roll P. van der Stok, Ed.
Internet-Draft consultant
Intended status: Standards Track July 15, 2018
Expires: January 16, 2019

A YANG model for Multicast Protocol for Low power and lossy Networks (MPL)
draft-ietf-roll-mpl-yang-02

Abstract

This document defines a YANG data model for management of Multicast Protocol for Low power and lossy Networks (MPL) implementations. The data model includes configuration data and state data.

Note

Discussion and suggestions for improvement are requested, and should be sent to roll@ietf.org.

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 January 16, 2019.

Copyright Notice

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

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.


Table of Contents

1. Introduction

This document defines a YANG [RFC7950] data model for management of Multicast Protocol for Low power and lossy Networks (MPL) [RFC7731] implementations. The data model covers configuration of MPL parameters per interface. It also provides information about which Multicast addresses are operationally used, and the seeds of the forwarded packets.

1.1. Terminology

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].

The following terms are defined in [RFC6241] and are not redefined here: [RFC7950] and are not redefined here: [RFC7950].

The following terms are defined in

The terminology for describing YANG data models is found in

Terms like message, domain, seed, I, k, c are defined in [RFC7731].

Terms like YANG Schema Item iDentifier (SID) and delta are defined in [I-D.ietf-core-sid].

Multiple copies of a message can be received or sent by a node.

1.1.1. Tree Diagrams

YANG tree diagrams provide a concise representation of a YANG module, and SHOULD be included to help readers understand YANG module structure. Guidelines on tree diagrams can be found in Section 3 of [I-D.ietf-netmod-yang-tree-diagrams]. Tree diagrams used in this document follow the notation defined in [RFC8340].

2. MPL model

This document defines the YANG modules "ietf-yang-mpl-xxx", which specify a data model for MPL servers. The model is separated into four modules which can be loaded independently to accommodate the storage space to the wanted functionality. The model consists of the following parts: (1) "mpl-domain", (2) "mpl-op", (3) "mpl-seeds", and (4) "mpl-statistics". The four models are discussed below accompanied by their trees.

2.1. NMDA considerations

The Network Management Data Architecture (NMDA) is specified in [RFC8342]. The MPL protocol is designed for low-resource nodes, where the hardware is fixed once and for all. The configuration of the node in the MPL context is limited to enabling the interface(s) with Multicast addresses. The interface configuration of the YANG module replaces the multicast address assignment of section 2.6.2 of [RFC7390].

Consequently, The contents of the "candidate", "startup", "running", and "intended" datastores are identical. The conceptual datastore consists of an "operational" and an "intended" datastore. The "intended" store contains the nodes of the modules: ietf-yang-mpl-domain, and ietf-yang-mpl-ops. The "running" store contains the nodes of the modules: ietf-yang-mpl-seeds, and ietf-yang-mpl-statistics. The ietf-yang-mpl-domain is necessary when any MPL management is wanted. The two modules of the "running" store need the two modules of the "intended" store, and can be loaded dependent on the management wishes and resource constraints.

The modules ietf-yang-mpl-ops, ietf-yang-mpl-seeds, and ietf-yang-mpl-statistics "augment" ietf-yang-mpl-domain.

2.2. MPL-domain tree

The "mpl-domain" module describes the MPL-domains and associated Multicast addresses and the interfaces on which the Multicast addresses are enabled. The model allow for a short single MPL-domain configuration or a multi-domain configuration that needs more storage space.

  
module: ietf-yang-mpl-domain
    +--rw domain
       +--rw (multiple)?
          +--:(mpl-domain)
          |  +--rw mpl-domain
          |     +--rw domains* [domainID]
          |     |  +--rw domainID    uint16
          |     |  +--rw MClist*     inet:ipv6-address
          |     +--rw addresses* [MCaddress]
          |        +--rw MCaddress     inet:ipv6-address
          |        +--rw interfaces*   string
          +--:(mpl-single)
             +--rw mpl-single
                +--rw MCaddresses*   inet:ipv6-address

2.3. MPL-ops tree

The generator node of a MPL message is called a seed that emits on a multicast address of a domain. The "mpl-ops" module describes the operational parameters settings per domain. The parameters determine the dynamics of the message reception intervals per domain [RFC7731].

  
module: ietf-yang-mpl-ops
  augment /mpl:domain:
    +--rw mpl-ops
       +--rw PROACTIVE_FORWARDING?      boolean
       +--rw SEED_SET_ENTRY_LIFETIME?   uint64
       +--rw mpl-parameter* [domainID]
          +--rw domainID                             uint16
          +--rw DATA_MESSAGE_IMIN?                   uint16
          +--rw DATA_MESSAGE_IMAX?                   uint16
          +--rw DATA_MESSAGE_K?                      uint16
          +--rw DATA_MESSAGE_TIMER_EXPIRATIONS?      uint16
          +--rw CONTROL_MESSAGE_IMIN?                uint16
          +--rw CONTROL_MESSAGE_IMAX?                uint16
          +--rw CONTROL_MESSAGE_K?                   uint16
          +--rw CONTROL_MESSAGE_TIMER_EXPIRATIONS?   uint16

2.4. MPL-seeds tree

The "mpl-seeds" part describes the MPL buffer contents and the Trickle timer values associated with each seed and domain. Multiple seeds per domain may exist. The module exposes the state of the MPL buffer and key information about the messages in the MPL buffers at a given acquisition moment.


 module: ietf-yang-mpl-seeds
  augment /mpl:domain:
    +--rw SE_LIFETIME?   uint16
    +--ro mpl-seeds* [seedID domainID]
       +--ro seedID               uint64
       +--ro domainID             uint16
       +--ro local?               boolean
       +--ro generate-seqno?      uint8
       +--ro life-time?           uint64
       +--ro min-seqno?           uint8
       +--ro data-number?         uint8
       +--ro control-number?      uint8
       +--ro buffered-messages* [seqno]
          +--ro seqno    uint8
          +--ro I?       uint8
          +--ro c?       uint8
          +--ro e?       uint8
          +--ro t?       uint8

2.5. MPL-statistics tree

The "mpl-statistics" module describes the number of lost and correctly forwarded messages and its copies.


  module: ietf-yang-mpl-statistics
  augment /mpl:domain:
    +--ro mpl-statistics* [seedID domainID]
    |  +--ro seedID                        uint64
    |  +--ro domainID                      uint16
    |  +--ro c-too-high?                   uint64
    |  +--ro nr-forwarded?                 uint64
    |  +--ro nr-of-messages-received?      uint64
    |  +--ro nr-of-messages-forwarded?     uint64
    |  +--ro nr-of-copies-received?        uint64
    |  +--ro nr-of-copies-forwarded?       uint64
    |  +--ro nr-of-refused-copies?         uint64
    |  +--ro nr-of-missed-messages?        uint64
    |  +--ro nr-of-notreceived-messages?   uint64
    |  +--ro nr-of-inconsistent-data?      uint64
    |  +--ro nr-of-consistent-data?        uint64
    |  +--ro nr-of-consistent-control?     uint64
    |  +--ro nr-of-inconsistent-control?   uint64
    |  +--ro statistics-interval?          uint64
    |  +---x reset-buffer-statistics
    +---x reset-all-statistics

3. SID file generation

YANG Schema Item iDentifiers (SID) are allocated to replace the relatively long YANG identifiers by the much shorter SIDs. Consequently, the payload size is considerably reduced. The assignment tool is https://comi.space/. SIDs are allocated to the identifiers specified in the four modules. Their values are:

3.1. mpl-domain


Module : ietf-yang-mpl-domain
Revision : 2018-07-06

SID	Namespace	YANG identifier
1004000	module	ietf-yang-mpl-domain
1004001	data	/ietf-yang-mpl-domain:domain
1004002	data	/ietf-yang-mpl-domain:domain/mpl-domain
1004003	data	/ietf-yang-mpl-domain:domain/mpl-domain
                                      /addresses
1004004	data	/ietf-yang-mpl-domain:domain/mpl-domain
                                      /addresses/MCaddress
1004005	data	/ietf-yang-mpl-domain:domain/mpl-domain
                                      /addresses/interfaces
1004006	data	/ietf-yang-mpl-domain:domain/mpl-domain
                                      /domains
1004007	data	/ietf-yang-mpl-domain:domain/mpl-domain
                                      /domains/MClist
1004008	data	/ietf-yang-mpl-domain:domain/mpl-domain
                                      /domains/domainID
1004009	data	/ietf-yang-mpl-domain:domain/mpl-single
1004010	data	/ietf-yang-mpl-domain:domain/mpl-single
                                      /MCaddresses

3.2. mpl-ops


Module : ietf-yang-mpl-ops
Revision : 2018-07-06

SID	Namespace	YANG identifier
1004050	module	ietf-yang-mpl-ops
1004051	data	/ietf-yang-mpl-domain:domain
                                   /ietf-yang-mpl-ops:mpl-ops
1004052	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-ops:
           mpl-ops/PROACTIVE_FORWARDING
1004053	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-ops:
           mpl-ops/SEED_SET_ENTRY_LIFETIME
1004054	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-ops:
           mpl-ops/mpl-parameter
1004055	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-ops:
           mpl-ops/mpl-parameter/CONTROL_MESSAGE_IMAX
1004056	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-ops:
           mpl-ops/mpl-parameter/CONTROL_MESSAGE_IMIN
1004057	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-ops:
           mpl-ops/mpl-parameter/CONTROL_MESSAGE_K
1004058	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-ops:
         mpl-ops/mpl-parameter/CONTROL_MESSAGE_TIMER_EXPIRATIONS
1004059	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-ops:
           mpl-ops/mpl-parameter/DATA_MESSAGE_IMAX
1004060	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-ops:
           mpl-ops/mpl-parameter/DATA_MESSAGE_IMIN
1004061	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-ops:
           mpl-ops/mpl-parameter/DATA_MESSAGE_K
1004062	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-ops:
           mpl-ops/mpl-parameter/DATA_MESSAGE_TIMER_EXPIRATIONS
1004063	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-ops:
           mpl-ops/mpl-parameter/domainID

3.3. mpl-seeds


Module : ietf-yang-mpl-seeds
Revision : 2018-07-06

SID	Namespace	YANG identifier
1004100	module	ietf-yang-mpl-seeds
1004101	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:SE_LIFETIME
1004102	data	/ietf-yang-mpl-domain:domain
                             /ietf-yang-mpl-seeds:mpl-seeds
1004103	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:
           mpl-seeds/buffered-messages
1004104	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:
           mpl-seeds/buffered-messages/I
1004105	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:
           mpl-seeds/buffered-messages/c
1004106	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:
           mpl-seeds/buffered-messages/e
1004107	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:
           mpl-seeds/buffered-messages/seqno
1004108	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:
           mpl-seeds/buffered-messages/t
1004109	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:
           mpl-seeds/control-number
1004110	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:
           mpl-seeds/data-number
1004111	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:
           mpl-seeds/domainID
1004112	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:
           mpl-seeds/generate-seqno
1004113	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:
           mpl-seeds/life-time
1004114	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:
           mpl-seeds/local
1004115	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:
           mpl-seeds/min-seqno
1004116	data	/ietf-yang-mpl-domain:domain/ietf-yang-mpl-seeds:
           mpl-seeds/seedID

3.4. mpl-statistics


Module : ietf-yang-mpl-statistics
Revision : 2018-07-06

SID	Namespace	YANG identifier
1004150	module	ietf-yang-mpl-statistics
1004151	data	/ietf-yang-mpl-domain:domain/
           ietf-yang-mpl-statistics:mpl-statistics
1004152	data	/ietf-yang-mpl-domain:domain/
    ietf-yang-mpl-statistics:mpl-statistics/c-too-high
1004153	data	/ietf-yang-mpl-domain:domain/
     ietf-yang-mpl-statistics:mpl-statistics/domainID
1004154	data	/ietf-yang-mpl-domain:domain/
     ietf-yang-mpl-statistics:mpl-statistics/nr-forwarded
1004155	data	/ietf-yang-mpl-domain:domain/
     ietf-yang-mpl-statistics:mpl-statistics
                              /nr-of-consistent-control
1004156	data	/ietf-yang-mpl-domain:domain/
      ietf-yang-mpl-statistics:mpl-statistics
                              /nr-of-consistent-data
1004157	data	/ietf-yang-mpl-domain:domain/
    ietf-yang-mpl-statistics:mpl-statistics
                              /nr-of-copies-forwarded
1004158	data	/ietf-yang-mpl-domain:domain/
    ietf-yang-mpl-statistics:mpl-statistics
                              /nr-of-copies-received
1004159	data	/ietf-yang-mpl-domain:domain/
    ietf-yang-mpl-statistics:mpl-statistics
                              /nr-of-inconsistent-control
1004160	data	/ietf-yang-mpl-domain:domain/
    ietf-yang-mpl-statistics:mpl-statistics
                              /nr-of-inconsistent-data
1004161	data	/ietf-yang-mpl-domain:domain/
    ietf-yang-mpl-statistics:mpl-statistics
                              /nr-of-messages-forwarded
1004162	data	/ietf-yang-mpl-domain:domain/
    ietf-yang-mpl-statistics:mpl-statistics
                              /nr-of-messages-received
1004163	data	/ietf-yang-mpl-domain:domain/
    ietf-yang-mpl-statistics:mpl-statistics
                              /nr-of-missed-messages
1004164	data	/ietf-yang-mpl-domain:domain/
    ietf-yang-mpl-statistics:mpl-statistics
                              /nr-of-notreceived-messages
1004165	data	/ietf-yang-mpl-domain:domain/
    ietf-yang-mpl-statistics:mpl-statistics
                              /nr-of-refused-copies
1004166	data	/ietf-yang-mpl-domain:domain/
    ietf-yang-mpl-statistics:mpl-statistics
                              /seedID
1004167	data	/ietf-yang-mpl-domain:domain/
     ietf-yang-mpl-statistics:mpl-statistics
                              /statistics-interval

4. yang-mpl modules

This section describes the four yang modules. The modules are based on the MPL specification published in [RFC7731] and the specification of [RFC6206]. The identification of the interfaces follows the specification of ietf-interfaces of [RFC8343].

The data model allows to set values to the parameters of the MPL algorithm. This approach requires an active manager process to set the values without use of DHCP as described in: [RFC7774].

The names of the four modules are: yang-mpl-domain, yang-mpl-ops, yang-mpl-seeds, and yang-mpl-statistics, described in subsections with the same name.

4.1. yang-mpl-domain module

This module describes (1) the MPL domains and the associated multicast addresses, and (2) the interfaces and the multicast addresses for which they are enabled.

The model features a choice such that:


<CODE BEGINS>file "ietf-yang-mpl-domain@2018-07-06.yang"


module ietf-yang-mpl-domain {

  yang-version 1.1;

  namespace 
      "urn:ietf:params:xml:ns:yang:ietf-yang-mpl-domain";

  prefix mpl;

import ietf-inet-types{
    prefix inet;
}

  organization
    "IETF ROLL (Routing Over Low power and lossy networks)
     Working Group";

  contact
    "WG Web:   http://tools.ietf.org/wg/roll/
     WG List:  mailto:roll@ietf.org

     WG Chair: Peter van der Stok
               mailto:consultancy@vanderstok.org

     WG Chair: Ines Robles
               mailto:maria.ines.robles@ericsson.com

     Editor:   Peter van der Stok
               mailto:consultancy@vanderstok.org";

  description
    "This module contains information about the state of the MPL domain.

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

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

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

revision "2018-07-06" {
      description "revision 3";
      reference
        "I-D:draft-ietf-roll-mpl-yang: A YANG model for Multicast
         Protocol for Low power and lossy Networks (MPL)";
    }
   container domain {
     description
        "High level container containing the choice statement 
         between single domain/interface and multiple
         domains and interfaces.";

   choice multiple {
     description
        "A choice for large devices with multiple domains 
         and interfaces.";
     container mpl-domain {
        description
           "The entries describe the MPL domains, the associated
            Multicast addresses and interfaces.";

        list domains {
          key domainID;
          description
             "The entries describe a given domain identified with
              domainID and the associated Multicast addresses.";

        leaf domainID {
          type uint16;
          description
             "Entry uniquely identifies the domain in the
              forwarder.";
         }

         leaf-list MClist{
            type inet:ipv6-address;
            description
               "List of associated IPv6 Addresses.";
         }
       }   // domains list

       list addresses {
         key MCaddress;
         description
            "The entries describe the interfaces enabled 
             with the specified MC address.";

          leaf MCaddress {
            type inet:ipv6-address;
            description
               "MC address belonging to a MPL domain.";
          }

          leaf-list interfaces {
             type string;
             description
                "List of names of interfaces enabled for this
                 Multicast address. Interface name is defined
                 in Appendix A of [RFC8343].";
         }
       }   // addresses list
     }   // container mpl-domain
     container mpl-single {
        description
           "A choice for constrained devices  with a list of 
            MC addresses for single interface and domain.";
        leaf-list MCaddresses{
           type inet:ipv6-address;
           description
              "list of MC addresses belonging to one single
               domain and interface.";
         }  
     }   // container mpl-simple
   }   // choice simple
}  // container module
}  //module ietf-yang-mpl-domain


<CODE ENDS>

4.2. yang-mpl-ops module

This module models the operational aspects of MPL. Per domain MPL specifies four parameters I_MAX, I_MIN, K, and TIMER_EXPIRATIONs for data and control messages. The value of the MPL intervals are expressed in TUNIT. The entry SE_LIFETIME taken over from [RFC7774] fixes TUNIT to milliseconds. For very constrained devices with only one domain there can be only one instance of mpl-parameter list. The module augments the ietf-yang-mpl-domain module.


<CODE BEGINS>file "ietf-yang-mpl-ops@2018-07-06.yang"

module ietf-yang-mpl-ops {

  yang-version 1.1;

  namespace 
      "urn:ietf:params:xml:ns:yang:ietf-yang-mpl-ops";
  prefix "mplo";

  import ietf-yang-mpl-domain{
     prefix "mpl";
  }

  organization
    "IETF ROLL (Routing over Low power and lossy networks)
 Working Group";

  contact
     "WG Web:   http://tools.ietf.org/wg/roll/
     WG List:  mailto:roll@ietf.org

     WG Chair: Peter van der Stok
               mailto:consultancy@vanderstok.org

     WG Chair: Ines Robles
               mailto:maria.ines.robles@ericsson.com

     Editor:   Peter van der Stok
               mailto:consultancy@vanderstok.org";

  description
     "This module contains information about the operation of 
      the MPL protocol.

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

     Redistribution and use in source and binary forms, with or

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

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

revision "2018-07-06" {
      description "revision 3";
      reference
        "I-D:draft-ietf-roll-mpl-yang: A YANG model for Multicast
         Protocol for Low power and lossy Networks (MPL)";
    }

    augment "/mpl:domain" {
       description 
          "additional MPL server settings to MPL domains";

    container mpl-ops {
      description
         "Parameter settings for each MPL server and for each 
          individual domain of the server.";

      leaf PROACTIVE_FORWARDING {
        type boolean;
        description
           "The boolean value indicates whether the MPL forwarder
            schedules MPL data message transmission after
            receiving them for the first time.
            Specified in section 5.4 of [RFC7731]";
      }

      leaf SEED_SET_ENTRY_LIFETIME {
         type uint64;
         units "seconds";
         default 1800;
         description
            "The value indicates the minimum lifetime for 
             an entry in the Seed set expressed in seconds.
             Default value is 30 minutes.
             Specified in section 5.4 of [RFC7731]";
       }

       list mpl-parameter{
          key  domainID;
          description
             "Each domain has a set of MPL forwarding parameters
              which regulate the forwarding operation.";

          leaf  domainID{
             type uint16;
             description
                "Each domainID must be present in  
                 mpl-parameter list.";
          }

          leaf DATA_MESSAGE_IMIN{
             type uint16;
             description
                "The minimum Trickle timer interval
                 for MPL Data Message transmissions.
                 mpl-ops/mpl-parameter/DATA_MESSAGE_IMIN <=
                 mpl-seeds/buffered-messages/I <=
                 mpl-ops/mpl-parameter/DATA_MESSAGE_IMAX 
                 Specified in section 5.4 of [RFC7731]";
           }

           leaf DATA_MESSAGE_IMAX{
              type uint16;
              description
                 "The maximum Trickle timer interval 
                  for MPL Data Message transmissions.
                  mpl-ops/mpl-parameter/DATA_MESSAGE_IMIN <=
                  mpl-seeds/buffered-messages/I <=
                  mpl-ops/mpl-parameter/DATA_MESSAGE_IMAX 
                  Specified in section 5.4 of [RFC7731]";
           }

           leaf DATA_MESSAGE_K{
              type uint16;
              default 1;
              description
                 "The redundancy constant
                  for MPL Data Message transmissions.
                  Specified in section 5.4 of [RFC7731]";
           }

           leaf DATA_MESSAGE_TIMER_EXPIRATIONS{
              type uint16;
              default 3;
              description
                  "The number of Trickle timer expirations, as
                   that occur before terminating the Trickle 
                   algorithm's retransmission of a given 
                   MPL Data Message.
                   Specified in section 5.4 of [RFC7731]";
            }

            leaf CONTROL_MESSAGE_IMIN{
               type uint16;
               description
                  "The minimum Trickle timer interval
                   for MPL Control Message transmissions.
                   Specified in section 5.4 of [RFC7731]";
            }

            leaf CONTROL_MESSAGE_IMAX{
               type uint16;
               description
                  "The maximum Trickle timer interval
                   for MPL Control Message transmissions.
                   Specified in section 5.4 of [RFC7731]";
            }

            leaf CONTROL_MESSAGE_K{
               type uint16;
               default 1;
               description
                  "The redundancy constant
                   for MPL Control Message transmissions.
                   Specified in section 5.4 of [RFC7731]";
            }

            leaf CONTROL_MESSAGE_TIMER_EXPIRATIONS{
               type uint16;
               default 10;
               description
                  "The number of Trickle time expirations,
                   that occur before terminating the Trickle
                   algorithm for MPL Control Message
                   transmissions.
                   Specified in section 5.4 of [RFC7731]";
            }

       }  // list MPL-parameter
     }  // container MPL-ops
   }  // augment ietf-yang-mpl-domain
} // module ietf-yang-mpl-ops

<CODE ENDS>

4.3. yang-mpl-seeds module

This module specifies the current values of the operation of the MPL forwarder. The values are acquired by the client and set by the server. The module specifies a set of message buffers, with a buffer per seed and domain. In constrained devices there will be only one domain, but probably multiple seeds.

The message buffer contains a set of messages where each message is uniquely identified by its sequence number and seed. The associated I, c, e, and t values indicate the progress of MPL with respect to this message, as specified in [RFC7731]. A forwarder sends and receives multiple copies of a message. When a forwarder has sent (received) a copy of a message, the forwarder has sent (received) that message.

For forwarders which are seeds, local has value true and seqno is the sequence number of the next message to send.

The module augments the ietf-yang-mpl-domain module.


<CODE BEGINS>file "ietf-yang-mpl-seeds@2018-07-06.yang"

module ietf-yang-mpl-seeds {

  yang-version 1.1;

  namespace 
      "urn:ietf:params:xml:ns:yang:ietf-yang-mpl-seeds";

  prefix "mplse";

  import ietf-yang-mpl-domain{
     prefix "mpl";
  }

  organization
    "IETF ROLL (Routing over Low power and lossy networks)
 Working Group";

  contact
    "WG Web:   http://tools.ietf.org/wg/roll/
     WG List:  mailto:roll@ietf.org

     WG Chair: Peter van der Stok
               mailto:consultancy@vanderstok.org

     WG Chair: Ines Robles
               mailto:maria.ines.robles@ericsson.com

     Editor:   Peter van der Stok
               mailto:consultancy@vanderstok.org";

  description
     "This module contains information about the operation 
      of the MPL protocol.

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

     Redistribution and use in source and binary forms, with or

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

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

revision "2018-07-06" {
      description "revision 3";
      reference
        "I-D:draft-ietf-roll-mpl-yang: A YANG model for Multicast
 Protocol for Low power and lossy Networks (MPL)";
    }
 
augment "/mpl:domain" {
       description "additional message buffer status to MPL 
       domains";

     leaf SE_LIFETIME {
        type uint16;
        units "milliseconds/timer units";
        description
           "Conversion from clock ticks to milliseconds,
            equivalent to SEED_SET_ENTRY_LIFETIME/TUNIT as
            specified in [RFC7774].";
     }

     list mpl-seeds{
        key "seedID domainID";
        config false;
        description
           "List describes all seeds that are active in the 
            server. Seed information contains the message buffer
            contents and the operational values of I, c, sequence
            number and the life-times per message.";

      leaf seedID{
         type uint64;
         description
            "value uniquely identifies the MPL Seed within a MPL
             domain.";
      }

      leaf domainID{
         type uint16;
         description
            "together with seedID uniquely identifies buffer 
             set.";
      }

      leaf local {
         type boolean;
         description
            "When local == true, seed originated in this
             forwarder.
             When local == false, seed originated in different
             forwarder.";
     }

     leaf generate-seqno {
        type uint8;
        description
           "Sequence number of next message to be generated by 
            this local seed.";
     }

     leaf life-time {
        type uint64;
        units   "milliseconds";
        description
           "Minimum remaining lifetime of the seed entry in
            milliseconds.";
     }

     leaf min-seqno{
        type uint8;
        description
           "Lower bound sequence number in the buffer of the 
            seed.";
     }

     leaf data-number{
        type uint8;
        description
           "Number of currently buffered data messages.";
     }

     leaf control-number{
        type uint8;
        description
           "Number of currently buffered control messages.";
     }

      list buffered-messages{
         key seqno;
         description
            "status of trickle intervals of the buffered message 
             identified by seqno. and seed/domain";

         leaf seqno{
            type uint8;
            description
               "Sequence number of message.";
         }

         leaf I{
            type uint8;
            units  "milliseconds";
            description
               "Current Trickle timer interval size in 
                milliseconds.
                mpl-ops/mpl-parameter/DATA_MESSAGE_IMIN <=
                mpl-seeds/buffered-messages/I <=
                mpl-ops/mpl-parameter/DATA_MESSAGE_IMAX"; 
         }

         leaf c{
            type uint8;
            description
               "number of times that a copy of this message has 
                been received in this interval.";
         }

         leaf e{
            type uint8;
            description
               "number of Trickle time expirations since last
                Trickle timer reset.";
         }

         leaf t{
            type uint8;
            units  "milliseconds";
            description
               "Time expressed in milliseconds
                that message will be (is) forwarded.
                mpl-seeds/buffered-messages/t < 
                mpl-seeds/buffered-messages/I";
         }

     } // list seed-timers
   } // list MPL-seeds
  } // augment
} // module ietf-yang-mpl-seeds


<CODE ENDS>

4.4. yang-mpl-statistics module

This module specifies the operation of the MPL forwarder expressed in number of messages and copies. The values are acquired by the client and set by the server. Statistics are specified per seed and domain. In constrained devices there will be only one domain, but probably multiple seeds.

The parameter k determines how many copies of a message can be forwarded. The counters c-too-high, nr-forwarded, and nr-not-forwarded give insight in the consequences of the current value of k.

The other counters give insight in the loss of messages caused by the medium or forwarding delays. The inconsistent/consistent counters indicate when consistent or inconsistent messages were received according to the definition of consistent in [RFC7731].

The module augments the ietf-yang-mpl-domain module.


<CODE BEGINS>file "ietf-yang-mpl-statistics@2018-07-06.yang"


module ietf-yang-mpl-statistics {

  yang-version 1.1;

  namespace 
      "urn:ietf:params:xml:ns:yang:ietf-yang-mpl-statistics";

  prefix "mplst";

  import ietf-yang-mpl-domain{
     prefix "mpl";
  }

  organization
    "IETF ROLL (Routing over Low power and lossy networks)
     Working Group";

  contact
    "WG Web:   http://tools.ietf.org/wg/roll/
     WG List:  mailto:roll@ietf.org

     WG Chair: Peter van der Stok
               mailto:consultancy@vanderstok.org

     WG Chair: Ines Robles
               mailto:maria.ines.robles@ericsson.com

     Editor:   Peter van der Stok
               mailto:consultancy@vanderstok.org";

  description
    "This module contains information about the operation 
     of the MPL protocol.

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

     Redistribution and use in source and binary forms, with or

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

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

revision "2018-07-06" {
      description "revision 3";
      reference
        "I-D:draft-ietf-roll-mpl-yang: A YANG model for Multicast
 Protocol for Low power and lossy Networks (MPL)";
    }

 augment "/mpl:domain" {
       description "additional MPL message statistics to MPL 
       domains";

     list mpl-statistics{
     key "seedID domainID";

     config false;
    
     description
        "List describes performance statistics integrated over
         the messages identified by seed and domain identifiers.
         A forwarder can receive and forward multiple copies of 
         a message uniquely identified by seqno, domain, and 
         seed.";
      
      leaf seedID{
         type uint64;
         description
            "value uniquely identifies the MPL Seed within a MPL
             domain.";
      }

      leaf domainID{
         type uint16;
         description
            "together with seed-ID uniquely identifies buffer 
             set.";
      }

      leaf c-too-high {
         type uint64;
         description
            "Number of times that a copy was not forwarded
             because c > k.";
      }

      leaf nr-forwarded {
         type uint64;
         description
            "number of times copies are forwarded, 
             while c <= k.";
      }

      leaf nr-of-messages-received{
         type uint64;
         description
            "number of messages received, 
             must be smaller than or equal to seqno.";
      }

         leaf nr-of-messages-forwarded{
         type uint64;
         description
            "number of forwarded messages, must be smaller 
             than or equal to nr-of-messages-received.";
      }


      leaf nr-of-copies-received{
         type uint64;
         description
            "total number of message copies received.";
      }

      leaf nr-of-copies-forwarded{
         type uint64;
         description
            "number of forwarded copies, can be larger than 
             number-of-copies-received.";
      }

      leaf nr-of-refused-copies{
         type uint64;
         description
            "number of refused copies because seqno too small.";
      }

      leaf nr-of-missed-messages{
         type uint64;
         description
            "number of messages that were not received 
             because seqno < min-seqno.";
      }

      leaf nr-of-notreceived-messages{
         type uint64;
         description
            "number of messages that were not received
             according to control message.";
      }

      leaf nr-of-inconsistent-data{
         type uint64;
         description
            "number of inconsistent data messages.";
      }

      leaf nr-of-consistent-data{
         type uint64;
         description
            "number of consistent data messages.";
      }

      leaf nr-of-consistent-control{
         type uint64;
         description
            "number of consistent control messages.";
      }

      leaf nr-of-inconsistent-control{
         type uint64; 
         description
            "number of inconsistent control messages.";
      }

      leaf statistics-interval{
         type uint64;
         description
            "Interval, expressed in seconds, during which
             the statistics are collected.";
      }

      action reset-buffer-statistics{
         description
            "set all statistics counters and 
             statistics-interval of buffer[seedID domainID}
             to zero.";
      }
 
   }  // list mpl statistics
   
   action reset-all-statistics{
      description
         "set all statistics counters and 
          statistics-interval of all buffers to zero.";
   }

  }  //  augment
} // module  ietf-yang-mpl-statistics


<CODE ENDS>

5. IANA Considerations

Registration of four YANG modules and corresponding SID files in the "YANG module assignment" registry is required.

6. Acknowledgements

Andy Bierman has commented on the use of YANG for mpl. Many thanks to Radi Krejci for yang review.

7. Changelog

Changes from version 01 to version 02

Changes from version 00 to version 01

Version ietf-00 copied from version vanderstok-02

8. References

8.1. Normative References

[I-D.ietf-core-sid] Veillette, M. and A. Pelov, "YANG Schema Item iDentifier (SID)", Internet-Draft draft-ietf-core-sid-04, June 2018.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997.
[RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011.
[RFC7731] Hui, J. and R. Kelsey, "Multicast Protocol for Low-Power and Lossy Networks (MPL)", RFC 7731, DOI 10.17487/RFC7731, February 2016.
[RFC7950] Bjorklund, M., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016.
[RFC8343] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 8343, DOI 10.17487/RFC8343, March 2018.

8.2. Informative References

[I-D.ietf-netmod-yang-tree-diagrams] Bjorklund, M. and L. Berger, "YANG Tree Diagrams", Internet-Draft draft-ietf-netmod-yang-tree-diagrams-06, February 2018.
[RFC6206] Levis, P., Clausen, T., Hui, J., Gnawali, O. and J. Ko, "The Trickle Algorithm", RFC 6206, DOI 10.17487/RFC6206, March 2011.
[RFC7390] Rahman, A. and E. Dijk, "Group Communication for the Constrained Application Protocol (CoAP)", RFC 7390, DOI 10.17487/RFC7390, October 2014.
[RFC7774] Doi, Y. and M. Gillmore, "Multicast Protocol for Low-Power and Lossy Networks (MPL) Parameter Configuration Option for DHCPv6", RFC 7774, DOI 10.17487/RFC7774, March 2016.
[RFC8340] Bjorklund, M. and L. Berger, "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K. and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018.

Author's Address

Peter van der Stok (editor) consultant Phone: +31-492474673 (Netherlands), +33-966015248 (France) EMail: consultancy@vanderstok.org URI: www.vanderstok.org