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Information Model for Large-Scale Measurement Platforms (LMAP)
draft-ietf-lmap-information-model-02

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 8193.
Authors Trevor Burbridge , Philip Eardley , Marcelo Bagnulo , Jürgen Schönwälder
Last updated 2014-12-15 (Latest revision 2014-08-20)
Replaces draft-burbridge-lmap-information-model
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IESG IESG state Became RFC 8193 (Proposed Standard)
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Responsible AD Benoît Claise
Send notices to draft-ietf-lmap-information-model.all@tools.ietf.org, lmap-chairs@tools.ietf.org, lmap@ietf.org
draft-ietf-lmap-information-model-02
Network Working Group                                       T. Burbridge
Internet-Draft                                                P. Eardley
Intended status: Standards Track                                      BT
Expires: February 21, 2015                                    M. Bagnulo
                                        Universidad Carlos III de Madrid
                                                        J. Schoenwaelder
                                                Jacobs University Bremen
                                                         August 20, 2014

     Information Model for Large-Scale Measurement Platforms (LMAP)
                  draft-ietf-lmap-information-model-02

Abstract

   This Information Model applies to the Measurement Agent within a
   Large-Scale Measurement Platform.  As such it outlines the
   information that is (pre-)configured on the MA or exists in
   communications with a Controller or Collector within an LMAP
   framework.  The purpose of such an Information Model is to provide a
   protocol and device independent view of the MA that can be
   implemented via one or more Control and Report protocols.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

Status of This Memo

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

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on February 21, 2015.

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Copyright Notice

   Copyright (c) 2014 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Notation  . . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  LMAP Information Model  . . . . . . . . . . . . . . . . . . .   4
     3.1.  Information Structure . . . . . . . . . . . . . . . . . .   4
     3.2.  Pre-Configuration Information . . . . . . . . . . . . . .   8
     3.3.  Configuration Information . . . . . . . . . . . . . . . .   9
     3.4.  Instruction Information . . . . . . . . . . . . . . . . .  11
     3.5.  Logging Information . . . . . . . . . . . . . . . . . . .  13
     3.6.  Capability and Status Information . . . . . . . . . . . .  15
     3.7.  Reporting Information . . . . . . . . . . . . . . . . . .  17
     3.8.  Schedules . . . . . . . . . . . . . . . . . . . . . . . .  18
     3.9.  Channels  . . . . . . . . . . . . . . . . . . . . . . . .  21
     3.10. Task Configurations . . . . . . . . . . . . . . . . . . .  22
     3.11. Timing Information  . . . . . . . . . . . . . . . . . . .  23
       3.11.1.  Periodic Timing  . . . . . . . . . . . . . . . . . .  24
       3.11.2.  Calendar Timing  . . . . . . . . . . . . . . . . . .  25
       3.11.3.  One-Off Timing . . . . . . . . . . . . . . . . . . .  26
       3.11.4.  Immediate Timing . . . . . . . . . . . . . . . . . .  26
       3.11.5.  Startup Timing . . . . . . . . . . . . . . . . . . .  26
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  26
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  26
   6.  Appendix: JSON Example  . . . . . . . . . . . . . . . . . . .  27
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  35
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  35
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  35
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  35
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  35

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1.  Introduction

   A large-scale measurement platform is a collection of components that
   work in a coordinated fashion to perform measurements from a large
   number of vantage points.  The main components of a large-scale
   measurement platform are the Measurement Agents (hereafter MAs), the
   Controller(s) and the Collector(s).

   The MAs are the elements actually performing the measurements.  The
   MAs are controlled by exactly one Controller at a time and the
   Collectors gather the results generated by the MAs.  In a nutshell,
   the normal operation of a large-scale measurement platform starts
   with the Controller instructing a set of one or more MAs to perform a
   set of one or more Measurement Tasks at a certain point in time.  The
   MAs execute the instructions from a Controller, and once they have
   done so, they report the results of the measurements to one or more
   Collectors.  The overall framework for a Large Measurement platform
   as used in this document is described in detail in
   [I-D.ietf-lmap-framework].

   A large-scale measurement platform involves basically three
   protocols, namely, a Control protocol between a Controller and the
   MAs, a Report protocol between the MAs and the Collector(s) and
   several measurement protocols between the MAs and Measurement Peers
   (MPs), used to actually perform the measurements.  In addition some
   information is required to be configured on the MA prior to any
   communication with the initial Controller.

   This document defines the information model for both the Control and
   the Report protocol along with pre-configuration information that is
   required before communicating with the Controller, broadly named as
   the LMAP Information Model.  The measurement protocols are out of the
   scope of this document.

   As defined in [RFC3444], the LMAP IM defines the concepts involved in
   a large-scale measurement platform at a high level of abstraction,
   independent of any specific implementation or actual protocol used to
   exchange the information.  It is expected that the proposed
   information model can be used with different protocols in different
   measurement platform architectures and across different types of MA
   devices (e.g., home gateway, smartphone, PC, router).

   The definition of an Information Model serves a number of purposes:

   1.  To guide the standardisation of one or more Control and Report
       protocol and data model implementations

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   2.  To enable high-level inter-operability between different Control
       and Report protocols by facilitating translation between their
       respective data models such that a Controller could instruct sub-
       populations of MAs using different protocols

   3.  To form agreement of what information needs to be held by an MA
       and passed over the Control and Report interfaces and support the
       functionality described in the LMAP framework

   4.  Enable existing protocols and data models to be assessed for
       their suitability as part of a large-scale measurement system

2.  Notation

   This document use an object-oriented programming-like notation to
   define the parameters (names/values) of the objects of the
   information model.  An optional field is enclosed by [ ], and an
   array is indicated by two numbers in angle brackets, <m..n>, where m
   indicates the minimal number of values, and n is the maximum.  The
   symbol * for n means no upper bound.

3.  LMAP Information Model

3.1.  Information Structure

   The information described herein relates to the information stored,
   received or transmitted by a Measurement Agent as described within
   the LMAP framework [I-D.ietf-lmap-framework].  As such, some subsets
   of this information model are applicable to the measurement
   Controller, Collector and systems that pre-configure the Measurement
   Agent.  The information described in these models will be transmitted
   by protocols using interfaces between the Measurement Agent and such
   systems according to a Data Model.

   For clarity the information model is divided into six sections:

   1.  Pre-Configuration Information.  Information pre-configured on the
       Measurement Agent prior to any communication with other
       components of the LMAP architecture (i.e., the Controller,
       Collector and Measurement Peers), specifically detailing how to
       communicate with a Controller and whether the device is enabled
       to participate as an MA.

   2.  Configuration Information.  Update of the pre-configuration
       information during the registration of the MA or subsequent
       communication with the Controller, along with the configuration
       of further parameters about the MA (rather than the Tasks it

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       should perform) that were not mandatory for the initial
       communication between the MA and a Controller.

   3.  Instruction Information.  Information that is received by the MA
       from the Controller pertaining to the Tasks that should be
       executed.  This includes the task execution Schedules (other than
       the Controller communication Schedule supplied as
       (pre)configuration information) and related information such as
       the Task Configuration, communication Channels to Collectors and
       schedule Timing information.  It also inlcudes Task Suppression
       information that is used to over-ride normal Task execution
       during emergency situations.

   4.  Logging Information.  Information transmitted from the MA to the
       Controller detailing the results of any configuration operations
       along with error and status information from the operation of the
       MA.

   5.  Capability and Status Information.  Information on the general
       status and capabilities of the MA.  For example, the set of
       measurements that are supported on the device.

   6.  Reporting Information.  Information transmitted from the MA to
       one or more Collectors including measurement results and the
       context in which they were conducted.

   In addition the MA may hold further information not described herein,
   and which may be optionally transferred to or from other systems
   including the Controller and Collector.  One example of information
   in this category is subscriber or line information that may be
   extracted by a task and reported by the MA in the reporting
   communication to a Collector.

   It should also be noted that the MA may be in communication with
   other management systems which may be responsible for configuring and
   retrieving information from the MA device.  Such systems, where
   available, can perform an important role in transferring the pre-
   configuration information to the MA or enabling/disabling the
   measurement functionality of the MA.

   The Information Model is divided into sub-sections for a number of
   reasons.  Firstly the grouping of information facilitates reader
   understanding.  Secondly, the particular groupings chosen are
   expected to map to different protocols or different transmissions
   within those protocols.

   The granularity of data transmitted in each operation of the Control
   and Report Protocols is not dictated by the Information Model.  For

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   example, the Instruction object may be delivered in a single
   operation.  Alternatively, Schedules and Task Configurations may be
   separated or even each Schdule/Task Configuration may be delivered
   individually.  Similarly the Information Model does not dictate
   whether data is read, write, or read/write.  For example, some
   Control Protocols may have the ability to read back Configuration and
   Instruction information which have been previosuly set on the MA.
   Lastly, while some protocols may simply overwrite information (for
   example refreshing the entire Instruction Information), other
   protocols may have the ability to update or delete selected items of
   information.

   The information in these six sections is captured by a number of
   common information objects.  These objects are also described later
   in this document and comprise of:

   1.  Schedules.  A set of Schedules tell the MA to do something.
       Without a Schedule no Task (from a measurement to reporting or
       communicating with the Controller) is ever executed.  Schedules
       are used within the Instruction to specify what tasks should be
       performed, when, and how to direct their results.  A Schedule is
       also used within the pre-Configuration and Configuration
       information in order to execute the Task or Tasks required to
       communicate with the Controller.

   2.  Channels.  A set of Channel objects are used to communicate with
       a number of endpoints (i.e. the Controller and Collectors).  Each
       Channel object contains the information required for the
       communication with a single endpoint such as the target location
       and security details.  Channels are referenced from within
       Schedules in order to say how Tasks should communicate.

   3.  Task Configurations.  A set of Task Configurations is used to
       configure the Tasks that are run by the MA.  This includes the
       registry entry for the Task and any configuration parameters.
       Task Configurations are referenced from a Schedule in order to
       specify what Tasks the MA should execute.

   4.  Timings.  A set of Timing objects that can be referenced from the
       Schedules.  Each Schedule always references exactly one Timing
       object.  A Timing object specfies either a singleton or series of
       time events.  They are used to indicate when Tasks should be
       executed.

   The following diagram illustrates the structure in which these common
   information objects are referenced.  The references are achieved by
   each object (Channel, Task Configuration, Timing) being given a short

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   text name that is used by other objects.  The objects shown in
   parenthesis are part of the internal object structure of a Schedule.

          Schedule
              |----------> Timing
              |----------> (Scheduled Tasks)
                                   |----------> Task Configuration
                                   |----------> (Task Channels and downstream Tasks)
                                                      |----------> Channels
                                                      |----------> Downstream Tasks

   It should be clear that the top-level bahaviour of an MA is simply to
   execute Schedules.  Every action referenced by a Schedule is defined
   as a Task.  As such, these actions are configured through Task
   Configurations and executed according to the Timing referenced by the
   Schedule in which they appear.  Tasks can implement a variety of
   different types of actions.  While in terms of the Information Model,
   all Tasks have the same structure, it can help conceptually to think
   of different Task categories:

   1.  Measurement Tasks

       A.  Measurement Tasks measure some aspect of network performance
           or traffic

       B.  Data Capture Tasks capture and analyse passive information
           stored on the MA device such as counters and device/network
           status information

   2.  Data Transfer Tasks

       A.  Reporting Tasks report the results or Measurement Tasks to
           Collectors

       B.  Control Task(s) implement the Control Protocol and
           communicate with the Controller.  Depending on the Control
           Protocol this may be a number of specialist tasks such as:
           Configuration Task; Instruction Task; Suppression Task;
           Capabilities Task; Logging Task etc.

   3.  Data Analysis Tasks can exist to analyse data from other
       Measurement Tasks locally on the MA

   4.  Data Management Tasks may exist to clean-up, filter or compress
       data on the MA such as Measurement Task results

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3.2.  Pre-Configuration Information

   This information is the minimal information that needs to be pre-
   configured to the MA in order for it to successfully communicate with
   a Controller during the registration process.  The pre-configuration
   information is a subset of the Configuration Information along with
   some parameters that are not under the control of the LMAP framework
   (such as the the device identifier and device security credentials).

   This pre-configuration information needs to include a URL of the
   initial Controller where configuration information can be retrieved
   along with the security information required for the communication
   including the certificate of the Controller (or the certificate of
   the Certification Authority which was used to issue the certificate
   for the Controller).  All this is expressed as a Channel.  While
   multiple Channels may be provided in the pre-configuration
   information they must all be associated with a single Controller
   (e.g. over different interfaces or network protocols).

   Where the MA pulls information from the Controller, the Pre-
   Configuration Information also needs to contain the timing of the
   communication with the Controller as well as the nature of the
   communication itself (such as the protocol and data to be
   transfered).  The timing is given as a Schedule that executes the
   Task(s) responsible for communication with the Controller.  It is
   this Task (or Tasks) that implement the Control protocol between the
   MA and the Controller.  The Task(s) may take additional parameters in
   which case a Task Configuration can also be included.

   Even where information is pushed to the MA from the Controller
   (rather than pulled by the MA), a Schedule still needs to be
   supplied.  In this case the Schedule will simply execute a Controller
   listener task when the MA is started.  A Channel is still required
   for the MA to establish secure communication with the Controller.

   It can be seen that these Channels, Schedules and Task Configurations
   for the initial MA-Controller communication are no different in terms
   of the Information Model to any other Channel, Schedule or Task
   Configuration that might execute a Measurement Task or report the
   measurement results (as described later).

   The MA may be pre-configured with an MA ID, or may use a Device ID in
   the initial Controller contact before it is assigned an MA ID.  The
   Device ID may be a MAC address or some other device identifier
   expressed as a URN.  If the MA ID is not provided at this stage then
   it must be provided by the Controller during Configuration.

   Detail of the information model elements:

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// MA pre-configuration minimal information to communicate initially with Controller

object {
    [uuid                ma-agent-id;]
     ma-task-obj         ma-control-tasks<1..*>;
     ma-channel-obj      ma-control-channels<1..*>;
     ma-schedule-obj     ma-control-schedules<1..*>;
    [urn                 ma-device-id;]
     credentials         ma-credentials;
} ma-config-obj;

   The detail of the Channel and Schedule objects are described later
   since they are common to several parts of the information model.

3.3.  Configuration Information

   During registration or at any later point at which the MA contacts
   the Controller (or vice-versa), the choice of Controller, details for
   the timing of communication with the Controller or parameters for the
   communication Task(s) can be changed (as captured by the Channels,
   Schedules and Task Configurations objects).  For example the pre-
   configured Controller (specified as a Channel or Channels) may be
   replaced with a specific Controller that is more appropriate to the
   MA device type, location or characteristics of the network (e.g.
   access technology type or broadband product).  The initial
   communication Schedule may be replaced with one more relevant to
   routine communications between the MA and the Controller.

   While some Control protocols and uses may only use a single Schedule,
   other protocols and uses may uses several Schedules (and related data
   transfer Tasks) to update the Configuration Information, transfer the
   Instruction Information, transfer Capability and Status Information
   and send other information to the Controller such as log or error
   notifications.  Multiple Channels may be used to communicate with the
   same Controller over multiple interfaces (e.g. to send logging
   information over a different network).

   In addition the MA will be given further items of information that
   relate specifically to the MA rather than the measurements it is to
   conduct or how to report results.  The assignment of an ID to the MA
   is mandatory.  If the MA Agent ID was not optionally provided during
   the pre-configuration then one must be provided by the Controller
   during Configuration.  Optionally a Group ID may also be given which
   identifies a group of interest to which that MA belongs.  For example
   the group could represent an ISP, broadband product, technology,
   market classification, geographic region, or a combination of
   multiple such characteristics.  Where the Measurement Group ID is set
   an additional flag (the Report MA ID flag) is required to control

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   whether the Measurement Agent ID is also to be reported.  The
   reporting of a Group ID without the MA ID allows the MA to remain
   anonymous, which may be particularly useful to prevent tracking of
   mobile MA devices.

   Optionally an MA can also be configured to stop executing any
   Instruction Schedule if the Controller is unreachable.  This can be
   used as a fail-safe to stop Measurement and other Tasks being
   conducted when there is doubt that the Instruction Information is
   still valid.  This is simply represented as a time window in
   milliseconds since the last communication with the Controller after
   which Instruction Schedules are to be suspended.  The appropriate
   vaue of the time window will depend on the specified communication
   Schedule with the Controller and the duration for which the system is
   willing to tolerate continued operation with potentially stale
   Instruction Information.

   While pre-configuration is persistent upon device reset or power
   cycle due to its very nature, the persistency of the addtional
   configuration information may be control protocol dependent.  Some
   protocols may assume that reset devices will revert back to their
   pre-configuration state, while other protocols may assume that all
   configuration and instruction information is held in persistent
   storage.

   It should be noted that control shedules and tasks cannot be
   suppressed as evidenced by the lack of suppression information in the
   Configuration.  The control schedule must only reference tasks listed
   as control tasks.  Any suppress-by-default flag against control tasks
   will be ignored.

   Detail of the additional and updated information model elements:

   // MA Configuration

   object {
       uuid                ma-agent-id;
      [ma-task-obj         ma-control-tasks<0..*>;]
       ma-channel-obj      ma-control-channels<1..*>;
      [ma-schedule-obj    ma-control-schedules<0..*>];
      [urn                 ma-device-id;]
       credentials         ma-credentials;
      [string              ma-group-id;]
      [boolean             ma-report-ma-id-flag;]
      [int                 ma-control-channel-failure-threshold;]
   } ma-config-obj;

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3.4.  Instruction Information

   The Instruction information model has four sub-elements:

   1.  Instruction Task Configurations

   2.  Report Channels

   3.  Instruction Schedules

   4.  Suppression

   The Instruction supports the exceution of all Tasks on the MA except
   those that deal with communication with the Controller (specified in
   (pre)configuration information).  The Tasks are configured in
   Instruction Task Configurations and inlcuded by reference in
   Instruction Schdules that specify when to execute them.  The results
   are communicated to other Tasks or over Report Channels.  Suppression
   is used to temporarily stop the excution of new Tasks as specified by
   the Instruction Schedules (and optionaly to stop ongoing Tasks).

   A Task Configuration is used to configure the optional parameters of
   a Task.  It also serves to instruct the MA about the Task including
   the ability to resolve the Task to an executable and specifying the
   schema for the Task parameters.

   A Report Channel defines how to communicate with a single remote
   system specified by a URL.  A Report Channel is used to send results
   to single Collector but is no different in terms of the Information
   Model to the Control Channel used to transfer information between the
   MA and the Controller.  Several Report Channels can be defined to
   enable results to be split or duplicated across different
   destinations.  A single Channel can also be used by multiple
   Schedules to transfer data at different cycles to the same Collector.
   E.g. a single Collector may receive data at three different cycle
   rates, one Schedule reporting hourly, another reporting daily and a
   third specifying that results should be sent immediately for on-
   demand measurement tasks.  Alternatively multiple Report Channels can
   be used to send Measurement Task results to different Collectors.
   The details of the Channel element is described later as it is common
   to several objects.

   Instruction Schedules specify which Tasks to execute according to a
   given Timing (that can execute a single or repeated series of Tasks).
   The Schedule also specifies how to deal with Task inputs and outputs
   - e.g. sending selected outputs to other Tasks or specifying the
   Report Channels that should be used to report results to Collectors.

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   Measurement Suppression information is used to over-ride the
   Instruction Schedule and temporarily stop measurements or other Tasks
   from running on the MA for a defined or indefinite period.  While
   conceptually measurements can be stopped by simply removing them from
   the Measurement Schedule, splitting out separate information on
   Measurement Suppression allows this information to be updated on the
   MA on a different timing cycle or protocol implementation to the
   Measurement Schedule.  It is also considered that it will be easier
   for a human operator to implement a temporary explicit suppression
   rather than having to move to a reduced Schedule and then roll-back
   at a later time.

   The explicit Suppression instruction message is able to simply
   enable/disable all Instruction Tasks (that are enabled for default
   suppression) as well as having fine control on which Tasks are
   suppressed.  Suppression of both specified Task Configurations and
   Measurement Schedules is supported.  Support for disabling specific
   Task Configurations allows malfunctioning or mis-configured Tasks or
   Task Configurations that have an impact on a particular part of the
   network infrastructure (e.g., a particular Measurement Peer) to be
   targetted.  Support for disabling specific Schedules allows for
   particularly heavy cycles or sets of less essential Measurement Tasks
   to be suppressed quickly and effectively.  Note that Suppression has
   no effect on either Controller Tasks or Controller Schedules.

   When no tasks or schedules are explicitly listed, all Instruction
   tasks will be suppressed (or not) as indicated by the suppress-by-
   default flag in the Task Configuration.  If tasks or schedules are
   listed explicitly then only these listed tasks or schedules will be
   suppressed regardless of the suppress-by-default flag.  If both
   individual tasks and individual schedules are listed then the union
   of these options is considered - i.e. the listed shcedules plus the
   listed tasks where present in other schedules.

   Suppression stops new Tasks from executing.  In addtion, the
   Suppression information also supports an additional Boolean that is
   used to select whether on-going tasks are also to be terminated.

   Unsuppression is achieved through either overwriting the Measurement
   Suppression information (e.g. changing 'enabled' to False) or through
   the use of an End time such that the Measurement Suppression will no
   longer be in effect beyond this time.  The datetime format used for
   all elements in the information model (e.g. the suppression start and
   end dates) MUST conform to RFC 3339 [RFC3339] and ISO8601.

   The goal when defining these four different elements is to allow each
   part of the information model to change without affecting the other
   three elements.  For example it is envisaged that the Report Channels

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   and the set of Task Configurations will be relatively static.  The
   Instruction Schedule, on the other hand, is likely to be more
   dynamic, as the measurement panel and test frequency are changed for
   various business goals.  Another example is that measurements can be
   suppressed with a Suppression command without removing the existing
   Instruction Schedules that would continue to apply after the
   Suppression expires or is removed.  In terms of the Controller-MA
   communication this can reduce the data overhead.  It also encourages
   the re-use of the same standard Task Configurations and Reporting
   Channels to help ensure consistency and reduce errors.

   Definition of the information model elements:

// Instruction to the MA to configure Tasks, Channels, Schedules and Suppression

object {
    ma-task-obj         ma-instruction-tasks<0..*>;
    ma-channel-obj      ma-report-channels<0..*>;
    ma-schedule-obj     ma-instruction-schedules<0..*>;
    ma-suppression-obj  ma-suppression;
} ma-instruction-obj;

// Suppression object to temporarily override new task execution in Instructions and optionally stop currently running tasks

object {
    boolean             ma-suppression-enabled;
   [boolean             ma-suppression-stop-ongoing-tasks;] // default: false
   [datetime            ma-suppression-start;] // default: immediate
   [datetime            ma-suppression-end;]   // default: indefinite
   [string              ma-suppression-task-names<0..*>;]
                        // default: all tasks if
                        // ma-suppression-task-names is empty
   [string              ma-suppression-schedule-names<0..*>;]
                        // default: all schedules if
                        // ma-suppression-schedule-names is empty
} ma-suppression-obj;

3.5.  Logging Information

   The MA may report on the success or failure of Configuration or
   Instruction communications from the Controller.  In addition further
   operational logs may be produced during the operation of the MA and
   updates to capabilities may also be reported.  Reporting this
   information is achieved simply and flexibly in exactly the same
   manner as any other Task.  We make no distinction between a
   Measurement Task conducting an active or passive network measurement
   and one which solely retrieves static or dynamic information from the
   MA such as capabilities or logging information.  One or more logging

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   tasks can be programmed or configured to capture subsets of the
   Logging Information.  These logging tasks are then executed by
   Schedules which also specify that the resultant data is to be
   transferred over the Controller Channels.

   The type of Logging Information will fall into three different
   categories:

   1.  Success/failure/warning messages in response to information
       updates from the Controller.  Failure messages could be produced
       due to some inability to receive or parse the Controller
       communication, or if the MA is not able to act as instructed.
       For example:

       *  "Measurement Schedules updated OK"

       *  "Unable to parse JSON"

       *  "Missing mandatory element: Measurement Timing"

       *  "'Start' does not conform to schema - expected datetime"

       *  "Date specified is in the past"

       *  "'Hour' must be in the range 1..24"

       *  "Schedule A refers to non-existent Measurement Task
          Configuration"

       *  "Measurement Task Configuration X registry entry Y not found"

       *  "Updated Measurement Task Configurations do not include M used
          by Measurement Schedule N"

   2.  Operational updates from the MA.  For example:

       *  "Out of memory: cannot record result"

       *  "Collector 'collector.example.com' not responding"

       *  "Unexpected restart"

       *  "Suppression timeout"

       *  "Failed to execute Measurement Task Configuration H"

   3.  Status updates from the MA.  For example:

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       *  "Interface added: eth3 "

       *  "Supported measurements updated"

       *  "New IP address on eth0: xxx.xxx.xxx.xxx"

   This Information Model document does not detail the precise format of
   logging information since it is to a large extent protocol and MA
   specific.  However, some common information can be identified.

   MA Logging information model elements:

   // Logging object

   object {
       uuid                ma-log-agent-id;
       datetime            ma-log-event-time;
       code                ma-log-code;
       string              ma-log-description;
   } ma-log-obj;

3.6.  Capability and Status Information

   The MA will hold Capability Information that can be retrieved by a
   Controller.  Capabilities include the interface details available to
   Measurement Tasks and Channels as well as the set of Measurement
   Tasks/Roles that are actually installed or available on the MA.
   Status information includes the times that operations were last
   performed such as contacting the Controller or producing Reports.

   MA Status information model elements:

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   // Main MA Status information object

   object {
       uuid                ma-agent-id;
       urn                 ma-device-id;
       string              ma-hardware;
       string              ma-firmware;
       string              ma-version;
       ma-interface-obj    ma-interfaces<0..*>;

       datetime            ma-last-measurement;
       datetime            ma-last-report;
       datetime            ma-last-instruction;
       datetime            ma-last-configuration;

       [ma-condition-obj    ma-conditions<0..*>;]

       ma-task-capability-obj   ma-supported-tasks<0..*>;
   } ma-status-obj;

   // Additional status conditions

   object {
     string                ma-condition-code;
     string                ma-condition-text;
   } ma-condition-obj

   // Interface information

   object {
       string              ma-interface-name;
       string              ma-interface-type;
      [int                 ma-interface-speed;]  // bps
      [string              ma-link-layer-address;]
      [ip-address          ma-interface-ip-addresses<0..*>];
      [ip-address          ma-interface-gateways<0..*>;]
      [ip-address          ma-interface-dns-servers<0..*>;]
   } ma-interface-obj;

   // Supported tasks/roles

   object {
       string              ma-task-name;
       uri                 ma-task-registry;
       string              ma-task-role;
   } ma-task-capability-obj;

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3.7.  Reporting Information

   At a point in time specified by a Schedule, the MA will execute a
   task or tasks that communicate a set of measurement results to the
   Collector.  Some of these Tasks (notably Reporting Tasks) will
   understand how to transmit task results over a specified Report
   Channel to a Collector.  Where to send the data is defined within the
   Schedule information.

   It should be noted that the output from Tasks does not need to be
   sent to communication Channels.  It can alternatively, or
   additionally, be sent to other Tasks on the MA.  This facilitates
   using a first Measurement Task to control the operation of a later
   Measurement Task (such as first probing available line speed and then
   adjusting the operation of a video testing measurement) and also to
   allow local processing of data to output alarms (e.g. when
   performance drops from earlier levels).  Of course, subsequent Tasks
   also include Tasks that implement the reporting protocol(s) and
   transfer data to one or more Collector(s).

   The report is structured hierarchically to avoid repetition of report
   header and Measurement Task Configuration information.  The report
   starts with the timestamp of the report generation on the MA and
   details about the MA including the optional Measurement Agent ID and
   Group ID (controlled by the Configuration Information).

   No context information, such as line speed or broadband product are
   included within the report header information as this data is
   reported by individual tasks at the time they execute.  Either a
   Measurement Task can report contextual parameters that are relevant
   to that particular measurement, or specific tasks can be used to
   gather a set of contextual and environmental data. at certain times
   independent of the reporting schedule.

   After the report header information the results are reported grouped
   according to different Measurement Task Configurations.  Each Task
   section starts with replicating the Measurement Task Configuration
   information before the result headers (titles for data columns) and
   the result data rows.

   The result row data inlcudes a time for the start of the measurement
   and optionally an end time where the duration also needs to be
   considered in the data analysis.  The result data rows may optionally
   include an indication of the cross-traffic.  Cross traffic is defined
   as the total number of Bytes both upstream and downstream of non-
   measurement traffic passing through the interfaces used by a
   Measurement Task during the measurement period.  The specific
   Measurement Task may also output other environmental measures in

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   addtion to cross-traffic such as CPU utlisation or interface speed.
   The encoding of this information will vary dependent upon the data
   model chosen for the Report Protocol.

   Where the Configuration and Instruction information represent
   information transmitted via the Control Protocol, the Report
   represents the information that is transmitted via the Report
   Protocol.  It is constructed at the time of sending a report and
   represents the inherent structure of the information that is sent to
   the Collector.

   Information model elements:

   // Main Report object with report header information

   object {
       datetime            ma-report-date;
      [uuid                ma-report-agent-id;]
      [string              ma-report-group-id;]
       ma-report-task-obj  ma-report-tasks<0..*>;
   } ma-report-obj;

   // Report task header information

   object {
       ma-task-obj         ma-report-task-config;
       string              ma-report-task-column-labels<0..*>;
       ma-result-row-obj   ma-report-task-rows<0..*>;
   } ma-report-task-obj;

// Report tasks result rows

object {
    datetime            ma-report-result-start-time;
   [datetime            ma-report-result-end-time;]
    string              ma-report-result-conflicting-tasks<0..*>;
   [int                 ma-report-result-cross-traffic;] // Bytes of non-measurement traffic
                                                         // on measurement interface during measurement period
    data                ma-report-result-values<0..*>;
} ma-result-row-obj;

3.8.  Schedules

   A Schedule specifies the execution of a single or repeated series of
   Tasks.  Each Schedule contains basically two elements: a list of
   Tasks to be executed and a timing object for the Schedule.  The
   Schedule states what Tasks to run (with what configuration), how to
   report the results, and when to run the Tasks.

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   Multiple Tasks in the list of a single Measurement Schedule will be
   executed in order with minimal gaps.  Tasks in different Schedules
   can execute in parallel with such conflicts beings reported in the
   Reporting Information.

   As well as specifying which Tasks to execute, the Schedule also
   specifies where to send the data outputs from each Task.  Specifying
   this within the Schedule allows the highest level of flexibility
   since it is even possible to send the output from different
   executions of the same Task to different destinations.  Since a
   single Task may have multiple outputs, the Schedule can independently
   specify which outputs go to which destinations.  For example, a
   Measurement Task might report routine results to a data Reporting
   Task that communicates hourly via the Broadband PPP interface, but
   also outputs emergency conditions via an alarm Reporting Task
   communicating immediately over a GPRS channel.

   The interface options for a Task are either another downstream Task
   or a Channel.  The output of a Task can be sent to another Task.  For
   example a Measurement Task may send its output to a data transfer
   Task that reports the batched data to a Collector at a later time.
   Alternatively the output from a Measurement Task may be fed to an
   alarm processing task that monitors the results of a series of
   Measurement Tasks.

   Only some Tasks will understand how to send/receive data to/from
   Channels using the Reporting/Control protocol.  Any Task that does
   not implement either the Reporting or Control protocol will not have
   any channel interfaces to configure.  Instead results should be
   passed to a Reporting Task that has the appropriate Collector
   specified as a Channel.

   When a task is referenced by a schedule there will be a simultaneous
   definition of which (if any) channels to use and which (if any) other
   downstream tasks to send data to.  Note that task-to-task data
   transfer is always specified in association with the scheduled
   execution of the sending task - there is no need for a corresponding
   input specification for the receiving task.

   Example:  A Schedule references a single Measurement Task
      Configuration for the UDP latency.  It specifies that results are
      to be sent to a Reporting Task.  This Reporting Task is executed
      by a separate Schedule that specifies that it should run hourly at
      5 minutes past the hour.  When run this Reporting Task takes the
      data generated by the UDP latency Task as well as any other data
      to be included in the hourly report and transfers it to the
      Collector over the Report Channel specified within its own
      Schedule.

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   // main Schedule object with Timing and list of Scheduled Tasks

   object {
       string              ma-schedule-name;
       ma-sched-task-obj   ma-schedule-tasks<0..*>;
       ma-timing-obj       ma-schedule-timing;
   } ma-schedule-obj;

// Scheduled Task object with reference (by name string) to Task Configuration to execute and mapping
// to channels and onward tasks

object {
    string                            ma-schedule-task-name;
    [ma-sched-channels-obj            ma-schedule-channels<0..*>;]
    [ma-sched-downstream-tasks-obj    ma-schedule-downstream-tasks<0..*>;]
 } ma-sched-task-obj;

// Selected Task channel interfaces (selected by integer from array defined by the task) can be connected to
// Channels (referenced by name string(s))

object {
    [int                 ma-schedule-channel-interface-selection<0..*>;]  // default: all
    [string              ma-schedule-channel-names<0..*>];
} ma-sched-channels-obj;

// Selected Task outputs to onward tasks (selected by integer from an output array defined by the task) can be sent to
// Task Configurations (referenced by name string(s))

object {
    [int                       ma-schedule-task-output-selection<0..*>;]  // default: all
    [string                    ma-schedule-task-downstream-task-configuration-names<0..*>];
} ma-sched-downstream-tasks-obj;

   Example:  A measurement task has two defined inter-task outputs, one
      for routine measurement results and one for errors during the task
      execution.  These are defined as available outputs by the task and
      are denoted by the integers 1 & 2.  In this example, both outputs
      are sent to the same reporting task called "Hourly reporting
      Task".  This is done by creating a ma-sched-send-to-tasks-obj with
      the output selection as [1,2] and the downstream task
      configuration names as ["Hourly Reporting Task"].

                          Measurement Task
                              Output 1 -------------+--------------> "Hourly Reporting Task"
                              Output 2 ------------/

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3.9.  Channels

   A Channel defines a bi-directional communication channel between the
   MA and a Controller or Collector.  Multiple Channels can be defined
   to enable results to be split or duplicated across different
   Collectors.

   Each Channel contains the details of the remote endpoint (including
   location and security credential information such as the
   certificate).  The timing of when to communicate over a Channel is
   specified within the Schedule.  The certificate can be the digital
   certificate associated to the FQDN in the URL or it can be the
   certificate of the Certification Authority that was used to issue the
   certificate for the FQDN (Fully Qualified Domain Name) of the target
   URL (which will be retrieved later on using a communication protocol
   such as TLS).  In order to establish a secure channel, the MA will
   use it's own security credentials (in the Configuration Information)
   and the given credentials for the individual Channel end-point.

   As with theTask Configurations, each Channel is also given a local
   short name by which it can be referenced from a Schedule.

   Although the same in terms of information, Channels used for
   communication with the Controller are refered to as Control Channels
   whereas Channels to Collectors are refered to as Report Channels.
   Hence Control Channels will be referenced from within the Control
   Schedule, whereas Report Channels will be referenced from within the
   Instruction Schedule.

   Multiple interfaces are also supported.  For example the Controller
   could choose to receive some results over GPRS.  This is especially
   useful when such results indicate the loss of connectivity on a
   different network interface.

   Example:  A Channel using for reporting results may specify that
      results are to be sent to the URL (https://collector.foo.org/
      report/), using the appropriate digital certificate to establish a
      secure channel..

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// Channel object with name string allowing reference from Schedule. Contains channel endpoint target URL and security
// credentials to establish secure channel. Optionally allows interface specification (by interface name string reference)
// and connection when no data is pending for transfer

object {
    string              ma-channel-name;
    url                 ma-channel-target;
    credentials         ma-channel-credentials;
   [string              ma-channel-interface-name;]
} ma-channel-obj;

3.10.  Task Configurations

   Conceptually each Task Configuration defines the parameters of a Task
   that the Measurement Agent (MA) may perform at some point in time.
   It does not by itself actually instruct the MA to perform them at any
   particular time (this is done by a Schedule).  Tasks can be
   Measurement Tasks (i.e. those Tasks actually performing some type of
   passive or active measurement) or any other scheduled activity
   performed by the MA such as transferring information to or from the
   Controller and Collectors.  Other examples of Tasks may include data
   manipulation or processing Tasks conducted on the MA.

   A Measurement Task Configuration is the same in information terms to
   any other Task Configuration.  Both measurement and non-measurement
   Tasks have a registry entry and specified role to enable the MA to
   uniquely identify the Task it should execute and retrieve the schema
   for any parameters that may be passed to the Task.  This registry
   entry is specified as a URI and can therefore bye used to identify
   the Task within a namespace or point to a web or local file location
   for the Task information.  As mentioned previously this entry may be
   used to identify the Measurement Task in a public namespace
   [I-D.bagnulo-ippm-new-registry] .

   Example:  A Measurement Task Configuration may configure a single
      Measurement Task for measuring UDP latency.  The Measurement Task
      Configuration could define the destination port and address for
      the measurement as well as the duration, internal packet timing
      strategy and other parameters (for example a stream for one hour
      and sending one packet every 500 ms).  It may also define the
      output type and possible parameters (for example the output type
      can be the 95th percentile mean) where the measurement task
      accepts such parameters.  It does NOT define when the task starts
      (this is defined by the Schedule element), so it does not by
      itself instruct the MA to actually perform this Measurement Task.

   The Task Configuration will include a local short name for reference
   by a Schedule.  Task Configurations will also contain a registry

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   entry as described above.  In addition the Task can be configured
   through a set of configuration Options.  The nature and number of
   these Options will depend upon the Task and will be resolved through
   the registry parameter.  These options are expressed as name-value
   pairs although the 'value' may be a structured object instead of a
   simple string or numeric value.  The implementation of these name-
   value pairs will vary between data models such as JSON, XML or TR-
   069.

   A parameter that may be present for Reporting Tasks is whether to
   report if there is no measurement result data pending to be
   transferred to the Collector.  In addtion many tasks will also take
   as a parameter which interface to operate over.

   The Task Configuration also contains a suppress-by-default flag that
   specifies the behaviour of a default suppress instruction (that does
   not list explicit tasks or schedules).  If this flag is set to FALSE
   then the Task will not be suppressed.  It should be noted that
   Controller Tasks are not subject to the suppression instruction and
   therefore this flag will be ignored in such cases.

   In addition the Task Configuration may optionally also be given a
   Measurement Cycle ID.  The purpose of this ID is to easily identify a
   set of measurement results that have been produced by Measurement
   Tasks with comparable Options.  This ID could be manually incremented
   or otherwise changed when an Option change is implemented which could
   mean that two sets of results should not be directly compared.

// Task Configuration object with string name to allow reference from Schedule. Contains URI to link to registry or local
// specification of the Task.
// Options allow the configuration of Task parameters (in the form of name-value pairs)

object {
    string              ma-task-name;
    uri                 ma-task-registry-entry;
    string              ma-role;
    name-value-pair     ma-task-options<0..*>;
   [boolean             ma-task-suppress-by-default;] // default: TRUE
   [string              ma-task-cycle-id;]
} ma-task-obj;

3.11.  Timing Information

   The Timing information object used throughout the information models
   can take one of five different forms:

   1.  Periodic.  Specifies a start, end and interval time in
       milliseconds

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   2.  Calendar: Specifies a calendar based pattern - e.g. 22 minutes
       past each hour of the day on weekdays

   3.  One Off: A single instance occurring at a specific time

   4.  Immediate: Should occur as soon as possible

   5.  Startup: Should occur whenever the MA is started (e.g. at device
       startup)

   Optionally each of the options may also specify a randomness that
   should be evaluated and applied separately to each indicated event.
   This randomness parameter defines a uniform interval in milliseconds
   over which the start of the task is delayed from the starting times
   specified by the timing object.

   Both the Periodic and Calendar timing objects allow for a series of
   tasks to be executed.  While both have an optional end time, it is
   best practice to always configure an end time and refresh the
   information periodically to ensure that lost MAs do not continue
   their tasks forever.

   The datetime format used for all elements in the information model
   MUST conform to RFC 3339 [RFC3339] and ISO8601.

// Main Timing object with name string to allow reference by Schedule
// Must be specialised by one of the Timing options.
// Includes optional uniform random spread in ms from start time given by Timing specialisation

object {
   [string              ma-timing-name;]
   union {
       ma-periodic-obj  ma-timing-periodic;
       ma-calendar-obj  ma-timing-calendar;
       ma-one-off-obj   ma-timing-one-off;
       ma-immediate-obj ma-timing-immediate;
       ma-startup-obj   ma-timing-startup;
   }
   [int                 ma-timing-random-spread;]     // milliseconds
} ma-timing-obj;

3.11.1.  Periodic Timing

   Information model elements:

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// Timing specialisation to run a series of Tasks repeated at set intervals

object {
   [datetime            ma-periodic start;]   // default: immediate
   [datetime            ma-periodic-end;]     // default: indefinite
    int                 ma-periodic-interval; // milliseconds
} ma-periodic-obj;

3.11.2.  Calendar Timing

   Calendar Timing supports the routine execution of Measurement Tasks
   at specific times and/or on specific dates.  It can support more
   flexible timing than Periodic Timing since the Measurement Task
   execution does not have to be uniformly spaced.  For example a
   Calendar Timing could support the execution of a Measurement Task
   every hour between 6pm and midnight on weekdays only.

   Calendar Timing is also required to perform measurements at
   meaningful instances in relation to network usage (e.g., at peak
   times).  If the optional timezone offset is not supplied then local
   system time is assumed.  This is essential in some use cases to
   ensure consistent peak-time measurements as well as supporting MA
   devices that may be in an unknown timezone or roam between different
   timezones (but know their own timezone information such as through
   the mobile network).

   Days of week are define using three character strings "Mon", "Tue",
   "Wed", "Thu", "Fri", "Sat", "Sun".

   If a day of the month is specified that does not exist in the month
   (e.g. 29 in Feburary) then those values are ignored.

   Information model elements:

// Timing specialisation to run repeated Tasks at specific times and/or days

object {
   [datetime            ma-calendar-start;] // default: immediate
   [datetime            ma-calendar-end;]   // default: indefinite
   [int                 ma-calendar-months<0..*>;]   // default: 1-12
   [days                ma-calendar-days-of-week<0..*>;] // default: all
   [int                 ma-calendar-days-of-month<0..*>;] // default 1-31
   [int                 ma-calendar-hours<0..*>;]    // default: 0-23
   [int                 ma-calendar-minutes<0..*>;]  // default: 0-59
   [int                 ma-calendar-seconds<0..*>;]  // default: 0-59
   [int                 ma-calendar-timezone-offset;]
                        // default: system timezone offset
} ma-calendar-obj;

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3.11.3.  One-Off Timing

   Information model elements:

   // Timing specialisation to run once at a specified time/date

   object {
       datetime            ma-one-off-time;
   } ma-one-off-obj;

3.11.4.  Immediate Timing

   The immediate timing object has no further information elements.  The
   measurement or report is simply to be done as soon as possible.

   // Timing specialisation to run immediately

   object {
                           // empty
   } ma-immediate-obj;

3.11.5.  Startup Timing

   The immediate timing object has no further information elements.  The
   measurement or report is simply done at MA initiation.

   // Timing specialisation to run at MA startup

   object {
                           // empty
   } ma-startup-obj;

4.  IANA Considerations

   This document makes no request of IANA.

   Note to RFC Editor: this section may be removed on publication as an
   RFC.

5.  Security Considerations

   This Information Model deals with information about the control and
   reporting of the Measurement Agent.  There are broadly two security
   considerations for such an Information Model.  Firstly the
   Information Model has to be sufficient to establish secure
   communication channels to the Controller and Collector such that
   other information can be sent and received securely.  Additionally,
   any mechanisms that the Network Operator or other device

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   administrator employs to pre-configure the MA must also be secure to
   protect unauthorized parties from modifying pre-configuration
   information.  The second consideration is that no mandated
   information items should pose a risk to confidentiality or privacy
   given such secure communication channels.  For this latter reason
   items such as the MA context and MA ID are left optional and can be
   excluded from some deployments.  This would, for example, allow the
   MA to remain anonymous and for information about location or other
   context that might be used to identify or track the MA to be omitted
   or blurred.

6.  Appendix: JSON Example

   In order to give an example of data in the Information Model we need
   to select a data model language.  In this example we have expressed
   the Data Model using JSON as this will be of direct interest to some
   Control and Report Protocols.  The example is broken down into a
   number of different steps that might adhere to the steps within a
   Control and Report Protocol:

   1.  Pre-configuration.

   2.  Configuration

   3.  Capabilities

   4.  Instruction

   5.  Report

   6.  Suppression

   While the pre-configuration is not delivered as part of the Control
   Protocol, the same JSON data model is used for consistency and to aid
   the reader.

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// Pre-Configuration

{
  "ma-config": {
    "ma-agent-id": "550e8400-e29b-41d4-a716-446655440000",
    "ma-control-tasks": [
      {
        "ma-task-name": "Controller configuration",
        "ma-task-registry-entry": "urn:ietf:lmap:control:http_controller_configuration"
      }
    ]
    "ma-control-channels": [
      {
        "ma-channel-name": "Controller channel",
        "ma-channel-target": "http://www.example.com/lmap/controller",
        "ma-channel-credientials": { } // structure of certificate ommitted for brevity
      }
    ]
    "ma-control-schedules": [
      {
        "ma-schedule-name": "pre-configured schedule",
        "ma-schedule-tasks": {
          {
            "ma-schedule-task-name": "Controller configuration",
            "ma-schedule-channels": [
              {
                "ma-schedule-channel-interface-selection": [1],
                "ma-schedule-task-source-channel-names": ["Controller channel"]
              }
            ]
          }
        }
        "ma-schedule-timing": {
          "ma-timing-name": "startup plus up to one hour",
          "ma-timing-startup": {
          }
          "ma-timing-random-spread": "3600000"
        }
      }
    ]
    "ma-credentials": { } // structure of certificate ommitted for brevity
  }
}

   Given the pre-configuration information the MA is able to contact the
   Controller and receive an updated/expanded Configuration.  In this

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   example additional Control Protocol tasks to post Status and
   Capabilities to the Controller and fetch the Instruction are added as
   well as moving the schedule timing for contacting the Controller to
   hourly.

// Configuration

{
  "ma-config": {
    "ma-agent-id": "550e8400-e29b-41d4-a716-446655440000",
    "ma-control-tasks": [
      {
        "ma-task-name": "Controller configuration",
        "ma-task-registry-entry": "urn:ietf:lmap:control:http_controller_configuration"
      },
      {
        "ma-task-name": "Controller status and capabilities",
        "ma-task-registry-entry": "urn:ietf:lmap:control:http_controller_status_and_capabilities"
      },
      {
        "ma-task-name": "Controller instruction",
        "ma-task-registry-entry": "urn:ietf:lmap:control:http_controller_instruction"
      }
    ]
    "ma-control-channels": [
      {
        "ma-channel-name": "Controller instruction",
        "ma-channel-target": "http://www.example.com/lmap/controller",
        "ma-channel-credientials": { } // structure of certificate ommitted for brevity
      }
    ]
    "ma-control-schedules": [
      {
        "ma-schedule-name": "Controller schedule",
        "ma-schedule-tasks": [
          {
            "ma-schedule-task-name": "Controller configuration",
            "ma-schedule-channels": [
              {
                "ma-schedule-channel-interface-selection": [1],
                "ma-schedule-task-source-channel-names": ["Controller channel"]
              }
            ]
          },
          {
            "ma-schedule-task-name": "Controller status and capabilities",
            "ma-schedule-channels": [
              {

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                "ma-schedule-channel-interface-selection": [1],
                "ma-schedule-task-source-channel-names": ["Controller channel"]
              }
            ]
          },
          {
            "ma-schedule-task-name": "Controller instruction",
            "ma-schedule-channels": [
              {
                "ma-schedule-channel-interface-selection": [1],
                "ma-schedule-task-source-channel-names": ["Controller channel"]
              }
            ]
          }
        ]
        "ma-schedule-timing": {
          "ma-timing-name": "hourly randomly",
          "ma-timing-calendar": {
            "ma-calendar-minutes": ["00"],
            "ma-calendar-seconds": ["00"]
          }
          "ma-timing-random-spread": "3600000"
        }
      }
    ]
    "ma-credentials": { } // structure of certificate ommitted for brevity
  }
}

   The above configuration now contacts the Controller randomnly within
   each hour.  The following is an example of the Status and
   Capabilities information that is transferred from the MA to the
   Controller.

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// Status and Capabilities

{
  ma-status-and-capabilities {
    "ma-agent-id": "550e8400-e29b-41d4-a716-446655440000",
    "ma-device-id": "urn:dev:mac:0024befffe804ff1"
    "ma-hardware": "mfr-home-gateway-v10"
    "ma-firmware": "25637748-rev2a"
    "ma-version": "ispa-v1.01"
    "ma-interfaces: [
      {
        "ma-interface-name": "broadband",
        "ma-interface-type": "PPPoE"
      }
    ]
    "ma-last-measurement: "",
    "ma-last-report: "",
    "ma-last-instruction: "",
    "ma-last-configuration: "2014-06-08T22:47:31+00:00",
    "ma-supported-tasks: [
      {
        "ma-task-name": "Controller configuration",
        "ma-task-registry": "urn:ietf:lmap:control:http_controller_configuration"
      },
      {
        "ma-task-name": "Controller status and capabilities",
        "ma-task-registry": "urn:ietf:lmap:control:http_controller_status_and_capabilities"
      },
      {
        "ma-task-name": "Controller instruction",
        "ma-task-registry": "urn:ietf:lmap:control:http_controller_instruction"
      },
      {
        "ma-task-name": "Report",
        "ma-task-registry": "urn:ietf:lmap:report:http_report"
      },
      {
        "ma-task-name": "UDP Latency",
        "ma-task-registry": "urn:ietf:ippm:measurement:UDPLatency-Poisson-XthPercentileMean"
      }
    ]
  }
}

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   After fetching the status and capabilties the Controller issues and
   Instruction to the MA to perform a single UDP latency measurement
   task 4 times a day and to report the results immediately.

// Instruction

{
  "ma-instruction": {
    "ma-instruction-tasks": [
      {
        "ma-task-name": "UDP Latency",
        "ma-task-registry-entry": "urn:ietf:ippm:measurement:UDPLatency-Poisson-XthPercentileMean",
        "ma-task-options": [
          {"name": "X", "value": "99"},
          {"name":"rate", "value": "5"},
          {"name":"duration", "value": "30.000"},
          {"name":"interface", "value": "broadband"},
          {"name":"destination-ip", "value": {"version":"ipv4", "ip-address":"192.168.2.54"}},
          {"name":"destination-port", "value": "50000"},
          {"name":"source-port", "value": "50000"}
        ],
        "ma-task-suppress-by-default": "TRUE"
      },
      {
        "ma-task-name": "Report",
        "ma-task-registry-entry": "urn:ietf:lmap:report:http_report",
        "ma-task-options": [
          {"name": "report-with-no-data", "value": "FALSE"}
        ],
        "ma-task-suppress-by-default": "FALSE"
      }
    ]
    "ma-report-channels": [
      {
        "ma-channel-name": "Collector A",
        "ma-channel-target": "http://www.example2.com/lmap/collector",
        "ma-channel-credientials": { } // structure of certificate ommitted for brevity
      }
    ]
    "ma-instruction-schedules": [
      {
        "ma-schedule-name": "4 times daily test UDP latency and report",
        "ma-schedule-tasks": {
          {
            "ma-schedule-task-name": "UDP Latency",
            "ma-schedule-downstream-tasks": [
              {
                "ma-schedule-task-output-selection": [1],

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                "ma-schedule-task-downstream-task-configuration-names": "Report"
              }
            ]
          },
          {
            "ma-schedule-task-name": "Report",
            "ma-schedule-channels": [
              {
                "ma-schedule-channel-interface-selection": [1],
                "ma-schedule-channel-names": "Collector A"
              }
            ]
          }
        }
        "ma-schedule-timing": {
          "ma-timing-name": "once every 6 hours",
          "ma-timing-calendar": {
            "ma-calendar-hours": ["00", "06", "12", "18"],
            "ma-calendar-minutes": ["00"],
            "ma-calendar-seconds": ["00"]
          }
          "ma-timing-random-spread": "21600000"
        }
      }
    ]
  }
}

   The report task in the Instruction is executed immediately after the
   UDP test and transfers the following data to the Collector.

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// Report

{
  ma-report: {
    "ma-report-date": "2014-06-09T02:30:45+00:00",
    "ma-report-agent-id": "550e8400-e29b-41d4-a716-446655440000",
    "ma-report-tasks": [
      "ma-report-task-config": {
        "ma-task-name": "UDP Latency",
        "ma-task-registry-entry": "urn:ietf:ippm:measurement:UDPLatency-Poisson-XthPercentileMean",
        "ma-task-options": [
          {"name": "X", "value": "99"},
          {"name":"rate", "value": "5"},
          {"name":"duration", "value": "30.000"},
          {"name":"interface", "value": "broadband"},
          {"name":"destination-ip", "value": {"version":"ipv4", "ip-address":"192.168.2.54"}},
          {"name":"destination-port", "value": "50000"},
          {"name":"source-port", "value": "50000"}
        ]
      },
      "ma-report-task-column-labels": ["start-time", "conflicting-tasks", "cross-traffic", "mean", "min", "max"],
      "ma-report-task-rows": [{"2014-06-09T02:30:10+00:00", "", "0", "20.13", "18.3", "24.1"}]
    ]
  }
}

   The Controller decides that there is a problem with the UDP L:atency
   test and issues a Suppression Instruction.  Since the task is marked
   as suppressable by default, simply turning on suppression will stop
   the task being executed in future.

   // Suppression

   {
     "ma-instruction": {
       "ma-suppression": {
          "ma-suppression-enabled": "TRUE"
       {
     }
   }

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7.  Acknowledgements

   The notation was inspired by the notation used in the ALTO protocol
   specification.

   Philip Eardley, Trevor Burbridge, Marcelo Bagnulo and Juergen
   Schoenwaelder work in part on the Leone research project, which
   receives funding from the European Union Seventh Framework Programme
   [FP7/2007-2013] under grant agreement number 317647.

8.  References

8.1.  Normative References

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

   [RFC3339]  Klyne, G., Ed. and C. Newman, "Date and Time on the
              Internet: Timestamps", RFC 3339, July 2002.

8.2.  Informative References

   [I-D.bagnulo-ippm-new-registry]
              Bagnulo, M., Burbridge, T., Crawford, S., Eardley, P., and
              A. Morton, "A registry for commonly used metrics", draft-
              bagnulo-ippm-new-registry-01 (work in progress), July
              2013.

   [I-D.ietf-lmap-framework]
              Eardley, P., Morton, A., Bagnulo, M., Burbridge, T.,
              Aitken, P., and A. Akhter, "A framework for large-scale
              measurement platforms (LMAP)", draft-ietf-lmap-
              framework-03 (work in progress), January 2014.

   [RFC3444]  Pras, A. and J. Schoenwaelder, "On the Difference between
              Information Models and Data Models", RFC 3444, January
              2003.

Authors' Addresses

   Trevor Burbridge
   BT
   Adastral Park, Martlesham Heath
   Ipswich  IP5 3RE
   United Kingdom

   Email: trevor.burbridge@bt.com

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   Philip Eardley
   BT
   Adastral Park, Martlesham Heath
   Ipswich  IP5 3RE
   United Kingdom

   Email: philip.eardley@bt.com

   Marcelo Bagnulo
   Universidad Carlos III de Madrid
   Av. Universidad 30
   Leganes, Madrid  28911
   Spain

   Email: marcelo@it.uc3m.es

   Juergen Schoenwaelder
   Jacobs University Bremen
   Campus Ring 1
   Bremen  28759
   Germany

   Email: j.schoenwaelder@jacobs-university.de

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