Internet DRAFT - draft-ietf-lmap-information-model
draft-ietf-lmap-information-model
Network Working Group T. Burbridge
Internet-Draft P. Eardley
Intended status: Standards Track BT
Expires: October 23, 2017 M. Bagnulo
Universidad Carlos III de Madrid
J. Schoenwaelder
Jacobs University Bremen
April 21, 2017
Information Model for Large-Scale Measurement Platforms (LMAP)
draft-ietf-lmap-information-model-18
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 Measurement Agent 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 Measurement
Agent 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 October 23, 2017.
Burbridge, et al. Expires October 23, 2017 [Page 1]
Internet-Draft LMAP Information Model April 2017
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Notation . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. LMAP Information Model . . . . . . . . . . . . . . . . . . . 6
3.1. Pre-Configuration Information . . . . . . . . . . . . . . 10
3.1.1. Definition of ma-preconfig-obj . . . . . . . . . . . 11
3.2. Configuration Information . . . . . . . . . . . . . . . . 11
3.2.1. Definition of ma-config-obj . . . . . . . . . . . . . 13
3.3. Instruction Information . . . . . . . . . . . . . . . . . 14
3.3.1. Definition of ma-instruction-obj . . . . . . . . . . 16
3.3.2. Definition of ma-suppression-obj . . . . . . . . . . 17
3.4. Logging Information . . . . . . . . . . . . . . . . . . . 18
3.4.1. Definition of ma-log-obj . . . . . . . . . . . . . . 20
3.5. Capability and Status Information . . . . . . . . . . . . 20
3.5.1. Definition of ma-capability-obj . . . . . . . . . . . 20
3.5.2. Definition of ma-capability-task-obj . . . . . . . . 21
3.5.3. Definition of ma-status-obj . . . . . . . . . . . . . 21
3.5.4. Definition of ma-status-schedule-obj . . . . . . . . 22
3.5.5. Definition of ma-status-action-obj . . . . . . . . . 23
3.5.6. Definition of ma-status-suppression-obj . . . . . . . 26
3.5.7. Definition of ma-status-interface-obj . . . . . . . . 26
3.6. Reporting Information . . . . . . . . . . . . . . . . . . 27
3.6.1. Definition of ma-report-obj . . . . . . . . . . . . . 29
3.6.2. Definition of ma-report-result-obj . . . . . . . . . 29
3.6.3. Definition of ma-report-conflict-obj . . . . . . . . 31
3.6.4. Definition of ma-report-table-obj . . . . . . . . . . 32
3.6.5. Definition of ma-report-row-obj . . . . . . . . . . . 32
3.7. Common Objects: Schedules . . . . . . . . . . . . . . . . 32
3.7.1. Definition of ma-schedule-obj . . . . . . . . . . . . 34
3.7.2. Definition of ma-action-obj . . . . . . . . . . . . . 35
3.8. Common Objects: Channels . . . . . . . . . . . . . . . . 36
3.8.1. Definition of ma-channel-obj . . . . . . . . . . . . 37
Burbridge, et al. Expires October 23, 2017 [Page 2]
Internet-Draft LMAP Information Model April 2017
3.9. Common Objects: Task Configurations . . . . . . . . . . . 37
3.9.1. Definition of ma-task-obj . . . . . . . . . . . . . . 39
3.9.2. Definition of ma-option-obj . . . . . . . . . . . . . 39
3.10. Common Objects: Registry Information . . . . . . . . . . 40
3.10.1. Definition of ma-registry-obj . . . . . . . . . . . 40
3.11. Common Objects: Event Information . . . . . . . . . . . . 40
3.11.1. Definition of ma-event-obj . . . . . . . . . . . . . 41
3.11.2. Definition of ma-periodic-obj . . . . . . . . . . . 43
3.11.3. Definition of ma-calendar-obj . . . . . . . . . . . 43
3.11.4. Definition of ma-one-off-obj . . . . . . . . . . . . 45
3.11.5. Definition of ma-immediate-obj . . . . . . . . . . . 46
3.11.6. Definition of ma-startup-obj . . . . . . . . . . . . 46
3.11.7. Definition of ma-controller-lost-obj . . . . . . . . 46
3.11.8. Definition of ma-controller-connected-obj . . . . . 46
4. Example Execution . . . . . . . . . . . . . . . . . . . . . . 47
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 48
6. Security Considerations . . . . . . . . . . . . . . . . . . . 49
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 49
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 50
8.1. Normative References . . . . . . . . . . . . . . . . . . 50
8.2. Informative References . . . . . . . . . . . . . . . . . 50
Appendix A. Change History . . . . . . . . . . . . . . . . . . . 51
A.1. Non-editorial changes since -17 . . . . . . . . . . . . . 51
A.2. Non-editorial changes since -16 . . . . . . . . . . . . . 51
A.3. Non-editorial changes since -15 . . . . . . . . . . . . . 51
A.4. Non-editorial changes since -14 . . . . . . . . . . . . . 51
A.5. Non-editorial changes since -13 . . . . . . . . . . . . . 52
A.6. Non-editorial changes since -12 . . . . . . . . . . . . . 52
A.7. Non-editorial changes since -11 . . . . . . . . . . . . . 52
A.8. Non-editorial changes since -10 . . . . . . . . . . . . . 52
A.9. Non-editorial changes since -09 . . . . . . . . . . . . . 52
A.10. Non-editorial changes since -08 . . . . . . . . . . . . . 53
A.11. Non-editorial changes since -07 . . . . . . . . . . . . . 53
A.12. Non-editorial changes since -06 . . . . . . . . . . . . . 53
A.13. Non-editorial changes since -05 . . . . . . . . . . . . . 54
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 54
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. A typical use case is the execution of
broadband measurements [RFC7536]. 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
Burbridge, et al. Expires October 23, 2017 [Page 3]
Internet-Draft LMAP Information Model April 2017
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-scale measurement
platform as used in this document is described in detail in
[RFC7594].
A large-scale measurement platform involves basically three types of
protocols, namely, a Control protocol (or protocols) between a
Controller and the MAs, a Report protocol (or protocols) 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 a Controller.
This document defines the information model for both Control and the
Report protocols along with pre-configuration information that is
required on the MA 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 Information Model 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). A YANG data model implementing the information model can be
found in [I-D.ietf-lmap-yang].
The definition of an Information Model serves a number of purposes:
1. To guide the standardisation of one or more Control and Report
protocols and data models
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
Burbridge, et al. Expires October 23, 2017 [Page 4]
Internet-Draft LMAP Information Model April 2017
4. To enable existing protocols and data models to be assessed for
their suitability as part of a large-scale measurement system
2. Notation
This document uses a programming language-like notation to define the
properties of the objects of the information model. An optional
property is enclosed by square brackets, [ ], and a list property 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.
The object definitions use a couple of base types that are defined as
follows:
int A type representing signed or unsigned integer numbers.
This information model does not define a precision nor
does it make a distinction between signed and unsigned
number ranges. This type is also used to represent
enumerations.
boolean A type representing a boolean value.
string A type representing a human-readable string consisting of
a (possibly restricted) subset of Unicode and ISO/IEC
10646 [ISO.10646] characters.
datetime A type representing a date and time using the Gregorian
calendar. The datetime format MUST conform to RFC 3339
[RFC3339].
uuid A type representing Universally Unique IDentifier (UUID(
as defined in RFC 4122 [RFC4122]. The UUID values are
expected to be unique within an installation of a large-
scale measurement system.
uri A type representing a Uniform Resource Identifier as
defined in STD 66 [RFC3986].
ip-address A type representing an IP address. This type supports
both IPv4 and IPv6 addresses.
counter A non-negative integer that monotonically increases.
Counters may have discontinuities and they are not
expected to persist across restarts.
credentials An opaque type representing credentials needed by a
cryptographic mechanism to secure communication. Data
Burbridge, et al. Expires October 23, 2017 [Page 5]
Internet-Draft LMAP Information Model April 2017
models must expand this opaque type as needed and
required by the security protocols utilized.
data An opaque type representing data obtained from
measurements.
Names of objects are generally assumed to be unique within an
implementation.
3. LMAP Information Model
The information described herein relates to the information stored,
received or transmitted by a Measurement Agent as described within
the LMAP framework [RFC7594]. As such, some subsets of this
information model are applicable to the measurement Controller,
Collector and any device management system that pre-configures 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.
The information model is divided into six aspects. 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.
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 Measurement
Tasks it 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 Measurement 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 Event and Timing information. It also includes Task
Suppression information that is used to over-ride normal Task
execution.
Burbridge, et al. Expires October 23, 2017 [Page 6]
Internet-Draft LMAP Information Model April 2017
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 granularity of data transmitted in each operation of the Control
and Report Protocols is not dictated by the Information Model. For
example, the Instruction object may be delivered in a single
operation. Alternatively, Schedules and Task Configurations may be
separated or even each Schedule/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 previously 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 modeled by the six aspects of the information model
is supported by a number of common information objects. These
objects are also described later in this document and comprise of:
a. Schedules. A set of Schedules tells the MA to execute Actions.
An Action of a Schedule leads to the execution of a Task.
Without a Schedule no Task (including measurements or reporting
Burbridge, et al. Expires October 23, 2017 [Page 7]
Internet-Draft LMAP Information Model April 2017
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. A specific Schedule
can only be active once. Attempts to start a Schedule while the
same Schedule is still running will fail.
b. 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.
c. Task Configurations. A set of Task Configurations is used to
configure the Tasks that are run by the MA. This includes the
registry entries for the Task and any configuration parameters,
represented as Task Options. Task Configurations are referenced
from a Schedule in order to specify what Tasks the MA should
execute.
d. Events. A set of Event objects that can be referenced from the
Schedules. Each Schedule always references exactly one Event
object that determines when the schedule is executed. An Event
object specifies either a singleton or series of events that
indicate when Tasks should be executed. A commonly used kind of
Event objects are Timing objects. For Event objects specifying a
series of events, it is generally a good idea to configure an end
time and to refresh the end time as needed to ensure that MAs
that loose connectivity to their controller do not continue
executing Schedules forever.
Figure 1 illustrates the structure in which these common information
objects are referenced. The references are achieved by each object
(Task Configuration, Event) being given a short textual name that is
used by other objects. The objects shown in parenthesis are part of
the internal object structure of a Schedule. Channels are not shown
in the diagram since they are only used as an option by selected Task
Configurations but are similarly referenced using a short text name.
Burbridge, et al. Expires October 23, 2017 [Page 8]
Internet-Draft LMAP Information Model April 2017
Schedule
|-- triggered by --> Event
|
|-- executes --> Action 1
| |-- using --> Task Configuration
| |
| `-- feeding to --> Destination Schedule
:
:
`-- executes --> Action N
|-- using --> Task Configuration
|
`-- feeding to --> Destination Schedule
Figure 1: Relationship between Schedules, Events, Actions, Task
Configurations, and Destination Schedules
The primary function of an MA is to execute Schedules. A Schedule,
which is triggered by an Event, executes a number of Actions. An
Action refers to a Configured Task and it may feed results to a
Destination Schedule. Both, Actions and Configured Tasks can provide
parameters, represented as Action Options and Task Options.
Tasks can implement a variety of different functions. 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 measure some aspect of network performance or
traffic. They may also capture contextual information from the
MA device or network interfaces such as the device type or
interface speed.
2. Data Transfer Tasks support the communication with a Controller
and Collectors:
A. Reporting Tasks report the results of Measurement Tasks to
Collectors
B. Control Task(s) implement the Control Protocol and
communicate with the Controller.
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
Burbridge, et al. Expires October 23, 2017 [Page 9]
Internet-Draft LMAP Information Model April 2017
Figure 1 indicates that Actions can produce data that is fed into
Destination Schedules. This can by used by Actions implementing
Measurement Tasks to feed measurement results to a Schedule that
triggers Actions implementing Reporting Tasks. Data fed to a
Destination Schedule is consumed by the first Action of the
Destination Schedule if the Destination Schedule is using sequential
or pipelined execution mode and it is consumed by all Actions of the
Destination Schedule if the Destination Schedule is using parallel
execution mode.
3.1. 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. Some of the Pre-
Configuration Information elements are repeated in the Configuration
Information in order to allow an LMAP Controller to update these
items. The pre-configuration information also contains some elements
that are not under the control of the LMAP framework (such as the
device identifier and device security credentials).
This Pre-Configuration Information needs to include a URL of the
initial Controller from where configuration information can be
communicated 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
transferred). The timing is represented as an Event that invokes 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 and utilises the
Channel information. The Task(s) may take additional parameters, as
defined by a Task Configuration.
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.
Burbridge, et al. Expires October 23, 2017 [Page 10]
Internet-Draft LMAP Information Model April 2017
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 first 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 URI. If the MA ID is not provided at this stage, then
it must be provided by the Controller during Configuration.
3.1.1. Definition of ma-preconfig-obj
object {
[uuid ma-preconfig-agent-id;]
ma-task-obj ma-preconfig-control-tasks<1..*>;
ma-channel-obj ma-preconfig-control-channels<1..*>;
ma-schedule-obj ma-preconfig-control-schedules<1..*>;
[uri ma-preconfig-device-id;]
credentials ma-preconfig-credentials;
} ma-preconfig-obj;
The ma-preconfig-obj describes information that needs to be available
to the MA in order to bootstrap communication with a Controller. The
ma-preconfig-obj consists of the following elements:
ma-preconfig-agent-id: An optional uuid uniquely identifying
the measurement agent.
ma-preconfig-control-tasks: An unordered set of task objects.
ma-preconfig-control-channels: An unordered set of channel objects.
ma-preconfig-control-schedules: An unordered set of scheduling
objects.
ma-preconfig-device-id: An optional identifier for the
device.
ma-preconfig-credentials: The security credentials used by the
measurement agent.
3.2. 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
Burbridge, et al. Expires October 23, 2017 [Page 11]
Internet-Draft LMAP Information Model April 2017
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
over-ridden 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 over-ridden with one more relevant to
routine communications between the MA and the Controller.
While some Control protocols may only use a single Schedule, other
protocols may use 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. Additional flags control whether the
MA ID or the Group ID are included in Reports. The reporting of a
Group ID without the MA ID may allow 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 seconds
since the last communication with the Controller after which an Event
is generated that can trigger the suspension of Instruction
Schedules. The appropriate value 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 Information is persistent upon device reset
or power cycle, the persistency of the Configuration Information may
be device dependent. Some devices may revert back to their pre-
Burbridge, et al. Expires October 23, 2017 [Page 12]
Internet-Draft LMAP Information Model April 2017
configuration state upon reboot or factory reset, while other devices
may store all Configuration and Instruction information in persistent
storage. A Controller can check whether an MA has the latest
Configuration and Instruction information by examining the Capability
and Status information for the MA.
3.2.1. Definition of ma-config-obj
object {
uuid ma-config-agent-id;
ma-task-obj ma-config-control-tasks<1..*>;
ma-channel-obj ma-config-control-channels<1..*>;
ma-schedule-obj ma-config-control-schedules<1..*>;
credentials ma-config-credentials;
[string ma-config-group-id;]
[string ma-config-measurement-point;]
[boolean ma-config-report-agent-id;]
[boolean ma-config-report-group-id;]
[boolean ma-config-report-measurement-point;]
[int ma-config-controller-timeout;]
} ma-config-obj;
The ma-config-obj consists of the following elements:
ma-config-agent-id: A uuid uniquely identifying the
measurement agent.
ma-config-control-tasks: An unordered set of task objects.
ma-config-control-channels: An unordered set of channel
objects.
ma-config-control-schedules: An unordered set of scheduling
objects.
ma-config-credentials: The security credentials used by
the measurement agent.
ma-config-group-id: An optional identifier of the
group of measurement agents this
measurement agent belongs to.
ma-config-measurement-point: An optional identifier for the
measurement point indicating
where the measurement agent is
located on a path (see [RFC7398]
for further details).
Burbridge, et al. Expires October 23, 2017 [Page 13]
Internet-Draft LMAP Information Model April 2017
ma-config-report-agent-id: An optional flag indicating
whether the agent identifier (ma-
config-agent-id) is included in
reports. The default value is
true.
ma-config-report-group-id: An optional flag indicating
whether the group identifier (ma-
config-group-id) is included in
reports. The default value is
false.
ma-config-report-measurement-point: An optional flag indicating
whether the measurement point
(ma-config-measurement-point)
should be included in reports.
The default value is false.
ma-config-controller-timeout: A timer is started after each
successful contact with a
controller. When the timer
reaches the controller-timeout
(measured in seconds), an event
is raised indicating that
connectivity to the controller
has been lost (see ma-controller-
lost-obj).
3.3. 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 execution 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 included by reference in the
Actions of Instruction Schedules that specify when to execute them.
The results can be communicated to other Schedules or a Task may
implement a Reporting Protocol and communicate results over Report
Channels. Suppression is used to temporarily stop the execution of
Burbridge, et al. Expires October 23, 2017 [Page 14]
Internet-Draft LMAP Information Model April 2017
new Tasks as specified by the Instruction Schedules (and optionally
to stop ongoing Tasks).
A Task Configuration is used to configure the mandatory and 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 a 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 be used by multiple (reporting)
Task Configurations to transfer data to the same Collector. A single
Reporting Task Configuration can also be included in multiple
Schedules. 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 Actions to execute according to a
given triggering Event. An Action extends a Configured Task with
additional specific parameters. An Event can trigger the execution
of a single Action or it can trigger a repeated series of Actions.
The Schedule also specifies how to link Tasks output data to other
Schedules.
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.
It should be noted that control schedules 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 (i.e., within the Configuration information).
Burbridge, et al. Expires October 23, 2017 [Page 15]
Internet-Draft LMAP Information Model April 2017
A single Suppression object is able to enable/disable a set of
Instruction Tasks that are tagged for suppression. This enables fine
grained control on which Tasks are suppressed. Suppression of both
matching Actions and Measurement Schedules is supported. Support for
disabling specific Actions allows malfunctioning or mis-configured
Tasks or Actions that have an impact on a particular part of the
network infrastructure (e.g., a particular Measurement Peer) to be
targeted. 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.
Suppression stops new Tasks from executing. In addition, 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 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
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.
3.3.1. Definition of ma-instruction-obj
object {
ma-task-obj ma-instruction-tasks<0..*>;
ma-channel-obj ma-instruction-channels<0..*>;
ma-schedule-obj ma-instruction-schedules<0..*>;
[ma-suppression-obj ma-instruction-suppressions<0..*>;]
} ma-instruction-obj;
An ma-instruction-obj consists of the following elements:
ma-instruction-tasks: A possibly empty unordered set of task
objects.
Burbridge, et al. Expires October 23, 2017 [Page 16]
Internet-Draft LMAP Information Model April 2017
ma-instruction-channels: A possibly empty unordered set of
channel objects.
ma-instruction-schedules: A possibly empty unordered set of
schedule objects.
ma-instruction-suppressions: An optional possibly empty unordered
set of suppression objects.
3.3.2. Definition of ma-suppression-obj
object {
string ma-suppression-name;
[ma-event-obj ma-suppression-start;]
[ma-event-obj ma-suppression-end;]
[string ma-suppression-match<0..*>;]
[boolean ma-suppression-stop-running;]
} ma-suppression-obj;
The ma-suppression-obj controls the suppression of schedules or
actions and consists of the following elements:
ma-suppression-name: A name uniquely identifying a
suppression.
ma-suppression-start: The optional event indicating when
suppression starts. If not present,
the suppression starts immediately,
i.e., as if the value would be
'immediate'.
ma-suppression-end: The optional event indicating when
suppression ends. If not present, the
suppression does not have a defined
end, i.e., the suppression remains for
an indefinite period of time.
ma-suppression-match: An optional and possibly empty
unordered set of match patterns. The
suppression will apply to all schedules
(and their actions) that have a
matching value in their ma-schedule-
suppression-tags and all actions that
have a matching value in their ma-
action-suppression-tags. Pattern
matching is done using glob style
pattern (see below).
Burbridge, et al. Expires October 23, 2017 [Page 17]
Internet-Draft LMAP Information Model April 2017
ma-suppression-stop-running: An optional boolean indicating whether
suppression will stop any running
matching schedules or actions. The
default value for this boolean is
false.
Glob style pattern matching is following POSIX.2 fnmatch() [POSIX.2]
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]).
3.4. 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 in exactly the same manner as scheduling 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 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:
Burbridge, et al. Expires October 23, 2017 [Page 18]
Internet-Draft LMAP Information Model April 2017
* "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:
* "Device 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.
Burbridge, et al. Expires October 23, 2017 [Page 19]
Internet-Draft LMAP Information Model April 2017
3.4.1. Definition of ma-log-obj
object {
uuid ma-log-agent-id;
datetime ma-log-event-time;
int ma-log-code;
string ma-log-description;
} ma-log-obj;
The ma-log-obj models the generic aspects of a logging object and
consists of the following elements:
ma-log-agent-id: A uuid uniquely identifying the measurement
agent.
ma-log-event-time: The date and time of the event reported in
the logging object.
ma-log-code: A machine readable code describing the
event.
ma-log-description: A human readable description of the event.
3.5. Capability and Status Information
The MA will hold Capability Information that can be retrieved by a
Controller. Capabilities include the device interface details
available to Measurement Tasks as well as the set of Measurement
Tasks/Roles (specified by registry entries) 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.
3.5.1. Definition of ma-capability-obj
object {
string ma-capability-hardware;
string ma-capability-firmware;
string ma-capability-version;
[string ma-capability-tags<0..*>;]
[ma-capability-task-obj ma-capability-tasks<0..*>;]
} ma-capability-obj;
The ma-capability-obj provides information about the capabilities of
the measurement agent and consists of the following elements:
ma-capability-hardware: A description of the hardware of the device
the measurement agent is running on.
Burbridge, et al. Expires October 23, 2017 [Page 20]
Internet-Draft LMAP Information Model April 2017
ma-capability-firmware: A description of the firmware of the device
the measurement agent is running on.
ma-capability-version: The version of the measurement agent.
ma-capability-tags: An optional unordered set of tags that
provide additional information about the
capabilities of the measurement agent.
ma-capability-tasks: An optional unordered set of capability
objects for each supported task.
3.5.2. Definition of ma-capability-task-obj
object {
string ma-capability-task-name;
ma-registry-obj ma-capability-task-functions<0..*>;
string ma-capability-task-version;
} ma-capability-task-obj;
The ma-capability-task-obj provides information about the capability
of a task and consists of the following elements:
ma-capability-task-name: A name uniquely identifying a task.
ma-capability-task-functions: A possibly empty unordered set of
registry entries identifying
functions this task implements.
ma-capability-task-version: The version of the measurement task.
3.5.3. Definition of ma-status-obj
object {
uuid ma-status-agent-id;
[uri ma-status-device-id;]
datetime ma-status-last-started;
ma-status-interface-obj ma-status-interfaces<0..*>;
[ma-status-schedule-obj ma-status-schedules<0..*>;]
[ma-status-suppression-obj ma-status-suppressions<0..*>;]
} ma-status-obj;
The ma-status-obj provides status information about the measurement
agent and consists of the following elements:
ma-status-agent-id: A uuid uniquely identifying the measurement
agent.
Burbridge, et al. Expires October 23, 2017 [Page 21]
Internet-Draft LMAP Information Model April 2017
ma-status-device-id: A URI identifying the device.
ma-status-last-started: The date and time the measurement agent
last started.
ma-status-interfaces: An unordered set of network interfaces
available on the device.
ma-status-schedules: An optional unordered set of status objects
for each schedule.
ma-status-suppressions: An optional unordered set of status objects
for each suppression.
3.5.4. Definition of ma-status-schedule-obj
object {
string ma-status-schedule-name;
string ma-status-schedule-state;
int ma-status-schedule-storage;
counter ma-status-schedule-invocations;
counter ma-status-schedule-suppressions;
counter ma-status-schedule-overlaps;
counter ma-status-schedule-failures;
datetime ma-status-schedule-last-invocation;
[ma-status-action-obj ma-status-schedule-actions<0..*>;]
} ma-status-schedule-obj;
The ma-status-schedule-obj provides status information about the
status of a schedule and consists of the following elements:
ma-status-schedule-name: The name of the schedule this
status object refers to.
ma-status-schedule-state: The state of the schedule. The
value 'enabled' indicates that
the schedule is currently
enabled. The value 'suppressed'
indicates that the schedule is
currently suppressed. The value
'disabled' indicates that the
schedule is currently disabled.
The value 'running' indicates
that the schedule is currently
running.
ma-status-schedule-storage: The amount of secondary storage
(e.g., allocated in a file
Burbridge, et al. Expires October 23, 2017 [Page 22]
Internet-Draft LMAP Information Model April 2017
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. Data
models should use a 64-bit
integer type.
ma-status-schedule-invocations 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.
ma-status-schedule-suppressions Number of suppressed executions
of this schedule.
ma-status-schedule-overlaps Number of executions prevented
due to overlaps with a previous
invocation of this schedule.
ma-status-schedule-failures Number of failed executions of
this schedule. A failed
execution is an execution where
at least one action failed.
ma-status-schedule-last-invocation: The date and time of the last
invocation of this schedule.
ma-status-schedule-actions: An optional ordered list of
status objects for each action of
the schedule.
3.5.5. Definition of ma-status-action-obj
Burbridge, et al. Expires October 23, 2017 [Page 23]
Internet-Draft LMAP Information Model April 2017
object {
string ma-status-action-name;
string ma-status-action-state;
int ma-status-action-storage;
counter ma-status-action-invocations;
counter ma-status-action-suppressions;
counter ma-status-action-overlaps;
counter ma-status-action-failures;
datetime ma-status-action-last-invocation;
datetime ma-status-action-last-completion;
int ma-status-action-last-status;
string ma-status-action-last-message;
datetime ma-status-action-last-failed-completion;
int ma-status-action-last-failed-status;
string ma-status-action-last-failed-message;
} ma-status-action-obj;
The ma-status-action-obj provides status information about an action
of a schedule and consists of the following elements:
ma-status-action-name: The name of the action of a
schedule this status object
refers to.
ma-status-action-state: The state of the action.
The value 'enabled'
indicates that the action is
currently enabled. The
value 'suppressed' indicates
that the action is currently
suppressed. The value
'disabled' indicates that
the action is currently
disabled. The value
'running' indicates that the
action is currently running.
ma-status-action-storage: The amount of secondary
storage (e.g., allocated in
a file system) holding
temporary data allocated to
the action in bytes. This
object reports the amount of
allocated physical storage
and not the storage used by
logical data records. Data
models should use a 64-bit
integer type.
Burbridge, et al. Expires October 23, 2017 [Page 24]
Internet-Draft LMAP Information Model April 2017
ma-status-action-invocations 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.
ma-status-action-suppressions Number of suppressed
executions of this action.
ma-status-action-overlaps Number of executions
prevented due to overlaps
with a previous invocation
of this action.
ma-status-action-failures Number of failed executions
of this action.
ma-status-action-last-invocation: The date and time of the
last invocation of this
action.
ma-status-action-last-completion: The date and time of the
last completion of this
action.
ma-status-action-last-status: The status code returned by
the last execution of this
action.
ma-status-action-last-message: The status message produced
by the last execution of
this action.
ma-status-action-last-failed-completion: The date and time of the
last failed completion of
this action.
ma-status-action-last-failed-status: The status code returned by
the last failed execution of
this action.
ma-status-action-last-failed-message: The status message produced
by the last failed execution
of this action.
Burbridge, et al. Expires October 23, 2017 [Page 25]
Internet-Draft LMAP Information Model April 2017
3.5.6. Definition of ma-status-suppression-obj
object {
string ma-status-suppression-name;
string ma-status-suppression-state;
} ma-status-suppression-obj;
The ma-status-suppression-obj provides status information about that
status of a suppression and consists of the following elements:
ma-status-suppression-name: The name of the suppression this status
object refers to.
ma-status-suppression-state: The state of the suppression. The
value 'enabled' indicates that the
suppression is currently enabled. The
value 'active indicates that the
suppression is currently active. The
value 'disabled' indicates that the
suppression is currently disabled.
3.5.7. Definition of ma-status-interface-obj
object {
string ma-status-interface-name;
string ma-status-interface-type;
[int ma-status-interface-speed;]
[string ma-status-interface-link-layer-address;]
[ip-address ma-status-interface-ip-addresses<0..*>;]
[ip-address ma-status-interface-gateways<0..*>;]
[ip-address ma-status-interface-dns-servers<0..*>;]
} ma-status-interface-obj;
The ma-status-interface-obj provides status information about network
interfaces and consists of the following elements:
ma-status-interface-name: A name uniquely identifying a
network interface.
ma-status-interface-type: The type of the network
interface.
ma-status-interface-speed: An optional indication of the
speed of the interface
(measured in bits-per-
second).
Burbridge, et al. Expires October 23, 2017 [Page 26]
Internet-Draft LMAP Information Model April 2017
ma-status-interface-link-layer-address: An optional link-layer
address of the interface.
ma-status-interface-ip-addresses: An optional ordered list of
IP addresses assigned to the
interface.
ma-status-interface-gateways: An optional ordered list of
gateways assigned to the
interface.
ma-status-interface-dns-servers: An optional ordered list of
DNS servers assigned to the
interface.
3.6. Reporting Information
At a point in time specified by a Schedule, the MA will execute tasks
that communicate a set of measurement results to the Collector.
These Reporting Tasks will be configured to transmit task results
over a specified Report Channel to a Collector.
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 generated by a Reporting Task 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).
Much of the report Information is optional and will depend on the
implementation of the Reporting Task and any parameters defined in
the Task Configuration for the Reporting Task. For example some
Reporting Tasks may choose not to include the Measurement Task
Configuration or Action parameters, while others may do so dependent
on the Controller setting a configurable parameter in the Task
Configuration.
Burbridge, et al. Expires October 23, 2017 [Page 27]
Internet-Draft LMAP Information Model April 2017
It is possible for a Reporting Task to send just the Report header
(datetime and optional agent ID and/or Group ID) if no measurement
data is available. Whether to send such empty reports again is
dependent on the implementation of the Reporting Task and potential
Task Configuration parameter.
The handling of measurement data on the MA before generating a Report
and transfer from the MA to the Collector is dependent on the
implementation of the device, MA and/or scheduled Tasks and not
defined by the LMAP standards. Such decisions may include limits to
the measurement data storage and what to do when such available
storage becomes depleted. It is generally suggested that
implementations running out of storage stop executing new measurement
tasks and retain old measurement data.
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 optionally starts with replicating the Measurement Task
Configuration information before the result headers (titles for data
columns) and the result data rows. The Options reported are those
used for the scheduled execution of the Measurement Task and
therefore include the Options specified in the Task Configuration as
well as additional Options specified in the Action. The Action
Options are appended to the Task Configuration Options in exactly the
same order as they were provided to the Task during execution.
The result row data includes 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.
Some Measurement Tasks may optionally include an indication of the
cross-traffic although the definition of cross-traffic is left up to
each individual Measurement Task. Some Measurement Tasks may also
output other environmental measures in addition to cross-traffic such
as CPU utlilisation or interface speed.
Whereas 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
Burbridge, et al. Expires October 23, 2017 [Page 28]
Internet-Draft LMAP Information Model April 2017
represents the inherent structure of the information that is sent to
the Collector.
3.6.1. Definition of ma-report-obj
object {
datetime ma-report-date;
[uuid ma-report-agent-id;]
[string ma-report-group-id;]
[string ma-report-measurement-point;]
[ma-report-result-obj ma-report-results<0..*>;]
} ma-report-obj;
The ma-report-obj provides the meta-data of a single report and
consists of the following elements:
ma-report-date: The date and time when the report was
sent to a collector.
ma-report-agent-id: An optional uuid uniquely identifying
the measurement agent.
ma-report-group-id: An optional identifier of the group of
measurement agents this measurement
agent belongs to.
ma-report-measurement-point: An optional identifier for the
measurement point indicating where the
measurement agent is located on a path
(see [RFC7398] for further details).
ma-report-results: An optional and possibly empty
unordered set of result objects.
3.6.2. Definition of ma-report-result-obj
Burbridge, et al. Expires October 23, 2017 [Page 29]
Internet-Draft LMAP Information Model April 2017
object {
string ma-report-result-schedule-name;
string ma-report-result-action-name;
string ma-report-result-task-name;
[ma-option-obj ma-report-result-options<0..*>;]
[string ma-report-result-tags<0..*>;]
datetime ma-report-result-event-time;
datetime ma-report-result-start-time;
[datetime ma-report-result-end-time;]
[string ma-report-result-cycle-number;]
int ma-report-result-status;
[ma-report-conflict-obj ma-report-result-conflicts<0..*>;]
[ma-report-table-obj ma-report-result-tables<0..*>;]
} ma-report-result-obj;
The ma-report-result-obj provides the meta-data of a result report of
a single executed action. It consists of the following elements:
ma-report-result-schedule-name: The name of the schedule that
produced the result.
ma-report-result-action-name: The name of the action in the
schedule that produced the result.
ma-report-result-task-name: The name of the task that produced
the result.
ma-report-result-options: An optional ordered joined list of
options provided by the task object
and the action object when the action
was started.
ma-report-result-tags: An optional unordered set of tags.
This is the joined set of tags
provided by the task object and the
action object and schedule object
when the action was started.
ma-report-result-event-time: 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.
ma-report-result-start-time: The date and time of the start of the
action that produced the reported
result values.
Burbridge, et al. Expires October 23, 2017 [Page 30]
Internet-Draft LMAP Information Model April 2017
ma-report-result-end-time: An optional date and time indicating
when the action finished.
ma-report-result-cycle-number: An optional cycle number derived from
ma-report-result-event-time. It is
the time closest to ma-report-result-
event-time that is a multiple of the
ma-event-cycle-interval of the event
that triggered the execution of the
schedule. The value is only present
in an ma-report-result-obj if the
event that triggered the execution of
the schedule has a defined ma-event-
cycle-interval. The cycle number is
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).
ma-report-result-status: The status code returned by the
execution of the action.
ma-report-result-conflicts: A possibly empty set of conflict
actions that might have impacted the
measurement results being reported.
ma-report-result-tables: An optional and possibly empty
unordered set of result tables.
3.6.3. Definition of ma-report-conflict-obj
object {
string ma-report-conflict-schedule-name;
string ma-report-conflict-action-name;
string ma-report-conflict-task-name;
} ma-report-conflict-obj;
The ma-report-conflict-obj provides the information about conflicting
action that might have impacted the measurement results. It consists
of the following elements:
ma-report-result-schedule-name: The name of the schedule that may
have impacted the result.
Burbridge, et al. Expires October 23, 2017 [Page 31]
Internet-Draft LMAP Information Model April 2017
ma-report-result-action-name: The name of the action in the
schedule that may have impacted the
result.
ma-report-result-task-name: The name of the task that may have
impacted the result.
3.6.4. Definition of ma-report-table-obj
object {
[ma-registry-obj ma-report-table-functions<0..*>;]
[string] ma-report-table-column-labels<0..*>;]
[ma-report-row-obj ma-report-table-rows<0..*>;]
} ma-report-table-obj;
The ma-report-table-obj represents a result table and consists of the
following elements:
ma-report-table-functions: An optional and possibly empty
unordered set of registry entries
identifying the functions for which
results that are reported.
ma-report-table-column-labels: An optional and possibly empty
ordered list of column labels.
ma-report-table-rows: A possibly empty ordered list of
result rows.
3.6.5. Definition of ma-report-row-obj
object {
data ma-report-row-values<0..*>;
} ma-report-row-obj;
The ma-report-row-obj represents a result row and consists of the
following elements:
ma-report-row-values: A possibly empty ordered list of result
values. When present, it contains an
ordered list of values that align to the
set of column labels for the report.
3.7. Common Objects: Schedules
A Schedule specifies the execution of a single or repeated series of
Actions. An Action extends a Configured Task with additional
specific parameters. Each Schedule contains basically two elements:
Burbridge, et al. Expires October 23, 2017 [Page 32]
Internet-Draft LMAP Information Model April 2017
an ordered list of Actions to be executed and an Event object
triggering the execution of the Schedule. The Schedule states what
Actions to run (with what configuration) and when to run the Actions.
A Schedule may optionally have an Event that stops the execution of
the Schedule or a maximum duration after which a schedule is stopped.
Multiple Actions contained as an ordered list of a single Measurement
Schedule will be executed according to the execution mode of the
Schedule. In sequential mode, Actions will be executed sequentially
and in parallel mode, all Actions will be executed concurrently. In
pipelined mode, data produced by one Action is passed to the
subsequent Action. Actions contained in different Schedules execute
in parallel with such conflicts being reported in the Reporting
Information where necessary. If two or more Schedules have the same
start time, then the two will execute in parallel. There is no
mechanism to prioritise one schedule over another or to mutex
scheduled tasks.
As well as specifying which Actions to execute, the Schedule also
specifies how to link the data outputs from each Action to other
Schedules. 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 Configuration to different
destinations. A single Task producing multiple different outputs is
expected to properly tag the different result. An Action receiving
the output can then filter the results based on the tag if necessary.
For example, a Measurement Task might report routine results to a
data Reporting Task in a Schedule that communicates hourly via the
Broadband PPP interface, but also outputs emergency conditions via an
alarm Reporting Task in a different Schedule communicating
immediately over a GPRS channel. 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. While it is likely that
an MA implementation will use a queue mechanism between the Schedules
or Actions, this Information Model does not mandate or define a
queue. The Information Model, however, reports the storage allocated
to Schedules and Actions so that storage usage can be monitored.
Furthermore, it is recommended that MA implementations by default
retain old data and stop the execution of new measurement tasks if
the MA runs out of storage capacity.
When specifying the task to execute within the Schedule, i.e.,
creating an Action, it is possible to add to the Action option
parameters. This allows the Task Configuration to determine the
common characteristics of a Task, while selected parameters (e.g.,
the test target URL) are defined within as option parameters of the
Action in the schedule. A single Tasks Configuration can even be
Burbridge, et al. Expires October 23, 2017 [Page 33]
Internet-Draft LMAP Information Model April 2017
used multiple times in the same schedule with different additional
parameters. This allows for efficiency in creating and transferring
the Instruction. Note that the semantics of what happens if an
option is defined multiple times (either in the Task Configuration,
Action or in both) is not standardised and will depend upon the Task.
For example, some tasks may legitimately take multiple values for a
single parameter.
Where Options are specified in both the Action and the Task
Configuration, the Action Options are appended to those specified in
the Task Configuration.
Example: An Action of a Schedule references a single Measurement
Task Configuration for measuring UDP latency. It specifies that
results are to be sent to a Schedule with a Reporting Action.
This Reporting Task of the Reporting Action is executed by a
separate Schedule that specifies that it should run hourly at 5
minutes past the hour. When run this Reporting Action takes the
data generated by the UDP latency Measurement 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.
Schedules and Actions may optionally also be given tags that are
included in result reports sent to a Collector. In addition,
schedules can be given suppression tags that may be used to select
Schedules and Actions for suppression.
3.7.1. Definition of ma-schedule-obj
object {
string ma-schedule-name;
ma-event-obj ma-schedule-start;
[ma-event-obj ma-schedule-end;]
[int ma-schedule-duration;]
ma-action-obj ma-schedule-actions<0..*>;
string ma-schedule-execution-mode;
[string ma-schedule-tags<0..*>;]
[string ma-schedule-suppression-tags<0..*>;]
} ma-schedule-obj;
The ma-schedule-obj is the main scheduling object. It consists of
the following elements:
ma-schedule-name: A name uniquely identifying a
scheduling object.
Burbridge, et al. Expires October 23, 2017 [Page 34]
Internet-Draft LMAP Information Model April 2017
ma-schedule-start: An event object indicating when the
schedule starts.
ma-schedule-end: An optional event object controlling
the forceful termination of scheduled
actions. When the event occurs, all
actions of the schedule will be forced
to terminate gracefully.
ma-schedule-duration: An optional duration in seconds for the
schedule. All actions of the schedule
will be forced to terminate gracefully
after the duration number of seconds
past the start of the schedule.
ma-schedule-actions: A possibly empty ordered list of
actions to invoke when the schedule
starts.
ma-schedule-execution-mode: Indicates whether the actions should be
executed sequentially, in parallel, or
in a pipelined mode (where data
produced by one action is passed to the
subsequent action). The default
execution mode is pipelined.
ma-schedule-tags: An optional unordered set of tags that
are reported together with the
measurement results to a collector.
ma-schedule-suppression-tags: An optional unordered set of
suppression tags that are used to
select schedules to be suppressed.
3.7.2. Definition of ma-action-obj
object {
string ma-action-name;
string ma-action-config-task-name;
[ma-option-obj ma-action-task-options<0..*>;]
[string ma-action-destinations<0..*>;]
[string ma-action-tags<0..*>;]
[string ma-action-suppression-tags<0..*>;]
} ma-action-obj;
The ma-action-obj models a task together with its schedule specific
task options and destination schedules. It consists of the following
elements:
Burbridge, et al. Expires October 23, 2017 [Page 35]
Internet-Draft LMAP Information Model April 2017
ma-action-name: A name uniquely identifying an action
of a scheduling object.
ma-action-config-task-name: A name identifying the configured task
to be invoked by the action.
ma-action-task-options: An optional and possibly empty ordered
list of options (name-value pairs) that
are passed to the task by appending
them to the options configured for the
task object.
ma-action-destinations: An optional and possibly empty
unordered set of names of destination
schedules that consume output produced
by this action.
ma-action-tags: An optional unordered set of tags that
are reported together with the
measurement results to a collector.
ma-action-suppression-tags: An optional unordered set of
suppression tags that are used to
select actions to be suppressed.
3.8. Common Objects: Channels
A Channel defines a bi-directional communication mechanism 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 a certificate).
The timing of when to communicate over a Channel is specified by the
Schedule which executes the corresponding Control or Reporting Task.
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 its own security
credentials (in the Configuration Information) and the given
credentials for the individual Channel end-point.
As with the Task Configurations, each Channel is also given a text
name by which it can be referenced as a Task Option.
Burbridge, et al. Expires October 23, 2017 [Page 36]
Internet-Draft LMAP Information Model April 2017
Although the same in terms of information, Channels used for
communication with the Controller are referred to as Control Channels
whereas Channels to Collectors are referred to as Report Channels.
Hence Control Channels will be referenced from Control Tasks executed
by a Control Schedule, whereas Report Channels will be referenced
from within Reporting Tasks executed by an Instruction Schedule.
Multiple interfaces are also supported. For example the Reporting
Task could be configured to send some results over GPRS. This is
especially useful when such results indicate the loss of connectivity
on a different network interface.
Example: A Channel used for reporting results may specify that
results are to be sent to the URL (https://collector.example.org/
report/), using the appropriate digital certificate to establish a
secure channel.
3.8.1. Definition of ma-channel-obj
object {
string ma-channel-name;
url ma-channel-target;
credentials ma-channel-credentials;
[string ma-channel-interface-name;]
} ma-channel-obj;
The ma-channel-obj consists of the following elements:
ma-channel-name: A unique name identifying the channel
object.
ma-channel-target: A URL identifying the target channel
endpoint.
ma-channel-credentials: The security credentials needed to
establish a secure channel.
ma-channel-interface-name: An optional name of the network interface
to be used. If not present, the IP
protocol stack will select a suitable
interface.
3.9. Common Objects: 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
Burbridge, et al. Expires October 23, 2017 [Page 37]
Internet-Draft LMAP Information Model April 2017
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 may have registry entries 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. Registry entries are specified as a
URI and can therefore be used to identify the Task within a namespace
or point to a web or local file location for the Task information.
As mentioned previously, these URIs may be used to identify the
Measurement Task in a public namespace
[I-D.ietf-ippm-metric-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 may also refer to registry
entries 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. 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.
An Option that must be present for Reporting Tasks is the Channel
reference specifying how to communicate with a Collector. This is
included in the task options and will have a value that matches a
channel name that has been defined in the Instruction. Similarly
Control Tasks will have a similar option with the value set to a
specified Control Channel.
A Reporting Task might also have a flag parameter, defined as an
Option, to indicate whether to send a report without measurement
results if there is no measurement result data pending to be
Burbridge, et al. Expires October 23, 2017 [Page 38]
Internet-Draft LMAP Information Model April 2017
transferred to the Collector. In addition many tasks will also take
as a parameter which interface to operate over.
In addition the Task Configuration may optionally also be given tags
that can carry 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.
3.9.1. Definition of ma-task-obj
object {
string ma-task-name;
ma-registry-obj ma-task-functions<0..*>;
[ma-option-obj ma-task-options<0..*>;]
[string ma-task-tags<0..*>;]
} ma-task-obj;
The ma-task-obj defines a configured task that can be invoked as part
of an action. A configured task can be referenced by its name and it
contains a possibly empty set of URIs to link to registry entries.
Options allow the configuration of task parameters (in the form of
name-value pairs). The ma-task-obj consists of the following
elements:
ma-task-name: A name uniquely identifying a configured
task object.
ma-task-functions: A possibly empty unordered set of registry
entries identifying the functions of the
configured task.
ma-task-options: An optional and possibly empty ordered list
of options (name-value pairs) that are
passed to the configured task.
ma-task-tags: An optional unordered set of tags that are
reported together with the measurement
results to a collector.
3.9.2. Definition of ma-option-obj
object {
string ma-option-name;
[object ma-option-value;]
} ma-option-obj;
Burbridge, et al. Expires October 23, 2017 [Page 39]
Internet-Draft LMAP Information Model April 2017
The ma-option-obj models a name-value pair and consists of the
following elements:
ma-option-name: The name of the option.
ma-option-value: The optional value of the option.
The ma-option-obj is used to define Task Configuration Options. Task
Configuration Options are generally task specific. For tasks
associated with an entry in a registry, the registry may define well-
known option names (e.g., the so-called parameters in the IPPM metric
registry [I-D.ietf-ippm-metric-registry]). Control and Reporting
Tasks need to know the Channel they are going to use. The common
option name for specifying the channel is "channel" where the
option's value refers to the name of an ma-channel-obj.
3.10. Common Objects: Registry Information
Tasks and actions can be associated with entries in a registry. A
registry object refers to an entry in a registry (identified by a
URI) and it may define a set of roles.
3.10.1. Definition of ma-registry-obj
object {
uri ma-registry-uri;
[string ma-registry-role<0..*>;]
} ma-registry-obj;
The ma-registry-obj refers to an entry of a registry and it defines
the associated role(s). The ma-registry-obj consists of the
following elements:
ma-registry-uri: A URI identifying an entry in a registry.
ma-registry-role: An optional and possibly empty unordered
set of roles for the identified registry
entry.
3.11. Common Objects: Event Information
The Event information object used throughout the information models
can initially take one of several different forms. Additional forms
may be defined later in order to bind the execution of schedules to
additional events. The initially defined Event forms are:
1. Periodic Timing: Emits multiple events periodically according to
an interval time defined in seconds
Burbridge, et al. Expires October 23, 2017 [Page 40]
Internet-Draft LMAP Information Model April 2017
2. Calendar Timing: Emits multiple events according to a calendar
based pattern, e.g., 22 minutes past each hour of the day on
weekdays
3. One Off Timing: Emits one event at a specific date and time
4. Immediate: Emits one event as soon as possible
5. Startup: Emits an event whenever the MA is started (e.g., at
device startup)
6. Controller Lost: Emits an event when connectivity to the
controller has been lost
7. Controller Connected: Emits an event when connectivity to the
controller has been (re-)established
Optionally each of the Event 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
seconds over which the start of the task is delayed from the starting
times specified by the event object.
Both the Periodic and Calendar timing objects allow for a series of
Actions 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.
Startup events are only created on device startup, not when a new
Instruction is transferred to the MA. If scheduled task execution is
desired both on the transfer of the Instruction and on device restart
then both the Immediate and Startup timing needs to be used in
conjunction.
The datetime format used for all elements in the information model
MUST conform to RFC 3339 [RFC3339].
3.11.1. Definition of ma-event-obj
Burbridge, et al. Expires October 23, 2017 [Page 41]
Internet-Draft LMAP Information Model April 2017
object {
string ma-event-name;
union {
ma-periodic-obj ma-event-periodic;
ma-calendar-obj ma-event-calendar;
ma-one-off-obj ma-event-one-off;
ma-immediate-obj ma-event-immediate;
ma-startup-obj ma-event-startup;
ma-controller-lost-obj ma-event-controller-lost;
ma-controller-connected-obj ma-event-controller-connected;
}
[int ma-event-random-spread;]
[int ma-event-cycle-interval;]
} ma-event-obj;
The ma-event-obj is the main event object. Event objects are
identified by a name. A generic event object itself contains a more
specific event object. The set of specific event objects should be
extensible. The initial set of specific event objects is further
described below. The ma-event-obj also includes an optional uniform
random spread that can be used to randomize the start times of
schedules triggered by an event. The ma-event-obj consists of the
following elements:
ma-event-name: The name uniquely identifies an event
object. Schedules refer to event
objects by this name.
ma-event-periodic: The ma-event-periodic is present for
periodic timing objects.
ma-event-calendar: The ma-event-calendar is present for
calendar timing objects.
ma-event-one-off: The ma-event-one-off is present for
one-off timing objects.
ma-event-immediate: The ma-event-immediate is present for
immediate event objects.
ma-event-startup: The ma-event-startup is present for
startup event objects.
ma-event-controller-lost: The ma-event-controller-lost is
present for connectivity to
controller lost event objects.
Burbridge, et al. Expires October 23, 2017 [Page 42]
Internet-Draft LMAP Information Model April 2017
ma-event-controller-connected: The ma-event-controller-connected is
present for connectivity to a
controller established event objects.
ma-event-random-spread: The optional ma-event-random-spread
adds a random delay defined in
seconds to the event object. No
random delay is added if ma-event-
random-spread does not exist.
ma-event-cycle-interval: The optional ma-event-cycle-interval
defines the duration of the time
interval in seconds that is used to
calculate cycle numbers. No cycle
number is calculated if ma-event-
cycle-interval does not exist.
3.11.2. Definition of ma-periodic-obj
object {
[datetime ma-periodic-start;]
[datetime ma-periodic-end;]
int ma-periodic-interval;
} ma-periodic-obj;
The ma-periodic-obj timing object has an optional start and an
optional end time plus a periodic interval. Schedules using an ma-
periodic-obj are started periodically between the start and end time.
The ma-periodic-obj consists of the following elements:
ma-periodic-start: The optional date and time at which
Schedules using this object are first
started. If not present it defaults to
immediate.
ma-periodic-end: The optional date and time at which
Schedules using this object are last
started. If not present it defaults to
indefinite.
ma-periodic-interval: The interval defines the time in seconds
between two consecutive starts of tasks.
3.11.3. Definition of ma-calendar-obj
Calendar Timing supports the routine execution of Schedules at
specific times and/or on specific dates. It can support more
flexible timing than Periodic Timing since the execution of Schedules
Burbridge, et al. Expires October 23, 2017 [Page 43]
Internet-Draft LMAP Information Model April 2017
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 times 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).
The calendar elements within the Calendar Timing do not have defaults
in order to avoid accidental high-frequency execution of Tasks. If
all possible values for an element are desired then the wildcard * is
used.
object {
[datetime ma-calendar-start;]
[datetime ma-calendar-end;]
[string ma-calendar-months<0..*>;]
[string ma-calendar-days-of-week<0..*>;]
[string ma-calendar-days-of-month<0..*>;]
[string ma-calendar-hours<0..*>;]
[string ma-calendar-minutes<0..*>;]
[string ma-calendar-seconds<0..*>;]
[int ma-calendar-timezone-offset;]
} ma-calendar-obj;
ma-calendar-start: The optional date and time at which
Schedules using this object are first
started. If not present it defaults to
immediate.
ma-calendar-end: The optional date and time at which
Schedules using this object are last
started. If not present it defaults to
indefinite.
ma-calendar-months: The optional set of months (1-12) on
which tasks scheduled using this object
are started. The wildcard * means all
months. If not present, it defaults to
no months.
ma-calendar-days-of-week: The optional set of days of a week
("Mon", "Tue", "Wed", "Thu", "Fri",
Burbridge, et al. Expires October 23, 2017 [Page 44]
Internet-Draft LMAP Information Model April 2017
"Sat", "Sun") on which tasks scheduled
using this object are started. The
wildcard * means all days of the week.
If not present, it defaults to no days.
ma-calendar-days-of-month: The optional set of days of a months
(1-31) on which tasks scheduled using
this object are started. The wildcard
* means all days of a months. If not
present, it defaults to no days.
ma-calendar-hours: The optional set of hours (0-23) on
which tasks scheduled using this object
are started. The wildcard * means all
hours of a day. If not present, it
defaults to no hours.
ma-calendar-minutes: The optional set of minutes (0-59) on
which tasks scheduled using this object
are started. The wildcard * means all
minutes of an hour. If not present, it
defaults to no hours.
ma-calendar-seconds: The optional set of seconds (0-59) on
which tasks scheduled using this object
are started. The wildcard * means all
seconds of an hour. If not present, it
defaults to no seconds.
ma-calendar-timezone-offset: The optional timezone offest in hours.
If not present, it defaults to the
system's local timezone.
If a day of the month is specified that does not exist in the month
(e.g., 29th of Feburary) then those values are ignored.
3.11.4. Definition of ma-one-off-obj
object {
datetime ma-one-off-time;
} ma-one-off-obj;
The ma-one-off-obj timing object specifies a fixed point in time.
Schedules using an ma-one-off-obj are started once at the specified
date and time. The ma-one-off-obj consists of the following
elements:
Burbridge, et al. Expires October 23, 2017 [Page 45]
Internet-Draft LMAP Information Model April 2017
ma-one-off-time: The date and time at which Schedules using
this object are started.
3.11.5. Definition of ma-immediate-obj
object {
// empty
} ma-immediate-obj;
The ma-immediate-obj event object has no further information
elements. Schedules using an ma-immediate-obj are started as soon as
possible.
3.11.6. Definition of ma-startup-obj
object {
// empty
} ma-startup-obj;
The ma-startup-obj event object has no further information elements.
Schedules or suppressions using an ma-startup-obj are started at MA
initialization time.
3.11.7. Definition of ma-controller-lost-obj
object {
// empty
} ma-controller-lost-obj;
The ma-controller-lost-obj event object has no further information
elements. The ma-controller-lost-obj indicates that connectivity to
the controller has been lost. This is determined by a timer started
after each successful contact with a controller. When the timer
reaches the controller-timeout (measured in seconds), an ma-
controller-lost-obj event is generated. This event may be used to
start a suppression.
3.11.8. Definition of ma-controller-connected-obj
object {
// empty
} ma-controller-connected-obj;
The ma-controller-connected-obj event object has no further
information elements. The ma-controller-connected-obj indicates that
connectivity to the controller has been established again after it
was lost. This event may be used to end a suppression.
Burbridge, et al. Expires October 23, 2017 [Page 46]
Internet-Draft LMAP Information Model April 2017
4. Example Execution
The example execution has two event sources E1 and E2 and three
schedules S1, S2, and S3. The schedule S3 is started by events of
event source E2 while the schedules S1 and S2 are both started by
events of the event source E1. The schedules S1 and S2 have two
actions each and schedule S3 has a single action. The event source
E2 has no randomization while the event source E1 has the
randomization r.
Figure 2 shows a possible timeline of an execution. The time T is
progressing downwards. The dotted vertial line indicates progress of
time while a dotted horizontal line indicates which schedule are
triggered by an event. Tilded lines indicate data flowing from an
action to another schedule. Actions within a schedule are named A1,
A2, etc.
Burbridge, et al. Expires October 23, 2017 [Page 47]
Internet-Draft LMAP Information Model April 2017
E2 E1 T S1 S2 S3
sequential parallel pipelined
:
e0 +
:
:
e0+r + .......... + .......... ++
: | A1 A1 || A2
: + |+ ~~~~~~~>
: | A2 |
: | + ~~~~~~~~>
: + ~~~~~~~~~~~~~~~~~~~~~>
:
:
e1 +
:
e1+r + .......... + .......... ++
: | A1 A1 ||
: | +|~~~~~~~>
: | | A2
: + +~~~~~~~>
: | A2
: + ~~~~~~~~~~~~~~~~~~~~>
e0 + ................................... +
: | A1
e3 + |
e3+r + .......... + .......... ++ |
: | A1 A1 || A2 |
: + ++ ~~~~~~> |
: | A2 +
: + ~~~~~~~~~~~~~~~~~~~~>
V
Figure 2: Example Execution
Note that implementations must handle possible concurrency issues.
In the example execution, action A1 of schedule S3 is consuming the
data that has been forwarded to schedule S3 while additional data is
arriving from action A2 of schedule S2.
5. IANA Considerations
This document makes no request of IANA.
Note to the RFC Editor: this section may be removed on publication as
an RFC.
Burbridge, et al. Expires October 23, 2017 [Page 48]
Internet-Draft LMAP Information Model April 2017
6. 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
administrator employs to pre-configure the MA must also be secure to
protect unauthorized parties from modifying pre-configuration
information. These mechanisms are important to ensure that the MA
cannot be hijacked, for example to participate in a distributed
denial of service attack.
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 may, 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.
Implementations and deployments should also be careful about exposing
device-ids when this is not strictly needed.
An implementation of this Information Model should support all the
security and privacy requirements associated with the LMAP Framework
[RFC7594]. In addition, users of this Information Model are advised
to choose identifiers for Group IDs, tags or names of information
model objects (e.g., configured tasks, schedules or actions) that do
not reveal any sensitive information to people authorized to process
measurement results but who are not authorized to know details about
the Measurement Agents that were used to perform the measurement.
7. Acknowledgements
Several people contributed to this specification by reviewing early
versions and actively participating in the LMAP working group
(apologies to those unintentionally omitted): Vaibhav Bajpai, Michael
Bugenhagen, Timothy Carey, Alissa Cooper, Kenneth Ko, Al Morton, Dan
Romascanu, Henning Schulzrinne, Andrea Soppera, Barbara Stark, and
Jason Weil.
Trevor Burbridge, Philip Eardley, Marcelo Bagnulo and Juergen
Schoenwaelder 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.
Burbridge, et al. Expires October 23, 2017 [Page 49]
Internet-Draft LMAP Information Model April 2017
Juergen Schoenwaelder was partly funded by Flamingo, a Network of
Excellence project (ICT-318488) supported by the European Commission
under its Seventh Framework Programme.
8. References
8.1. Normative References
[ISO.10646]
International Organization for Standardization,
"Information Technology - Universal Multiple-Octet Coded
Character Set (UCS)", ISO Standard 10646:2014, 2014.
[POSIX.2] The IEEE and The Open Group, "The Open Group Base
Specifications Issue 7", IEEE Standard 1003.1-2008, 2016.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/
RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet:
Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002,
<http://www.rfc-editor.org/info/rfc3339>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66, RFC
3986, DOI 10.17487/RFC3986, January 2005,
<http://www.rfc-editor.org/info/rfc3986>.
[RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally
Unique IDentifier (UUID) URN Namespace", RFC 4122, DOI 10
.17487/RFC4122, July 2005,
<http://www.rfc-editor.org/info/rfc4122>.
8.2. Informative References
[I-D.ietf-ippm-metric-registry]
Bagnulo, M., Claise, B., Eardley, P., Morton, A., and A.
Akhter, "Registry for Performance Metrics", draft-ietf-
ippm-metric-registry-10 (work in progress), November 2016.
[I-D.ietf-lmap-yang]
Schoenwaelder, J. and V. Bajpai, "A YANG Data Model for
LMAP Measurement Agents", draft-ietf-lmap-yang-10 (work in
progress), January 2017.
Burbridge, et al. Expires October 23, 2017 [Page 50]
Internet-Draft LMAP Information Model April 2017
[RFC3444] Pras, A. and J. Schoenwaelder, "On the Difference between
Information Models and Data Models", RFC 3444, DOI 10
.17487/RFC3444, January 2003,
<http://www.rfc-editor.org/info/rfc3444>.
[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,
<http://www.rfc-editor.org/info/rfc7398>.
[RFC7536] Linsner, M., Eardley, P., Burbridge, T., and F. Sorensen,
"Large-Scale Broadband Measurement Use Cases", RFC 7536,
DOI 10.17487/RFC7536, May 2015,
<http://www.rfc-editor.org/info/rfc7536>.
[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,
<http://www.rfc-editor.org/info/rfc7594>.
Appendix A. Change History
Note to the RFC Editor: this section should be removed on publication
as an RFC.
A.1. Non-editorial changes since -17
o The information model is subdivided into aspects and not sections.
o Changes to address the GEN-ART review comments.
A.2. Non-editorial changes since -16
o Addressing Alissa Cooper's review comments.
A.3. Non-editorial changes since -15
o The reference to the framework is now informational.
A.4. Non-editorial changes since -14
o Clarified that the cycle number is in UTC.
Burbridge, et al. Expires October 23, 2017 [Page 51]
Internet-Draft LMAP Information Model April 2017
A.5. Non-editorial changes since -13
o Removed the ma-config-device-id from the ma-config-obj.
o Added ma-config-report-group-id and clarified how two flags ma-
config-report-agent-id and ma-config-report-group-id work.
A.6. Non-editorial changes since -12
o Renamed the ma-metrics-registry-obj to ma-registry-obj since tasks
may refer to different registries (not just a metrics registry).
o Clarifications and bug fixes.
A.7. Non-editorial changes since -11
o Clarifications and bug fixes.
A.8. Non-editorial changes since -10
o Rewrote the text concerning the well-known "channel" option name.
o Added ma-report-result-event-time, ma-report-result-cycle-number,
and ma-event-cycle-interval.
o Added ma-capability-tags.
o Added a new section showing an example execution.
o Several clarifications and bug fixes.
A.9. Non-editorial changes since -09
o Added ma-status-schedule-storage and ma-status-action-storage.
o Removed suppress-by-default.
o Moved ma-report-result-metrics of the ma-report-result-obj to ma-
report-table-metrics of the ma-report-table-obj so that the
relationship between metrics and result tables is clear.
o Added ma-report-conflict-obj.
o Added ma-report-result-status to ma-report-result-obj.
o Several clarifications and bug fixes.
Burbridge, et al. Expires October 23, 2017 [Page 52]
Internet-Draft LMAP Information Model April 2017
A.10. Non-editorial changes since -08
o Refactored the ma-report-task-obj into the ma-report-result-obj.
o Introduced the ma-report-table-obj so that a result can contain
multiple tables.
o Report schedule, action, and task name as part of the ma-report-
result-obj.
o Report conflicts per ma-report-result-obj and not per ma-report-
row-obj.
o Report the start/end time as part of the ma-report-result-obj.
A.11. Non-editorial changes since -07
o Added ma-schedule-end and ma-schedule-duration.
o Changed the granularity of scheduler timings to seconds.
o Added ma-status-suppression-obj to report the status of
suppressions as done in the YANG data model.
o Added counters to schedule and action status objects to match the
counters in the YANG data model.
o Using tags to pass information such as a measurement cycle
identifier to the collector.
o Using suppression tags and glob-style matching to select schedules
and actions to be suppressed.
A.12. Non-editorial changes since -06
o The default execution mode is pipelined (LI12)
o Added text to define which action consumes data in sequential,
pipelines, and parallel execution mode (LI11)
o Added ma-config-measurement-point, ma-report-measurement-point,
and ma-config-report-measurement-point to configure and report the
measurement point (LI10)
o Turned ma-suppression-obj into a list that uses a start event and
a stop event to define the start and end of suppression; this
unifies the handling of suppression and loss of controller
connectivity (LI09)
Burbridge, et al. Expires October 23, 2017 [Page 53]
Internet-Draft LMAP Information Model April 2017
o Added ma-controller-lost-obj and ma-controller-ok-obj event
objects (LI09)
o Added ma-status-schedule-obj to report the status of a schedule
and refactored ma-task-status-obj into ma-status-action-obj to
report the status of an action (LI07, LI08)
o Introduced a common ma-metric-registry-obj that identifies a
metric and a set of associated roles and added this object to
expose metric capabilities and to support the configuration of
metrics and to report the metrics used (LI06)
o Introduced ma-capability-obj and ma-capability-task-obj to expose
the capabilities of a measurement agent (LI05)
o Use 'ordered list' or 'unordered set' instead of list, collection,
etc. (LI02)
o Clarification that Actions are part of a Schedule (LI03)
o Deleted terms that are not strictly needed (LI04)
A.13. Non-editorial changes since -05
o A task can now reference multiply registry entries.
o Consistent usage of the term Action and Task.
o Schedules are triggered by Events instead of Timings; Timings are
just one of many possible event sources.
o Actions feed into other Schedules (instead of Actions within other
Schedules).
o Removed the notion of multiple task outputs.
o Support for sequential, parallel, and pipelined execution of
Actions.
Authors' Addresses
Trevor Burbridge
BT
Adastral Park, Martlesham Heath
Ipswich IP5 3RE
United Kingdom
Email: trevor.burbridge@bt.com
Burbridge, et al. Expires October 23, 2017 [Page 54]
Internet-Draft LMAP Information Model April 2017
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
Burbridge, et al. Expires October 23, 2017 [Page 55]
