SPRING Working Group                                        S. Litkowski
Internet-Draft                                   Orange Business Service
Intended status: Standards Track                                   Y. Qu
Expires: September 11, 2017 January 2, 2018                                          Huawei
                                                               P. Sarkar
                                                             J. Tantsura
                                                              Individual
                                                          March 10,
                                                           July 01, 2017

                  YANG Data Model for Segment Routing
                      draft-ietf-spring-sr-yang-06
                      draft-ietf-spring-sr-yang-07

Abstract

   This document defines a YANG data model ([RFC6020], [RFC7950]) for
   segment routing ([I-D.ietf-spring-segment-routing]) configuration and
   operation.  This YANG model is intended to be used on network
   elements to configure or operate segment routing.  This document
   defines also generic containers that SHOULD be reused by IGP protocol
   modules to support segment routing.

Requirements Language

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

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 11, 2017. January 2, 2018.

Copyright Notice

   Copyright (c) 2017 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   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.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Tree diagram  . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Design of the Data Model  . . . . . . . . . . . . . . . . . .   3
   3.  Configuration . . . . . . . . . . . . . . . . . . . . . . . .   6
   4.  IGP Control plane configuration . . . . . . . . . . . . . . .   7
     4.1.  IGP interface configuration . . . . . . . . . . . . . . .   7
       4.1.1.  Adjacency SID properties  . . . . . . . . . . . . . .   8   7
         4.1.1.1.  Bundling  . . . . . . . . . . . . . . . . . . . .   8   7
         4.1.1.2.  Protection  . . . . . . . . . . . . . . . . . . .   8
   5.  States  . . . . . . . . . . . . . . . . . . . . . . . . . . .   9   8
   6.  Notifications . . . . . . . . . . . . . . . . . . . . . . . .   9   8
   7.  YANG Module . . . . . . . . . . . . . . . . . . . . . . . . .   9
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  28
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  28
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  28  29
   11. Normative References  . . . . . . . . . . . . . . . . . . . .  28  29
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  29

1.  Introduction

   This document defines a YANG data model for segment routing
   configuration and operation.  This document does not define the IGP
   extensions to support segment routing but defines generic groupings
   that SHOULD be reused by IGP extension modules.  The reason of this
   design choice is to not require implementations to support all IGP
   extensions.  For example, an implementation may support IS-IS
   extension but not OSPF.

1.1.  Tree diagram

   A simplified graphical representation of the data model is presented
   in Section 2.

   The meaning of the symbols in these diagrams is as follows:

   o  Brackets "[" and "]" enclose list keys.

   o  Curly braces "{" and "}" contain names of optional features that
      make the corresponding node conditional.

   o  Abbreviations before data node names: "rw" means configuration
      (read-write), and "ro" state data (read-only).

   o  Symbols after data node names: "?" means an optional node and "*"
      denotes a "list" or "leaf-list".

   o  Parentheses enclose choice and case nodes, and case nodes are also
      marked with a colon (":").

   o  Ellipsis ("...") stands for contents of subtrees that are not
      shown.

2.  Design of the Data Model

   As the module definition is just starting, it is expected that there
   will be changes as the module matures.

module: ietf-segment-routing
  augment /rt:routing:
    +--rw segment-routing
       +--rw transport-type?      identityref
       +--ro node-capabilities
       |  +--ro transport-planes* [transport-plane]
       |  |  +--ro transport-plane    identityref
       |  +--ro readable-label-stack-depth?   uint8
       +--rw msd {msd}?
       |  +--rw node-msd?   uint8
       |  +--rw link-msd
       |     +--rw link-msds* [interface]
       |        +--rw interface    if:interface-ref
       |        +--rw msd?         uint8
       +--rw bindings
       |  +--rw mapping-server {mapping-server}?
       |  |  +--rw policy* [name]
       |  |     +--rw name    string
       |  |     +--rw ipv4
       |  |     |  +--rw mapping-entry* [prefix algorithm]
       |  |     |     +--rw prefix        inet:ipv4-prefix
       |  |     |     +--rw value-type?   enumeration
       |  |     |     +--rw start-sid     uint32
       |  |     |     +--rw range?        uint32
       |  |     |     +--rw algorithm     identityref
       |  |     +--rw ipv6
       |  |        +--rw mapping-entry* [prefix algorithm]
       |  |           +--rw prefix        inet:ipv6-prefix
       |  |           +--rw value-type?   enumeration
       |  |           +--rw start-sid     uint32
       |  |           +--rw range?        uint32
       |  |           +--rw algorithm     identityref
       |  +--rw connected-prefix-sid-map
       |  |  +--rw ipv4
       |  |  |  +--rw ipv4-prefix-sid* [prefix algorithm]
       |  |  |     +--rw prefix               inet:ipv4-prefix
       |  |  |     +--rw value-type?          enumeration
       |  |  |     +--rw start-sid            uint32
       |  |  |     +--rw range?               uint32
       |  |  |     +--rw algorithm            identityref
       |  |  |     +--rw last-hop-behavior?   enumeration {sid-last-hop-behavior}?
       |  |  +--rw ipv6
       |  |     +--rw ipv6-prefix-sid* [prefix algorithm]
       |  |        +--rw prefix               inet:ipv6-prefix
       |  |        +--rw value-type?          enumeration
       |  |        +--rw start-sid            uint32
       |  |        +--rw range?               uint32
       |  |        +--rw algorithm            identityref
       |  |        +--rw last-hop-behavior?   enumeration {sid-last-hop-behavior}?
       |  +--rw local-prefix-sid
       |     +--rw ipv4
       |     |  +--rw ipv4-prefix-sid-local* [prefix algorithm]
       |     |     +--rw prefix        inet:ipv4-prefix
       |     |     +--rw value-type?   enumeration
       |     |     +--rw start-sid     uint32
       |     |     +--rw range?        uint32
       |     |     +--rw algorithm     identityref
       |     +--rw ipv6
       |        +--rw ipv6-prefix-sid-local* [prefix algorithm]
       |           +--rw prefix        inet:ipv6-prefix
       |           +--rw value-type?   enumeration
       |           +--rw start-sid     uint32
       |           +--rw range?        uint32
       |           +--rw algorithm     identityref
       +--rw global-srgb
       |  +--rw srgb* [lower-bound upper-bound]
       |     +--rw lower-bound    uint32
       |     +--rw upper-bound    uint32
       +--rw srlb
       |  +--rw srlb* [lower-bound upper-bound]
       |     +--rw lower-bound    uint32
       |     +--rw upper-bound    uint32
  augment /rt:routing-state:
    +--ro segment-routing
       +--ro node-capabilities
       |  +--ro transport-planes* [transport-plane]
       |  |  +--ro transport-plane    identityref
       |  +--ro readable-label-stack-depth?   uint8
       +--ro msd
       |  +--ro node-msd?   uint8
       |  +--ro link-msd
       |     +--ro link-msds* [interface]
       |        +--ro interface    if:interface-ref
       |        +--ro msd?         uint8
       +--ro label-blocks*
       |  +--ro lower-bound?   uint32
       |  +--ro upper-bound?   uint32
       |  +--ro size?          uint32
       |  +--ro free?          uint32
       |  +--ro used?          uint32
       |  +--ro scope?         enumeration
       +--ro sid-list
          +--ro sid* [target sid source source-protocol binding-type]
             +--ro target             string
             +--ro sid                uint32
             +--ro algorithm?         uint8
             +--ro source             inet:ip-address
             +--ro used?              boolean
             +--ro source-protocol    -> /rt:routing-state/control-plane-protocols /rt:routing/control-plane-protocols
             +                           /control-plane-protocol/name
             +--ro binding-type       enumeration
             +--ro scope?             enumeration

  notifications:
    +---n segment-routing-global-srgb-collision
    |  +--ro srgb-collisions*
    |     +--ro lower-bound?          uint32
    |     +--ro upper-bound?          uint32
    |     +--ro routing-protocol?     -> /rt:routing-state/control-plane-protocols
    |                                    /control-plane-protocol/name
    |     +--ro originating-rtr-id?   router-id
    +---n segment-routing-global-sid-collision
    |  +--ro received-target?       string
    |  +--ro new-sid-rtr-id?        router-id
    |  +--ro original-target?       string
    |  +--ro original-sid-rtr-id?   router-id
    |  +--ro index?                 uint32
    |  +--ro routing-protocol?      -> /rt:routing-state/control-plane-protocols
    |                                  /control-plane-protocol/name
    +---n segment-routing-index-out-of-range
       +--ro received-target?    string
       +--ro received-index?     uint32
       +--ro routing-protocol?   -> /rt:routing-state/control-plane-protocols
                                    /control-plane-protocol/name
notifications:
   +---n segment-routing-global-srgb-collision
   |  +--ro srgb-collisions*
   |     +--ro lower-bound?          uint32
   |     +--ro upper-bound?          uint32
   |     +--ro routing-protocol?     -> /rt:routing-state/control-plane-protocols /rt:routing/control-plane-protocols
    |                                    /control-plane-protocol/name
    |     +--ro originating-rtr-id?   router-id
    +---n segment-routing-global-sid-collision
    |  +--ro received-target?       string
    |  +--ro new-sid-rtr-id?        router-id
    |  +--ro original-target?       string
    |  +--ro original-sid-rtr-id?   router-id
    |  +--ro index?                 uint32
    |  +--ro routing-protocol?      -> /rt:routing-state/control-plane-protocols /rt:routing/control-plane-protocols
    |                                  /control-plane-protocol/name
    +---n segment-routing-index-out-of-range
       +--ro received-target?    string
       +--ro received-index?     uint32
       +--ro routing-protocol?   -> /rt:routing-state/control-plane-protocols /rt:routing/control-plane-protocols
                                    /control-plane-protocol/name

3.  Configuration

   This module augments the "/rt:routing:" with a segment-routing
   container.  This container defines all the configuration parameters
   related to segment-routing.

   The segment-routing configuration is split in global configuration
   and interface configuration.

   The global configuration includes :

   o  segment-routing transport type : The underlying transport type for
      segment routing.  The version of the model limits the transport
      type to an MPLS dataplane.  The transport-type is only defined
      once for a particular routing-instance and is agnostic to the
      control plane used.  Only a single transport-type is supported in
      this version of the model.

   o  bindings : Defines prefix to SID mappings.  The operator can
      control advertisement of Prefix-SID independently for IPv4 and
      IPv6.  Two types of mappings are available :

      *  Mapping-server : maps non local prefixes to a segment ID.
         Configuration of bindings does not automatically allow
         advertisement of those bindings.  Advertisement must be
         controlled by each routing-protocol instance (see Section 4).
         Multiple mapping policies may be defined.

      *  Connected prefixes : maps connected prefixes to a segment ID.
         Advertisement of the mapping will be done by IGP when enabled
         for segment routing (see Section 4).  The SID value can be
         expressed as an index (default), or an absolute value.  The
         "last-hop-behavior" configuration dictates the PHP behavior:
         "explicit-null", "php", or "non-php".

   o  SRGB (Segment Routing Global Block): Defines a list of label
      blocks represented by a pair of lower-bound/upper-bound labels.
      The SRGB is also agnostic to the control plane used.  So all
      routing-protocol instance will have to advertise the same SRGB.

   o  SRLB (Segment Routing Local Block): Defines a list of label blocks
      represented by a pair of lower-bound/upper-bound labels, reserved
      for lcoal SIDs.

4.  IGP Control plane configuration

   Support of segment-routing extensions for a particular IGP control
   plane is done by augmenting routing-protocol configuration with
   segment-routing extensions.  This augmentation SHOULD be part of
   separate YANG modules in order to not create any dependency for
   implementations to support all protocol extensions.

   This module defines groupings that SHOULD be used by IGP segment
   routing modules.

   The "controlplane-cfg" grouping defines the generic global
   configuration for the IGP.

   The "enabled" leaf enables segment-routing extensions for the
   routing-protocol instance.

   The "bindings" container controls the routing-protocol instance's
   advertisement of local bindings and the processing of received
   bindings.

4.1.  IGP interface configuration

   The interface configuration is part of the "igp-interface-cfg"
   grouping and includes Adjacency SID properties.

4.1.1.  Adjacency SID properties

4.1.1.1.  Bundling

   This section is a first proposal on how to use S-bit in Adj-SID to
   create bundles.  Authors would like to trigger discussion based on
   this first proposal.

   In case of parallel IP links between routers, an additional Adjacency
   SID may be advertised representing more than one adjacency (i.e., a
   bundle of adjacencies).  The "advertise-adj-group-sid" configuration
   controls whether or not an additional adjacency SID is advertised.

   The "advertise-adj-group-sid" would be a list of "group-id".  The
   "group-id" will permit to identify interfaces that must be bundled
   together.

           +-------+                 +------+
           |       | ------- L1 ---- |      |
           |   R1  | ------- L2 ---- |  R2  |
           |       | ------- L3 ---- |      |
           |       | ------- L4 ---- |      |
           +-------+                 +------+

   In the figure above, R1 and R2 are interconnected by four links.  A
   routing protocol adjacency is established on each link.  Operator
   would like to create segment-routing Adj-SID that represent some
   bundles of links.  We can imagine two different bundles : L1/L2 and
   L2/L3.  To achieve this behavior, the service provider will configure
   a "group-id" X for both interfaces L1 and L2 and a "group-id" Y for
   both interfaces L3 and L3.  This will result in R1 advertising an
   additional Adj-SID for each adjacency, for example a Adj-SID with S
   flag set and value of 400 will be added to L1 and L2.  A Adj-SID with
   S flag set and value of 500 will be added to L3 and L4.  As L1/L2 and
   L3/L4 does not share the same "group-id", a different SID value will
   be allocated.

4.1.1.2.  Protection

   The "advertise-protection" defines how protection for an interface is
   advertised.  It does not control the activation or deactivation of
   protection.  If the "single" option is used, a single Adj-SID will be
   advertised for the interface.  If the interface is protected, the
   B-Flag for the Adj-SID advertisement will be set.  If the "dual"
   option is used and if the interface is protected, two Adj-SIDs will
   be advertised for the interface adjacencies.  One Adj-SID will always
   have the B-Flag set and the other will have the B-Flag clear.  This
   option is intended to be used in the case of traffic engineering
   where a path must use either protected segments or non-protected
   segments.

5.  States

   The operational states contains information reflecting the usage of
   allocated SRGB labels.

   It also includes a list of all global SIDs, their associated
   bindings, and other information such as the source protocol and
   algorithm.

6.  Notifications

   The model defines the following notifications for segment-routing.

   o  segment-routing-global-srgb-collision: Rasied when a control plan
      advertised SRGB blocks have conflicts.

   o  segment-routing-global-sid-collision: Raised when a control plane
      advertised index is already associated with another target (in
      this version, the only defined targets are IPv4 and IPv6
      prefixes).

   o  segment-routing-index-out-of-range: Raised when a control plane
      advertised index fall outside the range of SRGBs configured for
      the network device.

7.  YANG Module

<CODE BEGINS> file "ietf-segment-routing-common@2017-03-10.yang" "ietf-segment-routing-common@2017-07-01.yang"
module ietf-segment-routing-common {
  namespace "urn:ietf:params:xml:ns:yang:ietf-segment-routing-common";
  prefix sr-cmn;

  import ietf-inet-types {
    prefix inet;
  }

  organization
    "IETF SPRING - SPRING Working Group";

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

     Editor:    Stephane Litkowski
               <mailto:stephane.litkowski@orange.com>
     Editor:    Yingzhen Qu
               <mailto:yingzhen.qu@huawei.com>

     Author:    Acee Lindem
               <mailto:acee@cisco.com>
     Author:    Yingzhen Qu
               <mailto:yingzhen.qu@huawei.com>
     Author:    Pushpasis Sarkar
               <mailto:pushpasis.ietf@gmail.com>
     Author:    Jeff Tantsura
               <jefftant.ietf@gmail.com>

    ";
  description
    "The YANG module defines a collection of types and groupings for
     Segment routing."; routing.

     Copyright (c) 2017 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).

     This version of this YANG module is part of RFC XXXX;
     see the RFC itself for full legal notices.";

  reference "RFC XXXX";

  revision 2017-07-01 {
    description
      "
       *Conform to RFC6087BIS Appendix C
      ";
    reference "RFC XXXX: YANG Data Model for Segment Routing.";
  }
  revision 2017-03-10 {
    description
      "
       * Add support of SRLB
      ";
    reference "RFC XXXX: YANG Data Model for Segment Routing.";
  }
  revision 2016-10-28 {
    description
      "
       * Add support of MSD (Maximum SID Depth)
       * Update contact info
      ";
    reference "RFC XXXX: YANG Data Model for Segment Routing.";
  }
  revision 2016-10-24 {
    description
      "Initial";
    reference "RFC XXXX: YANG Data Model for Segment Routing.";
  }

  feature sid-last-hop-behavior {
    description
      "Configurable last hop behavior.";
  }

  identity segment-routing-transport {
    description
      "Base identity for segment routing transport.";
  }

  identity segment-routing-transport-mpls {
    base segment-routing-transport;
    description
      "This identity represents MPLS transport for segment
       routing.";
  }

  identity segment-routing-transport-ipv6 {
    base segment-routing-transport;
    description
      "This identity represents IPv6 transport for segment
       routing.";
  }

  identity prefix-sid-algorithm {
    description
      "Base identity for prefix-sid algorithm.";
  }

  identity prefix-sid-algorithm-shortest-path {
    base prefix-sid-algorithm;
    description
      "The default behavior of prefix-sid algorithm.";
  }

  identity prefix-sid-algorithm-strict-spf {
    base prefix-sid-algorithm;
    description
      "This algorithm mandates that the packet is forwared
       according to ECMP-aware SPF algorithm.";
  }

  grouping srlr {
    description
      "Grouping for SR Label Range configuration.";
    leaf lower-bound {
        type uint32;
        description
          "Lower value in the block.";
      }
    leaf upper-bound {
        type uint32;
        description
          "Upper value in the block.";

      }
  }

  grouping srgb-cfg {
    description
      "Grouping for SR Label Range configuration.";
    list srgb {
      key "lower-bound upper-bound";
      ordered-by user;
      description
        "List of global blocks to be
         advertised.";
      uses srlr;
    }
  }

  grouping srlb-cfg {
    description
      "Grouping for SR Local Block range configuration.";
    list srlb {
      key "lower-bound upper-bound";
      ordered-by user;
      description
        "List of SRLBs.";
      uses srlr;
    }
  }

  grouping sid-value-type {
    description
      "Defines how the SID value is expressed.";
    leaf value-type {
      type enumeration {
        enum "index" {
          description
            "The value will be
             interpreted as an index.";
        }
        enum "absolute" {
          description
            "The value will become
             interpreted as an absolute
             value.";
        }
      }
      default "index";
      description
        "This leaf defines how value
         must be interpreted.";
    }
  }

  grouping ipv4-sid-cfg {
    description
      "This grouping defines cfg of prefix SID.";
    leaf prefix {
      type inet:ipv4-prefix;
      description
        "connected prefix sid.";
    }
    uses prefix-sid-attributes;
  }
  grouping ipv6-sid-cfg {
    description
      "This grouping defines cfg of prefix SID.";
    leaf prefix {
      type inet:ipv6-prefix;
      description
        "connected prefix sid.";
    }
    uses prefix-sid-attributes;
  }

  grouping last-hop-behavior {
    description
      "Defines last hop behavior";
    leaf last-hop-behavior {
      if-feature "sid-last-hop-behavior";
      type enumeration {
        enum "explicit-null" {
          description
            "Use explicit-null for the SID.";
        }
        enum "no-php" {
          description
            "Do no use PHP for the SID.";
        }
        enum "php" {
          description
            "Use PHP for the SID.";
        }
      }
      description
        "Configure last hop behavior.";
    }
  }
  grouping node-capabilities {
    description
      "Containing SR node capabilities.";
    container node-capabilities {
      config false;
      description
        "Shows the SR capability of the node.";
      list transport-planes {
        key "transport-plane";
        description
          "List of supported transport planes.";
        leaf transport-plane {
          type identityref {
            base segment-routing-transport;
          }
          description
            "Transport plane supported";
        }
      }
      leaf readable-label-stack-depth {
        type uint8;
        description
          "Number of MPLS labels that
           can be read in the stack.";
      }
    }
  }

  grouping prefix-sid-attributes {
    description
      "Containing SR attributes for a prefix.";
    uses sid-value-type;
    leaf start-sid {
      type uint32;
      mandatory true;
      description
        "Value associated with
         prefix. The value must
         be interpreted in the
         context of value-type.";
    }
    leaf range {
      type uint32;
      description
        "Describes how many SIDs could be
         allocated.";
    }
    leaf algorithm {
      type identityref {
        base prefix-sid-algorithm;
      }
      description
        "Prefix-sid algorithm.";
    }
  }
}
<CODE ENDS>
<CODE BEGINS> file "ietf-segment-routing@2017-03-10.yang" "ietf-segment-routing@2017-07-01.yang"
module ietf-segment-routing {
  namespace "urn:ietf:params:xml:ns:yang:ietf-segment-routing";
  prefix sr;

  import ietf-inet-types {
    prefix inet;
  }
  import ietf-yang-types {
    prefix yang;
  }
  import ietf-routing {
    prefix rt;
  }
  import ietf-interfaces {
    prefix if;
  }
  import ietf-segment-routing-common {
    prefix sr-cmn;
  }

  organization
    "IETF SPRING Working Group";
  contact
    "WG Web:   <http://tools.ietf.org/wg/spring/>
     WG List:  <mailto:spring@ietf.org>

     Editor:    Stephane Litkowski
               <mailto:stephane.litkowski@orange.com>
     Editor:    Yingzhen Qu
               <mailto:yingzhen.qu@huawei.com>

     Author:    Acee Lindem
               <mailto:acee@cisco.com>
     Author:    Yingzhen Qu
               <mailto:yingzhen.qu@huawei.com>
     Author:    Pushpasis Sarkar
               <mailto:pushpasis.ietf@gmail.com>
     Author:    Jeff Tantsura
               <jefftant.ietf@gmail.com>

    ";
  description
    "The YANG module defines a generic configuration model for
     Segment routing common across all of the vendor
     implementations.";

  revision 2017-03-10 {
    description
      "
       * Change global-sid-list to sid-list and
     implementations.

     Copyright (c) 2017 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).

     This version of this YANG module is part of RFC XXXX;
     see the RFC itself for full legal notices.";

  reference "RFC XXXX";

  revision 2017-07-01 {
    description
      "
       * Implement NMDA model
       *Conform to RFC6087BIS Appendix C
      ";
    reference "RFC XXXX: YANG Data Model for Segment Routing.";
  }

  revision 2017-03-10 {
    description
      "
       * Change global-sid-list to sid-list and add a leaf scope
       * Added support of SRLB
       * Added support of local sids
       * fixed indentations
      ";
    reference "RFC XXXX: YANG Data Model for Segment Routing.";
  }
  revision 2016-10-28 {
    description
      "
       * Add support of MSD (Maximum SID Depth)
       * Update contact info
      ";
    reference "RFC XXXX: YANG Data Model for Segment Routing.";
  }
  revision 2016-10-24 {
    description
      "
       * Moved common SR types and groupings to a seperate module
      ";
    reference "RFC XXXX: YANG Data Model for Segment Routing.";
  }
  revision 2016-07-07 {
    description
      "
       * Add support of prefix-sid algorithm configuration
       * change routing-protocols to control-plane-protocols
      ";
    reference "RFC XXXX: YANG Data Model for Segment Routing.";
  }
  revision 2016-03-17 {
    description
      "
       * Add notification segment-routing-global-srgb-collision
       * Add router-id to segment-routing-global-sid-collision
       * Remove routing-instance
       * Add typedef router-id
      ";
    reference "RFC XXXX: YANG Data Model for Segment Routing.";
  }
  revision 2015-10-17 {
    description
      "
       * Add per-protocol SRGB config feature
       * Move SRBG config to a grouping
      ";
    reference "RFC XXXX: YANG Data Model for Segment Routing.";
  }
  revision 2015-06-22 {
    description
      "
       * Prefix SID config moved to
       connected-prefix-sid-map in global SR cfg
       rather than IGP.
      ";
    reference "draft-litkowski-spring-sr-yang-01";
  }
  revision 2015-04-23 {
    description
      "
       * Node flag deprecated from prefixSID
       * SR interface cfg moved to protocol
       * Adding multiple binding policies for SRMS

      ";
    reference "";
  }
  revision 2015-02-27 {
    description
      "Initial";
    reference "draft-litkowski-spring-sr-yang-00";
  }

  feature mapping-server {
    description
      "Support of SRMS.";
  }

  feature protocol-srgb {
    description
      "Support per-protocol srgb configuration.";
  }

  feature msd {
    description
      "Support of signaling MSD (Maximum SID Depth) in IGP.";
  }

  typedef system-id {
    type string {
      pattern "[0-9A-Fa-f]{4}\\.[0-9A-Fa-f]{4}\\.[0-9A-Fa-f]{4}\\.00";
    }
    description
      "This type defines ISIS system id using pattern,
       system id looks like : 0143.0438.AeF0.00";
  }

  typedef router-id {
    type union {
      type system-id;
      type yang:dotted-quad;
    }
    description
      "OSPF/BGP router id or ISIS system ID.";
  }

  grouping controlplane-cfg {
    description
      "Defines protocol configuration.";
    container segment-routing {
      description
        "segment routing global config.";

      leaf enabled {
        type boolean;
        default "false";
        description
          "Enables segment-routing
           protocol extensions.";
      }
      container bindings {
        description
          "Control of binding advertisement
           and reception.";
        container advertise {
          description
            "Authorize the advertise
             of local mappings in binding TLV.";
          leaf-list policies {
            type string;
            description
              "List of policies to be advertised.";
          }
        }
        leaf receive {
          type boolean;
          default "true";
          description
            "Authorize the reception and usage
             of binding TLV.";
        }
      }
    }
  }

  grouping igp-interface-cfg {
    description
      "Grouping for IGP interface cfg.";
    container segment-routing {
      description
        "container for SR interface cfg.";
      container adjacency-sid {
        description
          "Defines the adjacency SID properties.";
        list advertise-adj-group-sid {
          key "group-id";
          description
            "Control advertisement of S flag.
             Enable to advertise a common Adj-SID
             for parallel links.";
          leaf group-id {
            type uint32;
            description
              "The value is an internal value to identify
               a group-ID. Interfaces with the same
               group-ID will be bundled together.";
          }
        }
        leaf advertise-protection {
          type enumeration {
            enum "single" {
              description
                "A single Adj-SID is associated
                 with the adjacency and reflects
                 the protection configuration.";
            }
            enum "dual" {
              description
                "Two Adj-SIDs will be associated
                 with the adjacency if interface
                 is protected. In this case
                 one will be enforced with
                 backup flag set, the other
                 will be enforced to backup flag unset.
                 In case, protection is not configured,
                 a single Adj-SID will be advertised
                 with backup flag unset.";
            }
          }
          description
            "If set, the Adj-SID refers to an
             adjacency being protected.";
        }
      }
    }
  }

  grouping msd-cfg {
    description
      "MSD configuration grouping.";
    leaf node-msd {
      type uint8;
      description
        "Node MSD is the lowest MSD supported by the node.";
    }
    container link-msd {
      description
        "Link MSD is a number represetns the particular link MSD value.";
      list link-msds {
        key "interface";
        description
          "List of link MSDs.";
        leaf interface {
          type if:interface-ref;
          description
            "Name of the interface.";
        }
        leaf msd {
          type uint8;
          description
            "SID depth of the interface associated with the link.";
        }
      }
    }
  }

  notification segment-routing-global-srgb-collision

  augment "/rt:routing" {
    description
      "This notification is sent when received SRGB blocks from
       a router conflict.";
    list srgb-collisions augments routing-instance
       configuration with segment-routing.";
    container segment-routing {
      description
        "List of SRGB blocks that conflict.";
        "segment routing global config.";
      leaf lower-bound transport-type {
        type uint32; identityref {
          base sr-cmn:segment-routing-transport;
        }
        default "sr-cmn:segment-routing-transport-mpls";
        description
          "Lower value in the block.";
          "Dataplane to be used.";
      }
      leaf upper-bound
      uses sr-cmn:node-capabilities;
      container msd {
        type uint32;
        if-feature "msd";
        description
          "Upper value in the block.";
          "MSD configuration.";
        uses msd-cfg;
      }
      leaf routing-protocol {
        type leafref
      container bindings {
          path "/rt:routing-state/rt:control-plane-protocols/"
             + "rt:control-plane-protocol/rt:name";
        }
        description
          "Routing protocol reference that received the event.";
      }
      leaf originating-rtr-id
          "List of bindings.";
        container mapping-server {
        type router-id;
          if-feature "mapping-server";
          description
          "Originating router id
            "Configuration of this SRGB block.";
      }
    }
  }
  notification segment-routing-global-sid-collision mapping-server
             local entries.";
          list policy {
            key "name";
            description
      "This notification is sent when a new mapping is learned
       , containing
              "Definition of mapping
       where the SID is already used.
       The notification generation must be throttled with at least
       a 5 second gap. "; policy.";
            leaf received-target name {
              type string;
              description
        "Target received in
                "Name of the controlplane that
                           caused SID collision."; mapping policy.";
            }
    leaf new-sid-rtr-id
            container ipv4 {
      type router-id;
              description
        "Router Id that advertising the conflicting SID.";
    }
    leaf original-target
                "IPv4 mapping entries.";
              list mapping-entry {
      type string;
                key "prefix algorithm";
                description
        "Target already available in database that have the same SID
         as the received target.";
                  "Mapping entries.";
                uses sr-cmn:ipv4-sid-cfg;
              }
    leaf original-sid-rtr-id
            }
            container ipv6 {
      type router-id;
              description
        "Original router ID that advertised the conflicting SID.";
    }
    leaf index
                "IPv6 mapping entries.";
              list mapping-entry {
      type uint32;
                key "prefix algorithm";
                description
        "Value of the index used by two different prefixes.";
                  "Mapping entries.";
                uses sr-cmn:ipv6-sid-cfg;
              }
    leaf routing-protocol {
      type leafref {
        path "/rt:routing-state/rt:control-plane-protocols/"
           + "rt:control-plane-protocol/rt:name";
            }
      description
        "Routing protocol reference that received the event.";
          }
        }
  notification segment-routing-index-out-of-range
        container connected-prefix-sid-map {
          description
      "This notification is sent when a binding
       is received, containing a segment index
       which is out of the local configured ranges.
       The notification generation must be throttled with at least
       a 5 second gap. ";
    leaf received-target
            "Prefix SID configuration.";
          container ipv4 {
      type string;
            description
        "Target received in the controlplane
                          that caused SID collision.";
    }
    leaf received-index
              "Parameters associated with IPv4 prefix SID";
            list ipv4-prefix-sid {
      type uint32;
              key "prefix algorithm";
              description
        "Value
                "List of the index received."; prefix SID
                 mapped to IPv4 local prefixes.";
              uses sr-cmn:ipv4-sid-cfg;
              uses sr-cmn:last-hop-behavior;
            }
    leaf routing-protocol
          }
          container ipv6 {
      type leafref
            description
              "Parameters associated with IPv6 prefix SID";

            list ipv6-prefix-sid {
        path "/rt:routing-state/rt:control-plane-protocols/"
           + "rt:control-plane-protocol/rt:name";
      }
              key "prefix algorithm";
              description
        "Routing protocol reference that received the event.";
                "List of prefix SID
                 mapped to IPv6 local prefixes.";
              uses sr-cmn:ipv6-sid-cfg;
              uses sr-cmn:last-hop-behavior;
            }
          }
  augment "/rt:routing"
        }
        container local-prefix-sid {
          description
      "This augments routing-instance
       configuration with segment-routing.";
            "Local sid configuration.";
          container segment-routing ipv4 {
            description
        "segment routing global config.";
      leaf transport-type {
        type identityref
              "List of local ipv4 sids.";
            list ipv4-prefix-sid-local {
          base sr-cmn:segment-routing-transport;
              key "prefix algorithm";
              description
                "List of local prefix-sid.";
              uses sr-cmn:ipv4-sid-cfg;
            }
        default "sr-cmn:segment-routing-transport-mpls";
          }
          container ipv6 {
            description
          "Dataplane to be used.";
              "List of local ipv6 sids.";
            list ipv6-prefix-sid-local {
              key "prefix algorithm";
              description
                "List of local prefix-sid.";
              uses sr-cmn:ipv6-sid-cfg;
            }
          }
        }
      }
      container msd global-srgb {
        if-feature "msd";
        description
          "MSD
          "Global SRGB configuration.";
        uses msd-cfg; sr-cmn:srgb-cfg;
      }
      container bindings srlb {
        description
          "SR Local Block configuration.";
        uses sr-cmn:srlb-cfg;
      }

      list label-blocks {
        config false;
        description
          "List of bindings.";
        container mapping-server labels blocks currently
           in use.";
        leaf lower-bound {
          if-feature "mapping-server";
          type uint32;
          description
            "Configuration
            "Lower bound of mapping-server
             local entries.";
          list policy the label block.";
        }
        leaf upper-bound {
            key "name";
          type uint32;
          description
              "Definition
            "Upper bound of mapping policy."; the label block.";
        }
        leaf name size {
          type string; uint32;
          description
                "Name
            "Number of indexes in the mapping policy."; block.";
        }
            container ipv4
        leaf free {
          type uint32;
          description
                "IPv4 mapping entries.";
              list mapping-entry
            "Number of indexes free in the block.";
        }
        leaf used {
                key "prefix algorithm";
          type uint32;
          description
                  "Mapping entries.";
                uses sr-cmn:ipv4-sid-cfg;
              }
            "Number of indexes used in the block.";
        }
            container ipv6
        leaf scope {
          type enumeration {
            enum "global" {
              description
                "IPv6 mapping entries.";
              list mapping-entry
                "Global sid.";
            }
            enum "local" {
                key "prefix algorithm";
              description
                  "Mapping entries.";
                uses sr-cmn:ipv6-sid-cfg;
                "Local sid.";
            }
          }
          description
            "Scope of this label block.";
        }
      }
      container connected-prefix-sid-map {
          description
            "Prefix SID configuration.";
          container ipv4 sid-list {
        config false;
        description
              "Parameters associated with IPv4
          "List of prefix SID"; and SID associations.";
        list ipv4-prefix-sid sid {
          key "prefix algorithm"; "target sid source source-protocol binding-type";
          ordered-by system;
          description
                "List
            "Binding.";
          leaf target {
            type string;
            description
              "Defines the target of the binding.
               It can be a prefix SID
                 mapped to IPv4 local prefixes.";
              uses sr-cmn:ipv4-sid-cfg;
              uses sr-cmn:last-hop-behavior;
            } or something else.";
          }
          container ipv6
          leaf sid {
            type uint32;
            description
              "Parameters
              "Index associated with IPv6 prefix SID";
            list ipv6-prefix-sid the prefix.";
          }
          leaf algorithm {
              key "prefix algorithm";
            type uint8;
            description
                "List of prefix SID
                 mapped
              "Algorithm to IPv6 local prefixes.";
              uses sr-cmn:ipv6-sid-cfg;
              uses sr-cmn:last-hop-behavior;
            }
          } be used for the prefix
               SID.";
          }
        container local-prefix-sid
          leaf source {
            type inet:ip-address;
            description
            "Local sid configuration.";
          container ipv4
              "IP address of the router than own
               the binding.";
          }
          leaf used {
            type boolean;
            description
              "List of local ipv4 sids.";
            list ipv4-prefix-sid-local
              "Defines if the binding is used
               in forwarding plane.";
          }
          leaf source-protocol {
            type leafref {
              key "prefix algorithm";
              description
                "List of local prefix-sid.";
              uses sr-cmn:ipv4-sid-cfg;
              path "/rt:routing/rt:control-plane-protocols/"
                 + "rt:control-plane-protocol/rt:name";
            }
            description
              "Rtg protocol that owns the binding";
          }
          container ipv6
          leaf binding-type {
            description
              "List of local ipv6 sids.";
            list ipv6-prefix-sid-local
            type enumeration {
              enum "prefix-sid" {
              key "prefix algorithm";
                description
                "List of local prefix-sid.";
              uses sr-cmn:ipv6-sid-cfg;
                  "Binding is learned from
                   a prefix SID.";
              }
              enum "binding-tlv" {
                description
                  "Binding is learned from
                   a binding TLV.";
              }
            }
            description
              "Type of binding.";
          }
      container global-srgb
          leaf scope {
            type enumeration {
              enum "global" {
                description
                  "Global SRGB configuration.";
        uses sr-cmn:srgb-cfg; sid.";
              }
      container srlb
              enum "local" {
                description
          "SR Local Block configuration.";
        uses sr-cmn:srlb-cfg;
                  "Local sid.";
              }
            }
            description
              "The sid is local or global.";
          }
        }
  augment "/rt:routing-state"
      }
    }
  }

  notification segment-routing-global-srgb-collision {
    description
      "This augments the operational states
       with segment-routing.";
    container segment-routing {
      description
        "Segment routing operational states.";
      uses sr-cmn:node-capabilities;
      container msd {
        description
          "MSD configuration state.";
        uses msd-cfg;
      } notification is sent when received SRGB blocks from
       a router conflict.";
    list label-blocks srgb-collisions {
      description
        "List of labels SRGB blocks currently
           in use."; that conflict.";
      leaf lower-bound {
        type uint32;
        description
          "Lower bound of value in the label block.";
      }
      leaf upper-bound {
        type uint32;
        description
          "Upper bound of the label block.";
        }
        leaf size {
          type uint32;
          description
            "Number of indexes value in the block.";
      }
      leaf free routing-protocol {
        type uint32;
          description
            "Number of indexes free in the block.";
        }
        leaf used leafref {
          type uint32;
          path "/rt:routing/rt:control-plane-protocols/"
             + "rt:control-plane-protocol/rt:name";
        }
        description
            "Number of indexes used in
          "Routing protocol reference that received the block."; event.";
      }
      leaf scope originating-rtr-id {
        type enumeration {
            enum "global" {
              description
                "Global sid.";
            }
            enum "local" {
              description
                "Local sid.";
            }
          } router-id;
        description
            "Scope
          "Originating router id of this label SRGB block.";
      }
    }
      container sid-list
  }
  notification segment-routing-global-sid-collision {
    description
          "List of prefix and
      "This notification is sent when a new mapping is learned
       , containing mapping
       where the SID associations.";
        list sid {
          key "target sid source source-protocol binding-type";
          ordered-by system;
          description
            "Binding."; is already used.
       The notification generation must be throttled with at least
       a 5 second gap. ";
    leaf target received-target {
      type string;
      description
              "Defines the target of
        "Target received in the binding.
               It can be a prefix or something else."; controlplane that
                           caused SID collision.";
    }
    leaf sid new-sid-rtr-id {
      type uint32; router-id;
      description
              "Index associated with
        "Router Id that advertising the prefix."; conflicting SID.";
    }
    leaf algorithm original-target {
      type uint8; string;
      description
              "Algorithm to be used for
        "Target already available in database that have the prefix
               SID."; same SID
         as the received target.";
    }
    leaf source original-sid-rtr-id {
      type inet:ip-address; router-id;
      description
              "IP address of the
        "Original router than own ID that advertised the binding."; conflicting SID.";
    }
    leaf used index {
      type boolean; uint32;
      description
              "Defines if
        "Value of the binding is index used
               in forwarding plane."; by two different prefixes.";
    }
    leaf source-protocol routing-protocol {
      type leafref {
        path "/rt:routing-state/rt:control-plane-protocols/" "/rt:routing/rt:control-plane-protocols/"
           + "rt:control-plane-protocol/rt:name";
      }
      description
              "Rtg
        "Routing protocol reference that owns received the binding"; event.";
    }
          leaf binding-type {
            type enumeration {
              enum "prefix-sid" {
                description
                  "Binding is learned from
                   a prefix SID.";
  }
              enum "binding-tlv"
  notification segment-routing-index-out-of-range {
    description
                  "Binding
      "This notification is learned from sent when a binding TLV.";
              }
            }
            description
              "Type
       is received, containing a segment index
       which is out of binding.";
          } the local configured ranges.
       The notification generation must be throttled with at least
       a 5 second gap. ";
    leaf scope received-target {
      type enumeration {
              enum "global" { string;
      description
                  "Global sid.";
        "Target received in the controlplane
                          that caused SID collision.";
    }
              enum "local"
    leaf received-index {
      type uint32;
      description
                  "Local sid.";
        "Value of the index received.";
    }
    leaf routing-protocol {
      type leafref {
        path "/rt:routing/rt:control-plane-protocols/"
           + "rt:control-plane-protocol/rt:name";
      }
      description
              "The sid is local or global.";

          }
        }
      }
        "Routing protocol reference that received the event.";
    }
  }
}
<CODE ENDS>

8.  Security Considerations

   TBD.

9.  Acknowledgements

   Authors would like to thank Derek Yeung, Acee Lindem, Greg Hankins,
   Hannes Gredler, Uma Chunduri, Jeffrey Zhang, Shradda Hedge, Les
   Ginsberg for their contributions.

10.  IANA Considerations

   TBD.

11.  Normative References

   [I-D.ietf-isis-segment-routing-msd]
              Tantsura, J., Chunduri, U., Aldrin, S., and L. Ginsberg,
              "Signaling MSD (Maximum SID Depth) using IS-IS", draft-
              ietf-isis-segment-routing-msd-02
              ietf-isis-segment-routing-msd-04 (work in progress), March June
              2017.

   [I-D.ietf-ospf-segment-routing-msd]
              Tantsura, J., Chunduri, U., Aldrin, S., and P. Psenak,
              "Signaling MSD (Maximum SID Depth) using OSPF", draft-
              ietf-ospf-segment-routing-msd-02
              ietf-ospf-segment-routing-msd-05 (work in progress), March June
              2017.

   [I-D.ietf-spring-segment-routing]
              Filsfils, C., Previdi, S., Decraene, B., Litkowski, S.,
              and R. Shakir, "Segment Routing Architecture", draft-ietf-
              spring-segment-routing-11
              spring-segment-routing-12 (work in progress), February June 2017.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC6020]  Bjorklund, M., "YANG - A Data Modeling Language for the
              Network Configuration Protocol (NETCONF)", RFC 6020,
              October 2010.

   [RFC7950]  Bjorklund, M., "The YANG 1.1 Data Modeling Language",
              RFC 7950, August 2016.

Authors' Addresses

   Stephane Litkowski
   Orange Business Service

   Email: stephane.litkowski@orange.com

   Yingzhen Qu
   Huawei

   Email: yingzhen.qu@huawei.com
   Pushpasis Sarkar
   Individual

   Email: pushpasis.ietf@gmail.com

   Jeff Tantsura
   Individual

   Email: jefftant.ietf@gmail.com