Network Working Group J. Quittek, Ed.
Internet-Draft R. Winter
Intended status: Informational T. Dietz
Expires: January 12, 2012 NEC Europe Ltd.
B. Claise
M. Chandramouli
Cisco Systems, Inc.
July 11, 2011
Requirements for Energy Management
draft-ietf-eman-requirements-04
Abstract
This document defines requirements for standards specifications for
energy management. Defined requirements concern monitoring functions
as well as control functions. Covered functions include
identification of powered entities, monitoring of their power state,
power inlets, power outlets, actual power, consumed energy, and
contained batteries. Further included is control of powered
entities' power supply and power state. This document does not
specify the features that must be implemented by compliant
implementations but rather features that must be supported by
standards for energy management.
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
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Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 12, 2012.
Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Conventional requirements for energy management . . . . . 4
1.2. Specific requirements for energy management . . . . . . . 5
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6
3. General Objectives of Energy Management . . . . . . . . . . . 8
3.1. Power states . . . . . . . . . . . . . . . . . . . . . . 8
3.2. Trade-offs . . . . . . . . . . . . . . . . . . . . . . . 8
3.3. Local and network-wide energy management . . . . . . . . 8
3.4. Energy monitoring . . . . . . . . . . . . . . . . . . . . 9
3.5. Overview of energy management requirements . . . . . . . 10
4. Identification of Powered Entities . . . . . . . . . . . . . . 10
5. Information on Powered Entities . . . . . . . . . . . . . . . 11
5.1. General information on powered entities . . . . . . . . . 11
5.2. Power state . . . . . . . . . . . . . . . . . . . . . . . 12
5.3. Power inlet and power outlet . . . . . . . . . . . . . . 14
5.4. Power . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.5. Energy . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.6. Battery State . . . . . . . . . . . . . . . . . . . . . . 19
6. Control of Powered Entities . . . . . . . . . . . . . . . . . 21
7. Reporting on Other Powered Entities . . . . . . . . . . . . . 22
8. Controlling Other Powered Entities . . . . . . . . . . . . . . 23
8.1. Controlling power states of other powered entities . . . 23
8.2. Controlling power supply of other powered entities . . . 24
9. Security Considerations . . . . . . . . . . . . . . . . . . . 25
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26
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11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 26
12. Open issues . . . . . . . . . . . . . . . . . . . . . . . . . 26
12.1. Revise security considerations . . . . . . . . . . . . . 26
12.2. High/Low power notifications . . . . . . . . . . . . . . 26
12.3. Power and energy time series? . . . . . . . . . . . . . . 26
12.4. Inlet/outlet combinations . . . . . . . . . . . . . . . . 26
12.5. Aggregation functions . . . . . . . . . . . . . . . . . . 27
12.6. Add a definition of 'demand' . . . . . . . . . . . . . . 27
12.7. IEC references . . . . . . . . . . . . . . . . . . . . . 27
12.8. Standard references for BACNET or MODBUS . . . . . . . . 27
12.9. IEEE 1621 and 802.3az references . . . . . . . . . . . . 27
12.10. DC power quality covered by IEC standard? . . . . . . . . 27
12.11. Introduce 'disconnected from power' as power state . . . 27
12.12. Need for basic state 'reduced power'? . . . . . . . . . . 27
12.13. Local and network-wide energy management . . . . . . . . 28
12.14. Do we need entity types? . . . . . . . . . . . . . . . . 28
12.15. Power availability mode 'minimum' or 'ready'? . . . . . . 28
12.16. Is there a need for metering power supply inpedance? . . 28
12.17. Confidence in power values . . . . . . . . . . . . . . . 28
12.18. Terminology for reporting on other entitites . . . . . . 28
13. Informative References . . . . . . . . . . . . . . . . . . . . 29
Appendix A. Existing Standards . . . . . . . . . . . . . . . . . 30
A.1. Existing IETF Standards . . . . . . . . . . . . . . . . . 30
A.1.1. ENTITY MIB . . . . . . . . . . . . . . . . . . . . . . 30
A.1.2. ENTITY STATE MIB . . . . . . . . . . . . . . . . . . . 31
A.1.3. ENTITY SENSOR MIB . . . . . . . . . . . . . . . . . . 31
A.1.4. UPS MIB . . . . . . . . . . . . . . . . . . . . . . . 32
A.1.5. POWER ETHERNET MIB . . . . . . . . . . . . . . . . . . 32
A.1.6. LLDP MED MIB . . . . . . . . . . . . . . . . . . . . . 33
A.2. Existing standards of other bodies . . . . . . . . . . . 33
A.2.1. DMTF . . . . . . . . . . . . . . . . . . . . . . . . . 33
A.2.2. OVDA . . . . . . . . . . . . . . . . . . . . . . . . . 33
A.2.3. IEEE-ISTO Printer WG . . . . . . . . . . . . . . . . . 33
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 34
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1. Introduction
With rising energy cost and with an increasing awareness of the
ecological impact of running IT and networking equipment, energy
management is becoming an additional basic requirement for network
management systems and frameworks.
This document defines requirements for standards specifications for
energy management. Defined requirements concern monitoring functions
as well as control functions. Covered functions include
identification of powered entities, monitoring of their power state,
power inlets, power outlets, actual power, consumed energy, and
contained batteries. Further included is control of powered
entities' power supply and power state. Note that this document does
not specify the features that must be implemented by compliant
implementations but rather features that must be supported by
standards for energy management.
The main subject of energy management are powered entities that
consume electric energy. Powered entities include devices that have
an IP address and can be addressed directly, such as hosts, routers,
and middleboxes, as well as devices indirectly connected to an IP
network, for which a proxy with an IP address provides a management
interface, for example, devices in a building management
infrastructure using BACNET or MODBUS protocols.
The requirements specified in this document explicitly concern the
standards specification process and not the implementation of
specified standards. All requirements in this document must be
reflected by standards specifications to be developed. But which of
the features specified by these standards will be mandatory,
recommended, or optional for compliant implementations is to be
defined by the concrete standards track document(s) and not in this
document.
This document first discusses general objectives of energy management
in Section 3. Requirements for an energy management standard are
specified in Sections 4 to 8.
1.1. Conventional requirements for energy management
The specification of requirements for an energy management standard
starts with Section 4 addressing the identification of powered
entities and the granularity of reporting of energy-related
information. A standard must support unique identification of
powered entities. Furthermore, it must support more than just
reporting per powered device. Support is required for also reporting
energy-related information on individual components of a device or
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subtended devices. This is why this draft uses the more general term
"powered entity" rather than "powered device". A powered entity may
be a device or a component of a device.
Section 5 specifies requirements related to monitoring of powered
entities. This includes general (type, context) information and
specific information on power states, power inlets, power outlets,
power, energy, and batteries. Control power state and power supply
of powered entities is covered by requirements specified in
Section 6.
1.2. Specific requirements for energy management
At first glance the rather conventional requirements summarized above
seem to be all that would be needed for energy management. But it
turns out that there are some significant differences between energy
management and most of the well known conventional network management
functions. The most significant difference from many other
management functions is the need for some devices to report on other
entities. There are three major reasons for this.
o For monitoring and controlling a particular powered entity in
general it is not sufficient to communicate with the powered
entity only, but in many cases also communication with other
powered entities along the power distribution path may be
necessary, for example, with power switches and power meters.
Indeed, there are situations where a power or energy meter is not
located in the powered entity, but in a different physical
location. For example, a Power Distribution Unit (PDU), which
supplies power for a server connected to a PDU socket, would meter
the power supplied, while the server may not have the capability
to measure its power consumption. A second example is a Power
over Ethernet port, which provides power to the attached device,
and which can meter how much power/energy it delivers to the
attached device.
o Energy management often extends its scope beyond powered entities
with IP network interfaces, for example toward non-IP building
networks, that are accessed via an IP gateway. Requirements in
this document do not fully cover all these networks, but they
cover means for opening IP network management towards them.
o For monitoring of particular powered entities, it is sometimes not
a scalable approach to communicate directly with all the powered
entities directly from a central energy management system as the
number of powered entities keeps increasing.
This specific issue of energy management and a set of further ones
are covered by requirements specified in Sections 7 and 8.
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2. Terminology
2.1. Energy
the definition of the term energy is to be agreed on in the EMAN WG.
The term 'energy consumption' is commonly used for both, for
referring to the amount of consumed energy and also for referring to
the rate of consuming energy. In the first case it addresses
consumed energy measured by joule, watthour, or another energy unit,
in the second one it addresses power, typically an average power
measured by watt.
However, in this document the term "consumed energy" always refers to
an energy quantity (measured in joule, watthour, etc.) and not to a
power quantity (measured in watt, etc.).
2.2. Power
the definition of the term power is to be agreed on in the EMAN WG.
2.3. Powered entity
A powered entity is a consumer of energy that is subject to energy
management. In general, all managed physical entities in a
communication network consume electric energy and thus are subject to
energy management including particularly energy monitoring and energy
control.
A powered entity can be a managed device or a component of a managed
device, which is monitored or controlled individually.
2.4. Power state
Power state of a powered entitiy is defined as a specific settings of
a powered entitiy that influences its power. Examples of power
states of a powered entitiy are on, off, and sleep.
2.5. Power monitor
Energy management requires retrieving energy-related information on
powered entities. In many cases this information is not available at
the powered entities themselves, but at other powered entities. For
example measurement of power and energy consumption can be conducted
by power meters at other locations along the power distribution tree
for the powered entity.
A power monitor is a module that reports energy-related information
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on powered entities. A power monitor may be integrated into a
powered entity or located remotely of the powered entity. Instances
of power monitors may report information on, for example, power
supply, power, and power state of a powered entity. There may be
multiple power monitors reporting information on the same powered
entity.
2.6. Power inlet
Powered entities receive power at their power inlets. Powered
entities may have multiple inlets, for example, servers with
redundant power supply. Examples for power inlets are AC power cords
of a powered entity or an Ethernet port at which the powered entity
receives DC Power over Ethernet (PoE).
2.7. Power outlet
Powered entities may have means to supply others with electrical
power. Power is delivered to other powered entities through power
outlets. Power sourcing entities often have more than one power
outlet. Examples for power outlets are AC power sockets at a Power
Distribution Unit (PDU) and Ethernet ports at a Power over Ethernet
(PoE) Power Sourcing Equipment (PSE), that can supply powered
entities with DC power using the Ethernet cable.
2.8. Energy management
the definition of the term power is to be agreed on in the EMAN WG.
2.9. Energy management standard
This document specifies requirements for an energy management
standard. This term refers to a collections of documents specifying
standards for energy-related monitoring and control. The energy
management standard specifies means for building energy management
systems.
Requirements specified in this document concern the means that an
energy management standard must provide. It does not imply that all
required means must be implemented in all energy standard scenarios.
Which means and features must be implemented by compliant
implementations is to be specified by the energy management standard
itself, not by this requirements document.
Note that for meeting individual requirements specified in this
document, new standards are not necessarily required. It is
recommended to rather use existing standards than specify new ones.
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3. General Objectives of Energy Management
The basic objective of energy management is operating communication
networks and other equipment with minimal amount of energy, while
maintaining a certain level of service. A set of use cases for
energy management can be found in
[I-D.tychon-eman-applicability-statement].
3.1. Power states
One approach to achieve this goal is by setting all powered entities
to an operational state that results in lower energy consumption, but
still meets the service level performance objectives. The sufficient
performance level may vary over time and can depend on several
factors. In principle, there are four basic types of power states
for a powered entity or for a whole system:
o full power state
o reduced power states (lower clock rate for processor, lower data
rate on a link, etc.)
o sleep state (not functional, but immediately available)
o off state (may imply requiring significant time for becoming
operational)
In actual implementations the number of power states and their
properties vary a lot. Very simple powered entities may just have
only the extreme states, full power and off state. Some
implementations might use IEEE1621 model of three states on, off, and
sleep. However, more granular power states can be implemented with
many levels of off, sleep, and reduced power states.
3.2. Trade-offs
While the general objective of energy management is quite clear, the
way to attain that goal is often difficult. In many cases there is
no way of reducing power consumption without the consequence of a
potential performance, service, or capacity degradation. Then a
trade-off needs to be dealt with between service level objectives and
energy efficiency. In other cases a reduction of energy consumption
can easily be achieved while still maintaining sufficient service
level performance, for example, by switching powered entities to
lower power states when higher performance is not needed.
3.3. Local and network-wide energy management
Many energy saving functions can be executed locally by a powered
entitiy. The basic principle is that a powered entitiy monitors its
usage and dynamically adapts its energy consumption according to the
required performance. It may switch to a sleep state when it is not
in use at all. Potential interactions with an energy management
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system for such an entity include the observation of the entity's
power state and the configuration of power saving policies, for
example, by setting thresholds for power state changes.
Energy savings can also be achieved with policies implemented by a
network management system that controls power states of managed
entities. In order to make policy decisions properly, information
about the energy consumption of powered entities in different power
states is required. Often this information is acquired best through
monitoring.
Both methods, network-wide and local energy management, have
advantages and disadvantages. Most buildings use both of them. In
some cases for example, significant energy savings can be achieved by
simply setting all powered entities in a network to sleep, when the
network is not needed. However, in general it is dangerous to set
all powered entities of a group to the same state, because there is a
risk that such actions ignore specifics of individual powered
entities or violate local service level agreements.
3.4. Energy monitoring
It should be noted that only monitoring energy consumption and power
states is obviously not a means to reduce the energy consumption of a
powered entitiy. In fact, it is likely to increase the power
consumption of a powered entitiy slightly because monitoring energy
may require instrumentation that consumes energy when in use. And
also reporting of measured quantities over the network consumes
energy. However, the acquired energy consumption and power state
information is essential for defining energy saving policies and can
be used as input to power state control loops that in total can lead
to energy savings.
Monitoring operational power states and energy consumption can also
be required for other energy management purposes including but not
limited to:
o investigating power saving potential
o evaluating the effectiveness of energy saving policies and
measures
o deriving, implementing, and testing power management strategies
o accounting for the total power consumption of a powered entity, a
network, or a service
o predicting a powered entitiy's reliability based on power usage
o choosing time of next maintenance cycle for a powered entitiy
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3.5. Overview of energy management requirements
From the considerations described above the following basic
management functions appear to be required for energy management:
o monitoring power states
o monitoring power (energy consumption rate)
o monitoring (accumulated) energy consumption
o setting power states
o setting and enforcing power saving policies
It should be noted that active power control is complementary (but
essential) to other energy savings measures such as low power
electronics, energy saving protocols (for example, IEEE 802.3az),
energy-efficient device design (for example, sleep and low-power
modes for individual components of a device), and energy-efficient
network architectures. Measurement of energy consumption may also
provide useful input for developing these technologies.
4. Identification of Powered Entities
As already stated Section 1.1, powered entities on which energy-
related information is provided are identified in a sufficiently
unique way. This holds in particular for powered entities that are
components of managed devices and in case that one powered entity
reports information on another one, see Section 7. For powered
entities that control other powered entities it is important to
identify the powered entities they control, see Section 8.
Also stated already in Section 1.1 is the requirement of providing
means for reporting energy-related information on components of a
managed device. An entity in this document may be an entire managed
device or just a component of it. Examples of components of interest
are a hard drive, a battery, or a line card. For controlling
entities it may be required to be able to address individual
components in order to save energy. For example, server blades can
be switched off when the overall load is low or line cards at
switches may be powered down at night times.
Instrumentation for measuring energy consumption of a device is
typically more expensive than instrumentation for retrieving the
devices power state. It may be a reasonable compromise in many cases
to provide power state information for all individually switchable
components of a device separately, while the energy consumption is
only measured for the entire device.
Detailed Requirements:
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4.1. Identifying powered entities
The energy management standard must provide means for uniquely and
persistently identifying powered entities that are monitored or
controlled by an energy management system. Uniqueness must be given
in a domain that is large enough to avoid collisions of identities at
potential receivers of monitored information.
4.2. Identifying components of powered devices
The energy management standard must provide means for identifying not
just entire devices as powered entities, but also individual
components of powered devices.
4.3. Persistency of Identifiers
The energy management standard must provide means for indicating
whether identifiers of powered entities are persistent across a re-
start of the powered entitiy that provides the identifiers.
5. Information on Powered Entities
This section describes energy-related information on powered entities
for which an energy management standard must provide means for
retrieving and reporting.
Note that the fact that an energy management standard provides
required means does not imply that all of them must be implemented by
every compliant implementation. The concrete specification of
standards based on these requirements may label individual features
as mandatory, recommended, or optional.
Required information on powered entities can be structured into six
groups. Section 5.1 specifies requirements for general information
on powered entities, such as type of powered entity or context
information. Section 5.2 covers requirements related to entities'
power states. Requirements for information on power inlets and power
outlets of powered entities are specified in Section 5.3. Monitoring
of power and energy is covered by Sections 5.4 and 5.5, respectively.
Finally, Section 5.6 specified requirements for monitoring batteries.
5.1. General information on powered entities
For energy management it may be required to understand the role and
context of a powered entitiy. When monitoring, it may be helpful to
group energy consumption per kind of entity. When controlling and
setting power states it may be helpful to understand the kind and
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role of a powered entitiy in a network, for example, in order to
avoid switching off vital network components.
Detailed Requirements:
5.1.1. Type of powered entity
The energy management standard must provide means to retrieve and
report the type of powered entities according to a standrdized
classification scheme.
5.1.2. Context information on powered entities
The energy management standard must provide means for retrieving and
reporting context information on powered entities, for example tags
associated with a powered entity that indicate the powered entitiy's
role, or importance.
5.1.3. Grouping of powered entities
The energy management standard must provide means for grouping
powered entities, for example, into energy monitoring domains, energy
control domains, power supply domains, groups of powered entities of
the same type, etc.
5.2. Power state
Many powered entities have a limited number of discrete power states,
such as, for example, full power, low power, sleep, and off.
Obviously, there is a need to report the actual power state of a
powered entitiy. Beyond that, there is also a requirement for
standardizing means for retrieving the list of all supported power
states of a powered entitiy.
Different standards bodies have already defined their own sets of
power states for powered entities. Further organizations are in the
process of adding more of these sets. In order to support multiple
management systems possibly using different power state sets, while
simultaneously interfacing with a particular powered entity, the
energy management standard must provide means for supporting multiple
power state sets used simultaneously at a powered entity.
Power states have parameters that describe its properties It is
required to have standardized means for reporting some key
properties, such as mean power and maximum power of a powered entitiy
in a certain state.
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There also is a need to report statistics on power states including
the time spent an the energy consumed in a power state.
For some network management tasks, it may be desirable to receive
notifications from powered entities, for example, when the components
or the entire entity change their power state.
Detailed Requirements:
5.2.1. Actual power state
The energy management standard must provide means for reporting the
actual power state of a powered entitiy.
5.2.2. List of supported power states
The energy management standard must provide means for retrieving the
list of all potential power states of a powered entitiy.
5.2.3. Multiple power state sets
The energy management standard must provide means for supporting
multiple power state sets simultaneously at a powered entity.
5.2.4. List of supported power state sets
The energy management standard must provide means for retrieving the
list of all power state sets supported by a powered entitiy.
5.2.5. List of supported power states
Referring to the "list of supported power state sets" requirement,
the energy management standard must provide means for retrieving the
list of all potential power states of a powered entitiy that belong
to a given power state set.
5.2.6. Maximum and average power per power state
The energy management standard must provide means for retrieving the
maximum power and the average power as a typically static property
for each supported power state.
5.2.7. Power state statistics
The energy management standard must provide means for monitoring
statistics per power state including at least the total time spent in
a power state, the number of times a state was entered and the last
time a state was entered. More power state statistics are addressed
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by requirement 5.5.3.
5.2.8. Power state changes
The energy management standard must provide means for generating a
notification when the actual power state of a powered entity changes.
5.3. Power inlet and power outlet
Powered entities have power inlets at which they are supplied with
electric power. Most powered entities just have a single power
inlet, while some have multiple ones. Often different power inlets
are connected to separate power distribution trees. For energy
monitoring, it is important information which power inlets a powered
entitiy has, if power is available at an inlet and which of them are
actually in use.
Some powered entities have power outlets for supplying other powered
entities with electric power. A powered entitiy may have multiple
power outlets. Examples are Power Distribution Units (PDUs) and
Power over Ethernet (PoE) Power Sourcing Equipment (PSE).
For identifying and potentially controlling the source of power
received at an inlet, it may be required to identify the power outlet
of another powered entity at which the received power is provided.
Analogously, for each outlet it is of interest to identify the power
inlets that receive the power provided at a certain outlet.
Static properties of each power inlet and each power outlet are
required information for energy management. Static properties
include the kind of electric current (Alternating Current (AC) or
Direct Current (DC)), the nominal voltage, the nominal AC frequency,
and the number of AC phases.
Detailed Requirements:
5.3.1. List of power inlets and power outlets
The energy management standard must provide means for monitoring the
list of power inlets and power outlets at a powered entitiy.
5.3.2. Corresponding power outlet
The energy management standard must provide means for identifying the
power outlet that provides the power received at a power inlet.
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5.3.3. Corresponding power inlets
The energy management standard must provide means for identifying the
list of power inlets that receive the power provided at a power
outlet.
5.3.4. Availability of power
The energy management standard must provide means for monitoring the
availability of power at each power inlet and each power outlet.
This information indicates whether at a power providing outlet power
supply is switched on or off.
5.3.5. Use of power
The energy management standard must provide means for monitoring for
each power inlet and each power outlet if it is in actual use. For
the inlet this means that the powered entitiy actually receives power
at the inlet. For the outlet this means that actually power is
provided to one or more powered entities at the outlet.
5.3.6. Type of current
The energy management standard must provide means for reporting the
type of current (Alternating Current (AC) or Direct Current (DC)) for
each power inlet and each power outlet of a powered entity.
5.3.7. Nominal voltage
The energy management standard must provide means for reporting the
nominal voltage for each power inlet and each power outlet of a
powered entity.
5.3.8. Nominal AC frequency
The energy management standard must provide means for reporting the
nominal AC frequency for each power inlet and each power outlet of a
powered entity.
5.3.9. number of AC phases
The energy management standard must provide means for reporting the
number of AC phases for each power inlet and each power outlet of a
powered entity.
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5.4. Power
Power is a quantity measured as instantaneous power or as average
power over a time interval. In contrast to power state values, this
quantity may change continuously.
Obtaining highly accurate values for power and energy may be costly.
Often dedicated metering hardware is needed for this purpose.
Powered entities without the ability to measure their power and
energy consumption with high accuracy may just report estimated
values, for example based on load monitoring or even just the entity
type.
Depending on how power and energy consumption values are obtained the
confidence in the reported value and its accuracy may vary. Powered
entities reporting such values should qualify the confidence in the
reported values and quantify the accuracy of measurements. For
reporting accuracy, the accuracy classes specified in IEC 62053-21
[IEC.62053-21] and IEC 62053-22 [IEC.62053-22] should be considered.
In addition to the plain real power value, also further properties of
the supplied power are subject to monitoring. In case of AC power
supply, there are more power values beyond the real power to be
reported including the apparent power, the reactive power, and the
phase angle of the current or the power factor. For both AC and DC
power the power quality is also subject of monitoring. Power quality
parameters include the actual voltage, the actual frequency, the
Total Harmonic Distortion (THD) of voltage and current, the impedance
of an AC phase or of the DC supply. Power quality monitoring should
be in line with existing standards, such as [IEC.61850-7-4].
For some network management tasks, it is required to obtain time
series of power values (or energy consumption values). In general
these could be obtained in many different ways. It should be avoided
that such time series can only be obtained by regular polling by the
energy management system. Means should be provided to either push
such values from the place they are available to the management
system or to have them stored at the powered entitiy for a
sufficiently long period of time such that a management system can
retrieve a stored time series of values.
Detailed Requirements:
5.4.1. Real power
The energy management standard must provide means for reporting the
real power for each power inlet and each power outlet of a powered
entity.
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5.4.2. Power measurement interval
The energy management standard must provide means for reporting the
corresponding time or time interval for which a power value is
reported. The power value can be measured at the corresponding time
or averaged over the corresponding time interval.
5.4.3. Confidence in power values
The energy management standard must provide means for reporting the
confidence in reported power values by indicating the way these
values have been obtained. for example, by power measurement, by
estimation based on performance values, or hard coding average power
values for a powered entity.
5.4.4. Accuracy of power and energy values
The energy management standard must provide means for reporting the
accuracy of reported power values.
5.4.5. Complex power
The energy management standard must provide means for reporting the
complex power for each power inlet and each power outlet of a powered
entity. Besides the real power, at least two out of the following
three quantities need to be reported: apparent power, reactive power,
phase angle. The phase angle can be substituted by the power factor.
In case of AC power supply, means must be provided for reporting the
complex power per phase.
5.4.6. Actual voltage and current
The energy management standard must provide means for reporting the
actual voltage and actual current for each power inlet and each power
outlet of a powered entity. In case of AC power supply, means must
be provided for reporting the actual voltage and actual current per
phase.
5.4.7. Actual AC frequency
The energy management standard must provide means for reporting the
actual AC frequency for each power inlet and each power outlet of a
powered entity.
5.4.8. Total harmonic distortion
The energy management standard must provide means for reporting the
Total Harmonic Distortion (THD) of voltage and current for each power
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inlet and each power outlet of a powered entity. In case of AC power
supply, means must be provided for reporting the THD per phase.
5.4.9. Power supply impedance
The energy management standard must provide means for reporting the
impedance of power supply for each power inlet and each power outlet
of a powered entity. In case of AC power supply, means must be
provided for reporting the impedance per phase.
5.4.10. Time series of power values
The energy management standard must provide means for collecting time
series of real power values for each power inlet and for each power
outlet of a powered entitiy without requiring to regularly poll the
powered entitiy from an energy management station. A solution for
this is that the concerned powered entity or another powered entity
closely interacting with the concerned powered entity collect time
series of power values and make them available via push or pull
mechanisms to receivers of the information.
5.5. Energy
Monitoring of electrical energy consumed (or converted) at a powered
entitiy can be done in various ways. One is collecting time series
of power values for the powered entitiy and calculating the consumed
energy from these values. An alternative is the powered entity
itself or another powered entity taking care of energy measurement
and reporting energy consumption values for certain time intervals.
Time intervals of interest are the time from the last restart of the
powered entitiy to the reporting time, the time from another past
event to the reporting time, or the last given amount of time before
the reporting time.
In order to monitor energy consumption in different power states, it
is useful if powered entities record their energy consumption per
power state and report these quantities.
For some network management tasks, it is required to obtain time
series of energy values. In general these could be obtained in many
different ways. It should be avoided that such time series can only
be obtained by regular polling by the energy management system.
Means should be provided to either push such values from the place
they are available to the management system or to have them stored at
the powered entitiy for a sufficiently long period of time such that
a management system can retrieve a stored time series of values.
Detailed Requirements:
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5.5.1. Energy
The energy management standard must provide means for reporting the
consumed energy received at a power input or provided at a power
outlet of a powered entitiy. Reports must be made for a clearly
specified time interval.
5.5.2. Time intervals
The energy management standard must provide means for reporting the
consumed energy of a powered entitiy for certain time intervals.
o Reports must be supported for the time interval starting at the
last restart of the powered entitiy and ending at a certain point
in time, such as the time when a report was delivered.
o Reports must be supported for a sequence of consecutive non-
overlapping time intervals of fixed size (periodic reports).
o Reports must be supported for a sequence of consecutive
overlapping time intervals of fixed size (periodic reports).
o Reports must be supported for an interval of given length ending
at a certain point in time, such as the time when a report was
delivered (sliding window)
5.5.3. Energy per power state
The energy management standard must provide means for reporting the
consumed energy individually for each power state. This extends the
requirement 5.2.7 on power state statistics.
5.5.4. Time series of energy values
The energy management standard must provide means for collecting time
series of energy values for each power inlet and for each power
outlet of a powered entitiy without requiring to regularly poll the
powered entitiy from an energy management station. A solution for
this is that the concerned powered entity or another powered entity
closely interacting with the concerned powered entity collect time
series of energy values and make them available via push or pull
mechanisms to receivers of the information.
5.6. Battery State
Today more and more powered entities contain batteries that supply
them with power when disconnected from electrical power distribution
grids. Common examples are nomadic and mobile devices, such as
notebook computers, netbooks, and smart phones. The status of
batteries in such an powered entity, particularly the charging status
is typically controlled by automatic functions that act locally on
the powered entitiy and manually by users of the powered entity. In
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addition to this, there is a need to monitor the battery status of
these entities by network management systems.
The management requirements discussed above in Sections 5.1 to 5.5
concern energy-related information on powered entities. Powered
entities may be powered devices or components of powered devices.
Devices containing batteries can be modeled in two ways. The entire
device can be modeled as a single powered entity on which energy-
related information is reported or the battery can be modeled as an
individual powered entity for which energy-related information is
monitored individually according to requirements in Sections 5.1 to
5.5.
In both cases further information on batteries is of interest for
energy management, such as the current charge of the battery, the
number of completed charging cycles, the charging state of the
battery, and further static and dynamic battery properties. Also
desirable is to receive notifications if the charge of a battery
becomes very low or if a battery needs to be replaced.
Detailed Requirements:
5.6.1. Battery charge
The energy management standard must provide means for reporting the
current charge of a battery.
5.6.2. Battery charging state
The energy management standard must provide means for reporting the
charging state (charged, discharged, etc.) of a battery.
5.6.3. Battery charging cycles
The energy management standard must provide means for reporting the
number of completed charging cycles of a battery.
5.6.4. Actual battery capacity
The energy management standard must provide means for reporting the
actual capacity of a battery.
5.6.5. Static battery properties
The energy management standard must provide means for reporting
static properties of a battery, including the nominal capacity, the
number of cells, the nominal voltage, and the battery technology.
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5.6.6. Low battery charge notification
The energy management standard must provide means for generating a
notification when a the charge of a battery decreases below a given
threshold.
5.6.7. Battery replacement notification
The energy management standard must provide means for generating a
notification when the number of charging cycles of battery exceeds a
given threshold.
5.6.8. Multiple batteries
The energy management standard must provide means for meeting
requirements 5.6.1 to 5.6.7 for each individual battery contained in
a single powered entity.
6. Control of Powered Entities
Many powered entities control their power state locally by self-
managed dynamic adaptation to the environment. But other powered
entities without that capability need interfaces for a energy
management system to control their power states in order to save
energy. Even for self-managed powered entities such interface may be
required for overruling local policy decisions by global ones from an
energy management system.
Power supply is typically not self-managed by powered entities. And
controlling power supply is typically not conducted as interaction
between energy management system and the powered entity itself. It
is rather an interaction between the management system and an entity
providing power at its power outlets. Still, requirements for power
state control apply accordingly to power supply control.
Note that shutting down the power supply abruptly may have severe
consequences for the powered entity.
Detailed Requirements:
6.1. Controlling power states
The energy management standard must provide means for setting power
states of powered entities.
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6.2. Controlling power supply
The energy management standard must provide means for switching power
supply off or turning power supply on at power outlets providing
power to one or more powered entity.
7. Reporting on Other Powered Entities
As already discussed in the introduction of Section 5, not all
energy-related information may be available at the concerned powered
entity. Such information may be provided by other powered entities,
such as a Power Distribution Unit (PDU), external power meter, or a
Power over Ethernet (PoE) Power Sourcing Equipment (PSE). Some of
these entities (PDU, PSE) can also control the power provided to the
other powered entities, while some can just report on the remote
powered entities (external power meter). This section covers
reporting of information (monitoring) only. See Section 8 for
requirements on controlling other powered entities.
There are cases where a power supply unit switches power for several
powered entities by turning power on or off at a single power outlet
or where a power meter measures the accumulated power of several
powered entities at a single power line. Consequently, it should be
possible to report that a monitored value does not relate to just a
single powered entity, but is an accumulated value for a set of
powered entities. All of these powered entities belonging to that
set need to be identified.
If a powered entity has information about where energy-related
information on itself can be retrieved, then it would be very useful
if it has a way to communicate this information to an energy
management system. This applies even if the information only
provides accumulated quantities for several powered entities.
Detailed Requirements:
7.1. Reports on other powered entities
The energy management standard must provide means for a powered
entitiy to report energy-related information on another powered
entity.
7.2. Identity of other powered entities on which is reported
The energy management standard must provide means for reporting the
identity of another powered entity on which energy-related
information is reported.
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7.3. Reporting quantities accumulated over multiple powered entities
For powered entities reporting single values that are accumulated
over multiple powered entities, the energy management standard must
provide means for reporting the list of all powered entities from
which contributions are included in the accumulated value.
7.4. List of all powered entities on which is reported
The energy management standard must provide means for a powered
entitiy to report the list of all other powered entities on which it
can report energy-related information.
7.5. Content of reports on other powered entities
The energy management standard must provide means for a powered
entitiy to indicate for each other powered entity on which it can
provide energy-related information which energy-related information
can be provided for this powered entity.
7.6. Indicating source of remote information
The energy management standard must provide means for a powered
entity to indicate another powered entity at which energy-related
information on itself can be retrieved.
7.7. Indicating source of remote information
For a powered entity that has another powered entity at which energy-
related information on itself can be retrieved, the energy management
standard must provide means for indicating the information that is
available at other powered entities per other powered entity.
8. Controlling Other Powered Entities
This section specifies requirements for controlling power states and
power supply of powered entities by communicating not with these
powered entities themselves, but with other powered entities that
have means for controlling power state or power supply of others.
8.1. Controlling power states of other powered entities
Some powered entities may have control of power states of other
powered entities. For example a gateway to a building network may
have means to control the power state of powered entities in the
building that do not have an IP interface. For this and similar
cases means are needed to make this control accessible to the energy
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management system.
In addition to this, it is required that a powered entitiy that has
its state controlled by other powered entities has means to report
the list of these other powered entities.
Detailed Requirements:
8.1.1. Control of power states of other powered entities
The energy management standard must provide means for an energy
management system to send power state control commands to a powered
entity that concern the power states of other powered entities than
the one the command was send to.
8.1.2. Identity of other power state controlled entities
The energy management standard must provide means for reporting the
identity of another powered entity for which the reporting powered
entity has means to control the power state.
8.1.3. List of all power state controlled entities
The energy management standard must provide means for a powered
entitiy to report the list of all powered entities for which it can
control the power state.
8.1.4. List of all power state controllers
The energy management standard must provide means for a powered
entitiy that receives commands controlling its power state from other
powered entities to report the list of all those entities.
8.2. Controlling power supply of other powered entities
Some powered entities may have control of the power supply of other
powered entities, for example, because the other powered entity is
supplied via a power outlet of the powered entitiy. For this and
similar cases means are needed to make this control accessible to the
energy management system.
In addition to this, it is very required that a powered entitiy that
has its supply controlled by other powered entities has means to
report the list of these other powered entities.
Detailed Requirements:
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8.2.1. Control of power supply of other powered entities
The energy management standard must provide means for an energy
management system to send power supply control commands to a powered
entity that concern the power supply of other powered entities than
the one the command was send to.
8.2.2. Identity of other power supply controlled powered entities
The energy management standard must provide means for reporting the
identity of another powered entity for which the reporting powered
entity has means to control the power supply.
8.2.3. List of all power supply controlled powered entities
The energy management standard must provide means for a powered
entitiy to report the list of all other powered entities for which it
can control the power supply.
8.2.4. List of all power supply controllers
The energy management standard must provide means for a powered
entitiy that has other powered entities controlling its power supply
to report the list of all those powered entities.
9. Security Considerations
The typical security threats for the management protocol for energy
monitoring are similar to the ones specified in the SNMP security
framework. In other words, from an energy monitoring point of view,
no additional security requirements have been imposed.
Link layer discovery mechanisms need to ensure that only the trusted
powered entities shall be discovered during discovery and detect/
discard powered entities without a trusted relationship to be
included among the powered entities for energy monitoring.
In terms of monitoring, considering that there can be some network
entities which shall be entitled to collect the measured data on
behalf of other powered entities, then it is important to
authenticate and/or authorize such powered entities. In addition, in
the case of control of other powered entities, it would be highly
desirable to have some form of an authentication mechanism to ensure
that only the designated powered entities shall control the powered
entities within its control domain. It should be possible to prevent
a powered entity which does not have the appropriate authorization
and authority to control or configure powered entities in its control
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domain/purview. Secondly, it should be possible to prevent malicious
powered entities from exercising control over entities.
10. IANA Considerations
This document has no actions for IANA.
11. Acknowledgements
The authors would like to thank Ralf Wolter for his first essay on
this draft. Many thanks to William Mielke, John Parello, Bruce
Nordman, JinHyeock Choi, Georgios Karagiannis, and Michael Suchoff
for helpful comments on the draft.
12. Open issues
12.1. Revise security considerations
A discussion of the sensitivity of the content of the monitoring data
is missing.
12.2. High/Low power notifications
For some network management tasks it may be desirable to receive
notifications from entities when the power of an powered entity
exceeds or falls below certain thresholds. Do we want to make this a
requirement?
Proposal: added "for example" so that we don't restrict the framework
to only this notification
12.3. Power and energy time series?
We have requirements for reporting of time series of power and energy
values. Do we need both or just one of them? If just one, then
which one?
12.4. Inlet/outlet combinations
How to model the case that an inlet or outlet changes during
operation from one kind to the other. An example is a battery that
receives power at a socket at one time. Then the socket is an inlet.
At another time the battery provides power at the same socket. Then
it's an outlet. The same holds for entities with integrated power
generators.
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One solution would be to introduce a new kind of hybrid in/outlets.
Another one would be to model the same socket as inlet as well as as
outlet. It would appear twice in the list of all inlets and outlets.
Then received power/energy would be reported under the inlet entry
and provided power/energy would be reported under the outlet entry.
These would be two solutions. What would be the concrete requirement
behind them?
12.5. Aggregation functions
Aggregation functions are not covered (yet). Are there requirements
on aggregation? Which are they?
12.6. Add a definition of 'demand'
12.7. IEC references
References to mentioned IEC standards are missing. Also these
references should be double checked.
12.8. Standard references for BACNET or MODBUS
Section 1 mentions BACNET or MODBUS as examples for building network
protocols. We need references to the standards specifications for
these protocols.
12.9. IEEE 1621 and 802.3az references
A reference to the IEEE 1621 standard is missing in section 3.1 and a
reference to IEEE 802.3az is missing in section 3.4. The references
should be double checked if they are well applicable in the
respective section.
12.10. DC power quality covered by IEC standard?
Is there an IEC standard on DC power quality?
12.11. Introduce 'disconnected from power' as power state
We need to introduce the concept of a device being "disconnected"
from power. This is a subset of the Off state. Shall we do it here
or rather in the framework draft?
12.12. Need for basic state 'reduced power'?
Are "full power" and "reduced power" really different basic types of
power states? Both may be forms of the on state. Identifying "full"
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separately is arbitrary. (For something like a computer, "idle" is
the most common state so would be the one to call out separately
rather than "full".)
12.13. Local and network-wide energy management
All but first sentence of the third paragraph in section 3.3 seem to
be true not needed here. Proposal: remove them.
12.14. Do we need entity types?
Or shall we remove Section 5.1.1?
12.15. Power availability mode 'minimum' or 'ready'?
Do we need an additional mode for power availability called "minimum"
or "ready" for power availability in xref target="availability"/>?
This would reflect a PoE state at which the PSE is ready to serve the
PD.
12.16. Is there a need for metering power supply inpedance?
12.17. Confidence in power values
Shall we rename "confidence in power values" to "method for
determining power values"?
12.18. Terminology for reporting on other entitites
In Section 7 we need some additional terms here to streamline the
text (and ultimately our thinking). Nominations include:
o "powered entity" (which may be "self-reporting")
o "reporting entity" (can be "self" or "other")
o "other entity" (a reporting entity reporting not on itself; likely
a different term would be better for this)
o "controlled entity", "controlling entity" (section 8.1)
o "switched entity", "switching entity" (section 8.2)
Also, there are two cases for an "other entity". One is where the
powered entity cannot report the value in question itself (either
because it can't report anything, or doesn't know the value in
question, e.g. when metering is external).
The second is where the powered entity can report, but the other
entity is doing the reporting for some convenience. We need to be
aware of both even if the framework does not need to make the
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distinction.
There may be multiple other reporting entities, not just a single
one.
Do components of devices ever report, or do only devices do the
reporting? This seems like an important point.
13. Informative References
[RFC1628] Case, J., "UPS Management Information Base", RFC 1628,
May 1994.
[RFC3433] Bierman, A., Romascanu, D., and K. Norseth, "Entity Sensor
Management Information Base", RFC 3433, December 2002.
[RFC3621] Berger, A. and D. Romascanu, "Power Ethernet MIB",
RFC 3621, December 2003.
[RFC3805] Bergman, R., Lewis, H., and I. McDonald, "Printer MIB v2",
RFC 3805, June 2004.
[RFC4133] Bierman, A. and K. McCloghrie, "Entity MIB (Version 3)",
RFC 4133, August 2005.
[RFC4268] Chisholm, S. and D. Perkins, "Entity State MIB", RFC 4268,
November 2005.
[I-D.tychon-eman-applicability-statement]
Tychon, E., Silver, L., and M. Chandramouli, "Energy
Management (EMAN) Applicability Statement",
draft-tychon-eman-applicability-statement-02 (work in
progress), June 2011.
[ACPI.R30b]
Hewlett-Packard Corporation, Intel Corporation, Microsoft
Corporation, Phoenix Corporation, and Toshiba Corporation,
"Advanced Configuration and Power Interface Specification,
Revision 3.0b", October 2006.
[DMTF.DSP1027]
Dasari (ed.), R., Davis (ed.), J., and J. Hilland (ed.),
"Power State Management Profile", September 2008.
[IEEE-ISTO]
Printer Working Group, "PWG 5106.4 - PWG Power Management
Model for Imaging Systems 1.0:", February 2011.
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[IEC.62053-21]
International Electrotechnical Commission, "Electricity
metering equipment (a.c.) - Particular requirements - Part
22: Static meters for active energy (classes 1 and 2)",
2003.
[IEC.62053-22]
International Electrotechnical Commission, "Electricity
metering equipment (a.c.) - Particular requirements - Part
22: Static meters for active energy (classes 0,2 S and
0,5 S)", 2003.
[IEC.61850-7-4]
International Electrotechnical Commission, "Communication
networks and systems for power utility automation - Part
7-4: Basic communication structure - Compatible logical
node classes and data object classes", 2010.
Appendix A. Existing Standards
This section analyzes existing standards for energy consumption and
power state monitoring. It shows that there are already several
standards that cover only some part of the requirements listed above,
but even all together they do not cover all of the requirements for
energy management.
A.1. Existing IETF Standards
There are already RFCs available that address a subset of the
requirements.
A.1.1. ENTITY MIB
The ENTITY-MIB module defined in [RFC4133] was designed to model
physical and logical entities of a managed system. A physical entity
is an identifiable physical component. A logical entity can use one
or more physical entities. From an energy monitoring perspective of
a managed system, the ENTITY-MIB modeling framework can be reused and
whenever RFC 4133 [RFC4133] has been implemented. The
entPhysicalIndex from entPhysicalTable can be used to identify an
entity/component. However, there are use cases of energy monitoring,
where the application of the ENTITY-MIB does not seem readily
apparent and some of those entities could be beyond the original
scope and intent of the ENTITY-MIB.
Consider the case of remote devices attached to the network, and the
network device could collect the energy measurement and report on
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behalf of such attached devices. Some of the remote devices such as
PoE phones attached to a switch port have been considered in the
Power-over-Ethernet MIB module [RFC3621]. However, there are many
other devices such as a computer, which draw power from a wall outlet
or building HVAC devices which seem to be beyond the original scope
of the ENTITY-MIB.
Yet another example, is smart-PDUs, which can report the energy
consumption of the device attached to the power outlet of the PDU.
In some cases, the device can be attached to multiple to power
outlets. Thus, the energy measured at multiple outlets need to be
aggregated to determine the consumption of a single device. From
mapping perspective, between the PDU outlets and the device this is a
many-to-one mapping. It is not clear if such a many-to-one mapping
is feasible within the ENTITY-MIB framework.
A.1.2. ENTITY STATE MIB
RFC 4268 [RFC4268] defines the ENTITY STATE MIB module.
Implementations of this module provide information on entities
including the standby status (hotStandby, coldStandby,
providingService), the operational status (disabled, enabled,
testing), the alarm status (underRepair, critical, major, minor,
warning), and the usage status (idle, active, busy). This
information is already useful as input for policy decisions and for
other network management tasks. However, the number of states would
cover only a small subset of the requirements for power state
monitoring and it does not provide means for energy consumption
monitoring. For associating the information conveyed by the ENTITY
STATE MIB to specific components of a device, the ENTITY STATE MIB
module makes use of the means provided by the ENTITY MIB module
[RFC4133]. Particularly, it uses the entPhysicalIndex for
identifying entities.
The standby status provided by the ENTITY STATE MIB module is related
to power states required for energy management, but the number of
states is too restricted for meeting all energy management
requirements. For energy management several more power states are
required, such as different sleep and operational states as defined
by the Advanced Configuration and Power Interface (ACPI) [ACPI.R30b]
or the DMTF Power State Management Profile [DMTF.DSP1027].
A.1.3. ENTITY SENSOR MIB
RFC 3433 [RFC3433] defines the ENTITY SENSOR MIB module.
Implementations of this module offer a generic way to provide data
collected by a sensor. A sensor could be an energy consumption meter
delivering measured values in Watt. This could be used for reporting
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current power of an entity and its components. Furthermore, the
ENTITY SENSOR MIB can be used to retrieve the accuracy of the used
power meter.
Similar to the ENTITY STATE MIB module, the ENTITY SENSOR MIB module
makes use of the means provided by the ENTITY MIB module [RFC4133]
for relating provided information to components of a device.
However, there is no unit available for reporting energy quantities,
such as, for example, watt seconds or kilowatt hours, and the ENTITY
SENSOR MIB module does not support reporting accuracy of measurements
according to the IEC / ANSI accuracy classes, which are commonly in
use for electric power and energy measurements. The ENTITY SENSOR
MIB modules only provides a coarse-grained method for indicating
accuracy by stating the number of correct digits of fixed point
values.
A.1.4. UPS MIB
RFC 1628 [RFC1628] defines the UPS MIB module. Implementations of
this module provide information on the current real power of entities
attached to an uninterruptible power supply (UPS) device. This
application would require identifying which entity is attached to
which port of the UPS device.
UPS MIB provides information on the state of the UPS network. The
MIB module contains several variables that are used to identify the
UPS entity (name, model,..), the battery state, to characterize the
input load to the UPS, to characterize the output from the UPS, to
indicate the various alarm events. The measurements of power in UPS
MIB are in Volts, Amperes and Watts. The units of power measurement
are RMS volts, RMS Amperes and are not based on Entity-Sensor MIB
[RFC3433].
A.1.5. POWER ETHERNET MIB
Similar to the UPS MIB, implementations of the POWER ETHERNET MIB
module defined in RFC3621 [RFC3621] provide information on the
current energy consumption of the entities that receive Power over
Ethernet (PoE). This information can be retrieved at the power
sourcing equipment. Analogous to the UPS MIB, it is required to
identify which entities are attached to which port of the power
sourcing equipment.
The POWER ETHERNET MIB does not report power and energy consumption
on a per port basis, but can report aggregated values for groups of
ports. It does not use objects of the ENTITY MIB module for
identifying entities, although this module existed already when the
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POWER ETHERNET MIB modules was standardized.
A.1.6. LLDP MED MIB
The Link Layer Discovery Protocol (LLDP) defined in IEEE 802.1ab is a
data link layer protocol used by network devices for advertising of
their identities, capabilities, and interconnections on a LAN
network. The Media Endpoint Discovery (MED) (ANSI/TIA-1057) is an
enhancement of LLDP known as LLDP-MED. The LLDP-MED enhancements
specifically address voice applications. LLDP-MED covers 6 basic
areas: capabilities discovery, LAN speed and duplex discovery,
network policy discovery, location identification discovery,
inventory discovery, and power discovery.
A.2. Existing standards of other bodies
A.2.1. DMTF
The DMTF has defined a power state management profile [DMTF.DSP1027]
that is targeted at computer systems. It is based on the DMTF's
Common Information Model (CIM) and rather an entity profile than an
actual energy consumption monitoring standard.
The power state management profile is used to describe and to manage
the power state of computer systems. This includes e.g. means to
change the power state of an entity (e.g. to shutdown the entity)
which is an aspect of but not sufficient for active energy
management.
A.2.2. OVDA
ODVA is an association consisting of members from industrial
automation companies. ODVA supports standardization of network
technologies based on the Common Industrial Protocol (CIP). Within
ODVA, there is a special interest group focused on energy and
standardization and inter-operability of energy aware entities.
A.2.3. IEEE-ISTO Printer WG
The charter of the IEEE-ISTO Printer Working Group is for open
standards that define printer related protocols, that printer
manufacturers and related software vendors shall benefit from the
interoperability provided by conformance to these standards. One
particular aspect the Printer WG is focused on is power monitoring
and management of network printers and imaging systems PWG Power
Management Model for Imaging Systems [IEEE-ISTO]. Clearly, these
devices are within the scope of energy management since these devices
consume power and are attached to the network. In addition, there is
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ample scope of power management since printers and imaging systems
are not used that often. IEEE-ISTO Printer working group has defined
MIB modules for monitoring the power consumption and power state
series that can be useful for power management of printers. The
energy management framework should also take into account the
standards defined in the Printer working group. In terms of other
standards, IETF Printer MIB RFC3805 [RFC3805] has been standardized,
however, this MIB module does not address power management of
printers.
Authors' Addresses
Juergen Quittek (editor)
NEC Europe Ltd.
NEC Laboratories Europe
Network Research Division
Kurfuersten-Anlage 36
Heidelberg 69115
DE
Phone: +49 6221 4342-115
Email: quittek@neclab.eu
Rolf Winter
NEC Europe Ltd.
NEC Laboratories Europe
Network Research Division
Kurfuersten-Anlage 36
Heidelberg 69115
DE
Phone: +49 6221 4342-121
Email: Rolf.Winter@neclab.eu
Thomas Dietz
NEC Europe Ltd.
NEC Laboratories Europe
Network Research Division
Kurfuersten-Anlage 36
Heidelberg 69115
DE
Phone: +49 6221 4342-128
Email: Thomas.Dietz@neclab.eu
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Benoit Claise
Cisco Systems, Inc.
De Kleetlaan 6a b1
Degem 1831
BE
Phone: +32 2 704 5622
Email: bclaise@cisco.com
Mouli Chandramouli
Cisco Systems, Inc.
Sarjapur Outer Ring Road
Bangalore,
IN
Phone: +91 80 4426 3947
Email: moulchan@cisco.com
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