TEAS Working Group                                              C. Barth
Internet-Draft                                               V.P. Beeram
Intended status: Standards Track                        Juniper Networks
Expires: 9 January 2025                                      8 July 2024


           YANG Data Model for Power-Group Aware TE Topology
                 draft-barth-teas-yang-pg-aware-topo-00

Abstract

   This document discusses the notion of a Power-Group construct as an
   attribute of a Traffic Engineered (TE) Link and defines a YANG data
   model for representing a Power-Group aware TE topology.

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 https://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 9 January 2025.

Copyright Notice

   Copyright (c) 2024 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 Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.






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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     1.3.  Tree Structure  . . . . . . . . . . . . . . . . . . . . .   3
   2.  Power-Group Aware TE Topology Data Model  . . . . . . . . . .   3
     2.1.  Model Structure . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  Augmenting TE Node Attributes . . . . . . . . . . . . . .   4
     2.3.  Augmenting TE Link Attributes . . . . . . . . . . . . . .   4
     2.4.  YANG Module . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   8
   4.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .   8
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  10
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  12
   Appendix A.  Complete Model Tree Structure  . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

1.  Introduction

   A Traffic Engineered (TE) topology is a schematic arrangement of TE
   nodes and TE links.  It is the topology on which path computational
   algorithms are run to compute TE paths.  This document introduces a
   TE link attribute called the Power-Group which can be used by TE path
   computational algorithms to facilitate Power-Group aware TE Path
   placement.  A Power-Group represents a set of TE links that are
   terminated on a specific TE node and have a common dependency on a
   forwarding engine component which when powered down will bring down
   all the TE links in the set.  Each Power-Group has a numerical rating
   associated with it - the lower the value, the better the rating.  The
   specifics of the algorithms used for computing Power-Group Aware TE
   paths is outside the scope of this document.

   RFC8795 defines the data model for representing TE topologies and
   contains technology-agnostic building blocks that can be augmented by
   other technology-specific TE topology models.  The Power-Group Aware
   TE Topology Data Model introduced in this document is an augmentation
   of the TE Topology model defined in RFC8795.










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1.1.  Requirements Language

   The key words "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] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

1.2.  Terminology

   The terminology for describing YANG data models is found in
   [RFC7950].

   The reader is expected to be familiar with the topology modeling
   terminology specified in [RFC8345], [RFC8776] and [RFC8795].

1.3.  Tree Structure

   A simplified graphical representation of the data model is presented
   in Appendix A of this document.  The tree format defined in [RFC8340]
   is used for the YANG data model tree representation.

2.  Power-Group Aware TE Topology Data Model

2.1.  Model Structure

   The high-level model structure defined by this document is as shown
   below:

   module: ietf-te-topology-pwrgrp
     augment /nw:networks/nw:network/nw:network-types/tet:te-topology:
       +--rw pg!
     augment /nw:networks/nw:network/nw:node/tet:te
               /tet:te-node-attributes:
       +--rw power-groups
          +--rw power-group* [name]
             +  ..........
     augment /nw:networks/nw:network/nt:link/tet:te
               /tet:te-link-attributes:
       + ..........

   The 'network-types/te-topology' container is augmented to carry the
   definition of a new TE topology type for Power-Group Aware TE
   Topology.  The 'node/te/te-node-attributes' container is augmented to
   carry the information about the set of Power-Groups associated with a
   given TE node.  And the 'link/te/te-link-attributes' container is
   augmented to carry the Power-Group specific information that the TE
   link is associated with.



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2.2.  Augmenting TE Node Attributes

   The 'power-groups' container carries a list of Power Groups
   associated with the given TE node.  Each power-group entry is
   identified by a 'name'.  It also carries a numerical 'value' leaf
   that uniquely identifies the Power-Group and a 'cost' leaf that
   provides a static rating of the Power-Group.  A lower 'cost'
   translates to a better rating.  It is to be noted that the identifier
   of a Power-Group is unique and significant only at the TE node level
   and not at the TE topology level.

     augment /nw:networks/nw:network/nw:node/tet:te
               /tet:te-node-attributes:
       +--rw power-groups
          +--rw power-group* [name]
             +--rw name     string
             +--rw value?   uint32
             +--rw cost?    decimal64

2.3.  Augmenting TE Link Attributes

   The augmented 'te-link-attributes' container includes a list of
   references to the Power-Groups that the TE link is associated with.
   It also carries information that specifies if the TE link can be
   placed in 'power-save' mode and the amount of bandwidth that is
   currently unavailable as a result of the link being in 'power-save'
   mode.  If this bandwidth is zero, then it means that the link is not
   in 'power-save' mode.

     augment /nw:networks/nw:network/nt:link/tet:te
               /tet:te-link-attributes:
       +--rw power-groups*           pg-ref
       +--rw power-save-capable?     boolean
       +--rw power-save-bandwidth
          +--rw te-bandwidth
             +--rw (technology)?
                +--:(generic)
                   +--rw generic?   te-bandwidth

2.4.  YANG Module

   <CODE BEGINS> file "ietf-te-topology-pwrgrp@2024-07-08.yang"
   module ietf-te-topology-pwrgrp {
     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-te-topology-pwrgrp";
     prefix "tet-pg";

     import ietf-network {



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       prefix "nw";
       reference
         "RFC 8345: A YANG Data Model for Network Topologies";
     }

     import ietf-network-topology {
       prefix "nt";
       reference
         "RFC 8345: A YANG Data Model for Network Topologies";
     }

     import ietf-te-topology {
       prefix "tet";
       reference
         "RFC 8795: YANG Data Model for Traffic Engineering (TE)
          Topologies";
     }

     import ietf-te-types {
       prefix te-types;
       reference
         "RFC 8776: Common YANG Data Types for Traffic Engineering";
     }

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

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

        Editor:   Colby Barth
                  <mailto:cbarth@juniper.net>

        Editor:   Vishnu Pavan Beeram
                  <mailto:vbeeram@juniper.net>";

     description
       "YANG data model for representing Power-Group aware TE
        topology.

        Copyright (c) 2024 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



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        forth in Section 4.c of the IETF Trust's Legal Provisions
        Relating to IETF Documents
        (https://trustee.ietf.org/license-info).

        This version of this YANG module is part of RFC XXXX
        (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself
        for full legal notices.";

     revision "2024-07-08" {
       description "Initial revision.";
       reference
         "RFC XXXX: YANG Data Model for Power-Group aware TE Topology";
     }

     /*
      * Typedefs
      */

     typedef pg-ref {
       type leafref {
         path "/nw:networks/nw:network/nw:node/tet:te/"
           + "tet:te-node-attributes/tet-pg:power-groups/"
           + "tet-pg:power-group/tet-pg:name";
       }
       description
         "This type is used to reference a Power-Group on a given node";
     }

     /*
      * Groupings
      */

     grouping pg-topology-type {
       description
         "Identifies the Power-Group aware TE topology type.";
       container pg {
         presence "Indicates that the TE topology is Power-Group
                   aware.";
         description
           "Its presence identifies that the TE topology is Power-Group
            aware.";
       }
     } // pg-topology-type

     grouping pg-node-attributes {
       description
         "Grouping for carrying Power-Group specific node attributes";
       container power-groups {



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         description
           "Container for Power-Groups.";
         list power-group {
           key "name";
           unique "value";
           description
             "List of Power-Groups.";
           leaf name {
             type string;
             description
               "A string that uniquely identifies the Power-Group on a
                given node.";
           }
           leaf value {
             type uint32;
             description
               "An integer that uniquely identifies the Power-Group on
                a given node.";
           }
           leaf cost {
             type decimal64 {
               fraction-digits 2;
             }
             description
               "Rating/Cost of the Power-Group.";
           }
         }
       }
     } // pg-node-attributes

     grouping pg-link-attributes {
       description
         "Grouping for carrying Power-Group specific link attributes";
       leaf-list power-groups {
         type pg-ref;
         description
           "List of associated Power-Groups";
       }
       leaf power-save-capable {
         type boolean;
         description
           "Can the link be placed in power-save mode?";
       }
       container power-save-bandwidth {
         uses te-types:te-bandwidth;
         description
           "Amount of bandwidth that is currently unavailable on this
            link as a result of the link being in power-save mode. If



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            the link is not in power-save mode, power-save-bandwidth
            is zero. Units are in bytes per second.";
       }
     } //pg-leaf-attributes

     /*
      * Augmentations
      */

     augment "/nw:networks/nw:network/nw:network-types/"
       + "tet:te-topology" {
       description
         "Defines the Power-Group aware TE topology type.";
       uses pg-topology-type;
     }

     augment "/nw:networks/nw:network/nw:node/tet:te/"
       + "tet:te-node-attributes" {
       description
         "Augmentation for Power-Group specific node attributes.";
       uses pg-node-attributes;
     }

     augment "/nw:networks/nw:network/nt:link/tet:te/"
       + "tet:te-link-attributes" {
       description
         "Augmentation for Power-Group specific link attributes.";
       uses pg-link-attributes;
     }
   }
   <CODE ENDS>

3.  Acknowledgements

   The authors would like to thank Chandra Ramachandran and Sudharsana
   Venkatraman for their input from discussions.

4.  Contributors

   The following individuals contributed to this document:

   Srihari R.  Sangli
   Juniper Networks
   Email: ssangli@juniper.net

   Vyasraj Satyanarayana
   Juniper Networks
   Email: vyasraj@juniper.net



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5.  IANA Considerations

   This document registers the following URI in the IETF XML registry
   [RFC3688].  Following the format in [RFC3688], the following
   registration is requested to be made.

   URI: urn:ietf:params:xml:ns:yang:ietf-te-topology-pwrgrp
   Registrant Contact: The TEAS WG of the IETF.
   XML: N/A, the requested URI is an XML namespace.

   This document registers a YANG module in the YANG Module Names
   registry [RFC6020].

   name: ietf-te-topology-pwrgrp
   namespace: urn:ietf:params:xml:ns:yang:ietf-te-topology-pwrgrp
   prefix: tet-pg
   reference: RFCXXXX

6.  Security Considerations

   The YANG module specified in this document defines a schema for data
   that is designed to be accessed via network management protocols such
   as NETCONF [RFC6241] or RESTCONF [RFC8040].  The lowest NETCONF layer
   is the secure transport layer, and the mandatory-to-implement secure
   transport is Secure Shell (SSH) [RFC6242].  The lowest RESTCONF layer
   is HTTPS, and the mandatory-to-implement secure transport is TLS
   [RFC8446].

   The Network Configuration Access Control Model (NACM) [RFC8341]
   provides the means to restrict access for particular NETCONF or
   RESTCONF users to a preconfigured subset of all available NETCONF or
   RESTCONF protocol operations and content.

   The data nodes defined in this YANG module that are
   writable/creatable/deletable (i.e., config true, which is the
   default) may be considered sensitive or vulnerable in some network
   environments.  Write operations (e.g., edit-config) to these data
   nodes without proper protection can have a negative effect on network
   operations.  These are the subtrees and data nodes and their
   sensitivity/vulnerability:

   *  "/nw:networks/nw:network/nw:network-types/tet:te-topology/pg":
      This subtree specifies the topology type.  Modifying the
      configurations can make the topology type invalid and cause
      interruption to the specified Power-Group Aware TE topology.






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   *
      "/nw:networks/nw:network/nw:node/tet:te/tet:te-node-attributes/
      power-groups": This subtree specifies the configurations for
      Power-Groups associated with a TE node.  By manipulating these
      data nodes, a malicious attacker may cause unauthorized and
      improper behavior to any TE path placement application that is
      making use of the compromised Power-Groups information.

   *  "/nw:networks/nw:network/nt:link/tet:te/tet:te-link-attributes":
      This augmented subtree includes the configurations for Power-Group
      specific information associated with a TE link.  By manipulating
      these data nodes, a malicious attacker may cause unauthorized and
      improper behavior to any TE path placement application that is
      making use of the compromised Power-Groups information.

   The readable data nodes in this YANG module may be considered
   sensitive or vulnerable in some network environments.  It is thus
   important to control read access (e.g., via get, get-config, or
   notification) to these data nodes.  These are the subtrees and data
   nodes and their sensitivity/vulnerability:

   *  "/nw:networks/nw:network/nw:network-types/tet:te-topology/pg":
      Unauthorized access to this subtree can disclose the Power-Group
      Aware TE topology type.

   *
      "/nw:networks/nw:network/nw:node/tet:te/tet:te-node-attributes/
      power-groups": Unauthorized access to this subtree can disclose
      the Power-Groups information associated with a given TE node.

   *  "/nw:networks/nw:network/nt:link/tet:te/tet:te-link-attributes":
      Unauthorized access to this augmented subtree can disclose the
      Power-Group specific information associated with a TE link.

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>.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.





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   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <https://www.rfc-editor.org/info/rfc6020>.

   [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>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [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>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/info/rfc8341>.

   [RFC8345]  Clemm, A., Medved, J., Varga, R., Bahadur, N.,
              Ananthakrishnan, H., and X. Liu, "A YANG Data Model for
              Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March
              2018, <https://www.rfc-editor.org/info/rfc8345>.

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/info/rfc8446>.

   [RFC8776]  Saad, T., Gandhi, R., Liu, X., Beeram, V., and I. Bryskin,
              "Common YANG Data Types for Traffic Engineering",
              RFC 8776, DOI 10.17487/RFC8776, June 2020,
              <https://www.rfc-editor.org/info/rfc8776>.







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   [RFC8795]  Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and
              O. Gonzalez de Dios, "YANG Data Model for Traffic
              Engineering (TE) Topologies", RFC 8795,
              DOI 10.17487/RFC8795, August 2020,
              <https://www.rfc-editor.org/info/rfc8795>.

7.2.  Informative References

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.

Appendix A.  Complete Model Tree Structure

   module: ietf-te-topology-pwrgrp
     augment /nw:networks/nw:network/nw:network-types/tet:te-topology:
       +--rw pg!
     augment /nw:networks/nw:network/nw:node/tet:te
               /tet:te-node-attributes:
       +--rw power-groups
          +--rw power-group* [name]
             +--rw name     string
             +--rw value?   uint32
             +--rw cost?    decimal64
     augment /nw:networks/nw:network/nt:link/tet:te
               /tet:te-link-attributes:
       +--rw power-groups*           pg-ref
       +--rw power-save-capable?     boolean
       +--rw power-save-bandwidth
          +--rw te-bandwidth
             +--rw (technology)?
                +--:(generic)
                   +--rw generic?   te-bandwidth

Authors' Addresses

   Colby Barth
   Juniper Networks
   Email: cbarth@juniper.net


   Vishnu Pavan Beeram
   Juniper Networks
   Email: vbeeram@juniper.net







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