Network Working Group J. Parello
Internet-Draft B. Claise
Intended Status: Informational Cisco Systems, Inc.
Expires: April 18, 2014 B. Schoening
Independent Consultant
J. Quittek
NEC Europe Ltd
October 18, 2013
Energy Management Framework
draft-ietf-eman-framework-11
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Abstract
This document defines a framework for Energy Management for
devices and device components within or connected to
communication networks. The framework presents a physical
reference model and information model. The information
model consists of an Energy Management Domain as a set of
Energy Objects. Each Energy Object can be attributed with
identity, classification, and context. Energy Objects can
be monitored and controlled with respect to power, Power
State, energy, demand, Power Attributes, and battery.
Additionally the framework models relationships and
capabilities between Energy Objects.
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Table of Contents
1. Introduction.......................................... 3
1.1. Energy Management Documents Overview............. 4
2. Terminology........................................... 5
3. Target Devices....................................... 10
4. Physical Reference Model............................. 11
5. Not Covered by the Framework......................... 12
6. Energy Management Abstraction........................ 13
6.1. Conceptual Model................................ 13
6.2. Energy Object (Class)........................... 14
6.3. Energy Object Attributes........................ 15
6.4. Measurements.................................... 18
6.5. Control......................................... 20
6.6. Relationships................................... 25
7. Energy Management Information Model.................. 29
8. Modeling Relationships between Devices............... 34
8.1. Power Source Relationship....................... 34
8.2. Metering Relationship........................... 38
8.3. Aggregation Relationship........................ 39
9. Relationship to Other Standards...................... 39
10. Security Considerations............................. 40
10.1. Security Considerations for SNMP............... 40
11. IANA Considerations................................. 41
11.1. IANA Registration of new Power State Sets...... 41
11.2. Updating the Registration...Power State Sets... 43
12. References.......................................... 43
13. Acknowledgments..................................... 46
1. Introduction
Network management is often divided into the five main
areas defined in the ISO Telecommunications Management
Network model: Fault, Configuration, Accounting,
Performance, and Security Management (FCAPS) [X.700]. Not
covered by this traditional management model is Energy
Management, which is rapidly becoming a critical area of
concern worldwide, as seen in [ISO50001].
This document defines an Energy Management framework for
devices within or connected to communication networks. The
devices, or components of these devices (such as line
cards, fans, disks) can then be monitored and controlled.
Monitoring includes measuring power, energy, demand, and
attributes of power. Energy control can be performed by
setting a devices' or components' state. The framework also
covers monitoring and control of batteries contained in
devices.
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This framework further describes how to identify, classify
and provide context for such devices. While context
information is not specific to Energy Management, some
context attributes are specified in the framework,
addressing the following use cases: how important is a
device in terms of its business impact, how should devices
be grouped for reporting and searching, and how should a
device role be described. Guidelines for using context for
Energy Management are described.
The framework introduces the concept of a Power Interface
that is analogous to a network interface. A Power Interface
is defined as an interconnection among devices where energy
can be provided, received, or both.
The most basic example of Energy Management is a single
device reporting information about itself. In many cases,
however, energy is not measured by the device itself, but
measured upstream in the power distribution tree. For
example, a power distribution unit (PDU) may measure the
energy it supplies to attached devices and report this to
an energy management system. Therefore, devices often have
relationships to other devices or components in the power
network. An EnMS (Energy Management System) generally
requires an understanding of the power topology (who
provides power to whom), the metering topology (who meters
whom), and an understanding of the potential aggregation
(who aggregates values of others).
The relationships build on the Power Interface concept. The
different relationships among devices and components,
specified in this document, include: power source,
metering, and aggregation relationships.
1.1. Energy Management Documents Overview
The EMAN standard provides a set of specifications for
Energy Management. This document specifies the framework,
per the Energy Management requirements specified in [EMAN-
REQ].
The applicability statement document [EMAN-AS] includes use
cases, a cross-reference between existing standards and the
EMAN standard, and a description of this framework's
relationship to other frameworks.
The Energy Object Context MIB [EMAN-OBJECT-MIB] specifies
objects for addressing device/component identification,
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classification, context information, and relationships from
the point of view of Energy Management.
The Power and Energy Monitoring MIB [EMAN-MON-MIB]
specifies objects for monitoring of power, energy, demand,
and control.
The Battery Monitoring MIB [EMAN-BATTERY-MIB] defines
managed objects that provide information on the status and
condition of batteries in managed devices.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL",
"SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
and "OPTIONAL" in this document are to be interpreted as
described in RFC-2119 [RFC2119].
In this document these words will appear with that
interpretation only when in ALL CAPS. Lower case uses of
these words are not to be interpreted as carrying RFC-
2119 significance.
In this section some terms have a NOTE that is not part of
the definition itself, but accounts for differences between
terminologies of different standards organizations or
further clarifies the definition.
The terms are listing in an order that aids in reading
where terms may build off a previous term as opposed to an
alphabetical ordering. Some terms that are common in
electrical engineering or that describe common physical
items use a lower case notation.
Energy Management
Energy Management is a set of functions for measuring,
modeling, planning, and optimizing networks to ensure
that the network and network attached devices use energy
efficiently and appropriately for the nature of the
application and the cost constraints of the organization.
Reference: Adapted from [ITU-T-M-3400]
NOTES:
1. Energy Management refers to the activities, methods,
procedures and tools that pertain to measuring, modeling,
planning, controlling and optimizing the use of energy in
networked systems [NMF].
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2. Energy Management is a management domain which is
congruent to any of the FCAPS areas of management in the
ISO/OSI Network Management Model [TMN]. Energy Management
for communication networks and attached devices is a
subset or part of an organization's greater Energy
Management Policies.
Energy Management System (EnMS)
An Energy Management System is a combination of hardware
and software used to administer a network with the
primary purpose of energy management.
NOTES:
1. An Energy Management System according to [ISO50001]
(ISO-EnMS) is a set of systems or procedures upon which
organizations can develop and implement an energy policy,
set targets, action plans and take into account legal
requirements related to energy use. An ISO-EnMS allows
organizations to improve energy performance and
demonstrate conformity to requirements, standards, and/or
legal requirements.
2. Example ISO-EnMS: Company A defines a set of policies
and procedures indicating there should exist multiple
computerized systems that will poll energy measurements
from their meters and pricing / source data from their
local utility. Company A specifies that their CFO (Chief
Financial Officer) should collect information and
summarize it quarterly to be sent to an accounting firm
to produce carbon accounting reporting as required by
their local government.
3. For the purposes of EMAN, the definition herein is the
preferred meaning of an Energy Management System (EnMS).
The definition from [ISO50001] can be referred to as ISO
Energy Management System (ISO-EnMS).
Energy Monitoring
Energy Monitoring is a part of Energy Management that
deals with collecting or reading information from devices
to aid in Energy Management.
Energy Control
Energy Control is a part of Energy Management that deals
with directing influence over devices.
electrical equipment
A general term including materials, fittings, devices,
appliances, fixtures, apparatus, machines, etc., used as
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a part of, or in connection with, an electric
installation.
Reference: [IEEE100]
non-electrical equipment (mechanical equipment)
A general term including materials, fittings, devices,
appliances, fixtures, apparatus, machines, etc., used as
a part of, or in connection with, non-electrical power
installations.
Reference: Adapted from [IEEE100]
device
A piece of electrical or non-electrical equipment.
Reference: Adapted from [IEEE100]
component
A part of an electrical or non-electrical equipment
(device).
Reference: Adapted from [ITU-T-M-3400]
power inlet
A power inlet (or simply inlet) is an interface at which
a device or component receives energy from another device
or component.
power outlet
A power outlet (or simply outlet) is an interface at
which a device or component provides energy to another
device or component.
energy
That which does work or is capable of doing work. As used
by electric utilities, it is generally a reference to
electrical energy and is measured in kilowatt hours
(kWh).
Reference: [IEEE100]
NOTES
1. Energy is the capacity of a system to produce external
activity or perform work [ISO50001]
power
The time rate at which energy is emitted, transferred, or
received; usually expressed in watts (joules per second).
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Reference: [IEEE100]
demand
The average value of power or a related quantity over a
specified interval of time. Note: Demand is expressed in
kilowatts, kilovolt-amperes, kilovars, or other suitable
units.
Reference: [IEEE100]
NOTES:
1. While IEEE100 defines demand in kilo measurements, for
EMAN we use watts with any suitable metric prefix.
provide energy
A device (or component) "provides" energy to another
device if there is an energy flow from this device to the
other one.
receive energy
A device (or component) "receives" energy from another
device if there is an energy flow from the other device
to this one.
meter (energy meter)
a device intended to measure electrical energy by
integrating power with respect to time.
Reference: Adapted from [IEC60050]
battery
one or more cells (consisting of an assembly of
electrodes, electrolyte, container, terminals and usually
separators) that are a source and/or store of electric
energy.
Reference: Adapted from [IEC60050]
Power Interface
A power inlet, outlet, or both.
Nameplate Power
The Nameplate Power is the nominal power of a device as
specified by the device manufacturer.
Power Attributes
Measurements of the electrical current, voltage, phase
and frequencies at a given point in an electrical power
system.
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Reference: Adapted from [IEC60050]
NOTES:
1. Power Attributes are not intended to be judgmental
with respect to a reference or technical value and are
independent of any usage context.
Power Quality
Characteristics of the electrical current, voltage, phase
and frequencies at a given point in an electric power
system, evaluated against a set of reference technical
parameters. These parameters might, in some cases, relate
to the compatibility between electricity supplied in an
electric power system and the loads connected to that
electric power system.
Reference: [IEC60050]
NOTES:
1. Electrical characteristics representing power quality
information are typically required by customer facility
energy management systems. It is not intended to satisfy
the detailed requirements of power quality monitoring.
Standards typically also give ranges of allowed values;
the information attributes are the raw measurements, not
the "yes/no" determination by the various standards.
Reference: [ASHRAE-201]
Power State
A Power State is a condition or mode of a device (or
component) that broadly characterizes its capabilities,
power, and responsiveness to input.
Reference: Adapted from [IEEE1621]
Power State Set
A Power State Set is a collection of Power States that
comprises a named or logical control grouping.
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3. Target Devices
With Energy Management, there exists a wide variety of
devices that may be contained in the same deployment as a
communication network but comprise a separate facility,
home, or power distribution network.
Energy Management has special challenges because a power
distribution network supplies energy to devices and
components, while a separate communications network
monitors and controls the power distribution network.
The target devices for Energy Management are all devices
that can be monitored or controlled (directly or
indirectly) by an Energy Management System (EnMS). These
target devices include, for example:
o Simple electrical appliances and fixtures
o Hosts, such as a PC, a server, or a printer
o Switches, routers, base stations, and other
network equipment and middle boxes
o Components within devices, such as a battery
inside a PC, a line card inside a switch, etc.
o Power over Ethernet (PoE) endpoints
o Power Distribution Units (PDU)
o Protocol gateway devices for Building Management
Systems (BMS)
o Electrical meters
o Sensor controllers with subtended sensors
Target devices include devices that communicate via the
Internet Protocol (IP) as well as devices using other means
for communication. The latter are managed through gateways
or proxies that can communicate using IP.
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4. Physical Reference Model
The following reference model describes physical power
topologies that exist in parallel to the communication
topology. While many more topologies can be created with
combination of devices, the following are some basic ones
that show how Energy Management topologies differ from
Network Management topologies.
NOTE: ### is used to denote a transfer of energy.
- > is used to denote a transfer of information.
Basic Energy Management
+--------------------------+
| Energy Management System |
+--------------------------+
^ ^
monitoring | | control
v v
+---------+
| device |
+---------+
Basic Power Supply
+-----------------------------------------+
| Energy Management System |
+-----------------------------------------+
^ ^ ^ ^
monitoring | | control monitoring | | control
v v v v
+--------------+ +-----------------+
| power source |########| device |
+--------------+ +-----------------+
Single Power Supply with Multiple Devices
+---------------------------------------+
| Energy Management System |
+---------------------------------------+
^ ^ ^ ^
monitoring | | control monitoring | | control
v v v v
+--------+ +------------------+
| power |########| device 1 |
| source | # +------------------+-+
+--------+ #######| device 2 |
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# +------------------+-+
#######| device 3 |
+------------------+
Multiple Power Supplies with Single Devices
+----------------------------------------------+
| Energy Management System |
+----------------------------------------------+
^ ^ ^ ^ ^ ^
mon. | | ctrl. mon. | | ctrl. mon. | | ctrl.
v v v v v v
+----------+ +----------+ +----------+
| power |######| device |######| power |
| source 1 |######| | | source 2 |
+----------+ +----------+ +----------+
5. Not Covered by the Framework
While this framework is intended as a framework for Energy
Management in general, there are some areas that are not
covered.
Non-Electrical Equipment
The primary focus of this framework is the management of
electrical equipment. Non-Electrical equipment can be
covered by the framework by providing interfaces that
comply with the framework. For example, using the same
units for power and energy. Therefore, non-electrical
equipment that do not convert-to or present-as equivalent
to electrical equipment are not addressed.
Energy Procurement and Manufacturing
While an EnMS may be a central point for corporate
reporting, cost computation, environmental impact analysis,
and regulatory compliance reporting - Energy Management in
this framework excludes energy procurement and the
environmental impact of energy use.
As such the framework does not include:
o Cost in currency or environmental units of
manufacturing a device.
o Embedded carbon or environmental equivalences of a
device
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o Cost in currency or environmental impact to dismantle
or recycle a device.
o Supply chain analysis of energy sources for device
deployment
o Conversion of the usage or production of energy to
units expressed from the source of that energy (such
as the greenhouse gas emissions associated the
transfer of energy from a diesel source).
6. Energy Management Abstraction
This section describes a conceptual model of information
that can be used for Energy Management. The classes and
categories of attributes in the model are described with
rationale for each.
6.1. Conceptual Model
This section describes an information model that addressing
issues specific to Energy Management, which complements
existing Network Management models.
An information model for Energy Management will need to
describe a means to monitor and control devices and
components. The model will also need to describe the
relationships among and connections between devices and
components.
This section proposes a similar conceptual model for
devices and components to that used in Network Management:
devices, components, and interfaces. This section then
defines the additional attributes specific to Energy
Management for those entities that are not available in
existing Network Management models.
For modeling the devices and components this section
describes three classes: a Device (Class), a Component
(Class), and a Power Interface (Class). These classes are
sub-types of an abstract Energy Object (Class).
Summary of Notation for Modeling Physical Equipment
Physical Modeling (Meta Data) Model Instance
---------------------------------------------------------
equipment Energy Object (Class) Energy Object
device Device (Class) Device
component Component (Class) Component
inlet / outlet Power Interface (Class) Power Interface
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This section then describes the attributes of an Energy
Object (Class) for identification, classification, context,
control, power and energy.
Since the interconnections between devices and components
for Energy Management may have no relation to the
interconnections for Network Management the Energy Object
(Classes) contain a separate Relationships (Class) as an
attribute to model these types of interconnections.
The next sections describe the each of the of the classes
and categories of attributes in the information model. The
formal definitions of the classes and attributes are
specified in Section 7.
6.2. Energy Object (Class)
An Energy Object (Class) represents a piece of equipment
that is part of, or attached to, a communications network
which is monitored, controlled, or aids in the management
of another device for Energy Management.
The Energy Object (Class) is an abstract class that
contains the base attributes to represent a piece of
equipment for Energy Management. There are three types of
Energy Object (Class)'s: Device (Class), Component
(Component) and Power Interface (Class).
6.2.1. Device (Class)
The Device (Class) is a sub-class of Energy Object (Class)
that represents a physical piece of equipment.
A Device (Class) instance represents a device that is a
consumer, producer, meter, distributor, or store of energy.
A Device (Class) instance may represent a physical device
that contains other components.
6.2.2. Component (Class)
The Component (Class) is a sub-class of Energy Object
(Class) that represents a part of a physical piece of
equipment.
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6.2.3. Power Interface (Class)
A Power Interface (Class) represents the interconnections
(inlet, outlet) among devices or components where energy
can be provided, received, or both.
The Power Interface (Class) is a sub-class of Energy Object
(Class) that represents a physical inlet or outlet.
There are some similarities between Power Interfaces and
network interfaces. A network interface can be set to
different states, such as sending or receiving data on an
attached line. Similarly, a Power Interface can be
receiving or providing energy.
A Power Interface (Class) instance can represent
(physically) an AC power socket, an AC power cord attached
to a device, or an 8P8C (RJ45) PoE socket, etc.
6.3. Energy Object Attributes
This section describes categories of attributes for an
Energy Object (Class).
6.3.1. Identification
A Universal Unique Identifier (UUID) [RFC4122] is used to
uniquely and persistently identify an Energy Object.
Every Energy Object has an optional unique printable name.
Possible naming conventions are: textual DNS name, MAC
address of the device, interface ifName, or a text string
uniquely identifying the Energy Object. As an example, in
the case of IP phones, the Energy Object name can be the
device's DNS name.
Additionally an alternate key is provided to allow an
Energy Object to be optionally linked with models in
different systems.
6.3.2. Context in General
In order to aid in reporting and in differentiation between
Energy Objects, each object optionally contains information
establishing its business, site, or organizational context
within a deployment.
The Energy Object (Class) contains a category attribute
that broadly describes how an instance is used in a
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deployment. The category indicates if the Energy Object is
primarily functioning as a consumer, producer, meter,
distributor or store of energy.
Given the category and context of an object, an EnMS can
summarize or analyze measurements for the site.
6.3.3. Context: Importance
An Energy Object can provide an importance value in the
range of 1 to 100 to help rank a device's use or relative
value to the site. The importance range is from 1 (least
important) to 100 (most important). The default importance
value is 1.
For example: A typical office environment has several types
of phones, which can be rated according to their business
impact. A public desk phone has a lower importance (for
example, 10) than a business-critical emergency phone (for
example, 100). As another example: A company can consider
that a PC and a phone for a customer-service engineer are
more important than a PC and a phone for lobby use.
Although EnMS and administrators can establish their own
ranking, the following example is a broad recommendation
for commercial deployments [CISCO-EW]:
90 to 100 Emergency response
80 to 90 Executive or business-critical
70 to 79 General or Average
60 to 69 Staff or support
40 to 59 Public or guest
1 to 39 Decorative or hospitality
6.3.4. Context: Keywords
The Energy Object (Class) contains an attribute with
context keywords.
An Energy Object can provide a set of keywords that are a
list of tags that can be used for grouping, for summary
reporting (within or between Energy Management Domains),
and for searching.
All alphanumeric characters and symbols (other than a
comma), such as #, (, $, !, and &, are allowed. Potential
examples are: IT, lobby, HumanResources, Accounting,
StoreRoom, CustomerSpace, router, phone, floor2, or
SoftwareLab.
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There is no default value for a keyword. Multiple keywords
can be assigned to an Energy Object. White spaces before
and after the commas are excluded, as well as within a
keyword itself. In such cases, commas separate the keywords
and no spaces between keywords are allowed. For example,
"HR,Bldg1,Private".
6.3.5. Context: Role
The Energy Object (Class) contains a role attribute. The
"role description" string indicates the primary purpose the
Energy Object serves in the deployment. This could be a
string representing the purpose the Energy Object fulfills
in the deployment.
Administrators can define any naming scheme for the role.
As guidance, a two-word role that combines the service the
Energy Object provides along with type can be used
[IPENERGY].
Example types of devices: Router, Switch, Light, Phone,
WorkStation, Server, Display, Kiosk, HVAC.
Example Services by Line of Business:
Line of Business Service
-----------------------------------------------------
Education Student, Faculty, Administration,
Athletic
Finance Trader, Teller, Fulfillment
Manufacturing Assembly, Control, Shipping
Retail Advertising, Cashier
Support Helpdesk, Management
Medical Patient, Administration, Billing
Role as a two-word string: "Faculty Desktop", "Teller
Phone", "Shipping HVAC", "Advertising Display", "Helpdesk
Kiosk", "Administration Switch".
6.3.6. Context: Domain
The Energy Object (Class) contains a string attribute to
indicate membership in an Energy Management Domain. An
Energy Management Domain can be any collection of Energy
Objects in a deployment, but it is recommended to map 1:1
with a metered or sub-metered portion of the site.
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In building management, a meter refers to the meter
provided by the utility used for billing and measuring
power to an entire building or unit within a building. A
sub-meter refers to a customer- or user-installed meter
that is not used by the utility to bill but is instead used
to get measurements from sub portions of a building.
An Energy Object should be a member of a single Energy
Management Domain therefore one attribute is provided.
6.4. Measurements
The Energy Object (Class) contains attributes to describe
power, energy and demand measurements.
An analogy for understanding power versus energy
measurements can be made to speed and distance in
automobiles. Just as a speedometer indicates the rate of
change of distance (speed), a power measurement indicates
the rate of transfer of energy. The odometer in an
automobile measures the cumulative distance traveled and
similarly an energy measurement indicates the accumulated
energy transferred.
Demand measurements are averages of power measurements over
time. So using the same analogy to an automobile: measuring
the average vehicle speed over multiple intervals of time
for a given distance travelled, demand is the average power
measured over multiple time intervals for a given energy
value.
Within this framework, energy will only be quantified in
units of watt-hours. Physical devices measuring energy in
other units must convert values to watt-hours or be
represented by Energy Objects that convert to watt-hours.
6.4.1. Measurements: Power
The Energy Object (Class) contains a Nameplate Power
attribute that describes the nominal power as specified by
the manufacturer of the device. The EnMS can use the
Nameplate Power for provisioning, capacity planning and
(potentially) billing.
The Energy Object (Class) has attributes that describe the
present power information, along with how that measurement
was obtained or derived (e.g., actual, estimated, or
static).
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A power measurement is qualified with the units, magnitude
and direction of power flow, and is qualified as to the
means by which the measurement was made.
Power measurement magnitude conforms to the [IEC61850]
definition of unit multiplier for the SI (System
International) units of measure. Measured values are
represented in SI units obtained by BaseValue * (10 ^
Scale). For example, if current power usage of an Energy
Object is 17, it could be 17 W, 17 mW, 17 kW, or 17 mW,
depending on the value of the scaling factor. 17 W implies
that the BaseValue is 17 and Scale = 0, whereas 17 mW
implies BaseValue = 17 and ScaleFactor = -3.
An Energy Object (Class) indicates how the power
measurement was obtained with a caliber and accuracy
attribute that indicates:
o Whether the measurements were made at the device
itself or at a remote source.
o Description of the method that was used to measure
the power and whether this method can distinguish
actual or estimated values.
o Accuracy for actual measured values
6.4.2. Measurements: Power Attributes
The Energy Object (Class) contains an optional attribute
that describes Power Attribute information reflecting the
electrical characteristics of the measurement. These Power
Attributes adhere to the [IEC-61850-7-2] standard for
describing AC measurements.
6.4.3. Measurements: Energy
The Energy Object (Class) contains optional attributes that
represent the energy used, received, produced and or
stored. Typically only devices or components that can
measure actual power will have the ability to measure
energy.
6.4.4. Measurements: Demand
The Energy Object (Class) contains optional attributes that
represent demand information over time. Typically only
devices or components that can report actual power are
capable of measuring demand.
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6.5. Control
The Energy Object (Class) contains a Power State Set
(Class) attribute that represents the set of Power States a
device or component supports.
A Power State describes a condition or mode of a device or
component. While Power States are typically used for
control they may be used for monitoring only.
A device or component is expected to support at least one
set of Power States consisting of at least two states, an
on state and an off state.
There are many existing standards describing device and
component Power States. The framework supports modeling a
mixed set of Power States defined in different standards. A
basic example is given by the three Power States defined in
IEEE1621 [IEEE1621]: on, off, and sleep. The DMTF [DMTF],
ACPI [ACPI], and PWG all define larger numbers of Power
States.
The semantics of a Power State are specified by
a) the functionality provided by an Energy Object in
this state,
b) a limitation of the power that an Energy Object uses
in this state,
c) a combination of a) and b)
The semantics of a Power State should be clearly defined.
Limitation (curtailment) of the power used by an Energy
Object in a state may be specified by:
o an absolute power value
o a percentage value of power relative to the energy
object's nameplate power
o an indication of power relative to another power
state. For example: Specify that power in state A is
less than in state B.
o For supporting Power State management an Energy
Object provides statistics on Power States including
the time an Energy Object spent in a certain Power
State and the number of times an Energy Object
entered a power state.
When requesting an Energy Object to enter a Power State an
indication of the Power State's name or number can be used.
Optionally an absolute or percentage of Nameplate Power can
be provided to allow the Energy Object to transition to a
nearest or equivalent Power State.
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When an Energy Object is set to a particular Power State,
the represented device or component may be busy. The Energy
Object should set the desired Power State and then update
the actual Power State when the device or component
changes. There are then two Power State (Class) control
attributes: actual and requested.
The following sections describe well-known Power States for
devices and components that should be modeled in the
information model.
6.5.1. Power State Sets
There are several standards and implementations of Power
State Sets. The Energy Object (Class) support modeling one
or multiple Power State Set implementation(s) on the device
or component concurrently.
There are currently three Power State Sets advocated:
IEEE1621(256) - [IEEE1621]
DMTF(512) - [DMTF]
EMAN(768) - [EMAN-MON-MIB]
The respective specific states related to each Power State
Set are specified in the following sections. The guidelines
for the modification of Power State Sets are specified in
the IANA Considerations Section.
6.5.2. Power State Set: IEEE1621
The IEEE1621 Power State Set [IEEE1621] consists of 3
rudimentary states: on, off or sleep.
In IEEE1621 devices are limited to the three basic power
states' on, sleep, and off. Any additional power states
are variants of one of the basic states rather than a
fourth state [IEEE1621].
6.5.3. Power State Set: DMTF
The DMTF [DMTF] standards organization has defined a power
profile standard based on the CIM (Common Information
Model) model that consists of 15 power states:
{ON (2), SleepLight (3), SleepDeep (4), Off-Hard (5), Off-
Soft (6), Hibernate(7), PowerCycle Off-Soft (8), PowerCycle
Off-Hard (9), MasterBus reset (10), Diagnostic Interrupt
(11), Off-Soft-Graceful (12), Off-Hard Graceful (13),
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MasterBus reset Graceful (14), Power-Cycle Off-Soft
Graceful (15), PowerCycle-Hard Graceful (16)}
The DMTF standard is targeted for hosts and computers.
Details of the semantics of each Power State within the
DMTF Power State Set can be obtained from the DMTF Power
State Management Profile specification [DMTF].
The DMTF power profile extends ACPI power states. The
following table provides a mapping between DMTF and ACPI
Power State Set:
DMTF ACPI
Reserved(0)
Reserved(1)
ON (2) G0-S0
Sleep-Light (3) G1-S1 G1-S2
Sleep-Deep (4) G1-S3
Power Cycle (Off-Soft) (5) G2-S5
Off-hard (6) G3
Hibernate (Off-Soft) (7) G1-S4
Off-Soft (8) G2-S5
Power Cycle (Off-Hard) (9) G3
Master Bus Reset (10) G2-S5
Diagnostic Interrupt (11) G2-S5
Off-Soft Graceful (12) G2-S5
Off-Hard Graceful (13) G3
MasterBus Reset Graceful (14) G2-S5
Power Cycle off-soft Graceful (15) G2-S5
Power Cycle off-hard Graceful (16) G3
6.5.4. Power State Set: IETF EMAN
The EMAN Power States are an expansion of the basic Power
States as defined in [IEEE1621] that also incorporates the
Power States defined in [ACPI] and [DMTF]. Therefore, in
addition to the non-operational states as defined in [ACPI]
and [DMTF] standards, several intermediate operational
states have been defined.
Physical devices and components are expected to support the
EMAN Power State Set or to be modeled via an Energy Object
the supports these states.
An Energy Object may implement fewer or more Power States
than a particular EMAN Power State Set specifies. In that
case, the Energy Object implementation can determine its
own mapping to the predefined EMAN Power States within the
EMAN Power State Set.
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There are twelve EMAN Power States that expand on
[IEEE1621]. The expanded list of Power States is derived
from [CISCO-EW] and is divided into six operational states
and six non-operational states.
The lowest non-operational state is 1 and the highest is 6.
Each non-operational state corresponds to an [ACPI] Global
and System state between G3 (hard-off) and G1 (sleeping).
Each operational state represents a performance state, and
may be mapped to [ACPI] states P0 (maximum performance
power) through P5 (minimum performance and minimum power).
In each of the non-operational states (from mechoff(1) to
ready(6)), the Power State preceding it is expected to have
a lower Power value and a longer delay in returning to an
operational state:
mechoff(1) : An off state where no Energy Object
features are available. The Energy Object is unavailable.
No energy is being consumed and the power connector can be
removed.
softoff(2) : Similar to mechoff(1), but some
components remain powered or receive trace power so that
the Energy Object can be awakened from its off state. In
softoff(2), no context is saved and the device typically
requires a complete boot when awakened.
hibernate(3): No Energy Object features are
available. The Energy Object may be awakened without
requiring a complete boot, but the time for availability is
longer than sleep(4). An example for state hibernate(3) is
a save to-disk state where DRAM context is not maintained.
Typically, energy consumption is zero or close to zero.
sleep(4) : No Energy Object features are
available, except for out-of-band management, such as wake-
up mechanisms. The time for availability is longer than
standby(5). An example for state sleep(4) is a save-to-RAM
state, where DRAM context is maintained. Typically, energy
consumption is close to zero.
standby(5) : No Energy Object features are
available, except for out-of-band management, such as wake-
up mechanisms. This mode is analogous to cold-standby.
The time for availability is longer than ready(6). For
example processor context is may not be maintained.
Typically, energy consumption is close to zero.
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ready(6) : No Energy Object features are
available, except for out-of-band management, such as wake-
up mechanisms. This mode is analogous to hot-standby. The
Energy Object can be quickly transitioned into an
operational state. For example, processors are not
executing, but processor context is maintained.
lowMinus(7) : Indicates some Energy Object
features may not be available and the Energy Object has
taken measures or selected options to use less energy than
low(8).
low(8) : Indicates some features may not be
available and the Energy Object has taken measures or
selected options to use less energy than mediumMinus(9).
mediumMinus(9): Indicates all Energy Object
features are available but the Energy Object has taken
measures or selected options to use less energy than
medium(10).
medium(10) : Indicates all Energy Object features
are available but the Energy Object has taken measures or
selected options to use less energy than highMinus(11).
highMinus(11): Indicates all Energy Object
features are available and has taken measures or selected
options to use less energy than high(12).
high(12) : Indicates all Energy Object features
are available and the Energy Object may use the maximum
energy as indicated by the Nameplate Power.
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6.5.5. Power State Sets Comparison
A comparison of Power States from different Power State
Sets can be seen in the following table:
IEEE1621 DMTF ACPI EMAN
Non-operational states
off Off-Hard G3, S5 MechOff(1)
off Off-Soft G2, S5 SoftOff(2)
off Hibernate G1, S4 Hibernate(3)
sleep Sleep-Deep G1, S3 Sleep(4)
sleep Sleep-Light G1, S2 Standby(5)
sleep Sleep-Light G1, S1 Ready(6)
Operational states:
on on G0, S0, P5 LowMinus(7)
on on G0, S0, P4 Low(8)
on on G0, S0, P3 MediumMinus(9)
on on G0, S0, P2 Medium(10)
on on G0, S0, P1 HighMinus(11)
on on G0, S0, P0 High(12)
6.6. Relationships
The Energy Object (Class) contains a set of Relationship
(Class) attributes to model the relationships between
devices and components. Two Energy Objects can establish
an Energy Object Relationship to model the deployment
topology with respect to Energy Management.
Relationships are modeled with a Relationship (Class) that
contains the UUID of the other participant in the
relationship and a name that describes the type of
relationship [CHEN]. The types of relationships are: Power
Source, Metering, and Aggregations.
o A Power Source Relationship is relationship where one
Energy Object provides power to one or more Energy
Objects. The Power Source Relationship gives a view
of the physical wiring topology. For example: a data
center server receiving power from two specific Power
Interfaces from two different PDUs.
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Note: A Power Source Relationship may or may not
change as the direction of power changes between two
Energy Objects. The relationship may remain to
indicate the change of power direction was unintended
or an error condition.
o A Metering Relationship is relationship where one
Energy Object measures power, energy, demand or Power
Attributes of one or more other Energy Objects. The
Metering Relationship gives the view of the metering
topology. Physical meters can be placed anywhere in
a power distribution tree. For example, utility
meters monitor and report accumulated power
consumption of the entire building. Logically, the
metering topology overlaps with the wiring topology,
as meters are connected to the wiring topology. A
typical example is meters that clamp onto the
existing wiring.
o An Aggregation Relationship is a relationship where
one Energy Object aggregates Energy Management
information of one or more other Energy Objects. The
Aggregation Relationship gives a model of devices
that may aggregate (sum, average, etc) values for
other devices. The Aggregation Relationship is
slightly different compared to the other
relationships as this refers more to a management
function.
In some situations, it is not possible to discover the
Energy Object relationships, and an EnMS or administrator
must set them. Given that relationships can be assigned
manually, the following sections describe guidelines for
use.
6.6.1. Relationship Conventions and Guidelines
This Energy Management framework does not impose many
"MUST" rules related to Energy Object Relationships. There
are always corner cases that could be excluded with too
strict specifications of relationships. However, the
framework proposes a series of guidelines, indicated with
"SHOULD" and "MAY".
6.6.2. Guidelines: Power Source
Power Source relationships are intended to identify the
connections between Power Interfaces. This is analogous to
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a Layer 2 connection in networking devices (a "one-hop
connection").
The preferred modeling would be for Power Interfaces to
participate in Power Source Relationships. It some cases
Energy Objects may not have the capability to model Power
Interfaces. Therefore a Power Source Relationship can be
established between two Energy Objects or two non-connected
Power Interfaces.
While strictly speaking Components and Power Interfaces on
the same Device do provide or receive energy from each
other, the Power Source relationship is intended to show
energy transfer between Devices. Therefore the relationship
is implied when on the same Device.
An Energy Object SHOULD NOT establish a Power Source
Relationship with a Component.
o A Power Source Relationship SHOULD be established
with the next known Power Interface in the wiring
topology.
o The next known Power Interface in the wiring topology
would be the next device implementing the framework.
In some cases the domain of devices under management
may include some devices that do not implement the
framework. In these cases, the Power Source
relationship can be established with the next device
in the topology that implements the framework and
logically shows the Power Source of the device.
o Transitive Power Source relationships SHOULD NOT be
established. For example, if an Energy Object A has
a Power Source Relationship "Poweredby" with the
Energy Object B, and if the Energy Object B has a
Power Source Relationship "Poweredby" with the Energy
Object C, then the Energy Object A SHOULD NOT have a
Power Source Relationship "Poweredby" with the Energy
Object C.
6.6.3. Guidelines: Metering Relationship
Metering Relationships are intended to show when one device
acting as a meter is measuring the power or energy at a
point in a power distribution system. Since one point of a
power distribution system may cover many devices within a
wiring topology, this relationship type can be seen as a
set.
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Some devices, however, may include measuring hardware for
components, and outlets or for the entire device. For
example, some PDUs may have the ability to measure power
for each outlet and are commonly referred to as metered-by-
outlet. Others may be able to control power at each power
outlet but can only measure power at the power inlet -
commonly referred to as metered-by-device.
While the Metering Relationship could be used to represent
a device as metered-by-outlet or metered-by-device, the
Metering Relationship SHOULD be used to model the
relationship between a meter and all devices covered by the
meter downstream in the power distribution system
In general:
o A Metering Relationship MAY be established with any
other Energy Object, Component, or Power Interface.
o Transitive Metering Relationships MAY be used.
o When there is a series of meters for one Energy
Object, the Energy Object MAY establish a Metering
relationship with one or more of the meters.
6.6.4. Guidelines: Aggregation
Aggregation relationships are intended to identify when one
device is used to accumulate values from other devices.
Typically this is for energy or power values among devices
and not for Components or Power Interfaces on the same
device.
The intent of Aggregation relationships is to indicate when
one device is providing aggregate values for a set of other
devices when it is not obvious from the power source or
simple containment within a device.
Establishing aggregation relationships within the same
device would make modeling more complex and the aggregated
values can be implied from the use of Power Inlets, outlet
and Energy Object values on the same device.
Since an EnMS is naturally a point of aggregation it is not
necessary to model aggregation for Energy Management
Systems.
The Aggregation Relationship is intended for power and
energy. It MAY be used for aggregation of other values from
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the information model, but the rules and logical ability to
aggregate each attribute is out of scope for this document.
In general:
o A Device SHOULD NOT establish an Aggregation
Relationship with Components contained on the same
device.
o A Device SHOULD NOT establish an Aggregation
Relationship with the Power Interfaces contained on
the same device.
o A Device SHOULD NOT establish an Aggregation
Relationship with an EnMS.
o Aggregators SHOULD log or provide notification in the
case of errors or missing values while performing
aggregation.
6.6.5. Energy Object Relationship Extensions
This framework for Energy Management is based on three
relationship types: Aggregation , Metering, and Power
Source.
This framework is defined with possible future extension of
new Energy Object Relationships in mind.
For example:
o Some Devices that may not be IP connected. This can
be modeled with a proxy relationship to an Energy
Object within the domain. This type of proxy
relationship is left for further development.
o A Power Distribution Unit (PDU) that allows devices
and components like outlets to be "ganged" together
as a logical entity for simplified management
purposes, could be modeled with an extension called a
"gang relationship", whose semantics would specify
the Energy Objects' grouping.
7. Energy Management Information Model
This section presents an information model expression of
the concepts in this framework as a reference for
implementers. The information model is implemented as a MIB
in the different related IETF EMAN documents. However,
other programming structures with different data models
could be used as well.
Data modeling specifications of this information model may
where needed specify which attributes are required or
optional.
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EDITORs NOTE: The working group is converging on the use
of code/pseudo-code rather than ascii UML diagram. If so we
would have to define primitive type as reference (eg. Int,
string, etc)If agreeable we can indicate a BNF syntax in a
formal syntax section, use a schema definition from
JSON/XML, or use the following table if obvious:
Syntax
UML Construct
[ISO-IEC-19501-2005] Equivalent Notation
-------------------- ------------------------------------
Notes // Notes
Class
(Generalization) CLASS name {member..}
Sub-Class
(Specialization) CLASS subclass
EXTENDS superclass {member..}
Class Member
(Attribute) attribute : type
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Model
CLASS EnergyObject {
// identification / classification
index : int
identifier : uuid
alternatekey : string
// context
domainName : string
role : string
keywords [0..n] : string
importance : int
// relationship
relationships [0..n] : Relationship
// measurements
nameplate : Nameplate
power : PowerMeasurement
energy : EnergyMeasurment
demand : DemandMeasurement
// control
powerControl [0..n] : PowerStateSet
}
CLASS PowerInterface EXTENDS EnergyObject{
eoIfType : enum { inlet, outlet, both}
}
CLASS Device EXTENDS EnergyObject {
eocategory : enum { producer, consumer, meter,
distributor, store }
powerInterfaces[0..n]: PowerInterface
components [0..n] Component
}
CLASS Component EXTENDS EnergyObject
eocategory : enum { producer, consumer, meter,
distributor, store }
powerInterfaces[0..n]: PowerInterface
components [0..n] Component
}
// EDITOR NOTE: Component could sub-class from Device
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CLASS Nameplate {
nominalPower : PowerMeasurement
details : URI
}
CLASS Relationship {
relationshipType : enum { meters, meteredby,
powers, poweredby, aggregates, aggregatedby }
relationshipObject : uuid
}
CLASS Measurement {
multiplier: enum { -24..24}
caliber : enum { actual, estimated, static }
accuracy : enum { 0..10000} // hundreds of percent
}
CLASS PowerMeasurement EXTENDS Measurement {
value : long
units : "W"
powerAttribute : PowerAttribute
}
CLASS EnergyMeasurement EXTENDS Measurement {
startTime : time
units : "kWh"
provided : long
used : long
produced : long
stored : long
}
CLASS TimedMeasurement EXTENDS Measurement {
startTime : timestamp
value : Measurement
maximum : Measurement
}
CLASS TimeInterval {
value : long
units : enum { seconds, miliseconds,...}
}
CLASS DemandMeasurement EXTENDS Measurement {
intervalLength : TimeInterval
interval : long
intervalMode : enum { periodic, sliding, total }
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intervalWindow : TimeInterval
sampleRate : TimeInterval
status : enum { active, inactive }
measurements[0..n] : TimedMeasurements
}
CLASS PowerStateSet {
powerSetIdentifier : int
name : string
powerStates [0..n] : PowerState
operState : int
adminState : int
reason : string
configuredTime : timestamp
}
CLASS PowerState {
powerStateIdentifier : int
name : string
cardinality : int
maximumPower : PowerMeasurement
totalTimeInState : time
entryCount : long
}
CLASS PowerAttribute {
acQuality : ACQuality
}
CLASS ACQuality {
acConfiguration : enum {SNGL, DEL,WYE}
avgVoltage : long
avgCurrent : long
frequency : long
unitMultiplier : int
accuracy : int
totalActivePower : long
totalReactivePower : long
totalApparentPower : long
totalPowerFactor : long
phases [0..2] : ACPhase
}
CLASS ACPhase {
phaseIndex : long
avgCurrent : long
activePower : long
reactivePower : long
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apparentPower : long
powerFactor : long
}
CLASS DelPhase EXTENDS ACPhase {
phaseToNextPhaseVoltage : long
thdVoltage : long
thdCurrent : long
}
CLASS WYEPhase EXTENDS ACPhase {
phaseToNeutralVoltage : long
thdCurrent : long
thdVoltage : long
}
8. Modeling Relationships between Devices
In this section we give examples of how to use the EMAN
information model to model physical topologies. Where
applicable, we show how the framework can be applied when
devices can be modeled with Power Interfaces. We also show
how the framework can be applied when devices cannot be
modeled with Power Interfaces but only monitored or control
as a whole. For instance, a PDU may only be able to measure
power and energy for the entire unit without the ability to
distinguish among the inlets or outlets.
8.1. Power Source Relationship
The Power Source relationship is used to model the
interconnections between devices, components and/Power
Interfaces to indicate the source of energy for a device.
In the following examples we show variations on modeling
the reference topologies using relationships.
Given for all cases:
Device W: A computer with one power supply. Power Interface
1 is an inlet for Device W.
Device X: A computer with two power supplies. Power
Interface 1 and power interface 2 are both inlets for
Device X.
Device Y: A PDU with multiple Power Interfaces numbered
0..10. Power Interface 0 is an inlet and Power Interface
1..10 are outlets.
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Device Z: A PDU with multiple Power Interfaces numbered
0..10. Power Interface 0 is an inlet and Power Interface
1..10 are outlets.
Case 1: Simple Device with one Source
Physical Topology:
o Device W inlet 1 is plugged into Device Y outlet 8.
With Power Interfaces:
o Device W has an Energy Object representing the
computer itself as well as one Power Interface
defined as an inlet.
o Device Y would have an Energy Object representing the
PDU itself (the Device), with a Power Interface 0
defined as an inlet and Power Interfaces 1..10
defined as outlets.
The interfaces of the devices would have a Power Source
Relationship such that:
Device W inlet 1 is powered by Device Y outlet 8.
+-------+------+ poweredBy +------+----------+
| PDU Y | PI 8 |-----------------| PI 1 | Device W |
+-------+------+ powers +------+----------+
Without Power Interfaces:
o Device W has an Energy Object representing the
computer.
o Device Y would have an Energy Object representing the
PDU.
The devices would have a Power Source Relationship such
that:
Device W is powered by Device Y.
+----------+ poweredBy +------------+
| PDU Y |-----------------| Device W |
+----------+ powers +------------+
Case 2: Multiple Inlets
Physical Topology:
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o Device X inlet 1 is plugged into Device Y outlet 8.
o Device X inlet 2 is plugged into Device Y outlet 9.
With Power Interfaces:
o Device X has an Energy Object representing the
computer itself. It contains two Power Interfaces
defined as inlets.
o Device Y would have an Energy Object representing the
PDU itself (the Device), with a Power Interface 0
defined as an inlet and Power Interfaces 1..10
defined as outlets.
The interfaces of the devices would have a Power Source
Relationship such that:
Device X inlet 1 is powered by Device Y outlet 8.
Device X inlet 2 is powered by Device Y outlet 9.
+-------+------+ poweredBy+------+----------+
| | PI 8 |-----------------| PI 1 | |
| | |powers | | |
| PDU Y +------+ poweredBy+------+ Device X |
| | PI 9 |-----------------| PI 2 | |
| | |powers | | |
+-------+------+ +------+----------+
Without Power Interfaces:
o Device X has an Energy Object representing the
computer. Device Y has an Energy Object representing
the PDU.
The devices would have a Power Source Relationship such
that:
Device X is powered by Device Y.
+----------+ poweredBy +------------+
| PDU Y |-----------------| Device X |
+----------+ powers +------------+
Case 3: Multiple Sources
Physical Topology:
o Device X inlet 1 is plugged into Device Y outlet 8.
o Device X inlet 2 is plugged into Device Z outlet 9.
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With Power Interfaces:
o Device X has an Energy Object representing the
computer itself. It contains two Power Interface
defined as inlets.
o Device Y would have an Energy Object representing the
PDU itself (the Device), with a Power Interface 0
defined as an inlet and Power Interfaces 1..10
defined as outlets.
o Device Z would have an Energy Object representing the
PDU itself (the Device), with a Power Interface 0
defined as an inlet and Power Interfaces 1..10
defined as outlets.
The interfaces of the devices would have a Power Source
Relationship such that:
Device X inlet 1 is powered by Device Y outlet 8.
Device X inlet 2 is powered by Device Z outlet 9.
+-------+------+ poweredBy+------+----------+
| PDU Y | PI 8 |-----------------| PI 1 | |
| | |powers | | |
+-------+------+ +------+ |
| Device X |
+-------+------+ poweredBy+------+ |
| PDU Z | PI 9 |-----------------| PI 2 | |
| | |powers | | |
+-------+------+ +------+----------+
Without Power Interfaces:
o Device X has an Energy Object representing the
computer. Device Y and Z would both have respective
Energy Objects representing each entire PDU.
The devices would have a Power Source Relationship such
that:
Device X is powered by Device Y and powered by Device Z.
+----------+ poweredBy +------------+
| PDU Y |---------------------| Device X |
+----------+ powers +------------+
+----------+ poweredBy +------------+
| PDU Z |---------------------| Device X |
+----------+ powers +------------+
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8.2. Metering Relationship
A meter in a power distribution system can logically
measure the power or energy for all devices downstream from
the meter in the power distribution system. As such, a
Metering relationship can be seen as a relationship between
a meter and all of the devices downstream from the meter.
We define in this case a Metering relationship between a
meter and devices downstream from the meter.
+-----+---+ meteredBy +--------+ poweredBy +-------+
|Meter| PI|--------------| switch |-------------| phone |
+-----+---+ meters +--------+ powers +-------+
| |
| meteredBy |
+-------------------------------------------+
meters
In cases where the Power Source topology cannot be
discovered or derived from the information available in the
Energy Management Domain, the metering topology can be used
to relate the upstream meter to the downstream devices in
the absence of specific Power Source relationships.
A Metering Relationship can occur between devices that are
not directly connected, as shown in the following figure:
+---------------+
| Device 1 |
+---------------+
| PI |
+---------------+
|
+---------------+
| Meter |
+---------------+
.
.
.
meters meters meters
+----------+ +----------+ +-----------+
| Device A | | Device B | | Device C |
+----------+ +----------+ +-----------+
An analogy to communications networks would be modeling
connections between servers (meters) and clients (devices)
when the complete Layer 2 topology between the servers and
clients is not known.
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8.3. Aggregation Relationship
Some devices can act as aggregation points for other
devices. For example, a PDU controller device may contain
the summation of power and energy readings for many PDU
devices. The PDU controller will have aggregate values for
power and energy for a group of PDU devices.
This aggregation is independent of the physical power or
communication topology.
The functions that the aggregation point may perform
include the calculation of values such as average, count,
maximum, median, minimum, or the listing (collection) of
the aggregation values, etc.
Based on the experience gained on aggregations at the IETF
[draft-ietf-ipfix-a9n-08], the aggregation function in the
EMAN framework is limited to the summation.
When aggregation occurs across a set of entities, values to
be aggregated may be missing for some entities. The EMAN
framework does not specify how these should be treated, as
different implementations may have good reason to take
different approaches. One common treatment is to define
the aggregation as missing if any of the constituent
elements are missing (useful to be most precise). Another
is to treat the missing value as zero (useful to have
continuous data streams).
The specifications of aggregation functions are out of
scope of the EMAN framework, but must be clearly specified
by the equipment vendor.
9. Relationship to Other Standards
This Energy Management framework uses, as much as possible,
existing standards especially with respect to information
modeling and data modeling [RFC3444].
The data model for power- and energy-related objects is
based on [IEC61850].
Specific examples include:
o The scaling factor, which represents Energy Object
usage magnitude, conforms to the [IEC61850]
definition of unit multiplier for the SI (System
International) units of measure.
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o The electrical characteristic is based on the ANSI
and IEC Standards, which require that we use an
accuracy class for power measurement. ANSI and IEC
define the following accuracy classes for power
measurement:
o IEC 62053-22 60044-1 class 0.1, 0.2, 0.5, 1 3.
o ANSI C12.20 class 0.2, 0.5
o The electrical characteristics and quality adhere
closely to the [IEC61850-7-2] standard for describing
AC measurements.
o The power state definitions are based on the DMTF
Power State Profile and ACPI models, with operational
state extensions.
10. Security Considerations
Regarding the data attributes specified here, some or all
may be considered sensitive or vulnerable in some network
environments. Reading or writing these attributes without
proper protection such as encryption or access
authorization may have negative effects on the network
capabilities.
10.1. Security Considerations for SNMP
Readable objects in MIB modules (i.e., objects with a MAX-
ACCESS other than not-accessible) may be considered
sensitive or vulnerable in some network environments. It
is important to control GET and/or NOTIFY access to these
objects and possibly to encrypt the values of these objects
when sending them over the network via SNMP.
The support for SET operations in a non-secure environment
without proper protection can have a negative effect on
network operations.
For example:
o Unauthorized changes to the Energy Management Domain
or business context of a device may result in
misreporting or interruption of power.
o Unauthorized changes to a power state may disrupt the
power settings of the different devices, and
therefore the state of functionality of the
respective devices.
o Unauthorized changes to the demand history may
disrupt proper accounting of energy usage.
With respect to data transport, SNMP versions prior to
SNMPv3 did not include adequate security. Even if the
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network itself is secure (for example, by using IPsec),
there is still no secure control over who on the secure
network is allowed to access and GET/SET
(read/change/create/delete) the objects in these MIB
modules.
It is recommended that implementers consider the security
features as provided by the SNMPv3 framework (see
[RFC3410], section 8), including full support for the
SNMPv3 cryptographic mechanisms (for authentication and
privacy).
Further, deployment of SNMP versions prior to SNMPv3 is not
recommended. Instead, it is recommended to deploy SNMPv3
and to enable cryptographic security. It is then a
customer/operator responsibility to ensure that the SNMP
entity giving access to an instance of these MIB modules is
properly configured to give access to the objects only to
those principals (users) that have legitimate rights to GET
or SET (change/create/delete) them.
11. IANA Considerations
11.1. IANA Registration of new Power State Sets
This document specifies an initial set of Power State Sets.
The list of these Power State Sets with their numeric
identifiers is given is Section 6. IANA maintains the lists
of Power State Sets.
New assignments for Power State Set are administered by
IANA through Expert Review [RFC5226], i.e., review by one
of a group of experts designated by an IETF Area Director.
The group of experts MUST check the requested state for
completeness and accuracy of the description. A pure vendor
specific implementation of Power State Set shall not be
adopted; since it would lead to proliferation of Power
State Sets.
Power states in a Power State Set are limited to 255
distinct values. New Power State Set must be assigned the
next available numeric identifier that is a multiple of
256.
11.1.1. IANA Registration of the IEEE1621 Power State Set
This document specifies a set of values for the IEEE1621
Power State Set [IEEE1621]. The list of these values with
their identifiers is given in Section 6.6.2. IANA created
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a new registry for IEEE1621 Power State Set identifiers and
filled it with the initial list of identifiers.
New assignments (or potentially deprecation) for the
IEEE1621 Power State Set is administered by IANA through
Expert Review [RFC5226], i.e., review by one of a group of
experts designated by an IETF Area Director. The group of
experts must check the requested state for completeness and
accuracy of the description.
11.1.2. IANA Registration of the DMTF Power State Set
This document specifies a set of values for the DMTF Power
State Set. The list of these values with their identifiers
is given in Section 6. IANA has created a new registry for
DMTF Power State Set identifiers and filled it with the
initial list of identifiers.
New assignments (or potentially deprecation) for the DMTF
Power State Set is administered by IANA through Expert
Review [RFC5226], i.e., review by one of a group of experts
designated by an IETF Area Director. The group of experts
must check the conformance with the DMTF standard [DMTF],
on the top of checking for completeness and accuracy of the
description.
11.1.3. IANA Registration of the EMAN Power State Set
This document specifies a set of values for the EMAN Power
State Set. The list of these values with their identifiers
is given in Section 6.6.4. IANA has created a new registry
for EMAN Power State Set identifiers and filled it with the
initial list of identifiers.
New assignments (or potentially deprecation) for the EMAN
Power State Set is administered by IANA through Expert
Review [RFC5226], i.e., review by one of a group of experts
designated by an IETF Area Director. The group of experts
must check the requested state for completeness and
accuracy of the description.
11.1.4. Batteries Power State Set
Batteries have operational and administrational states that
could be represented as a Power State Set. Since the work
for battery management is parallel to this document, we are
not proposing any Power State Sets for batteries at this
time.
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11.2. Updating the Registration of Existing Power State Sets
With the evolution of standards, over time, it may be
important to deprecate some of the existing the Power State
Sets, or to add or deprecate some Power States within a
Power State Set.
The registrant shall publish an Internet-draft or an
individual submission with the clear specification on
deprecation of Power State Sets or Power States registered
with IANA. The deprecation or addition shall be
administered by IANA through Expert Review [RFC5226], i.e.,
review by one of a group of experts designated by an IETF
Area Director. The process should also allow for a
mechanism for cases where others have significant
objections to claims on deprecation of a registration.
12. References
Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to
Indicate Requirement Levels", BCP 14, RFC 2119,
March 1997
[RFC3410] Case, J., Mundy, R., Partain, D., and B.
Stewart, "Introduction and Applicability
Statements for Internet Standard Management
Framework ", RFC 3410, December 2002
[RFC4122] Leach, P., Mealling, M., and R. Salz," A
Universally Unique Identifier (UUID) URN
Namespace", RFC 4122, July 2005
[RFC5226] Narten, T., and H. Alvestrand, "Guidelines for
Writing an IANA Considerations Section in RFCs",
RFC 5226, May 2008
[RFC6933] Bierman, A. and K. McCloghrie, "Entity MIB
(Version4)", RFC 6933, May 2013
[RFC3444] Pras, A., Schoenwaelder, J. "On the Differences
between Information Models and Data Models", RFC
3444, January 2003
[ISO-IEC-19501-2005] ISO/IEC 19501:2005, Information
technology, Open Distributed Processing --
Unified Modeling Language (UML), January 2005
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Informative References
[RFC2578] McCloghrie, K., Perkins, D., and J.
Schoenwaelder, "Structure of Management
Information Version 2 (SMIv2", RFC 2578, April
1999
[RFC5101bis] Claise, B., Ed., and Trammel, T., Ed.,
"Specification of the IP Flow Information Export
(IPFIX) Protocol for the Exchange of IP Traffic
Flow Information ", draft-ietf-ipfix-protocol-
rfc5101bis-08, (work in progress), June 2013
[RFC6020] M. Bjorklund, Ed., " YANG - A Data Modeling
Language for the Network Configuration Protocol
(NETCONF)", RFC 6020, October 2010
[ACPI] "Advanced Configuration and Power Interface
Specification", http://www.acpi.info/spec30b.htm
[IEEE1621] "Standard for User Interface Elements in Power
Control of Electronic Devices Employed in
Office/Consumer Environments", IEEE 1621,
December 2004
[LLDP] IEEE Std 802.1AB, "Station and Media Control
Connectivity Discovery", 2005
[LLDP-MED-MIB] ANSI/TIA-1057, "The LLDP Management
Information Base extension module for TIA-TR41.4
media endpoint discovery information", July 2005
[EMAN-REQ] Quittek, J., Winter, R., Dietz, T., Claise, B.,
and M. Chandramouli, "Requirements for Energy
Management", draft-ietf-eman-requirements-14,
(work in progress), May 2013
[EMAN-OBJECT-MIB] Parello, J., and B. Claise, "Energy
Object Contet MIB", draft-ietf-eman-energy-aware-
mib-08, (work in progress), April 2013
[EMAN-MON-MIB] Chandramouli, M.,Schoening, B., Quittek, J.,
Dietz, T., and B. Claise, "Power and Energy
Monitoring MIB", draft-ietf-eman-energy-
monitoring-mib-05, (work in progress), April 2013
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[EMAN-BATTERY-MIB] Quittek, J., Winter, R., and T. Dietz, "
Definition of Managed Objects for Battery
Monitoring", draft-ietf-eman-battery-mib-08,
(work in progress), February 2013
[EMAN-AS] Schoening, B., Chandramouli, M., and B. Nordman,
"Energy Management (EMAN) Applicability
Statement", draft-ietf-eman-applicability-
statement-03, (work in progress), April 2013
[ITU-T-M-3400] TMN Recommendation on Management Functions
(M.3400), 1997
[NMF] "Network Management Fundamentals", Alexander Clemm,
ISBN: 1-58720-137-2, 2007
[TMN] "TMN Management Functions : Performance Management",
ITU-T M.3400
[IEEE100] "The Authoritative Dictionary of IEEE Standards
Terms"
http://ieeexplore.ieee.org/xpl/mostRecentIssue.js
p?punumber=4116785
[ISO50001] "ISO 50001:2011 Energy management systems -
Requirements with guidance for use",
http://www.iso.org/
[IEC60050] International Electrotechnical Vocabulary
http://www.electropedia.org/iev/iev.nsf/welcome?o
penform
[IEC61850] Power Utility Automation,
http://www.iec.ch/smartgrid/standards/
[IEC61850-7-2] Abstract communication service interface
(ACSI), http://www.iec.ch/smartgrid/standards/
[IEEE-802.3at] IEEE 802.3 Working Group, "IEEE Std 802.3at-
2009 - IEEE Standard for Information technology -
Telecommunications and information exchange
between systems - Local and metropolitan area
networks - Specific requirements - Part 3:
Carrier Sense Multiple Access with Collision
Detection (CSMA/CD) Access Method and Physical
Layer Specifications - Amendment: Data Terminal
Equipment (DTE) - Power via Media Dependent
Interface (MDI) Enhancements", October 2009
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[DMTF] "Power State Management Profile DMTF DSP1027
Version 2.0" December 2009
http://www.dmtf.org/sites/default/files/standards
/documents/DSP1027_2.0.0.pdf
[IPENERGY] R. Aldrich, J. Parello "IP-Enabled Energy
Management", 2010, Wiley Publishing
[X.700] CCITT Recommendation X.700 (1992), Management
framework for Open Systems Interconnection (OSI)
for CCITT applications
[ASHRAE-201] "ASHRAE Standard Project Committee 201
(SPC 201)Facility Smart Grid Information
Model", http://spc201.ashraepcs.org
[CHEN] "The Entity-Relationship Model: Toward a Unified
View of Data", Peter Pin-shan Chen, ACM
Transactions on Database Systems, 1976
[CISCO-EW] "Cisco EnergyWise Design Guide", John Parello,
Roland Saville, Steve Kramling, Cisco Validated
Designs, September 2010,
http://www.cisco.com/en/US/docs/solutions/Enterpr
ise/Borderless_Networks/Energy_Management/energyw
isedg.html
13. Acknowledgments
The authors would like to thank Michael Brown for his
editorial work improving the text dramatically. Thanks to
Rolf Winter for his feedback and to Bill Mielke for
feedback and very detailed review. Thanks to Bruce Nordman
for brainstorming with numerous conference calls and
discussions. Finally, the authors would like to thank the
EMAN chairs: Nevil Brownlee, Bruce Nordman, and Tom Nadeau.
This document was prepared using 2-Word-v2.0.template.dot.
Authors' Addresses
John Parello
Cisco Systems, Inc.
3550 Cisco Way
San Jose, California 95134
US
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Phone: +1 408 525 2339
Email: jparello@cisco.com
Benoit Claise
Cisco Systems, Inc.
De Kleetlaan 6a b1
Diegem 1813
BE
Phone: +32 2 704 5622
Email: bclaise@cisco.com
Brad Schoening
44 Rivers Edge Drive
Little Silver, NJ 07739
US
Phone:
Email: brad.schoening@verizon.net
Juergen Quittek
NEC Europe Ltd.
Network Laboratories
Kurfuersten-Anlage 36
69115 Heidelberg
Germany
Phone: +49 6221 90511 15
EMail: quittek@netlab.nec.de
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