
         when "../../../../../../nw:network-types/tet:te-topology/"
            + "mpls-tp-topo:mpls-tp-topology" {
           description "MPLS-TP TE bandwidth.";
         }
         description "MPLS-TP bandwidth.";
         case mpls-tp {
           uses mpls-tp-types:mpls-tp-bandwidth;
         }
       }

       augment "/nw:networks/nw:network/nt:link/tet:te/"
             + "tet:te-link-attributes/tet:unreserved-bandwidth/"
             + "tet:te-bandwidth/tet:technology" {
         when "../../../../../../nw:network-types/tet:te-topology/"
            + "mpls-tp-topo:mpls-tp-topology" {



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           description "MPLS-TP TE bandwidth.";
         }
         description "MPLS-TP bandwidth.";
         case mpls-tp {
           uses mpls-tp-types:mpls-tp-bandwidth;
         }
       }
     }
   <CODE ENDS>

5.2. YANG Code for MPLS-TP Tunnel Augmentation

   <CODE BEGINS>file "ietf-mpls-tp-tunnel@2019-03-11.yang"
     module ietf-mpls-tp-tunnel {
       //yang-version 1.1;

       namespace "urn:ietf:params:xml:ns:yang:ietf-mpls-tp-tunnel";
       prefix "mpls-tp-tunnel";

       import ietf-te {
         prefix "te";
       }

       import ietf-mpls-tp-types {
         prefix "mpls-tp-types";
       }
       organization
         "Internet Engineering Task Force (IETF) TEAS WG";
       contact
         "
           WG List: <mailto:teas@ietf.org>

           ID-draft editor:
             Italo Busi (italo.busi@huawei.com);
             Haomian Zheng (zhenghaomian@huawei.com);
         ";
       description
         "This module defines technology-specific MPLS-TP tunnel
          data model.";
       revision 2019-03-11 {
         description
           "version -00 as an I-D";
         reference
           "draft-busizheng-teas-mpls-tp-yang";
       }



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       augment "/te:te/te:tunnels/te:tunnel/"
             + "te:te-bandwidth/te:technology" {
         description "MPLS-TP bandwidth.";
         case mpls-tp {
           uses mpls-tp-types:mpls-tp-path-bandwidth;
         }
       }

       augment "/te:te/te:tunnels/te:tunnel/"
             + "te:p2p-primary-paths/te:p2p-primary-path/"
             + "te:computed-paths-properties/"
             + "te:computed-path-properties/"
             + "te:path-properties/te:path-route-objects/"
             + "te:path-computed-route-object/te:type/te:label/"
             + "te:label-hop/te:te-label/te:technology" {
         description "MPLS-TP label.";
         case mpls-tp {
           uses mpls-tp-types:mpls-tp-path-label;
         }
       }

       augment "/te:te/te:tunnels/te:tunnel/"
             + "te:p2p-primary-paths/te:p2p-primary-path/"
             + "te:lsps/te:lsp/"
             + "te:path-properties/te:path-route-objects/"
             + "te:path-computed-route-object/te:type/te:label/"
             + "te:label-hop/te:te-label/te:technology" {
         description "MPLS-TP label.";
         case mpls-tp {
           uses mpls-tp-types:mpls-tp-path-label;
         }
       }

       augment "/te:te/te:tunnels/te:tunnel/"
             + "te:p2p-secondary-paths/te:p2p-secondary-path/"
             + "te:computed-paths-properties/"
             + "te:computed-path-properties/"
             + "te:path-properties/te:path-route-objects/"
             + "te:path-computed-route-object/te:type/te:label/"
             + "te:label-hop/te:te-label/te:technology" {
         description "MPLS-TP label.";
         case mpls-tp {
           uses mpls-tp-types:mpls-tp-path-label;
         }
       }




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       augment "/te:te/te:tunnels/te:tunnel/"
             + "te:p2p-secondary-paths/te:p2p-secondary-path/"
             + "te:lsps/te:lsp/"
             + "te:path-properties/te:path-route-objects/"
             + "te:path-computed-route-object/te:type/te:label/"
             + "te:label-hop/te:te-label/te:technology" {
         description "MPLS-TP label.";
         case mpls-tp {
           uses mpls-tp-types:mpls-tp-path-label;
         }
       }
     }
   <CODE ENDS>

5.3. MPLS-TP Specific YANG Types

   <CODE BEGINS>file "ietf-mpls-tp-types@2019-03-11.yang"
     module ietf-mpls-tp-types {
       namespace "urn:ietf:params:xml:ns:yang:ietf-mpls-tp-types";
       prefix "mpls-tp-types";

       import ietf-routing-types {
         prefix "rt-types";

       }
       import ietf-eth-tran-types {
         prefix "etht-types";

       }
       organization
         "Internet Engineering Task Force (IETF) TEAS WG";
       contact
         "
           WG List: <mailto:teas@ietf.org>

           ID-draft editor:
             Italo Busi (italo.busi@huawei.com);
             Haomian Zheng (zhenghaomian@huawei.com);
         ";
       description
         "This module defines technology-specific MPLS-TP types
          data model.";
       revision 2019-03-11 {
         description
           "version -00 as an I-D";
         reference


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           "draft-busizheng-teas-mpls-tp-yang";
       }

       grouping mpls-tp-path-bandwidth {
         description
           "Path bandwidth for MPLS-TP. ";
         leaf bandwidth-profile-name{
           type string;
           description "Name of Bandwidth Profile.";
         }
         leaf bandwidth-profile-type {
           type identityref {
             base etht-types:bandwidth-profile-type;
           }
           description "Type of Bandwidth Profile.";
         }

         leaf CIR {
           type uint64;
             description
               "Committed Information Rate in Kbps";
         }

         leaf EIR {
           type uint64;
           /*
             Need to indicate that EIR is not supported by RFC 2697

             must
                 '../bw-profile-type = "etht-types:mef-10-bwp" or ' +
                 '../bw-profile-type = "etht-types:rfc-2698-bwp" or ' +
                 '../bw-profile-type = "etht-types:rfc-4115-bwp"'

             must
                 '../bw-profile-type != "etht-types:rfc-2697-bwp"'
           */
           description
             "Excess Information Rate in Kbps
             In case of RFC 2698, PIR = CIR + EIR";
         }

         leaf CBS {
           type uint64;
           description
             "Committed Burst Size in in KBytes";
         }



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         leaf EBS {
           type uint64;
           description
             "Excess Burst Size in KBytes.
               In case of RFC 2698, PBS = CBS + EBS";
         }
       }

       grouping mpls-tp-bandwidth {
         description
           "Bandwidth for MPLS-TP. ";
         leaf mpls-tp-bandwidth {
           type uint64{
             range "0..10000000000";
           }
           units "Kbps";
           description
             "Available bandwith value expressed in kilobits per
     second";
         }
       }

       grouping mpls-tp-path-label {
         description
           "Path Label for MPLS-TP. ";
         leaf mpls-label {
           type rt-types:mpls-label;
           description
             "MPLS-TP Label.";
         }
       }
     }
   <CODE ENDS>

6. Open Issues

   A few open issues are listed in this section for discussion with the
   WG experts:

   - The value for 'encoding' in ietf-te-topology and ietf-te should be
     configured as 'lsp-encoding-packet' for MPLS-TP;
   - The value for 'switching-type' in ietf-te-topology and ietf-te
     should be configured as 'switching-psc1' for MPLS-TP;




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   - There are still open issues for [TE-Tunnel], so the right
     directory may need to be confirmed up to the latest module ietf-te
     after maturity;
   - Is it possible to integrate the proposal augmentation into [TE-
     MPLS]?

   If the answer is 'yes', the following open issues need to address in
   the merged document.

   - Some attributes will be needed to understand whether MPLS-TP
     specific features (such as no ECMP, no PHP, bidirectional LSP and
     GAL) are supported by the MPLS-TE topology and/or required to be
     supported by the MPLS-TE tunnel to be setup
   - Per Tunnel-Termination-Point(TTP) modeling, one TTP per physical
     PE node should be sufficient for MPLS-TP;
   - An empty container should be set for client-layer-adaption in the
     topology model for MPLS-TP;

   Finally, it is not clear how to generate the inter-layer-lock-id for
   MPLS-TP and other layers, which may be considered in future.

7. Security

   TBD.


8. Acknowledgements

   We thank Loa Andersson and Igor Bryskin for providing useful
   suggestions for this draft.

9. References

9.1. Normative References

   [RFC6991] J. Schoenwaelder, "Common YANG Data Types", RFC6991.

   [RFC8294] X. Liu, et. al., "Common YANG Data Types for the Routing
             Area", RFC8294.

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

   [TE-Tunnel] T. Saad (Editor), "A YANG Data Model for Traffic
             Engineering Tunnels and Interfaces", draft-ietf-teas-yang-
             te, work in progress.



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9.2. Informative References

   [RFC5921] M. Bocci, et., al., "A Framework for MPLS in Transport
             Networks", RFC5921.

    [TE-MPLS] T. Saad, et. al., "A YANG Data Model for MPLS Traffic
             Engineering Tunnels", draft-ietf-teas-yang-te-mpls, work
             in progress.

Authors' Addresses

   Italo Busi
   Huawei Technologies
   Email: Italo.Busi@huawei.com

   Haomian Zheng
   Huawei Technologies
   Email: zhenghaomian@huawei.com































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