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Network Working Group                                    J. Quittek, Ed.
Internet-Draft                                                 R. Winter
Intended status: Informational                                  T. Dietz
Expires: May 4, 2012                                     NEC Europe Ltd.
                                                               B. Claise
                                                         M. Chandramouli
                                                     Cisco Systems, Inc.
                                                        November 1, 2011


                   Requirements for Energy Management
                    draft-ietf-eman-requirements-05

Abstract

   This document defines requirements for standards specifications for
   energy management.  The requirements presented in this document
   include monitoring functions as well as control functions.  In
   detail, the focus of the requirements is on the following features:
   identification of powered entities, monitoring of their power state,
   power inlets, power outlets, actual power, power quality, consumed
   energy, and contained batteries.  Further, requirements are included
   to enable 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
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

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

   This Internet-Draft will expire on May 4, 2012.

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.



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










































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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  5
     1.1.  Conventional requirements for energy management  . . . . .  6
     1.2.  Specific requirements for energy management  . . . . . . .  6

   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  7

   3.  General Considerations Related to Energy Management  . . . . .  7
     3.1.  Power states . . . . . . . . . . . . . . . . . . . . . . .  7
     3.2.  Saving energy versus maintaining service level
           agreements . . . . . . . . . . . . . . . . . . . . . . . .  8
     3.3.  Local versus network-wide energy management  . . . . . . .  8
     3.4.  Energy monitoring versus energy saving . . . . . . . . . .  9
     3.5.  Overview of energy management requirements . . . . . . . .  9

   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  . . . . . . . . . . . . . . . . . . . . . . 20
     5.7.  Notifications  . . . . . . . . . . . . . . . . . . . . . . 21

   6.  Control of Powered Entities  . . . . . . . . . . . . . . . . . 22

   7.  Reporting on Other Powered Entities  . . . . . . . . . . . . . 22

   8.  Controlling Other Powered Entities . . . . . . . . . . . . . . 24
     8.1.  Controlling power states of other powered entities . . . . 24
     8.2.  Controlling power supply of other powered entities . . . . 25

   9.  Security Considerations  . . . . . . . . . . . . . . . . . . . 26

   10. IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 26

   11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 26

   12. Open issues  . . . . . . . . . . . . . . . . . . . . . . . . . 27
     12.1. Improve references . . . . . . . . . . . . . . . . . . . . 27
     12.2. Do we need entity types? . . . . . . . . . . . . . . . . . 27

   13. Informative References . . . . . . . . . . . . . . . . . . . . 27

   Appendix A.  Existing Standards  . . . . . . . . . . . . . . . . . 29



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     A.1.  Existing IETF Standards  . . . . . . . . . . . . . . . . . 29
       A.1.1.  ENTITY MIB . . . . . . . . . . . . . . . . . . . . . . 29
       A.1.2.  ENTITY STATE MIB . . . . . . . . . . . . . . . . . . . 30
       A.1.3.  ENTITY SENSOR MIB  . . . . . . . . . . . . . . . . . . 31
       A.1.4.  UPS MIB  . . . . . . . . . . . . . . . . . . . . . . . 31
       A.1.5.  POWER ETHERNET MIB . . . . . . . . . . . . . . . . . . 31
       A.1.6.  LLDP MED MIB . . . . . . . . . . . . . . . . . . . . . 32
     A.2.  Existing standards of other bodies . . . . . . . . . . . . 32
       A.2.1.  DMTF . . . . . . . . . . . . . . . . . . . . . . . . . 32
       A.2.2.  OVDA . . . . . . . . . . . . . . . . . . . . . . . . . 32
       A.2.3.  IEEE-ISTO Printer WG . . . . . . . . . . . . . . . . . 32

   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 33






































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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 the
   network devices and the associated network management systems.

   This document defines requirements for standards specifications for
   energy management.  This doccument contains the requirements that
   concern monitoring functions as well as control functions.  In
   detail, the requirements listed are focussed on the following
   features: identification of powered entities, monitoring of their
   power state, power inlets, power outlets, actual power, power
   quality, consumed energy, and contained batteries.  Further included
   is control of powered entities' power supply and power state.

   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 the BACnet [ANSI/ASHRAE-135-2010] or MODBUS
   [MODBUS-Protocol] 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 elaborates a set of general considerations
   related to energy management in Section 3.  Requirements for an
   energy management standard are specified in Sections 4 to 8.

   Sections 4 to 6 contain rather conventional requirements specifying
   which information on powered entities needs to be covered by an
   energy management standard, and which control functions are needed.

   Sections 7 and 8 contain requirements that are very specific to
   energy management.  They result from the fact that due to the nature
   of power supply, some of the monitoring and control functions are not
   conducted by interacting with the powered entity of interest, but
   with other entities, for example, with entities upstream in the power
   distribution tree.



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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
   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 a particular powered entity in general it is not
      sufficient to communicate with the powered entity only,
      particularly if the powered entity has no instrumentation for
      measuring power.  In such cases it might still be possible to
      obtain power values for the entity by communication with other
      entities in the same power distribution tree.
      A very simple example would be retrieving power values from a
      dedicated power meter at the power line of the powered entity.
      More common examples are a Power Distribution Unit (PDU) and a
      Power over Ethernet (PoE) switch.  Both supply power to other
      entities at sockets or ports, respectively, and are often
      instrumented to measure power per socket or port.
   o  Similar considerations apply to controlling power supply of a
      powered entity which often needs direct or indirect communication
      with another entity upstream in the power distribution tree.
      Again, a PDU and a PoE switch are common examples, if they have
      the capability to switch on or off power at their sockets or
      ports, respectively.




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   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.

   For meeting the requirements specified in these sections first a new
   energy management framework needs to be specified that gives
   directions on how to deal with the specific nature of energy
   management.  Based on such a framework, energy management standards
   can be specified that meet the requirements below.  The actual
   standards documents, such as, for example, MIB module specifications,
   will address conformance issues by specifying which feature must,
   should, or may to be implemented by compliant implementations.


2.  Terminology

   Terminology to be used by the eman WG is currently discussed in
   [I-D.parello-eman-definitions].  After final definitions of terms
   have been agreed, they will be listed here.


3.  General Considerations Related to Energy Management

   The basic objective of energy management is operating sets of devices
   with minimal amount of energy, while maintaining a certain level of
   service.  A set of use cases and the target devices for the
   application of 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:





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   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 the IEEE 1621 [IEEE-1621] model of three
   states on, off, and sleep.  However, more finely grained power states
   can be implemented with many levels of off, sleep, and reduced power
   states.

3.2.  Saving energy versus maintaining service level agreements

   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 versus network-wide energy management

   Many energy saving functions can be executed locally by a powered
   entity.  The basic principle is that a powered entity monitors its
   usage and dynamically adapts its energy consumption according to the
   required performance.  It may, for example, switch to a sleep state
   when it is not in use or out of scheduled business hours.  Potential
   interactions with an energy management 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 or schedules 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 and often it is a good choice to combine
   them.  Central management is often favorable for setting power states



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   of a large number of entities at the same time, for example, at
   beginning and end of business hours in a building.  Local management
   appears often to be preferable for dynamic power saving measures
   based on local observations, such as high or low load of an entity.

3.4.  Energy monitoring versus energy saving

   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 entity.  In fact, it is likely to increase the power
   consumption of a powered entity 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 entity's reliability based on power usage
   o  choosing time of next maintenance cycle for a powered entity

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  monitoring power quality
   o  setting power states
   o  setting and enforcing power saving policies

   It should be noted that power control is complementary (but
   essential) to other energy savings measures such as low power
   electronics, energy saving protocols (for example, Energy-Efficient
   Ethernet [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



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   technologies.


4.  Identification of Powered Entities

   As already stated in 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.

   Identifiers to other devices and to components of devices are already
   defined in standard MIB modules, such as the LLDP MIB module
   [IEEE-802.1AB] and the LLDP-MED MIB module [ANSI/TIA-1057] for
   devices and the Entity MIB module [RFC4133] and the Power Ethernet
   MIB [RFC3621] for components of devices.  For energy management it is
   necessary to have means for linking energy-related information to
   such identifiers.

   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:

4.1.  Identifying powered entities

   The energy management standard must provide means for uniquely
   identifying powered entities that are monitored or controlled by an
   energy management system.  Uniqueness must be preserved in a domain
   that is large enough to avoid collisions of identities at potential
   receivers of monitored information.




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4.2.  Identifying components of powered devices

   The energy management standard must provide means for identifying
   individual sub-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 entity.

4.4.  Using entity identifiers of other MIB modules

   The energy management standard must provide means for re-using entity
   identifiers from other standards including at least the following:
   o  the LldpPortNumber in the LLDP MIB module [IEEE-802.1AB]and in the
      LLDP-MED MIB module [ANSI/TIA-1057]
   o  the entPhysicalIndex in the Entity MIB module [RFC4133]
   o  the pethPsePortIndex and the pethPsePortGroupIndex in the Power
      Ethernet MIB [RFC3621]
   Additionally, generic means for re-using further entity identifiers
   must be provided.


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.

   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 entity.  From the point of view of monitoring
   and management of a large network perspective, it may be helpful to
   aggregate the energy consumption according to a defined grouping of
   entities.  When controlling and setting power states it may be
   helpful to understand the the grouping of the entity and role of a
   powered entity in a network, for example, in order to avoid switching



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   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 standardized
   classification scheme.

   YCM --- This issue has been discussed and the feeling was that type
   may not be needed and thus it is better to drop this requirement. ---
   YCM

   The energy management standard must provide means to configure,
   retrieve and report a textual name or a description of a powered
   entity.  In addition to the unique identity, such a textual
   description shall be useful.

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 entity'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 entity.  Beyond that, there is also a requirement for
   standardizing means for retrieving the list of all supported power
   states of a powered entity.

   Presently, different standards bodies have already defined their own
   sets of power states for some powered entities.  Beyond those, other
   standards organizations are in the process of adding more of these
   power state sets for the devices considered in their scope.  Given
   this context, it is desirable that the energy management standard



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   shall be interoperable across these multiple power state standards.
   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 average power and maximum power of a powered
   entity in a certain state.

   There also is a need to report statistics on power states including
   the time spent and 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 entire
   entity or some of the components of the 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 entity.

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 entity.

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 entity.

5.2.5.  List of supported power states within a set

   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 entity that belong to
   a given power state set.



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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 for each supported power
   state.  These values may be static properties of a 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
   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 useful to retrieve information on the number of
   inlets of a powered entity, the availability of power at inlets and
   which of them are actually in use.

   Some powered entities have power outlets for supplying other powered
   entities with electric power.  A powered entity may have multiple
   power outlets.

   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:





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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 entity.

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.

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 at 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 entity actually receives power
   at the inlet.  For the outlet this means that power is actually
   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.



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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.

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.  Measuring and estimating power must be sensitive to detect and
   report if the energy is consumed or produced.

   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 measurements, qualitative
   properties of the supplied power are of interest from a monitoring
   point of view.  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 entity for a
   sufficiently long period of time such that a management system can
   retrieve a stored time series of values.



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   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, including whether the energy is produced or consumed.

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.  Power measurement method

   The energy management standard must provide means to indicating the
   method how these values have been obtained.  Based on how the
   measurement was obtained, it is possible to associate a certain
   degree of confidence on the reported power value.  For example, there
   are methods of measurement such as direct power measurement, or 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.




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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
   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 entity without requiring to regularly poll the
   powered entity 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
   entity can be done in various ways.  One is collecting time series of
   power values for the powered entity 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 entity 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.




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   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 entity for a sufficiently long period of time such that a
   management system can retrieve a stored time series of values.

   Detailed Requirements:

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 entity.  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 entity for certain time intervals.
   o  Reports must be supported for the time interval starting at the
      last restart of the powered entity 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 entity without requiring to regularly poll the
   powered entity 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



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   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 a powered entity, particularly the charging status
   is typically controlled by automatic functions that act locally on
   the powered entity and manually by users of the powered entity.  In
   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.  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 (charging, discharging, 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.





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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.

5.6.6.  Low battery charge notification

   The energy management standard must provide means for generating a
   notification when 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.

5.7.  Notifications

   Often it is needed to check if values of monitored energy-related
   quantities rise or fall above or below certain thresholds.  In such
   cases, polling these values is a very inefficient way.  Preferable,
   values should be checked locally and notifications should be send
   when thresholds get exceeded.  This can be achieved by using generic
   mechanism that are not specific to energy management.

   Detailed Requirement:

5.7.1.  High/low value notifications

   The energy management standard must provide means for creating
   notifications if values of measured quantities are above or below
   given thresholds.






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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 interfaces may
   be required for configuring local policy parameters and 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.  Similar to power state
   control, power supply control may be policy driven.  Note that
   shutting down the power supply abruptly may have severe consequences
   for the powered entity.

   Detailed Requirement:

6.1.  Controlling power states

   The energy management standard must provide means for setting power
   states of powered entities.

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



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   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
   entity to report energy-related information on another powered
   entity.

7.2.  Identity of other powered entities on which is reported

   For entities that report on one or more other entities, the energy
   management standard must provide means for reporting the identity of
   another powered entity on which energy-related information is
   reported.

7.3.  Reporting quantities accumulated over multiple powered entities

   For entities that report quantities 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 an accumulated value.

7.4.  List of all powered entities on which is reported

   For entities that report on other entities, the energy management
   standard must provide means for reporting the complete list of those
   powered entities on which energy-related information can be reported.

7.5.  Content of reports on other powered entities

   For entities that report on other entities, the energy management
   standard must provide means for indicating which energy-related
   information it can reported for which of those powered entities.




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7.6.  Indicating source of remote information

   For an entity that has one or more other entities reporting on it,
   the energy management standard must provide means for the entity to
   indicate which information is available at which other entities.

7.7.  Indicating content of remote information

   For an entity that has one or more other entities reporting on it,
   the energy management standard must provide means for indicating the
   content that other designated entities can report on it.


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 scenario and
   other similar cases means are needed to make this control accessible
   to the energy management system.

   In addition to this, it is required that a powered entity 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 sent to.

8.1.2.  Identity of other power state controlled entities

   The energy management standard must provide means for reporting the
   identities of the powered entities for which the reporting powered
   entity has means to control their power states.




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8.1.3.  List of all power state controlled entities

   The energy management standard must provide means for a powered
   entity 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
   entity 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 entity.  For this and
   similar cases means are needed to make this control accessible to the
   energy management system.

   In addition to this, it is required that a powered entity that has
   its supply controlled by other powered entities has means to report
   the list of these other powered entities.

   Detailed Requirements:

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 sent 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
   entity to report the list of all other powered entities for which it
   can control the power supply.







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8.2.4.  List of all power supply controllers

   The energy management standard must provide means for a powered
   entity that has other powered entities controlling its power supply
   to report the list of all those powered entities.


9.  Security Considerations

   Controlling power state and power supply of powered entities are
   highly sensitive actions since they can significantly affect the
   operation of directly and indirectly affected devices.  Therefore all
   control actions addressed in Sections Section 6 and Section 8 must be
   sufficiently protected through authentication, authorization, and
   integrity protection mechanisms.

   Monitoring energy-related quantities of a powered entity addressed in
   Sections Section 5 - Section 8 can be used to derive more information
   than just the consumed power.  Therefore, monitored data requires
   privacy protection.  Since the monitored data may be used as input to
   control, accounting, and other actions, integrity of transmitted
   information and authentication of the origin may be needed.

   Detailed Requirements:

9.1.  Secure energy management

   The energy management standard must provide privacy, integrity, and
   authentication mechanisms for all actions addressed in Sections
   Section 5 - Section 8.  The security mechanisms must address all
   threats listed in Section 1.4 of [RFC3411].


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.







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12.  Open issues

12.1.  Improve references

   DC power quality covered by IEC standard?
   Is there an IEC standard on DC power quality?

12.2.  Do we need entity types?

   Or shall we remove Section 5.1.1?  The issue is unsolved on the
   mailing list.


13.  Informative References

   [RFC1628]  Case, J., "UPS Management Information Base", RFC 1628,
              May 1994.

   [RFC3411]  Harrington, D., Presuhn, R., and B. Wijnen, "An
              Architecture for Describing Simple Network Management
              Protocol (SNMP) Management Frameworks", STD 62, RFC 3411,
              December 2002.

   [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.parello-eman-definitions]
              Parello, J., "Energy Management Terminology",
              draft-parello-eman-definitions-03 (work in progress),
              October 2011.

   [I-D.tychon-eman-applicability-statement]
              Tychon, E., Silver, L., and B. Nordman, "Energy Management
              (EMAN) Applicability Statement",
              draft-tychon-eman-applicability-statement-05 (work in
              progress), October 2011.



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   [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.

   [ANSI/TIA-1057]
              Telecommunications Industry Association, "ANSI/
              TIA-1057-2006 - TIA Standard - Telecommunications - IP
              Telephony Infrastructure - Link Layer Discovery Protocol
              for Media Endpoint Devices", April 2006.

   [ANSI/ASHRAE-135-2010]
              American Society of Heating,  Refrigerating and Air-
              Conditioning Engineers, "Standard 135-2010 - BACnet A Data
              Communication Protocol  for Building Automation and
              Control Networks (ANSI Approved) -  SSPC 135 and TC 1.4,
              Control Theory and Application", 2011.

   [DMTF.DSP1027]
              Dasari (ed.), R., Davis (ed.), J., and J. Hilland (ed.),
              "Power State Management Profile", September 2008.

   [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.

   [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.

   [IEEE-1621]
              Institute of Electrical and  Electronics Engineers, "IEEE
              P1621-2004 -Draft Standard for User Interface  Elements in
              Power Control of Electronic Devices Employed  in Office/
              Consumer Environments", June 2005.

   [IEEE-802.1AB]



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              IEEE Computer Society, "IEEE Std 802.1AB-2009 - IEEE
              Standard for Local and metropolitan area networks -
              Station and Media Access  Control Discovery",
              September 2009.

   [IEEE-802.3az]
              IEEE Computer Society, "IEEE-802.3az-2010 - IEEE Standard
              for 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 5:  Media Access Control
              Parameters, Physical Layers, and  Management Parameters
              for Energy-Efficient Ethernet", October 2010.

   [IEEE-ISTO]
              Printer Working Group, "PWG 5106.4 - PWG Power Management
              Model for Imaging Systems 1.0:", February 2011.

   [MODBUS-Protocol]
              Modbus-IDA, "MODBUS Application Protocol Specification
              V1.1b", December 2006.


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
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   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
   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].






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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
   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



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   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
   POWER ETHERNET MIB modules was standardized.

A.1.6.  LLDP MED MIB

   The Link Layer Discovery Protocol (LLDP) defined in IEEE 802.1AB
   [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) is an enhancement of LLDP known as LLDP-MED [ANSI/TIA-1057].
   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 it is 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



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   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
   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










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   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


   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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