Internet Engineering Task Force (IETF)                  J. Schoenwaelder
Request for Comments: 8194                      Jacobs University Bremen
Category: Standards Track                                      V. Bajpai
ISSN: 2070-1721                           Technical University of Munich
                                                             August 2017

A YANG Data Model for LMAP Measurement Agents

Abstract

   This document defines a data model for Large-Scale Measurement
   Platforms (LMAPs).  The data model is defined using the YANG data
   modeling language.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc8194.

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.

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   2
     1.2.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Data Model Overview . . . . . . . . . . . . . . . . . . . . .   3
   3.  Relationship to the Information Model . . . . . . . . . . . .   9
   4.  YANG Modules  . . . . . . . . . . . . . . . . . . . . . . . .  10
     4.1.  LMAP Common YANG Module . . . . . . . . . . . . . . . . .  10
     4.2.  LMAP Control YANG Module  . . . . . . . . . . . . . . . .  18
     4.3.  LMAP Report YANG Module . . . . . . . . . . . . . . . . .  40
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  45
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  47
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  48
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  48
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  49
   Appendix A.  Example Parameter Extension Module . . . . . . . . .  51
   Appendix B.  Example Configuration  . . . . . . . . . . . . . . .  53
   Appendix C.  Example Report . . . . . . . . . . . . . . . . . . .  56
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  59
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  59

1. Introduction

   This document defines a data model for Large-Scale Measurement
   Platforms (LMAPs) [RFC7594].  The data model is defined using the
   YANG [RFC7950] data modeling language.  It is based on the LMAP
   Information Model [RFC8193].

1.1. Terminology

   This document uses the LMAP terminology defined in [RFC7594].

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

1.2. Tree Diagrams

   A simplified graphical representation of the data model is used in
   this document.  The meaning of the symbols in these diagrams is as
   follows:

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

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

   o  Symbols after data node names: "?" means an optional node, "!"
      means a presence container, and "*" denotes a list and 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. Data Model Overview

   The LMAP framework has three basic elements: Measurement Agents
   (MAs), Controllers, and Collectors.  Measurement Agents initiate the
   actual measurements, which are called Measurement Tasks in the LMAP
   terminology.  The Controller instructs one or more MAs and
   communicates the set of Measurement Tasks an MA should perform and
   when.  The Collector accepts Reports from the MAs with the Results
   from their Measurement Tasks.

   The YANG data model for LMAP has been split into three modules:

   1.  The module ietf-lmap-common.yang provides common definitions such
       as LMAP-specific data types.

   2.  The module ietf-lmap-control.yang defines the data structures
       exchanged between a Controller and Measurement Agents.

3. The module ietf-lmap-report.yang defines the data structures
exchanged between Measurement Agents and Collectors.

   As shown in Figure 1, a Controller, implementing
   ietf-lmap-common.yang and ietf-lmap-control.yang as a client, will
   instruct Measurement Agents, which implement ietf-lmap-common.yang
   and ietf-lmap-control.yang as servers.  A Measurement Agent,
   implementing ietf-lmap-common.yang and ietf-lmap-report.yang, will
   send results to a Collector, which implements ietf-lmap-common.yang
   and ietf-lmap-report.yang as a server.

       +--rw suppressions
       |  +--rw suppression* [name]
       |     +--rw name            lmap:identifier
       |     +--rw start?          event-ref
       |     +--rw end?            event-ref
       |     +--rw match*          lmap:glob-pattern
       |     +--rw stop-running?   boolean
       |     +--ro state           enumeration
       +--rw events
          +--rw event* [name]
             +--rw name                    lmap:identifier
             +--rw random-spread?          uint32
             +--rw cycle-interval?         uint32
             +--rw (event-type)?
                +--:(periodic)
                |  +--rw periodic
                |     +--rw interval    uint32
                |     +--rw start?      yang:date-and-time
                |     +--rw end?        yang:date-and-time
                +--:(calendar)
                |  +--rw calendar
                |     +--rw month*             lmap:month-or-all
                |     +--rw day-of-month*      lmap:day-of-months-or-all
                |     +--rw day-of-week*       lmap:weekday-or-all
                |     +--rw hour*              lmap:hour-or-all
                |     +--rw minute*            lmap:minute-or-all
                |     +--rw second*            lmap:second-or-all
                |     +--rw timezone-offset?   lmap:timezone-offset
                |     +--rw start?             yang:date-and-time
                |     +--rw end?               yang:date-and-time
                +--:(one-off)
                |  +--rw one-off
                |     +--rw time    yang:date-and-time
                +--:(immediate)
                |  +--rw immediate               empty
                +--:(startup)
                |  +--rw startup                 empty
                +--:(controller-lost)
                |  +--rw controller-lost         empty
                +--:(controller-connected)
                   +--rw controller-connected    empty

   The tree diagram below shows the structure of the reporting data
   model.

   module: ietf-lmap-report

     rpcs:
       +---x report
          +---w input
             +---w date                 yang:date-and-time
             +---w agent-id?            yang:uuid
             +---w group-id?            string
             +---w measurement-point?   string
             +---w result*
                +---w schedule?       lmap:identifier
                +---w action?         lmap:identifier
                +---w task?           lmap:identifier
                +---w parameters
                |  +---w (extension)?
                +---w option* [id]
                |  +---w id       lmap:identifier
                |  +---w name?    string
                |  +---w value?   string
                +---w tag*            lmap:tag
                +---w event?          yang:date-and-time
                +---w start           yang:date-and-time
                +---w end?            yang:date-and-time
                +---w cycle-number?   lmap:cycle-number
                +---w status          lmap:status-code
                +---w conflict*
                |  +---w schedule-name?   lmap:identifier
                |  +---w action-name?     lmap:identifier
                |  +---w task-name?       lmap:identifier
                +---w table*
                   +---w function* [uri]
                   |  +---w uri     inet:uri
                   |  +---w role*   string
                   +---w column*     string
                   +---w row*
                      +---w value*   string

3.  Relationship to the Information Model

   The LMAP Information Model [RFC8193] is divided into six aspects.
   They are mapped into the YANG data model as explained below:

   o  Preconfiguration Information: This is not modeled explicitly since
      bootstrapping information is outside the scope of this data model.
      Implementations may use some of the Configuration Information also
      for bootstrapping purposes.

   o  Configuration Information: This is modeled in the /lmap/agent
      subtree, the /lmap/schedules subtree, and the /lmap/tasks subtree
      described below.  Some items have been left out because they are
      expected to be dealt with by the underlying protocol.

   o  Instruction Information: This is modeled in the /lmap/suppressions
      subtree, the /lmap/schedules subtree, and the /lmap/tasks subtree
      described below.

   o  Logging Information: Some of the Logging Information, in
      particular 'success/failure/warning messages in response to
      information updates from the Controller', will be handled by the
      protocol used to manipulate the LMAP-specific configuration.  The
      LMAP data model defined in this document assumes that runtime
      Logging Information will be communicated using protocols that do
      not require a formal data model, e.g., the syslog protocol defined
      in [RFC5424].

   o  Capability and Status Information: Some of the Capability and
      Status Information is modeled in the /lmap/capability subtree.
      The list of supported Tasks is modeled in the /lmap/capabilities/
      task list.  Status Information about Schedules and Actions is
      included in the /lmap/schedules subtree.  Information about
      network interfaces can be obtained from the ietf-interfaces YANG
      data model [RFC7223].  Information about the hardware and the
      firmware can be obtained from the ietf-system YANG data model
      [RFC7317].  A device identifier can be obtained from the ietf-
      hardware YANG data model [YANG-HARDWARE].

   o  Reporting Information: This is modeled by the report data model to
      be implemented by the Collector.  Measurement Agents send results
      to the Collector by invoking an RPC on the Collector.

   These six Information Model aspects use a collection of common
   information objects.  These common information objects are
   represented in the YANG data model as follows:

   o  Schedules: Schedules are modeled in the /lmap/schedules subtree.

   o  Channels: Channels are not modeled since the NETCONF server
      configuration data model [NETCONF-CLIENT-SERVER] already provides
      a mechanism to configure NETCONF server Channels.

   o  Task Configurations: Configured Tasks are modeled in the /lmap/
      tasks subtree.

   o  Event Information: Event definitions are modeled in the /lmap/
      events subtree.

4. YANG Modules

4.1. LMAP Common YANG Module

   This module imports definitions from [RFC6536], and it references
   [ISO-8601].

   <CODE BEGINS> file "ietf-lmap-common@2017-08-08.yang"
   module ietf-lmap-common {

     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-lmap-common";
     prefix "lmap";

     import ietf-inet-types {
       prefix inet;
     }

     organization
       "IETF Large-Scale Measurement of Broadband Performance
        Working Group";

     contact
       "WG Web:   <https://datatracker.ietf.org/wg/lmap>
        WG List:  <mailto:lmap@ietf.org>

        Editor:   Juergen Schoenwaelder
                  <j.schoenwaelder@jacobs-university.de>

        Editor:   Vaibhav Bajpai
                  <bajpaiv@in.tum.de>";

     description
       "This module provides common definitions used by the data
        models written for Large-Scale Measurement Platforms (LMAPs).
        This module defines typedefs and groupings but no schema
        tree elements.";

     revision "2017-08-08" {
       description
         "Initial version";
       reference
         "RFC 8194: A YANG Data Model for LMAP Measurement Agents";
     }

     /*
      * Typedefs
      */

     typedef identifier {
       type string {
         length "1..max";
       }
       description
         "A string value used to name something.";
     }

     typedef tag {
       type string {
         length "1..max";
       }
       description
         "A tag consists of at least one character.";
     }

     typedef glob-pattern {
       type string {
         length "1..max";
       }
       description
         'A glob style pattern (following POSIX.2 fnmatch() without
          special treatment of file paths):

            *         matches a sequence of characters
            ?         matches a single character
            [seq]     matches any character in seq
            [!seq]    matches any character not in seq

          A backslash followed by a character matches the following
          character.  In particular:

            \*        matches *
            \?        matches ?
            \\        matches \

          A sequence seq may be a sequence of characters (e.g., [abc]
          or a range of characters (e.g., [a-c]).';
     }

     typedef wildcard {
       type string {
         pattern '\*';
       }
       description
         "A wildcard for calendar scheduling entries.";
     }

     typedef cycle-number {
       type string {
         pattern '[0-9]{8}\.[0-9]{6}';
       }
       description
         "A cycle number represented in the format YYYYMMDD.HHMMSS
          where YYYY represents the year, MM the month (1..12), DD
          the day of the months (01..31), HH the hour (00..23), MM
          the minute (00..59), and SS the second (00..59).  The cycle
          number is using Coordinated Universal Time (UTC).";
     }

     typedef month {
       type enumeration {
         enum january {
           value 1;
           description
             "January of the Gregorian calendar.";
         }
         enum february {
           value 2;
           description
             "February of the Gregorian calendar.";
         }
         enum march {
           value 3;
           description
             "March of the Gregorian calendar.";
         }
         enum april {
           value 4;
           description
             "April of the Gregorian calendar.";
         }

         enum may {
           value 5;
           description
             "May of the Gregorian calendar.";
         }
         enum june {
           value 6;
           description
             "June of the Gregorian calendar.";
         }
         enum july {
           value 7;
           description
             "July of the Gregorian calendar.";
         }
         enum august {
           value 8;
           description
             "August of the Gregorian calendar.";
         }
         enum september {
           value 9;
           description
             "September of the Gregorian calendar.";
         }
         enum october {
           value 10;
           description
             "October of the Gregorian calendar.";
         }
         enum november {
           value 11;
           description
             "November of the Gregorian calendar.";
         }
         enum december {
           value 12;
           description
             "December of the Gregorian calendar.";
         }
       }
       description
         "A type modeling the month in the Gregorian calendar.";
     }

     typedef month-or-all {
       type union {
         type month;
         type wildcard;
       }
       description
         "A month or a wildcard indicating all twelve months.";
     }

     typedef day-of-month {
       type uint8 { range "1..31"; }
       description
         "A day of a month of the Gregorian calendar.";
     }

     typedef day-of-months-or-all {
       type union {
         type day-of-month;
         type wildcard;
       }
       description
         "A day of a month or a wildcard indicating all days
          of a month.";
     }

     typedef weekday {
       type enumeration {
         enum monday {
           value 1;
           description
             "Monday of the Gregorian calendar.";
         }
         enum tuesday {
           value 2;
           description
             "Tuesday of the Gregorian calendar.";
         }
         enum wednesday {
           value 3;
           description
             "Wednesday of the Gregorian calendar.";
         }
         enum thursday {
           value 4;
           description
             "Thursday of the Gregorian calendar.";
         }

         enum friday {
           value 5;
           description
             "Friday of the Gregorian calendar.";
         }
         enum saturday {
           value 6;
           description
             "Saturday of the Gregorian calendar.";
         }
         enum sunday {
           value 7;
           description
             "Sunday of the Gregorian calendar.";
         }
       }
       description
        "A type modeling the weekdays in the Gregorian calendar.
         The numbering follows the ISO 8601 scheme.";
       reference
        "ISO 8601:2004: Data elements and interchange formats --
                        Information interchange -- Representation
                        of dates and times";
     }

     typedef weekday-or-all {
       type union {
         type weekday;
         type wildcard;
       }
       description
         "A weekday or a wildcard indicating all seven weekdays.";
     }

     typedef hour {
       type uint8 { range "0..23"; }
       description
         "An hour of a day.";
     }

     typedef hour-or-all {
       type union {
         type hour;
         type wildcard;
       }
       description
         "An hour of a day or a wildcard indicating all hours
          of a day.";

     }

     typedef minute {
       type uint8 { range "0..59"; }
       description
         "A minute of an hour.";
     }

     typedef minute-or-all {
       type union {
         type minute;
         type wildcard;
       }
       description
         "A minute of an hour or a wildcard indicating all
          minutes of an hour.";
     }

     typedef second {
       type uint8 { range "0..59"; }
       description
         "A second of a minute.";
     }

     typedef second-or-all {
       type union {
         type second;
         type wildcard;
       }
       description
         "A second of a minute or a wildcard indicating all
          seconds of a minute.";
     }

     typedef status-code {
       type int32;
       description
         "A status code returned by the execution of a Task.  Note
          that the actual range is implementation dependent, but it
          should be portable to use values in the range 0..127 for
          regular exit codes.  By convention, 0 indicates successful
          termination.  Negative values may be used to indicate
          abnormal termination due to a signal; the absolute value
          may identify the signal number in this case.";
     }

     typedef timezone-offset {
       type string {
         pattern 'Z|[\+\-]\d{2}:\d{2}';
       }
       description
         "A time zone offset as it is used by the date-and-time type
          defined in the ietf-yang-types module.  The value Z is
          equivalent to +00:00.  The value -00:00 indicates an
          unknown time-offset.";
       reference
         "RFC 6991: Common YANG Data Types";
     }

     /*
      * Groupings
      */

     grouping registry-grouping {
       description
         "This grouping models a list of entries in a registry
          that identify functions of a Task.";

       list function {
         key uri;
         description
           "A list of entries in a registry identifying functions.";

         leaf uri {
           type inet:uri;
           description
             "A URI identifying an entry in a registry.";
         }

         leaf-list role {
           type string;
           description
             "A set of roles for the identified registry entry.";
         }
       }
     }

     grouping options-grouping {
       description
         "A list of options of a Task.  Each option is a name/value
          pair (where the value may be absent).";

       list option {
         key "id";

         ordered-by user;
         description
           "A list of options passed to the Task.  It is a list of
            key/value pairs and may be used to model options.
            Options may be used to identify the role of a Task
            or to pass a Channel name to a Task.";

         leaf id {
           type lmap:identifier;
           description
             "An identifier uniquely identifying an option.  This
              identifier is required by YANG to uniquely identify
              a name/value pair, but it otherwise has no semantic
              value";
         }

         leaf name {
           type string;
           description
             "The name of the option.";
         }

         leaf value {
           type string;
           description
             "The value of the option.";
         }
       }
     }
   }
   <CODE ENDS>

4.2. LMAP Control YANG Module

   This module imports definitions from [RFC6536], [RFC6991], and the
   common LMAP module, and it references [RFC7398].

   <CODE BEGINS> file "ietf-lmap-control@2017-08-08.yang"
   module ietf-lmap-control {

     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-lmap-control";
     prefix "lmapc";

     import ietf-yang-types {
       prefix yang;
     }
     import ietf-netconf-acm {

       prefix nacm;
     }
     import ietf-lmap-common {
       prefix lmap;
     }

     organization
       "IETF Large-Scale Measurement of Broadband Performance
        Working Group";

     contact
       "WG Web:   <https://datatracker.ietf.org/wg/lmap>
        WG List:  <mailto:lmap@ietf.org>

        Editor:   Juergen Schoenwaelder
                  <j.schoenwaelder@jacobs-university.de>

        Editor:   Vaibhav Bajpai
                  <bajpaiv@in.tum.de>";

     description
       "This module defines a data model for controlling Measurement
        Agents that are part of a Large-Scale Measurement Platform
        (LMAP).  This data model is expected to be implemented by
        Measurement Agents.";

     revision "2017-08-08" {
       description
         "Initial version";
       reference
         "RFC 8194: A YANG Data Model for LMAP Measurement Agents";
     }

     /*
      * Typedefs
      */

     typedef event-ref {
       type leafref {
         path "/lmap/events/event/name";
       }
       description
         "This type is used by data models that need to reference
          a configured event source.";
     }

     typedef task-ref {
       type leafref {

         path "/lmap/tasks/task/name";
       }
       description
         "This type is used by data models that need to reference
          a configured Task.";
     }

     typedef schedule-ref {
       type leafref {
         path "/lmap/schedules/schedule/name";
       }
       description
         "This type is used by data models that need to reference
          a configured Schedule.";
     }

     /*
      * Groupings
      */

     grouping start-end-grouping {
       description
         "A grouping that provides start and end times for
          Event objects.";
       leaf start {
         type yang:date-and-time;
         description
           "The date and time when the Event object
            starts to create triggers.";
       }
       leaf end {
         type yang:date-and-time;
         description
           "The date and time when the Event object
            stops to create triggers.

            It is generally a good idea to always configure
            an end time and to refresh the end time as needed
            to ensure that agents that lose connectivity to
            their Controller do not continue executing Schedules
            forever.";
       }
     }

     /*
      * Capability, configuration, and state data nodes
      */

     container lmap {
       description
         "Configuration and control of a Measurement Agent.";

       container capabilities {
         config false;
         description
           "Agent capabilities including a list of supported Tasks.";

         leaf version {
           type string;
           config false;
           mandatory true;
           description
             "A short description of the software implementing the
              Measurement Agent.  This should include the version
              number of the Measurement Agent software.";
         }

         leaf-list tag {
           type lmap:tag;
           config false;
           description
             "An optional unordered set of tags that provide
              additional information about the capabilities of
              the Measurement Agent.";
         }

         container tasks {
           description
             "A list of Tasks that the Measurement Agent supports.";

           list task {
             key name;
             description
               "The list of Tasks supported by the Measurement Agent.";

             leaf name {
               type lmap:identifier;
               description
                 "The unique name of a Task capability.";
             }

             uses lmap:registry-grouping;

             leaf version {
               type string;

               description
                 "A short description of the software implementing
                  the Task.  This should include the version
                  number of the Measurement Task software.";
             }

             leaf program {
               type string;
               description
                 "The (local) program to invoke in order to execute
                  the Task.";
             }
           }
         }
       }

       /*
        * Agent Configuration
        */

       container agent {
         description
           "Configuration of parameters affecting the whole
            Measurement Agent.";

         leaf agent-id {
           type yang:uuid;
           description
             "The agent-id identifies a Measurement Agent with
              a very low probability of collision.  In certain
              deployments, the agent-id may be considered
              sensitive, and hence this object is optional.";
         }

         leaf group-id {
           type string;
           description
             "The group-id identifies a group of Measurement
              Agents.  In certain deployments, the group-id
              may be considered less sensitive than the
              agent-id.";
         }

         leaf measurement-point {
           type string;
           description
             "The measurement point indicating where the
               Measurement Agent is located on a path.";

           reference
             "RFC 7398: A Reference Path and Measurement Points
                        for Large-Scale Measurement of Broadband
                        Performance";
         }

         leaf report-agent-id {
           type boolean;
           must '. != "true" or ../agent-id' {
             description
               "An agent-id must exist for this to be set
                to true.";
           }
           default false;
           description
             "The 'report-agent-id' controls whether the
              'agent-id' is reported to Collectors.";
         }

         leaf report-group-id {
           type boolean;
           must '. != "true" or ../group-id' {
             description
               "A group-id must exist for this to be set
                to true.";
           }
           default false;
           description
             "The 'report-group-id' controls whether the
              'group-id' is reported to Collectors.";
         }

         leaf report-measurement-point {
           type boolean;
           must '. != "true" or ../measurement-point' {
             description
               "A measurement-point must exist for this to be
                set to true.";
           }
           default false;
           description
             "The 'report-measurement-point' controls whether
              the 'measurement-point' is reported to Collectors.";
         }

         leaf controller-timeout {
           type uint32;
           units "seconds";

           description
             "A timer is started after each successful contact
              with a Controller.  When the timer reaches the
              controller-timeout, an event (controller-lost) is
              raised indicating that connectivity to the Controller
              has been lost.";
         }

         leaf last-started {
           type yang:date-and-time;
           config false;
           mandatory true;
           description
             "The date and time the Measurement Agent last started.";
         }
       }

       /*
        * Task Configuration
        */

       container tasks {
         description
           "Configuration of LMAP Tasks.";

         list task {
           key name;
           description
             "The list of Tasks configured on the Measurement
              Agent.  Note that a configured Task MUST resolve to a
              Task listed in the capabilities.  Attempts to execute
              a configured Task that is not listed in the capabilities
              result in a runtime execution error.";

           leaf name {
             type lmap:identifier;
             description
               "The unique name of a Task.";
           }

           uses lmap:registry-grouping;

           leaf program {
             type string;
             nacm:default-deny-write;

             description
               "The (local) program to invoke in order to execute
                the Task.  If this leaf is not set, then the system
                will try to identify a suitable program based on
                the registry information present.";
           }

           uses lmap:options-grouping {
             description
               "The list of Task-specific options.";
           }

           leaf-list tag {
             type lmap:identifier;
             description
               "A set of Task-specific tags that are reported
                together with the measurement results to a Collector.
                A tag can be used, for example, to carry the
                Measurement Cycle ID.";
           }
         }
       }

       /*
        * Schedule Instructions
        */

       container schedules {
         description
           "Configuration of LMAP Schedules.  Schedules control
            which Tasks are executed by the LMAP implementation.";

         list schedule {
           key name;
           description
             "Configuration of a particular Schedule.";

           leaf name {
             type lmap:identifier;
             description
               "The locally unique, administratively assigned name
                for this Schedule.";
           }

           leaf start {
             type event-ref;
             mandatory true;

             description
               "The event source controlling the start of the
                scheduled Actions.";
           }

           choice stop {
             description
               "This choice contains optional leafs that control the
                graceful forced termination of scheduled Actions.
                When the end has been reached, the scheduled Actions
                should be forced to terminate the measurements.
                This may involve being active some additional time in
                order to properly finish the Action's activity (e.g.,
                waiting for any messages that are still outstanding).";

             leaf end {
               type event-ref;
               description
                 "The event source controlling the graceful
                  forced termination of the scheduled Actions.";
             }

             leaf duration {
               type uint32;
               units "seconds";
               description
                 "The duration controlling the graceful forced
                  termination of the scheduled Actions.";
             }
           }

           leaf execution-mode {
             type enumeration {
               enum sequential {
                 value 1;
                 description
                   "The Actions of the Schedule are executed
                    sequentially.";
               }
               enum parallel {
                 value 2;
                 description
                   "The Actions of the Schedule are executed
                    concurrently.";
               }
               enum pipelined {
                 value 3;

                 description
                   "The Actions of the Schedule are executed in a
                    pipelined mode.  Output created by an Action is
                    passed as input to the subsequent Action.";
               }
             }
             default pipelined;
             description
               "The execution mode of this Schedule determines in
                which order the Actions of the Schedule are executed.";
           }

           leaf-list tag {
             type lmap:tag;
             description
               "A set of Schedule-specific tags that are reported
                together with the measurement results to a Collector.";
           }

           leaf-list suppression-tag {
             type lmap:tag;
             description
               "A set of Suppression tags that are used to select
                Schedules to be suppressed.";
           }

           leaf state {
             type enumeration {
               enum enabled {
                 value 1;
                 description
                   "The value 'enabled' indicates that the
                    Schedule is currently enabled.";
               }
               enum disabled {
                 value 2;
                 description
                   "The value 'disabled' indicates that the
                    Schedule is currently disabled.";
               }
               enum running {
                 value 3;
                 description
                   "The value 'running' indicates that the
                    Schedule is currently running.";
               }
               enum suppressed {
                 value 4;

                 description
                   "The value 'suppressed' indicates that the
                    Schedule is currently suppressed.";
               }
             }
             config false;
             mandatory true;
             description
               "The current state of the Schedule.";
           }

           leaf storage {
             type yang:gauge64;
             units "bytes";
             config false;
             mandatory true;
             description
               "The amount of secondary storage (e.g., allocated in a
                file system) holding temporary data allocated to the
                Schedule in bytes.  This object reports the amount of
                allocated physical storage and not the storage used
                by logical data records.";
           }

           leaf invocations {
             type yang:counter32;
             config false;
             mandatory true;
             description
               "Number of invocations of this Schedule.  This counter
                does not include suppressed invocations or invocations
                that were prevented due to an overlap with a previous
                invocation of this Schedule.";
           }

           leaf suppressions {
             type yang:counter32;
             config false;
             mandatory true;
             description
               "Number of suppressed executions of this Schedule.";
           }

           leaf overlaps {
             type yang:counter32;
             config false;
             mandatory true;

             description
               "Number of executions prevented due to overlaps with
                a previous invocation of this Schedule.";
           }

           leaf failures {
             type yang:counter32;
             config false;
             mandatory true;
             description
               "Number of failed executions of this Schedule.  A
                failed execution is an execution where at least
                one Action failed.";
           }

           leaf last-invocation {
             type yang:date-and-time;
             config false;
             description
               "The date and time of the last invocation of
                this Schedule.";
           }

           list action {
             key name;
             description
               "An Action describes a Task that is invoked by the
                Schedule.  Multiple Actions are invoked according to
                the execution-mode of the Schedule.";

             leaf name {
               type lmap:identifier;
               description
                 "The unique identifier for this Action.";
             }

             leaf task {
               type task-ref;
               mandatory true;
               description
                 "The Task invoked by this Action.";
             }

             container parameters {
               description
                 "This container is a placeholder for runtime
                  parameters defined in Task-specific data models
                  augmenting the base LMAP control data model.";

               choice extension {
                 description
                   "This choice is provided to augment in different
                    sets of parameters.";
               }
             }

             uses lmap:options-grouping {
               description
                 "The list of Action-specific options that are
                  appended to the list of Task-specific options.";
             }

             leaf-list destination {
               type schedule-ref;
               description
                 "A set of Schedules receiving the output produced
                  by this Action.  The output is stored temporarily
                  since the Destination Schedules will in general
                  not be running when output is passed to them.  The
                  behavior of an Action passing data to its own
                  Schedule is implementation specific.

                  Data passed to a sequential or pipelined Schedule
                  is received by the Schedule's first Action.  Data
                  passed to a parallel Schedule is received by all
                  Actions of the Schedule.";
             }

             leaf-list tag {
               type lmap:tag;
               description
                 "A set of Action-specific tags that are reported
                  together with the measurement results to a
                  Collector.";
             }

             leaf-list suppression-tag {
               type lmap:tag;
               description
                 "A set of Suppression tags that are used to select
                  Actions to be suppressed.";
             }

             leaf state {
               type enumeration {
                 enum enabled {
                   value 1;

                   description
                     "The value 'enabled' indicates that the
                      Action is currently enabled.";
                 }
                 enum disabled {
                   value 2;
                   description
                     "The value 'disabled' indicates that the
                      Action is currently disabled.";
                 }
                 enum running {
                   value 3;
                   description
                     "The value 'running' indicates that the
                      Action is currently running.";
                 }
                 enum suppressed {
                   value 4;
                   description
                     "The value 'suppressed' indicates that the
                      Action is currently suppressed.";
                 }
               }
               config false;
               mandatory true;
               description
                 "The current state of the Action.";
             }

             leaf storage {
               type yang:gauge64;
               units "bytes";
               config false;
               mandatory true;
               description
                 "The amount of secondary storage (e.g., allocated in a
                  file system) holding temporary data allocated to the
                  Schedule in bytes.  This object reports the amount of
                  allocated physical storage and not the storage used
                  by logical data records.";
             }

             leaf invocations {
               type yang:counter32;
               config false;
               mandatory true;

               description
                 "Number of invocations of this Action.  This counter
                  does not include suppressed invocations or invocations
                  that were prevented due to an overlap with a previous
                  invocation of this Action.";
             }

             leaf suppressions {
               type yang:counter32;
               config false;
               mandatory true;
               description
                 "Number of suppressed executions of this Action.";
             }

             leaf overlaps {
               type yang:counter32;
               config false;
               mandatory true;
               description
                 "Number of executions prevented due to overlaps with
                  a previous invocation of this Action.";
             }

             leaf failures {
               type yang:counter32;
               config false;
               mandatory true;
               description
                 "Number of failed executions of this Action.";
             }

             leaf last-invocation {
               type yang:date-and-time;
               config false;
               mandatory true;
               description
                 "The date and time of the last invocation of
                  this Action.";
             }

             leaf last-completion {
               type yang:date-and-time;
               config false;
               mandatory true;
               description
                 "The date and time of the last completion of
                  this Action.";

             }

             leaf last-status {
               type lmap:status-code;
               config false;
               mandatory true;
               description
                 "The status code returned by the last execution of
                  this Action.";
             }

             leaf last-message {
               type string;
               config false;
               mandatory true;
               description
                 "The status message produced by the last execution
                  of this Action.";
             }

             leaf last-failed-completion {
               type yang:date-and-time;
               config false;
               mandatory true;
               description
                 "The date and time of the last failed completion
                  of this Action.";
             }

             leaf last-failed-status {
               type lmap:status-code;
               config false;
               mandatory true;
               description
                 "The status code returned by the last failed
                  execution of this Action.";
             }

             leaf last-failed-message {
               type string;
               config false;
               mandatory true;
               description
                 "The status message produced by the last failed
                  execution of this Action.";
             }
           }
         }

       }

       /*
        * Suppression Instructions
        */

       container suppressions {
         description
           "Suppression information to prevent Schedules or
            certain Actions from starting.";

         list suppression {
           key name;
           description
             "Configuration of a particular Suppression.";

           leaf name {
             type lmap:identifier;
             description
               "The locally unique, administratively assigned name
                for this Suppression.";
           }

           leaf start {
             type event-ref;
             description
               "The event source controlling the start of the
                Suppression period.";
           }

           leaf end {
             type event-ref;
             description
               "The event source controlling the end of the
                Suppression period.  If not present, Suppression
                continues indefinitely.";
           }

           leaf-list match {
             type lmap:glob-pattern;
             description
               "A set of Suppression match patterns.  The Suppression
                will apply to all Schedules (and their Actions) that
                have a matching value in their suppression-tags
                and to all Actions that have a matching value in
                their suppression-tags.";
           }

           leaf stop-running {
             type boolean;
             default false;
             description
               "If 'stop-running' is true, running Schedules and
                Actions matching the Suppression will be terminated
                when Suppression is activated.  If 'stop-running' is
                false, running Schedules and Actions will not be
                affected if Suppression is activated.";
           }

           leaf state {
             type enumeration {
               enum enabled {
                 value 1;
                 description
                   "The value 'enabled' indicates that the
                    Suppression is currently enabled.";
               }
               enum disabled {
                 value 2;
                 description
                   "The value 'disabled' indicates that the
                    Suppression is currently disabled.";
               }
               enum active {
                 value 3;
                 description
                   "The value 'active' indicates that the
                    Suppression is currently active.";
               }
             }
             config false;
             mandatory true;
             description
               "The current state of the Suppression.";
           }
         }
       }

       /*
        * Event Instructions
        */

       container events {
         description
           "Configuration of LMAP events.

            Implementations may be forced to delay acting
            upon the occurrence of events in the face of local
            constraints.  An Action triggered by an event
            therefore should not rely on the accuracy
            provided by the scheduler implementation.";

         list event {
           key name;
           description
             "The list of event sources configured on the
              Measurement Agent.";

           leaf name {
             type lmap:identifier;
             description
               "The unique name of an event source.";
           }

           leaf random-spread {
             type uint32;
             units seconds;
             description
               "This optional leaf adds a random spread to the
                computation of the event's trigger time.  The
                random spread is a uniformly distributed random
                number taken from the interval [0:random-spread].";
           }

           leaf cycle-interval {
             type uint32;
             units seconds;
             description
               "The optional cycle-interval defines the duration
                of the time interval in seconds that is used to
                calculate cycle numbers.  No cycle number is
                calculated if the optional cycle-interval does
                not exist.";
           }

           choice event-type {
             description
               "Different types of events are handled by
                different branches of this choice.  Note that
                this choice can be extended via augmentations.";

             case periodic {
               container periodic {

                 description
                   "A periodic timing object triggers periodically
                    according to a regular interval.";

                 leaf interval {
                   type uint32 {
                     range "1..max";
                   }
                   units "seconds";
                   mandatory true;
                   description
                     "The number of seconds between two triggers
                      generated by this periodic timing object.";
                 }
                 uses start-end-grouping;
               }
             }

             case calendar {
               container calendar {
                 description
                   "A calendar timing object triggers based on the
                    current calendar date and time.";

                 leaf-list month {
                   type lmap:month-or-all;
                   min-elements 1;
                   description
                     "A set of months at which this calendar timing
                      will trigger.  The wildcard means all months.";
                 }

                 leaf-list day-of-month {
                   type lmap:day-of-months-or-all;
                   min-elements 1;
                   description
                     "A set of days of the month at which this
                      calendar timing will trigger.  The wildcard means
                      all days of a month.";
                 }

                 leaf-list day-of-week {
                   type lmap:weekday-or-all;
                   min-elements 1;
                   description
                     "A set of weekdays at which this calendar timing
                      will trigger.  The wildcard means all weekdays.";
                 }

                 leaf-list hour {
                   type lmap:hour-or-all;
                   min-elements 1;
                   description
                     "A set of hours at which this calendar timing will
                      trigger.  The wildcard means all hours of a day.";
                 }

                 leaf-list minute {
                   type lmap:minute-or-all;
                   min-elements 1;
                   description
                     "A set of minutes at which this calendar timing
                      will trigger.  The wildcard means all minutes of
                      an hour.";
                 }

                 leaf-list second {
                   type lmap:second-or-all;
                   min-elements 1;
                   description
                     "A set of seconds at which this calendar timing
                      will trigger.  The wildcard means all seconds of
                      a minute.";
                 }

                 leaf timezone-offset {
                   type lmap:timezone-offset;
                   description
                     "The time zone in which this calendar timing
                      object will be evaluated.  If not present,
                      the system's local time zone will be used.";
                 }
                 uses start-end-grouping;
               }
             }

             case one-off {
               container one-off {
                 description
                   "A one-off timing object triggers exactly once.";

                 leaf time {
                   type yang:date-and-time;
                   mandatory true;
                   description
                     "This one-off timing object triggers once at
                      the configured date and time.";

                 }
               }
             }

             case immediate {
               leaf immediate {
                 type empty;
                 mandatory true;
                 description
                   "This immediate Event object triggers immediately
                    when it is configured.";
               }
             }

             case startup {
               leaf startup {
                 type empty;
                 mandatory true;
                 description
                   "This startup Event object triggers whenever the
                    Measurement Agent (re)starts.";
               }
             }

             case controller-lost {
               leaf controller-lost {
                 type empty;
                 mandatory true;
                 description
                   "The controller-lost Event object triggers when
                    the connectivity to the Controller has been lost
                    for at least 'controller-timeout' seconds.";
               }
             }

             case controller-connected {
               leaf controller-connected {
                 type empty;
                 mandatory true;
                 description
                   "The controller-connected Event object triggers
                    when the connectivity to the Controller has been
                    restored after it was lost for at least
                    'controller-timeout' seconds.";
               }
             }
           }

         }
       }
     }
   }
   <CODE ENDS>

4.3. LMAP Report YANG Module

   This module imports definitions from [RFC6536] and the common LMAP
   module.

   <CODE BEGINS> file "ietf-lmap-report@2017-08-08.yang"
   module ietf-lmap-report {

     yang-version 1.1;
     namespace "urn:ietf:params:xml:ns:yang:ietf-lmap-report";
     prefix "lmapr";

     import ietf-yang-types {
       prefix yang;
     }
     import ietf-lmap-common {
       prefix lmap;
     }

     organization
       "IETF Large-Scale Measurement of Broadband Performance
        Working Group";

     contact
       "WG Web:   <https://datatracker.ietf.org/wg/lmap>
        WG List:  <mailto:lmap@ietf.org>

        Editor:   Juergen Schoenwaelder
                  <j.schoenwaelder@jacobs-university.de>

        Editor:   Vaibhav Bajpai
                  <bajpaiv@in.tum.de>";

     description
       "This module defines a data model for reporting results from
        Measurement Agents, which are part of a Large-Scale Measurement
        Platform (LMAP), to result data Collectors.  This data model is
        expected to be implemented by a Collector.";

     revision "2017-08-08" {
       description
         "Initial version";

       reference
         "RFC 8194: A YANG Data Model for LMAP Measurement Agents";
     }

     rpc report {
       description
         "The report operation is used by a Measurement Agent to
          submit measurement results produced by Measurement Tasks to
          a Collector.";

       input {

         leaf date {
           type yang:date-and-time;
           mandatory true;
           description
             "The date and time when this result report was sent to
              a Collector.";
         }

         leaf agent-id {
           type yang:uuid;
           description
             "The agent-id of the agent from which this
              report originates.";
         }

         leaf group-id {
           type string;
           description
             "The group-id of the agent from which this
              report originates.";
         }

         leaf measurement-point {
           type string;
           description
             "The measurement-point of the agent from which this
              report originates.";
         }

         list result {
           description
             "The list of Tasks for which results are reported.";

           leaf schedule {
             type lmap:identifier;

             description
               "The name of the Schedule that produced the result.";
           }

           leaf action {
             type lmap:identifier;
             description
               "The name of the Action in the Schedule that produced
                the result.";
           }

           leaf task {
             type lmap:identifier;
             description
               "The name of the Task that produced the result.";
           }

           container parameters {
             description
               "This container is a placeholder for runtime
                parameters defined in Task-specific data models
                augmenting the base LMAP report data model.";

             choice extension {
               description
                 "This choice is provided to augment in different
                  sets of parameters.";
             }
           }

           uses lmap:options-grouping {
             description
               "The list of options there were in use when the
                measurement was performed.  This list must include
                both the Task-specific options as well as the
                Action-specific options.";
           }

           leaf-list tag {
             type lmap:tag;
             description
               "A tag contains additional information that is passed
                with the result record to the Collector.  This is the
                joined set of tags defined for the Task object, the
                Schedule object, and the Action object.  A tag can be
                used to carry the Measurement Cycle ID.";
           }

           leaf event {
             type yang:date-and-time;
             description
               "The date and time of the event that triggered the
                Schedule of the Action that produced the reported
                result values.  The date and time does not include
                any added randomization.";
           }

           leaf start {
             type yang:date-and-time;
             mandatory true;
             description
               "The date and time when the Task producing
                this result started.";
           }

           leaf end {
             type yang:date-and-time;
             description
               "The date and time when the Task producing
                this result finished.";
           }

           leaf cycle-number {
             type lmap:cycle-number;
             description
               "The optional cycle number is the time closest to
                the time reported in the event leaf that is a multiple
                of the cycle-interval of the event that triggered the
                execution of the Schedule.  The value is only present
                if the event that triggered the execution of the
                Schedule has a defined cycle-interval.";
           }

           leaf status {
             type lmap:status-code;
             mandatory true;
             description
               "The status code returned by the execution of this
                Action.";
           }

           list conflict {
             description
               "The names of Tasks overlapping with the execution
                of the Task that has produced this result.";

             leaf schedule-name {
               type lmap:identifier;
               description
                 "The name of a Schedule that might have impacted
                  the execution of the Task that has produced this
                  result.";
             }

             leaf action-name {
               type lmap:identifier;
               description
                 "The name of an Action within the Schedule that
                  might have impacted the execution of the Task that
                  has produced this result.";
             }

             leaf task-name {
               type lmap:identifier;
               description
                 "The name of the Task executed by an Action within
                  the Schedule that might have impacted the execution
                  of the Task that has produced this result.";
             }
           }

           list table {
             description
               "A list of result tables.";

             uses lmap:registry-grouping;

             leaf-list column {
               type string;
               description
                 "An ordered list of column labels.  The order is
                  determined by the system and must match the order
                  of the columns in the result rows.";
             }

             list row {
               description
                 "The rows of a result table.";

               leaf-list value {
                 type string;
                 description
                   "The value of a cell in the result row.";
               }

             }
           }
         }
       }
     }
   }
   <CODE ENDS>

5. Security Considerations

   The YANG module defined in this document is designed to be accessed
   via network management protocols such as NETCONF [RFC6241] or
   RESTCONF [RFC8040].  The lowest NETCONF layer is the secure transport
   layer, and the mandatory-to-implement secure transport is Secure
   Shell (SSH) [RFC6242].  The lowest RESTCONF layer is HTTPS, and the
   mandatory-to-implement secure transport is Transport Layer Security
   (TLS) [RFC5246].

   The NETCONF access control model [RFC6536] provides the means to
   restrict access for particular NETCONF or RESTCONF users to a
   preconfigured subset of all available NETCONF or RESTCONF protocol
   operations and content.

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

   /lmap/agent           This subtree configures general properties of
                         the Measurement Agent such as its identity,
                         measurement point, or Controller timeout.  This
                         subtree should only have write access for the
                         system responsible for configuring the
                         Measurement Agent.

   /lmap/tasks           This subtree configures the Tasks that can be
                         invoked by a Controller.  This subtree should
                         only have write access for the system
                         responsible for configuring the Measurement
                         Agent.  Care must be taken to not expose Tasks
                         to a Controller that can cause damage to the
                         system or the network.

   /lmap/schedules       This subtree is used by a Controller to define
                         the Schedules and Actions that are executed
                         when certain events occur.  Unauthorized access
                         can cause unwanted load on the device or
                         network, or it might direct measurement traffic
                         to targets that become victims of an attack.

   /lmap/suppressions    This subtree is used by a Controller to define
                         Suppressions that can temporarily disable the
                         execution of Schedules or Actions.
                         Unauthorized access can either disable
                         measurements that should normally take place or
                         cause measurements to take place during times
                         when normally no measurements should take
                         place.

   /lmap/events          This subtree is used by a Controller to define
                         events that trigger the execution of Schedules
                         and Actions.  Unauthorized access can either
                         disable measurements that should normally take
                         place or cause measurements to take place
                         during times when normally no measurements
                         should take place or at a frequency that is
                         higher than normally expected.

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

   /lmap/agent           This subtree provides information about the
                         Measurement Agent.  This information may be
                         used to select specific targets for attacks.

   /lmap/capabilities    This subtree provides information about the
                         capabilities of the Measurement Agent,
                         including its software version number and the
                         Tasks that it supports.  This information may
                         be used to execute targeted attacks against
                         specific implementations.

   /lmap/schedules       This subtree provides information about the
                         Schedules and their associated Actions executed
                         on the Measurement Agent.  This information may
                         be used to check whether attacks against the
                         implementation are effective.

   /lmap/suppressions    This subtree provides information about the
                         Suppressions that can be active on the
                         Measurement Agent.  This information may be
                         used to predict time periods where measurements
                         take place (or do not take place).

   Some of the RPC operations in this YANG module may be considered
   sensitive or vulnerable in some network environments.  It is thus
   important to control access to these operations.  These are the
   operations and their sensitivity/vulnerability:

   /report   The report operation is used to send locally collected
             measurement results to a remote Collector.  Unauthorized
             access may leak measurement results, including those from
             passive measurements.

   The data model uses a number of identifiers that are set by the
   Controller.  Implementors may find these identifiers useful for the
   identification of resources, e.g., to identify objects in a file
   system providing temporary storage.  Since the identifiers used by
   the YANG data model may allow characters that may be given special
   interpretation in a specific context, implementations must ensure
   that identifiers are properly mapped into safe identifiers.

   The data model allows specifying options in the form of name/value
   pairs that are passed to programs.  Implementors ought to take care
   that option names and values are passed literally to programs.  In
   particular, shell expansions that may alter option names and values
   must not be performed.

6. IANA Considerations

   This document registers three URIs in the "IETF XML Registry"
   [RFC3688].  Following the format in RFC 3688, the following
   registrations have been made.

         URI: urn:ietf:params:xml:ns:yang:ietf-lmap-common
         Registrant Contact: The IESG.
         XML: N/A; the requested URI is an XML namespace.

         URI: urn:ietf:params:xml:ns:yang:ietf-lmap-control
         Registrant Contact: The IESG.
         XML: N/A; the requested URI is an XML namespace.

         URI: urn:ietf:params:xml:ns:yang:ietf-lmap-report
         Registrant Contact: The IESG.
         XML: N/A; the requested URI is an XML namespace.

   This document registers three YANG modules in the "YANG Module Names"
   registry [RFC6020].

         Name: ietf-lmap-common
         Namespace: urn:ietf:params:xml:ns:yang:ietf-lmap-common
         Prefix: lmap
         Reference: RFC 8194

         Name: ietf-lmap-control
         Namespace: urn:ietf:params:xml:ns:yang:ietf-lmap-control
         Prefix: lmapc
         Reference: RFC 8194

         Name: ietf-lmap-report
         Namespace: urn:ietf:params:xml:ns:yang:ietf-lmap-report
         Prefix: lmapr
         Reference: RFC 8194

7. References

7.1. Normative References

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

   [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
              (TLS) Protocol Version 1.2", RFC 5246,
              DOI 10.17487/RFC5246, August 2008,
              <https://www.rfc-editor.org/info/rfc5246>.

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

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

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

   [RFC6536]  Bierman, A. and M. Bjorklund, "Network Configuration
              Protocol (NETCONF) Access Control Model", RFC 6536,
              DOI 10.17487/RFC6536, March 2012,
              <https://www.rfc-editor.org/info/rfc6536>.

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

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

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

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

   [RFC8193]  Burbridge, T., Eardley, P., Bagnulo, M., and J.
              Schoenwaelder, "Information Model for Large-Scale
              Measurement Platforms (LMAPs)", DOI 10.17487/RFC8193,
              RFC 8193, August 2017,
              <http://www.rfc-editor.org/info/rfc8193>.

7.2. Informative References

   [ISO-8601]
              International Organization for Standardization, "Data
              elements and interchange formats -- Information
              interchange -- Representation of dates and times", ISO
              Standard 8601:2004, December 2004.

   [NETCONF-CLIENT-SERVER]
              Watsen, K., Wu, G., and J. Schoenwaelder, "NETCONF Client
              and Server Models", Work in Progress, draft-ietf-netconf-
              netconf-client-server-04, July 2017.

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

   [RFC5424]  Gerhards, R., "The Syslog Protocol", RFC 5424,
              DOI 10.17487/RFC5424, March 2009,
              <https://www.rfc-editor.org/info/rfc5424>.

   [RFC7223]  Bjorklund, M., "A YANG Data Model for Interface
              Management", RFC 7223, DOI 10.17487/RFC7223, May 2014,
              <https://www.rfc-editor.org/info/rfc7223>.

   [RFC7317]  Bierman, A. and M. Bjorklund, "A YANG Data Model for
              System Management", RFC 7317, DOI 10.17487/RFC7317, August
              2014, <https://www.rfc-editor.org/info/rfc7317>.

   [RFC7398]  Bagnulo, M., Burbridge, T., Crawford, S., Eardley, P., and
              A. Morton, "A Reference Path and Measurement Points for
              Large-Scale Measurement of Broadband Performance",
              RFC 7398, DOI 10.17487/RFC7398, February 2015,
              <https://www.rfc-editor.org/info/rfc7398>.

   [RFC7594]  Eardley, P., Morton, A., Bagnulo, M., Burbridge, T.,
              Aitken, P., and A. Akhter, "A Framework for Large-Scale
              Measurement of Broadband Performance (LMAP)", RFC 7594,
              DOI 10.17487/RFC7594, September 2015,
              <https://www.rfc-editor.org/info/rfc7594>.

   [W3C.REC-xml-20081126]
              Bray, T., Paoli, J., Sperberg-McQueen, M., Maler, E., and
              F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fifth
              Edition)", World Wide Web Consortium Recommendation REC-
              xml-20081126, November 2008,
              <http://www.w3.org/TR/2008/REC-xml-20081126>.

   [YANG-HARDWARE]
              Bierman, A., Bjorklund, M., Dong, J., and D. Romascanu, "A
              YANG Data Model for Hardware Management", Work in
              Progress, draft-ietf-netmod-entity-03, March 2017.

Appendix A. Example Parameter Extension Module

   Sometimes Tasks may require complicated parameters that cannot easily
   be fit into options, i.e., a list of name/value pairs.  In such a
   situation, it is possible to augment the ietf-lmap-control.yang and
   ietf-lmap-report.yang data models with definitions for more complex
   parameters.  The following example module demonstrates this idea
   using the parameters of UDP latency metrics as an example (although
   UDP latency metric parameters do not really need such an extension
   module).

  module example-ietf-ippm-udp-latency {

    namespace "urn:example:ietf-ippm-udp-latency";
    prefix "ippm-udp-latency";

    import ietf-inet-types {
      prefix inet;
    }
    import ietf-lmap-control {
      prefix "lmapc";
    }
    import ietf-lmap-report {
      prefix "lmapr";
    }

    grouping ippm-udp-latency-parameter-grouping {
      leaf src-ip {
        type inet:ip-address;
        description
          "The source IP address of the UDP measurement traffic.";
      }

      leaf src-port {
        type inet:port-number;
        description
          "The source port number of the UDP measurement traffic.";
      }

      leaf dst-ip {
        type inet:ip-address;
        description
          "The destination IP address of the UDP measurement traffic.";
      }

      leaf dst-port {
        type inet:port-number;
        description
          "The destination port number of the UDP measurement traffic.";
      }

      leaf poisson-lambda {
        type decimal64 {
          fraction-digits 4;
        }
        units "seconds";
        default 1.0000;
        description
          "The average interval for the poisson stream with a resolution
           of 0.0001 seconds (0.1 ms).";
      }

      leaf poisson-limit {
        type decimal64 {
          fraction-digits 4;
        }
        units "seconds";
        default 30.0000;
        description
          "The upper limit on the poisson distribution with a resolution
           of 0.0001 seconds (0.1 ms).";
      }
    }

    augment "/lmapc:lmap/lmapc:schedules/lmapc:schedule/lmapc:action"
          + "/lmapc:parameters/lmapc:extension" {
      description
        "This augmentation adds parameters specific to IP Performance
          Metrics (IPPM) and UDP latency metrics to Actions.";

      case "ietf-ippm-udp-latency" {
        uses ippm-udp-latency-parameter-grouping;
      }
    }

    augment "/lmapr:report/lmapr:input/lmapr:result"
          + "/lmapr:parameters/lmapr:extension" {
      description
        "This augmentation adds parameters specific to IPPM and
         UDP latency metrics to reports.";

      case "ietf-ippm-udp-latency" {
        uses ippm-udp-latency-parameter-grouping;
      }
    }

  }

Appendix B. Example Configuration

The configuration below is in XML [W3C.REC-xml-20081126].

   <config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
     <lmap xmlns="urn:ietf:params:xml:ns:yang:ietf-lmap-control">

       <agent>
         <agent-id>550e8400-e29b-41d4-a716-446655440000</agent-id>
         <report-agent-id>true</report-agent-id>
       </agent>

       <schedules>
         
         <schedule>
           <name>S1</name>
           <start>E1</start>
           <execution-mode>sequential</execution-mode>
           <action>
             <name>A1</name>
             <task>update-ping-targets</task>
           </action>
           <action>
             <name>A2</name>
             <task>ping-all-targets</task>
             <destination>S3</destination>
           </action>
           <suppression-tag>measurement:ping</suppression-tag>
         </schedule>
         
         <schedule>
           <name>S2</name>
           <start>E1</start>
           <execution-mode>parallel</execution-mode>

<action>
             <name>A1</name>
             <task>traceroute</task>
             <option>
               <id>target</id>
               <name>target</name>
               <value>2001:db8::1</value>
             </option>
             <destination>S3</destination>
           </action>
           <action>
             <name>A2</name>
             <task>traceroute</task>
             <option>
               <id>target</id>
               <name>target</name>
               <value>2001:db8::2</value>
             </option>
             <destination>S3</destination>
           </action>
           <suppression-tag>measurement:traceroute</suppression-tag>
         </schedule>
         
         <schedule>
           <name>S3</name>
           <start>E2</start>
           <action>
             <name>A1</name>
             <task>report</task>
             <option>
               <id>collector</id>
               <name>collector</name>
               <value>https://collector.example.com/</value>
             </option>
           </action>
         </schedule>
       </schedules>

       <suppressions>
         
         <suppression>
           <name>orphaned</name>
           <start>controller-lost</start>
           <end>controller-connected</end>
           <match>measurement:*</match>
         </suppression>
       </suppressions>

<tasks>
         
         <task>
           <name>update-ping-targets</name>
           <program>fping-update-targets</program>
         </task>
         
         <task>
           <name>ping-all-targets</name>
           <program>fping</program>
         </task>
         
         <task>
           <name>traceroute</name>
           <program>mtr</program>
           <option>
             <id>csv</id>
             <name>--csv</name>
           </option>
         </task>
         
         <task>
           <name>report</name>
           <program>lmap-report</program>
         </task>

         <task>
           <name>ippm-udp-latency-client</name>
           <program>ippm-udp-latency</program>
           <function>
             <uri>urn:example:tbd</uri>
             <role>client</role>
           </function>
           <tag>active</tag>
         </task>
       </tasks>

       <events>
         
         <event>
           <name>E1</name>
           <random-spread>60</random-spread>   
           <periodic>
             <interval>3600000</interval>
             <start>2016-09-01T00:00:00+00:00</start>
             <end>2016-11-01T00:00:00+00:00</end>
           </periodic>

</event>
         
         <event>
           <name>E2</name>
           <calendar>
             <month>*</month>
             <day-of-week>monday</day-of-week>
             <day-of-month>*</day-of-month>
             <hour>4</hour>
             <minute>0</minute>
             <second>0</second>
             <timezone-offset>+00:00</timezone-offset>
           </calendar>
         </event>
         
         <event>
           <name>controller-lost</name>
           <controller-lost/>
         </event>
         
         <event>
           <name>controller-connected</name>
           <controller-connected/>
         </event>
       </events>
     </lmap>
   </config>

Appendix C. Example Report

   The report below is in XML [W3C.REC-xml-20081126].

   <rpc xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"
        message-id="1">
     <report xmlns="urn:ietf:params:xml:ns:yang:ietf-lmap-report">
       <date>2015-10-28T13:27:42+02:00</date>
       <agent-id>550e8400-e29b-41d4-a716-446655440000</agent-id>
       <result>
         <schedule>S1</schedule>
         <action>A1</action>
         <task>update-ping-targets</task>
         <start>2016-03-21T10:48:55+01:00</start>
         <end>2016-03-21T10:48:57+01:00</end>
         <status>0</status>
       </result>

       <result>
         <schedule>S1</schedule>
         <action>A2</action>
         <task>ping-all-targets</task>
         <start>2016-03-21T10:48:55+01:00</start>
         <end>2016-03-21T10:48:57+01:00</end>
         <status>0</status>
         <table>
           <column>target</column>
           <column>rtt</column>
           <row>
             <value>2001:db8::1</value>
             <value>42</value>
           </row>
           <row>
             <value>2001:db8::2</value>
             <value>24</value>
           </row>
         </table>
       </result>
       <result>
         <schedule>S2</schedule>
         <action>A1</action>
         <task>traceroute</task>
         <option>
           <id>target</id>
           <name>target</name>
           <value>2001:db8::1</value>
         </option>
         <option>
           <id>csv</id>
           <name>--csv</name>
         </option>
         <start>2016-03-21T10:48:55+01:00</start>
         <end>2016-03-21T10:48:57+01:00</end>
         <status>1</status>
         <table>
           <column>hop</column>
           <column>ip</column>
           <column>rtt</column>
           <row>
             <value>1</value>
             <value>2001:638:709:5::1</value>
             <value>10.5</value>
           </row>
           <row>
             <value>2</value>
             <value>?</value>

             <value></value>
           </row>
         </table>
       </result>
       <result>
         <schedule>S2</schedule>
         <action>A2</action>
         <task>traceroute</task>
         <option>
           <id>target</id>
           <name>target</name>
           <value>2001:db8::2</value>
         </option>
         <option>
           <id>csv</id>
           <name>--csv</name>
         </option>
         <start>2016-03-21T10:48:55+01:00</start>
         <end>2016-03-21T10:48:57+01:00</end>
         <status>1</status>
         <table>
           <column>hop</column>
           <column>ip</column>
           <column>rtt</column>
           <row>
             <value>1</value>
             <value>2001:638:709:5::1</value>
             <value>11.8</value>
           </row>
           <row>
             <value>2</value>
             <value>?</value>
             <value></value>
           </row>
         </table>
       </result>
     </report>
   </rpc>

Acknowledgements

   Several people contributed to this specification by reviewing early
   draft versions and actively participating in the LMAP Working Group
   (apologies to those unintentionally omitted): Marcelo Bagnulo, Martin
   Bjorklund, Trevor Burbridge, Timothy Carey, Alissa Cooper, Philip
   Eardley, Al Morton, Dan Romascanu, Andrea Soppera, Barbara Stark, and
   Qin Wu.

   Juergen Schoenwaelder and Vaibhav Bajpai worked in part on the Leone
   research project, which received funding from the European Union
   Seventh Framework Programme [FP7/2007-2013] under grant agreement
   number 317647.

   Juergen Schoenwaelder and Vaibhav Bajpai were partly funded by
   Flamingo, a Network of Excellence project (ICT-318488) supported by
   the European Commission under its Seventh Framework Programme.

Authors' Addresses

   Juergen Schoenwaelder
   Jacobs University Bremen

   Email: j.schoenwaelder@jacobs-university.de

   Vaibhav Bajpai
   Technical University of Munich

   Email: bajpaiv@in.tum.de