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     Network Working Group                                  B. Claise
     Internet-Draft                                        J. Parello
     Intended Status: Informational               Cisco Systems, Inc.
     Expires: July 12, 2013                              B. Schoening
                                                Independent Consultant
                                                            J. Quittek
                                                        NEC Europe Ltd
     
     
     
                                                         July 9, 2013
     
     
     
     
                        Energy Management Framework
                       draft-ietf-eman-framework-08
     
     
     Status of this Memo
     
        This Internet-Draft is submitted to IETF in full conformance
        with the provisions of BCP 78 and BCP 79.
     
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        This Internet-Draft will expire on July, 2013.
     
     
     
     
     
     
     
     
     
     
     
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     Copyright Notice
     
        Copyright (c) 2013 IETF Trust and the persons identified as
        the document authors.  All rights reserved.
     
        This document is subject to BCP 78 and the IETF Trust's Legal
        Provisions Relating to IETF Documents
        (http://trustee.ietf.org/license-info) in effect on the date
        of publication of this document.  Please review these
        documents carefully, as they describe your rights and
        restrictions with respect to this document.  Code Components
        extracted from this document must include Simplified BSD
        License text as described in Section 4.e of the Trust Legal
        Provisions and are provided without warranty as described in
        the Simplified BSD License.
     
     
     
     Abstract
     
        This document defines a framework for providing Energy
        Management for devices and device components within or
        connected to communication networks.  The framework defines an
        Energy Management Domain as a set of Energy Objects. Each
        Energy Object is identified, classified and given context.
        Energy Objects can be monitored and controlled with respect to
        Power, Power State, Energy, Demand, Power Attributes, and
        Battery.  Additionally the framework models relationships and
        capabilities between Energy Objects.
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
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     Table of Contents
     
        1. Introduction .......................................... 5
           1.1. Energy Management Documents Overview ............. 6
        2. Terminology ........................................... 6
           Device................................................. 7
           Component.............................................. 7
           Energy Management...................................... 7
           Energy Management System (EnMS)........................ 7
           Power.................................................. 9
           Demand................................................. 9
           Power Attributes....................................... 9
           Power Quality.......................................... 9
           Electrical Equipment.................................. 10
           Non-Electrical Equipment (Mechanical Equipment)....... 10
           Energy Object......................................... 10
           Energy Monitoring..................................... 10
           Energy Control........................................ 11
           Provide Energy........................................ 11
           Receive Energy........................................ 11
           Power Interface....................................... 11
           Energy Management Domain.............................. 11
           Energy Object Identification.......................... 12
           Energy Object Context................................. 12
           Energy Object Relationship............................ 12
           Aggregation Relationship.............................. 12
           Metering Relationship................................. 12
           Power Source Relationship............................. 13
           Power State........................................... 13
           Power State Set....................................... 13
           Nameplate Power....................................... 13
        3. Concerns Specific to Energy Management ............... 13
           3.1. Concern #1: Power Supply ........................ 15
           3.2. Concern #2: Power and Energy Measurement ........ 20
           3.3. Concern #3: Reporting Sleep and Off States ...... 21
           3.4. Concern #4: Devices and Components .............. 22
           3.5. Concern #5: Non-Electrical Equipment ............ 22
           3.6. Concern #6: Energy Procurement .................. 23
        4. Energy Management Abstraction ........................ 24
           4.1 Conceptual Model.................................. 24
           4.2 Energy Object..................................... 25
           4.3 Energy Object Attributes.......................... 25
           4.4 Measurements...................................... 28
           4.5 Control........................................... 31
           4.6 Power State Sets Comparison....................... 37
           4.7 Relationships..................................... 38
           4.8 Relationship Conventions and Guidelines........... 38
     
     
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           4.9 Energy Object Relationship Extensions............. 41
        5. Energy Management Information Model................... 41
        6. Example Topologies.................................... 46
           6.1 Example I: Simple Device with one Source.......... 47
           6.2 Example II: Multiple Inlets....................... 48
           6.3 Example III: Multiple Sources..................... 48
           6.4 Relationships Between Devices..................... 49
        7. Relationship with Other Standards .................... 54
        8. Security Considerations .............................. 55
        9. IANA Considerations .................................. 56
           9.1 IANA Registration of new Power State Set.......... 56
           9.2 Updating the Registration......................... 58
        10. Acknowledgments ..................................... 59
        11. References .......................................... 59
           Normative References.................................. 59
           Informative References................................ 59
     
     
     
     
        OPEN ISSUES:
        - Are Tracked via Issue Tracker. See
          https://trac.tools.ietf.org/wg/eman/trac/report/1
     
     
     
     
     
     
     
     
     
     
     
     
     
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     1. Introduction
     
        Network management is often divided into the five main areas
        defined in the ISO Telecommunications Management Network
        model: Fault, Configuration, Accounting, Performance, and
        Security Management (FCAPS) [X.700].  Not covered by this
        traditional management model is Energy Management, which is
        rapidly becoming a critical area of concern worldwide, as seen
        in [ISO50001].
     
        This document defines an energy management framework for
        devices within or connected to communication networks.  The
        devices, or components of these devices (such as router line
        cards, fans, disks), can then be monitored and controlled.
        Monitoring includes power, energy, demand, and attributes of
        power.  Energy control can be performed by setting devices' or
        components' power state. If a device contains batteries, these
        can also be monitored and controlled.
     
        This framework further describes how to identify, classify and
        provide context for such devices.  While the context
        information is not specific to Energy Management, some context
        attributes are specified in the framework, addressing the
        following use cases: how important is a device in terms of its
        business impact, how should devices be grouped for reporting
        and searching, and how should a device role be described.
        These context attributes help in fault management and impact
        analysis while controlling the power states.  Guidelines for
        using context for energy management are described.
     
        The framework introduces the concept of a power interface that
        is analogous to a network interface. A power interface is
        defined as an interconnection among devices where energy can
        be provided, received, or both.
     
        The most basic example of Energy Management is a single device
        reporting information about itself.  In many cases, however,
        energy is not measured by the device itself, but metered
        upstream in the power distribution tree.  For example, a power
        distribution unit (PDU) may measure the energy it supplies to
        attached devices and report this to an energy management
        system.  Therefore, devices often have relationships to other
        devices or components in the power network.  An EnMS generally
        requires an understanding of the power topology (who provides
        power to whom), the metering topology (who meters whom), and
     
     
     
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        an understanding of the potential aggregation (does a meter
        aggregate values from other devices).
     
        The relationships build on the power interface concept. The
        different relationships among devices and components,
        specified in this document, include: power source
        relationship, metering relationship, and aggregation
        relationship.
     
     
       1.1.  Energy Management Documents Overview
     
     
        The EMAN standard provides a set of specifications for Energy
        Management.  This document specifies the framework, per the
        Energy Management requirements specified in [EMAN-REQ].
     
        The applicability statement document [EMAN-AS] includes use
        cases, a cross-reference between existing standards and the
        EMAN standard, and a description of this frameworks
        relationship to other frameworks.
     
        The Energy Object Context MIB [EMAN-OBJECT-MIB] specifies
        objects for addressing Energy Object Identification,
        classification, context information, and relationships from
        the point of view of Energy Management.
     
        The Power and Energy Monitoring MIB [EMAN-MON-MIB] specifies
        objects for monitoring of Power, Energy,  Demand, Power
        Attributes, and Power States.
     
        The Battery Monitoring MIB [EMAN-BATTERY-MIB] defines managed
        objects that provide information on the status of batteries in
        managed devices.
     
     
     2.    Terminology
     
        The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
        NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and
        "OPTIONAL" in this document are to be interpreted as described
        in RFC 2119 [RFC2119].
     
       Some terms have a NOTE that is not part of the
       definition itself, but accounts for differences
       between terminologies of different standards
       organizations or further clarifies the definition.
     
     
     
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       Device
     
          A piece of electrical or non-electrical equipment.
          Reference: Adapted from [IEEE100]
     
     
       Component
     
          A part of an electrical or non-electrical equipment
          (Device).
     
          Reference: Adapted from [ITU-T-M-3400]
     
     
       Energy Management
     
          Energy Management is a set of functions for
          measuring, modeling, planning, and optimizing
          networks to ensure that the network and network
          attached devices use energy efficiently and
          appropriately for the nature of the application
          and the cost constraints of the organization.
          Reference: Adapted from [ITU-T-M-3400]
          NOTES:
          1. Energy management refers to the activities,
            methods, procedures and tools that pertain to
            measuring, modeling, planning, controlling and
            optimizing the use of energy in networked
            systems [NMF].
          2. Energy Management is a management domain which
            is congruent to any of the FCAPS areas of
            management in the ISO/OSI Network Management
            Model [TMN]. Energy Management for
            communication networks and attached devices is
            a subset or part of an organization's greater
            Energy Management Policies.
     
       Energy Management System (EnMS)
     
          An Energy Management System is a combination of
          hardware and software used to administer a
          network with the primary purpose of energy
          management.
     
     
     
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          Reference: Adapted from [1037C]
          NOTES:
          1. An Energy Management System according to
            [ISO50001] (ISO-EnMS) is a set of systems or
            procedures upon which organizations can develop
            and implement an energy policy, set targets,
            action plans and take into account legal
            requirements related to energy use.  An ISO-
            EnMS allows organizations to improve energy
            performance and demonstrate conformity to
            requirements, standards, and/or legal
            requirements.
          2. Example ISO-EnMS:  Company A defines a set of
            policies and procedures indicating there should
            exist multiple computerized systems that will
            poll energy from their meters and pricing /
            source data from their local utility. Company A
            specifies that their CFO should collect
            information and summarize it quarterly to be
            sent to an accounting firm to produce carbon
            accounting reporting as required by their local
            government.
          3. For the purposes of EMAN, the definition from
            [1037C] is the preferred meaning of an Energy
            Management System (EnMS). The definition from
            [ISO50001] can be referred to as ISO Energy
            Management System (ISO-EnMS).
     
       Energy
          That which does work or is capable of doing work.
          As used by electric utilities, it is generally a
          reference to electrical energy and is measured in
          kilowatt hours (kWh).
          Reference: [IEEE100]
          NOTES
          1. Energy is the capacity of a system to produce
            external activity or perform work [ISO50001]
     
     
     
     
     
     
     
     
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       Power
     
          The time rate at which energy is emitted,
          transferred, or received; usually expressed in
          watts (joules per second).
          Reference: [IEEE100]
     
       Demand
     
          The average value of power or a related quantity
          over a specified interval of time. Note: Demand
          is expressed in kilowatts, kilovolt-amperes,
          kilovars, or other suitable units.
          Reference: [IEEE100]
          NOTES:
          1.  For EMAN we use kilowatts.
     
     
        Power Attributes
     
          Measurements of the electrical current, voltage, phase and
          frequencies at a given point in an electrical power system.
     
          Reference: Adapted from [IEC60050]
     
          NOTES:
     
          1. Power Attributes are not intended to be judgmental with
          respect to a reference or technical value and are
          independent of any usage context.
     
        Power Quality
     
          Characteristics of the electrical current, voltage, phase
          and frequencies at a given point in an electric power
          system, evaluated against a set of reference technical
          parameters. These parameters might, in some cases, relate to
          the compatibility between electricity supplied in an
          electric power system and the loads connected to that
          electric power system.
     
          Reference: [IEC60050]
     
          NOTES:
     
     
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          1. Electrical characteristics representing power quality
          information are typically required by customer facility
          energy management systems. It is not intended to satisfy the
          detailed requirements of power quality monitoring. Standards
          typically also give ranges of allowed values; the
          information attributes are the raw measurements, not the
          "yes/no" determination by the various standards.
     
          Reference: [ASHRAE-201]
     
     
     
       Electrical Equipment
     
          A general term including materials, fittings,
          devices, appliances, fixtures, apparatus,
          machines, etc., used as a part of, or in
          connection with, an electric installation.
          Reference: [IEEE100]
     
       Non-Electrical Equipment (Mechanical Equipment)
     
           A general term including materials, fittings,
          devices appliances, fixtures, apparatus,
          machines, etc., used as a part of, or in
          connection with, non-electrical power
          installations.
          Reference: Adapted from [IEEE100]
     
       Energy Object
     
          An Energy Object (EO) is an information model
          (class) that represents a piece of equipment that
          is part of, or attached to, a communications
          network which is monitored, controlled, or aids
          in the management of another device for Energy
          Management.
     
     
       Energy Monitoring
     
          Energy Monitoring is a part of Energy Management
          that deals with collecting or reading information
          from Energy Objects to aid in Energy Management.
     
     
     
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       Energy Control
     
          Energy Control is a part of Energy Management
          that deals with directing influence over Energy
          Objects.
     
     
       Provide Energy
     
          An Energy Object "provides" energy to another Energy Object
          if there is an energy flow from this Energy Object to the
          other one.
     
        Receive Energy
     
          An Energy Object "receives" energy from another Energy
          Object if there is an energy flow from the other Energy
          Object to this one.
     
     
        Power Interface
     
           A Power Interface (or simply interface) is an information
           model (class) that represents the interconnections among
           devices or components where energy can be provided,
           received, or both.
     
     
        Power Inlet
     
           A Power Inlet (or simply inlet) is an interface at which a
           device or component receives energy from another device or
           component.
     
     
        Power Outlet
     
          A Power Outlet (or simply outlet) is an interface at which
          a device or component provides energy to another device or
          component.
     
       Energy Management Domain
     
          An Energy Management Domain is a set of Energy Objects that
          is considered one unit of management.
     
     
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       Energy Object Identification
     
          Energy Object Identification is a set of
          attributes that enable an Energy Object to be
          universally unique or linked to other systems.
     
       Energy Object Context
          Energy Object Context is a set of attributes that
          allow an Energy Management System to classify an
          Energy Object within an organization.
     
       Energy Object Relationship
     
          An Energy Object Relationship is an association among
          Energy Objects.
     
          NOTES
          1. Relationships can be named and could include
          Aggregation, Metering, and Power Source.
     
          Reference: Adapted from [CHEN]
     
     
        Aggregation Relationship
     
          An Aggregation Relationship is an Energy Object
          Relationship where one Energy Object aggregates Energy
          Management information of one or more other Energy Objects.
          The aggregating Energy Object has an Aggregation
          Relationship with each of the other Energy Objects.
     
     
        Metering Relationship
     
          A Metering Relationship is an Energy Object Relationship
          where one Energy Object measures power, energy, demand or
          power attributes of one or more other Energy Objects. The
          measuring Energy Object has a Metering Relationship with
          each of the measured objects.
     
     
     
     
     
     
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        Power Source Relationship
     
          A Power Source Relationship is an Energy Object
          Relationship where one Energy Object provides power to one
          or more Energy Objects. These Energy Objects are referred
          to as having a Power Source Relationship.
     
     
       Power State
     
          A Power State is a condition or mode of a device
          that broadly characterizes its capabilities,
          power consumption, and responsiveness to input.
     
          Reference: Adapted from [IEEE1621]
     
     
       Power State Set
     
          A Power State Set is a collection of Power States
          that comprises a named or logical control
          grouping.
     
     
       Nameplate Power
     
          The Nameplate Power is the nominal Power of a
          device as specified by the device manufacturer.
     
     
     
     3.    Concerns Specific to Energy Management
     
        With Energy Management, there exists a wide variety of devices
        that may be contained in the same deployments as a
        communication network but comprise a separate facility, home,
        or power distribution network.
     
        Target devices for Energy Management are all Energy Objects
        that can be monitored or controlled (directly or indirectly)
        by an Energy Management System (EnMS) using the Internet
        protocol. These target devices include:
            - Simple electrical appliances and fixtures
            - Hosts, such as a PC, a server, or a printer
            - Switches, routers, base stations, and other network
        equipment and middle boxes
            - Components within devices, such as a battery inside a
        PC, a line card inside a switch, etc.
     
     
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            - Power over Ethernet (PoE) endpoints
            - Power Distribution Units (PDU)
            - Protocol gateway devices for Building Management Systems
        (BMS)
            - Electrical meters
            - Sensor controllers with subtended sensors
     
        There may also exist varying protocols deployed among these
        power distribution and communication networks.
     
        An Energy Management framework should also apply to these
        types of separate networks as they connect to and interact
        with a communications network.
     
        This section explains special issues of Energy Management
        concerning power supply, Power and Energy metering, and the
        reporting of Power States.
     
        Energy Management has special challenges because a power
        distribution network supplies energy to devices and
        components, while a separate communications network monitors
        and controls the power distribution network.
     
        To illustrate this point, consider the basic scenario where a
        single powered device receives Energy and reports energy-
        related information about itself to an Energy Management
        System (EnMS) (see Figure 1).
     
     
                               +--------------------------+
                               | Energy Management System |
                               +--------------------------+
                                           ^  ^
                                monitoring |  | control
                                           v  v
                                    +-----------------+
                                    | powered device  |
                                    +-----------------+
     
                  Figure 1: Basic energy management scenario
     
     
        The powered device may have local energy control mechanisms,
        such as putting itself into a sleep mode when appropriate, and
        it may receive energy control commands for similar purposes
        from the EnMS. Information reported from a powered device to
        the EnMS includes at least the Power State of the powered
        device (on, sleep, off, etc.).
     
     
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        This and similar cases are well understood and common in
        Energy Management.  They can be handled with well-established
        and standardized management procedures.  The only missing
        components today are standardized information and data models
        for reporting and configuration, such as energy-specific MIB
        modules [RFC2578] and YANG modules [RFC6020].
     
        Energy Management presents no new issues for fault,
        configuration, performance or security management. We can re-
        use standard network management procedures to handle these
        issues in an EnMS. For example, with faults we can re-use rmon
        or SNMP traps. For security, existing means like SNMPv3
        security can be used.
     
        But when there are issues specific to Energy Management then
        this framework adds them. The following subsections address
        these issues and illustrate them by extending the basic
        scenario in Figure 1.
     
     
     
       3.1.  Concern #1: Power Supply
     
        Most powered devices that are managed by an EnMS receive
        external power.
     
        While many devices receive Power from unmanaged supply
        systems, the number of manageable power supply devices is
        increasing.
     
        In datacenters, for example, many Power Distribution Units
        (PDUs) allow the EnMS to switch power individually for each
        socket and also to measure the provided Power.  This is very
        different from many other network management tasks. In this
        and similar cases, switching the power supply for a powered
        device or monitoring its power is not done by communicating
        with the actual powered device itself, but with an external
        device (in this case, the PDU).
     
        Consequently, a standard for Energy Management must not only
        cover the powered devices that provide services for users, but
        also the power supply devices (which are themselves powered
        devices) that monitor or control the power supply for other
        powered devices.
     
        A simple device such as a light bulb can be switched on or off
        only by switching its power supply.  More complex devices may
        have the ability to switch off themselves or to bring
     
     
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        themselves to states in which they consume very little power.
        For these devices as well, it is desirable to monitor and
        control their power supply.
     
        This extends the basic scenario from Figure 1 by adding a
        power supply device (see Figure 2).
     
     
                    +-----------------------------------------+
                    |         energy management system        |
                    +-----------------------------------------+
                          ^  ^                       ^  ^
               monitoring |  | control    monitoring |  | control
                          v  v                       v  v
                    +--------------+        +-----------------+
                    | power supply |########| powered device  |
                    +--------------+        +-----------------+
     
                            ######## power supply line
     
              Figure 2: Basic Scenario with Power Supply Device
     
        The power supply device can be as simple as a plain power
        switch.  It may offer interfaces to the EnMS to monitor and to
        control the status of its power outlets, as with PDUs and
        Power over Ethernet (PoE) [IEEE-802.3at] switches.
     
        The relationship between supply devices and the powered
        devices they serve creates several problems for managing power
        supply:
           o  Identification of corresponding devices:
              *  A given powered device may need to identify the
                 device supplying power.
              *  A given power supply device may need to identify the
                 corresponding power-supplied device(s).
           o  Aggregation of monitoring and control for multiple
                 powered devices:
              *  A power supply device may supply multiple
                 devices from a single power supply line.
           o  Coordination of power control for devices with multiple
              power inlets:
              *  A powered device may receive power via multiple power
                 lines controlled by the same or different power
                 supply devices.
     
     
        3.1.1 Identification of Power Supply and Powered Devices
     
     
     
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        When a power supply device controls or monitors power supply
        at one of its power outlets, the effect on other devices is
        not always clear without knowledge about wiring of power
        lines.  The same holds for monitoring.  The power supplying
        device can report that a particular socket is powered, and it
        may even be able to measure power and conclude that there is a
        consumer drawing power at that socket, but it may not know
        which powered device(s)receives the provided power.
     
        In many cases it is obvious which other device is supplied by
        a certain outlet, but this always requires additional
        (reliable) information about power line wiring.  Without
        knowing which device(s) are powered via a certain outlet,
        monitoring data are of limited value and the consequences of
        switching power on or off may be hard to predict.
     
        Even in well-organized operations, powered devices' power
        cords can be plugged into the wrong socket, or wiring plans
        changed without updating the EnMS accordingly.
     
        For reliable monitoring and control of power supply devices,
        additional information is needed to identify the device(s)
        that receive power provided at a particular monitored and
        controlled socket.
     
        This problem also occurs in the opposite direction.  If power
        supply control or monitoring for a certain device is needed,
        then the supplying power supply device has to be identified.
     
        To conduct Energy Management tasks for both power supply
        devices and other powered devices, sufficiently unique
        identities are needed, and knowledge of their power supply
        relationship is required.
     
     
        3.1.2 Multiple Devices Supplied by a Single Power Line
     
        The second fundamental problem is the aggregation of
        monitoring and control that occurs when multiple powered
        devices are supplied by a single power supply line.  It is
        often necessary for the EnMS to discover the full list of
        powered devices connected to a power supply line, as in Figure
        3.
     
     
                      +---------------------------------------+
                      |       energy management system        |
                      +---------------------------------------+
     
     
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                         ^  ^                       ^  ^
              monitoring |  | control    monitoring |  | control
                         v  v                       v  v
                      +--------+        +------------------+
                      | power  |########| powered device 1 |
                      | supply |   #    +------------------+-+
                      +--------+   #######| powered device 2 |
                                     #    +------------------+-+
                                     #######| powered device 3 |
                                            +------------------+
     
                 Figure 3: Multiple Powered Devices Supplied
                             by Single Power Line
     
     
        With this list, the single status value has a clear meaning
        and is the sum of all powered devices.  Control functions are
        limited by the fact that supply for the concerned devices can
        only be switched on or off for all of them at once.
        Individual control at the supply is not possible.
     
        If the full list of devices powered by a single supply line is
        not known by the controlling power supply device, then control
        of power supply is problematic, because the complete
        consequences of a control action cannot be known.
     
     
        3.1.3 Multiple Power Supply for a Single Powered Device
     
        The third problem arises from the fact that there are devices
        with multiple power supplies.  Some have this for redundancy
        of power supply, some for redundancy of internal power
        converters (for example, from AC mains power to DC internal
        power), and some because the capacity of a single supply line
        is insufficient.
     
                   +----------------------------------------------+
                   |          energy management system            |
                   +----------------------------------------------+
                       ^  ^              ^  ^              ^  ^
                  mon. |  | ctrl.   mon. |  | ctrl.   mon. |  | ctrl.
                       v  v              v  v              v  v
                   +----------+      +----------+      +----------+
                   | power    |######| powered  |######| power    |
                   | supply 1 |######| device   |      | supply 2 |
                   +----------+      +----------+      +----------+
     
     
     
     
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          Figure 4: Multiple Power Supply for Single Powered Device
     
        The example in Figure 4 does not necessarily show a real world
        scenario, but it shows the two cases to consider:
           o  Multiple power supply lines between a single power
              supply device and a powered device
           o  Different power supply devices supplying a single
              powered device
        In any such case, there may be a need to identify the
        supplying power supply device individually for each power
        inlet of a powered device.
     
        Without this information, monitoring and control of power
        supply for the powered device may be limited.
     
     
     
        3.1.4 Bidirectional Power Interfaces
     
        Some power technologies (mostly low power DC) allow power to
        be delivered bi-directionally.  For example, energy stored in
        batteries on one device can be delivered back to a power hub,
        which redirects the power to another device.  In this
        situation, the interface can function as both an inlet and
        outlet at different times.
     
        A Power Interface can model a power inlet or a power outlet,
        depending on the conditions.  Information of interest for
        Power Interfaces includes the power direction, as well as the
        energy received, provided, and the net result.
     
     
        3.1.5 Relevance of Power Supply Concerns
     
        In some scenarios, the problems with power supply do not exist
        or can be solved sufficiently.  With Power over Ethernet (PoE)
        [IEEE-802.3at], there is always a one-to-one relationship
        between a Power Sourcing Equipment (PSE) and a Powered Device
        (PD).  Also, the Ethernet link on the line used for powering
        can be used to identify the PD and in many cases also the PSE.
     
        For supply of AC mains power, the three problems described
        above cannot be solved in general.  There is no commonly
        available protocol or automatic mechanism for identifying
        endpoints of a power line.
     
     
     
     
     
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        In addition, AC power lines support supplying multiple powered
        devices with a single line, and are commonly used in this
        fashion.
     
     
     
        3.1.6 Remote Power Supply Control
     
        There are three ways for an energy management system to change
        the Power State of powered devices.  First is for the EnMS to
        provide policy or other useful information (like the
        electricity price) to the powered device for it to use in
        determining its Power State.  The second is sending the
        powered device a command to switch to another Power State.
        The third is to use an upstream (to the powered device) device
        that can switch on and off power at its outlet.
     
        Some devices cannot receive commands or change their Power
        State by themselves. Such Energy Objects may be controlled by
        switching on and off their power supply, and so have a
        particular need for the third method.
     
        In Figure 4, the power supply can switch power at its power
        outlet and thereby switch on and off power for the connected
        powered device.
     
     
       3.2.  Concern #2: Power and Energy Measurement
     
        Some devices include hardware to directly measure their Power
        and Energy consumption.  However, most common networked
        devices do not provide an interface that gives access to
        Energy and Power measurements.  Hardware instrumentation for
        this kind of measurement is typically not in place and adding
        it incurs an additional cost.
     
        With the increasing cost of Energy and the growing importance
        of Energy Monitoring, it is likely that more devices in future
        will include instrumentation for power and energy
        measurements. It is also likely that it will take a long time
        for this to become commonplace.
     
     
        3.2.1 Local Estimates
     
        One solution to this problem is for the powered device to
        estimate its own Power and consumed Energy.  For many Energy
        Management tasks, getting an estimate is much better than not
     
     
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        getting any information at all.  Estimates can be based on
        actual measured activity level of a device or it can just
        depend on the power state (on, sleep, off, etc.).
     
        An advantage of estimates is that they can be realized locally
        and with much lower cost than hardware instrumentation.  Local
        estimates can be dealt with in traditional ways.  They don't
        need an extension of the basic scenarios above.  However, the
        powered device needs an energy model of itself to make
        estimates.
     
     
     
        3.2.2 Management System Estimates
     
        Another approach to the lack of instrumentation is estimation
        by the EnMS.  The EnMS can estimate Power based on basic
        information on the powered device, such as the type of device,
        or its brand/model and functional characteristics.
     
        Energy estimates can combine the typical power level by Power
        State with reported data about the Power State.
     
        If the EnMS has a detailed energy model of the device, it can
        produce better estimates, including the actual power state and
        actual activity level of the device.  This information can be
        obtained by monitoring the device with conventional means of
        performance monitoring.
     
     
       3.3.  Concern #3: Reporting Sleep and Off States
     
        Low-power states pose special challenges for energy reporting
        because they may preclude a device from listening to and
        responding to network requests.  Devices may still be able to
        reliably track energy use in these states, as power levels are
        usually static and internal clocks can track elapsed time in
        these states.
     
        Some devices have out-of-band or proxy abilities to respond to
        network requests in low-power states.  Others could use proxy
        abilities in an energy management protocol to improve this
        reporting, particularly if the powered device sends out
        notifications of power state changes.
     
     
     
     
     
     
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       3.4.  Concern #4: Devices and Components
     
        While the typical focus of energy management is entire powered
        devices, sometimes it is desirable to manage individual
        components of devices, such as line cards, fans, disks, etc.
     
        This framework uses a much simpler model for components than
        for entire devices.  The concept of Power Interfaces is not
        used between a device and its contained components.  Reporting
        of energy-related quantities for individual components is
        limited to the most important ones.  Simplifications for
        components in this framework include
           o  identifying components like devices but without
              distinct context information,
           o  reporting a containment relationship to the containing
              device,
           o  inheriting all context information from the containing
              device,
           o  not modeling power interfaces and power lines between
              a component and its containing device or other
              components, and
           o  only reporting real power and energy values for
              components.
     
     
        Power state monitoring and control are not simplified.  These
        have the same functionality for devices and components.  In
        rare cases where there is a need to model components of a
        device in more detail, components of a device can be modeled
        as individual devices.  Then all considerations for devices
        also apply to these components.  This model has a higher
        overhead and should be used only when needed. If used, it is
        not necessarily visible whether a set of components belongs to
        a single device or not, but for energy management purposes
        this might not be of high relevance.
     
     
     
       3.5.  Concern #5: Non-Electrical Equipment
     
        The primary focus of this framework is the management of
        Electrical Equipment.  Some Non-Electrical Equipment may be
        connected to communication networks and could have their
        energy managed if normalized to the electrical units for power
        and energy.
     
        Some examples of Non-Electrical Equipment that may be
        connected to a communication network are:
     
     
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        1) A controller for compressed air.  The controller is
          electrical only for its network connection.  The controller
          is fueled by natural gas and produces compressed air.  The
          energy transferred via compressed air is distributed to
          devices on a factory floor via a Power Interface which
          consists of tools (drills, screwdrivers, assembly line
          conveyor belts). The energy measured is non-electrical
          (compressed air).
     
        2) A controller for steam. The controller is electrical for its
          network attachment but it burns tallow and produces steam to
          subtended boilers. The energy is non-electrical (steam).
     
        3) A controller or regulator for gas. The controller is
          electrical for its network attachment but it has physical
          non-electrical components for control. The energy is non-
          electrical (BTU).
     
     
       3.6.  Concern #6: Energy Procurement
     
        While an EnMS may be a central point for corporate reporting,
        cost, environmental impact, and regulatory compliance, Energy
        Management in this framework excludes Energy procurement and
        the environmental impact of energy use.  As such the framework
        does not include:
        - Cost in currency or environmental units of manufacturing an
        Energy Object
        - Embedded carbon or environmental equivalences of an Energy
        Object
        - Cost in currency or environmental impact to dismantle or
        recycle an Energy Object
        - Supply chain analysis of energy sources for Energy Object
        deployment
        - Conversion of the usage or production of energy to units
        expressed from the source of that energy (such as the
        greenhouse gas emissions associated with 1000kW from a diesel
        source)
     
     
     
     
     
     
     
     
     
     
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     4. Energy Management Abstraction
     
        Network management is often divided into the five main areas
        defined in the ISO Telecommunications Management Network
        model: Fault, Configuration, Accounting, Performance, and
        Security Management (FCAPS) [X.700].  This traditional
        management model does not cover Energy Management.
     
        This section describes a conceptual model of information that
        can be used for Energy Management. The classes and categories
        of attributes in the model are described with rationale for
        each. A UML description of the model can be found in Section
        5.
     
        4.1 Conceptual Model
     
        To address Energy Management this specification describes an
        information model that can exist along with Network Management
        while addressing issues specific to Energy Management (Section
        3).
     
        An information model for Energy Management will need to
        describe a means to report information, provide control, and
        model the interconnections among physical entities.
     
        Therefore, this section proposes a similar conceptual model
        for physical entities to that used in Network Management:
        devices, components, and interfaces. This section then defines
        the additional attributes specific to Energy Management for
        those entities that are not available in existing Network
        Management models.
     
        For modeling the physical entities this section describes
        three classes:  a Device, a Component, and a Power Interface.
        These classes are sub-types of an abstract Energy Object
        class.
     
        For modeling the additional attributes, this section describes
        attributes of an Energy Object for: identification,
        classification, context, control, power and energy.
     
        Since the interconnections between physical entities for
        Energy Management may have no relation to the interconnections
        for Network Management the Energy Object classes contain a
        separate Relationships class as an attribute to model these
        types of interconnections.
     
     
     
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        The remainder of this section describes the conceptual model
        of the classes and categories of attributes in the information
        model. The exact definitions of the classes and attributes are
        specified using UML in Section 5.
     
        4.2 Energy Object
     
        An Energy Object is an abstract class that contains the base
        attributes for Energy Management.  There are three types of
        Energy Objects: Device, Component and Power Interface.
     
        4.2.1 Device Class
     
        The Device Class is a sub-class of Energy Object that
        represents a physical piece of equipment.
     
        A Device Class instance may represent a device that is a
        consumer, producer, or meter of energy.
     
        A Device Class instance may represent a physical device that
        contains other components.
     
        4.2.2 Component Class
     
        The Component Class is a sub-class of Energy Object that
        represents a part of a physical piece of equipment.
     
        4.2.3 Power Interface Class
     
        The power interface class is a sub-class of Energy Object that
        represents the interconnection among devices and components.
     
        There are some similarities between Power Interfaces and
        network interfaces.  A network interface can be set to
        different states, such as sending or receiving data on an
        attached line.  Similarly, a Power Interface can be receiving
        or providing power.
     
        Physically, a Power Interface instance can represent an AC
        power socket, an AC power cord attached to a device, or an
        8P8C (RJ45) PoE socket, etc.
     
        4.3 Energy Object Attributes
     
        This section describes categories of attributes for an Energy
        Object. Section 5 contains the specific UML definitions of the
        modeled attribute.
     
     
     
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        4.3.1 Identification
     
        A Universal Unique Identifier (UUID) [RFC4122] is used to
        uniquely and persistently identify an Energy Object. Ideally
        the UUID is used to distinguish the Energy Object within the
        EnMS.
     
        Every Energy Object has an optional unique printable name.
        Possible naming conventions are: textual DNS name, MAC address
        of the device, interface ifName, or a text string uniquely
        identifying the Energy Object.  As an example, in the case of
        IP phones, the Energy Object name can be the device's DNS
        name.
     
        Additionally an alternate key is provided to allow an Energy
        Object to be optionally linked with models in different
        systems.
     
        4.3.2 Context in General
     
        In order to aid in reporting and in differentiation between
        Energy Objects, each Energy Object optionally contains
        information establishing its business, site, or organizational
        context within a deployment
     
        4.3.3 Context: Importance
     
        An Energy Object can provide an importance value in the range
        of 1 to 100 to help rank a device's use or relative value to
        the site.  The importance range is from 1 (least important) to
        100 (most important).  The default importance value is 1.
     
        For example: A typical office environment has several types of
        phones, which can be rated according to their business impact.
        A public desk phone has a lower importance (for example, 10)
        than a business-critical emergency phone (for example, 100).
        As another example: A company can consider that a PC and a
        phone for a customer-service engineer are more important than
        a PC and a phone for lobby use.
     
        Although EnMS and administrators can establish their own
        ranking, the following example is a broad recommendation for
        commercial deployments [CISCO-EW]:
     
        .  90 to 100 Emergency response
     
        .  80 to 90 Executive or business-critical
     
     
     
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        .  70 to 79 General or Average
     
        .  60 to 69 Staff or support
     
        .  40 to 59 Public or guest
     
        .  1  to 39 Decorative or hospitality
     
     
     
        4.3.4 Context: Keywords
     
        An Energy Object can provide a set of keywords.  These
        keywords are a list of tags that can be used for grouping,
        summary reporting within or between Energy Management Domains,
        and for searching.  All alphanumeric characters and symbols
        (other than a comma), such as #, (, $, !, and &, are allowed.
        Potential examples are: IT, lobby, HumanResources, Accounting,
        StoreRoom, CustomerSpace, router, phone, floor2, or
        SoftwareLab.  There is no default value for a keyword.
     
        Multiple keywords can be assigned to a device.  White spaces
        before and after the commas are excluded, as well as within a
        keyword itself. In such cases, commas separate the keywords
        and no spaces between keywords are allowed.  For example,
        "HR,Bldg1,Private".
     
     
     
        4.3.5 Context: Role
     
        An Energy Object contains a "role description" string that
        indicates the purpose the Energy Object serves in the EnMS.
        This could be a string describing the context the device
        fulfills in deployment.
     
        Administrators can define any naming scheme for the role of a
        device.  As guidance, a two-word role that combines the
        service the device provides along with type can be used
        [IPENERGY].
     
        Example types of devices: Router, Switch, Light, Phone,
        WorkStation, Server, Display, Kiosk, HVAC.
     
        Example Services by Line of Business:
     
           Line of Business     Service
     
     
     
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           Education            Student, Faculty, Administration,
     
                                Athletic
     
           Finance              Trader, Teller, Fulfillment
     
           Manufacturing        Assembly, Control, Shipping
     
           Retail               Advertising, Cashier
     
           Support              Helpdesk, Management
     
           Medical              Patient, Administration, Billing
     
        Role as a two-word string: "Faculty Desktop", "Teller Phone",
        "Shipping HVAC", "Advertising Display", "Helpdesk Kiosk",
        "Administration Switch".
     
     
     
        4.3.6 Context: Domain
     
        An Energy Object contains a string to indicate membership in
        an Energy Management Domain. An Energy Management Domain can
        be any collection of devices in a deployment, but it is
        recommended to map 1:1 with a metered or sub-metered portion
        of the site.
     
        In building management, a meter refers to the meter provided
        by the utility used for billing and measuring power to an
        entire building or unit within a building.  A sub-meter refers
        to a customer- or user-installed meter that is not used by the
        utility to bill but is instead used to get readings from sub
        portions of a building.
     
        A meter is a type Energy Object and any Energy Object can
        perform metering.
     
        An Energy Object should be a member of a single Energy
        Management Domain therefore one field is provided.  The Energy
        Management Domain may be configured on an Energy Object.
     
        4.4 Measurements
     
        An Energy Object contains attributes to describe power, energy
        and demand measurements.
     
     
     
     
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        For the purposes of this framework, energy will be limited to
        electrical energy in watt-hours.  Other forms of Energy
        Objects that use or produce non-electrical energy may be
        modeled as an Energy Object but must provide information
        converted to and expressed in watt-hours.
     
        An analogy for understanding power versus energy measurements
        can be made to speed and distance in automobiles. Just as a
        speedometer indicates the rate of change of distance (speed),
        a power meter indicates the rate of transfer of energy. The
        odometer in an automobile measures the cumulative distance
        traveled and an energy meter indicates the accumulated energy
        transferred.
     
        Demand measurements are averages of power measurements over
        time. So using the same analogy to an automobile: measuring
        the average vehicle speed over multiple intervals of time for
        a given distance travelled, demand is the average device power
        over multiple time intervals for a given energy value.
     
        4.4.1 Measurements: Power
     
        Each Energy Object contains a Nameplate Power attribute that
        describes the nominal power as specified by the manufacturer.
     
        Power Measurement. The EnMS can use the Nameplate Power for
        provisioning, capacity planning and (potentially) billing.
     
        Each Energy Object will have information that describes
        present power information, along with how that measurement was
        obtained or derived (e.g., measured, estimated, or presumed).
     
        A power measurement is be qualified with the units, magnitude
        and direction of power flow, and is be qualified as to the
        means by which the measurement was made (e.g., Root Mean
        Square versus Nameplate).
     
        In addition, the Energy Object describes how it intends to
        measure power. This intention can be described as one of the
        following: consumer, producer,  meter or distributir of power.
        Given the intent, the EnMS can summarize or analyze the
        measurement. For example, metered usage reported by a meter
        and consumption usage reported by a device connected to that
        meter will naturally measure the same usage. With the two
        measurements identified by intent, the EnMS can make a proper
        summarization.
     
     
     
     
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        Power measurement magnitude conforms to the IEC 61850
        definition of unit multiplier for the SI (System
        International) units of measure.  Measured values are
        represented in SI units obtained by BaseValue * (10 ^ Scale).
        For example, if current power usage of an Energy Object is 3,
        it could be 3 W, 3 mW, 3 KW, or 3 MW, depending on the value
        of the scaling factor.  3W implies that the BaseValue is 3 and
        Scale = 0, whereas 3mW implies BaseValue = 3 and ScaleFactor =
        -3.
     
        In addition to knowing the power and magnitude an Energy
        Object indicates how the  measurement was obtained:
     
        - Whether the measurements were made at the device itself or
        at a remote source.
     
        - Description of the method that was used to measure the power
        and whether this method can distinguish actual or estimated
        values.
     
        An EnMS can use this information to account for the accuracy
        and nature of the reading between different implementations.
     
        4.4.2 Measurements: Power Attributes
     
        Optionally, an Energy Object describes the Power measurements
        with Power Attribute information reflecting the electrical
        characteristics of the measurement. These Power Attributes
        adhere to the IEC 61850 7-2 standard for describing AC
        measurements.
     
        4.4.3 Measurements: Energy
     
        Optionally, an Energy Object that can report actual power
        readings will have energy attributes that provide the energy
        used, produced, and net energy in kWh. These values are energy
        measurements that accumulate the power readings. If energy
        values are returned, then the three measurements are provided
        along with a description of accuracy.
     
        4.4.4 Measurements: Demand
     
        Optionally, an Energy Object will provide demand information
        over time. Demand measurements can be provided when the Energy
        Object is capable of measuring actual power
     
     
     
     
     
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        4.5 Control
     
        An Energy Object can be controlled by setting it to a specific
        Power State.  An Energy Object implements at least one set of
        Power States consisting of at least two states, an on state
        and an off state.
     
        Each Energy Object should indicate the sets of Power States
        that it implements.  Well known Power States / Sets are
        registered with IANA.
     
        When a device is set to a particular Power State, it may be
        busy. The device will set the desired Power State and then
        update the actual Power State when it changes.  There are then
        two Power State control variables: actual and requested.
     
        There are many existing standards for and implementations of
        Power States.  An Energy Object can support a mixed set of
        Power States defined in different standards. A basic example
        is given by the three Power States defined in IEEE1621
        [IEEE1621]: on, off, and sleep. The DMTF [DMTF], ACPI [ACPI],
        and PWG define larger numbers of Power States.
     
        The semantics of a power state are specified by
     
           a) the functionality provided by an Energy Object in this
        state,
     
           b) a limitation of the power that an Energy Object uses in
        this state,
     
           c) a combination of a) and b)
     
        The semantics of a Power State should be clearly defined.
        Limitation (curtailment) of the power used by an Energy Object
        in a state is be specified by
     
           - an absolute power value
     
           - a percentage value of power relative to the energy
        object's nameplate power
     
           - an indication of used power relative to another power
        state. For example: Specify that used power in state A is less
        than in state B.
     
        For supporting Power State management an Energy Object
        provides statistics on Power States including the time an
     
     
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        Energy Object spent in a certain Power State and the number of
        times an Energy Object entered a power state.
     
        When requesting an Energy Object to enter a Power State an
        indication of the Power State's name or number can be used.
        Optionally an absolute or percentage of Nameplate Power can be
        provided to allow the Energy Object to transition to a nearest
        or equivalent Power State.
     
     
     
        4.5.1 Power State Sets
     
        There are several standards and implementations of Power State
        Sets.  An Energy Object can support one or multiple Power
        State Set implementation(s) concurrently.
     
        There are currently three Power State Sets advocated:
     
        IEEE1621(256) - [IEEE1621]
     
        DMTF(512)     - [DMTF]
     
        EMAN(768)     - [EMAN-MONITORING-MIB]
     
        The respective specific states related to each Power State Set
        are specified in the following sections. The guidelines for
        addition of new Power State Sets are specified in the IANA
        Considerations Section.
     
        4.5.2 IEEE1621 Power State Set
     
        The IEEE1621 Power State Set [IEEE1621] consists of 3
        rudimentary states: on, off or sleep.
     
     
     
           on(0)    - The device is fully On and all features of the
        device are in working mode.
     
           off(1)   - The device is mechanically switched off and does
        not consume energy.
     
           sleep(2) - The device is in a power saving mode, and some
        features may not be available immediately.
     
     
     
     
     
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        4.5.3 DMTF Power State Set
     
        DMTF [DMTF] standards organization has defined a power profile
        standard based on the CIM (Common Information Model) model
        that consists of 15 power states ON (2), SleepLight (3),
        SleepDeep (4), Off-Hard (5), Off-Soft (6), Hibernate(7),
        PowerCycle Off-Soft (8), PowerCycle Off-Hard (9), MasterBus
        reset (10), Diagnostic Interrupt (11), Off-Soft-Graceful (12),
        Off-Hard Graceful (13), MasterBus reset Graceful (14), Power-
        Cycle Off-Soft Graceful (15), PowerCycle-Hard Graceful (16).
        DMTF standard is targeted for hosts and computers.  Details of
        the semantics of each Power State within the DMTF Power State
        Set can be obtained from the DMTF Power State Management
        Profile specification [DMTF].
     
        DMTF power profile extends ACPI power states. The following
        table provides a mapping between DMTF and ACPI Power State
        Set:
     
     
     
           ---------------------------------------------------
     
           |  DMTF                             | ACPI        |
     
           |  Power State                      | Power State |
     
           ---------------------------------------------------
     
           | Reserved(0)                       |             |
     
           ---------------------------------------------------
     
           | Reserved(1)                       |             |
     
           ---------------------------------------------------
     
           | ON (2)                            | G0-S0       |
     
           --------------------------------------------------
     
           | Sleep-Light (3)                   | G1-S1 G1-S2 |
     
           --------------------------------------------------
     
           | Sleep-Deep (4)                    | G1-S3       |
     
           --------------------------------------------------
     
     
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           | Power Cycle (Off-Soft) (5)        | G2-S5       |
     
           ---------------------------------------------------
     
           | Off-hard (6)                      | G3          |
     
           ---------------------------------------------------
     
           | Hibernate (Off-Soft) (7)          | G1-S4       |
     
           ---------------------------------------------------
     
           | Off-Soft (8)                      | G2-S5       |
     
           ---------------------------------------------------
     
           | Power Cycle (Off-Hard) (9)        | G3          |
     
           ---------------------------------------------------
     
           | Master Bus Reset (10)             | G2-S5       |
     
           ---------------------------------------------------
     
           | Diagnostic Interrupt (11)         | G2-S5       |
     
           ---------------------------------------------------
     
           | Off-Soft Graceful (12)            | G2-S5       |
     
           ---------------------------------------------------
     
           | Off-Hard Graceful (13)            | G3          |
     
           ---------------------------------------------------
     
           | MasterBus Reset Graceful (14)     | G2-S5       |
     
           ---------------------------------------------------
     
           | Power Cycle off-soft Graceful (15)| G2-S5       |
     
           ---------------------------------------------------
     
           | Power Cycle off-hard Graceful (16)| G3          |
     
           ---------------------------------------------------
     
     
     
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                Figure 5: DMTF and ACPI Powe State Set Mapping
     
        4.5.4 EMAN Power State Set
     
        An EMAN Power State Set represents an attempt at a standard
        approach for modeling the different levels of power of a
        device.  The EMAN Power States are an expansion of the basic
        Power States as defined in [IEEE1621] that also incorporates
        the Power States defined in [ACPI] and [DMTF].  Therefore, in
        addition to the non-operational states as defined in [ACPI]
        and [DMTF] standards, several intermediate operational states
        have been defined.
     
        An Energy Object may implement fewer or more Power States than
        a particular EMAN Power State Set specifies. In this case, the
        Energy Object implementation can determine its own mapping to
        the predefined EMAN Power States within the EMAN Power State
        Set.
     
        There are twelve EMAN Power States that expand on [IEEE1621].
        The expanded list of Power States is derived from [CISCO-EW]
        and is divided into six operational states and six non-
        operational states.  The lowest non-operational state is 1 and
        the highest is 6.  Each non-operational state corresponds to
        an [ACPI] Global and System state between G3 (hard-off) and G1
        (sleeping).  Each operational state represents a performance
        state, and may be mapped to [ACPI] states P0 (maximum
        performance power) through P5 (minimum performance and minimum
        power).
     
        In each of the non-operational states (from mechoff(1) to
        ready(6)), the Power State preceding it is expected to have a
        lower Power value and a longer delay in returning to an
        operational state:
     
                 mechoff(1) : An off state where no Energy Object
        features are available.  The Energy Object is unavailable.  No
        energy is being consumed and the power connector can be
        removed.
     
                 softoff(2) : Similar to mechoff(1), but some
        components remain powered or receive trace power so that the
        Energy Object can be awakened from its off state.  In
        softoff(2), no context is saved and the device typically
        requires a complete boot when awakened.
     
     
     
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                 hibernate(3): No Energy Object features are
        available.   The Energy Object may be awakened without
        requiring a complete boot, but the time for availability is
        longer than sleep(4). An example for state hibernate(3) is a
        save to-disk state where DRAM context is not maintained.
        Typically, energy consumption is zero or close to zero.
     
                 sleep(4)    : No Energy Object features are
        available, except for out-of-band management, such as wake-up
        mechanisms.  The time for availability is longer than
        standby(5). An example for state sleep(4) is a save-to-RAM
        state, where DRAM context is maintained.  Typically, energy
        consumption is close to zero.
     
                 standby(5) : No Energy Object features are available,
        except for out-of-band management, such as wake-up mechanisms.
        This mode is analogous to cold-standby.  The time for
        availability is longer than ready(6).  For example processor
        context is may not be maintained. Typically, energy
        consumption is close to zero.
     
                 ready(6)    : No Energy Object features are
        available, except for out-of-band management, such as wake-up
        mechanisms. This mode is analogous to hot-standby.  The Energy
        Object can be quickly transitioned into an operational state.
        For example, processors are not executing, but processor
        context is maintained.
     
                 lowMinus(7) : Indicates some Energy Object features
        may not be available and the Energy Object has taken measures
        or selected options to provide less than low(8) usage.
     
                 low(8)      : Indicates some features may not be
        available and the Energy Object has taken measures or selected
        options to provide less than mediumMinus(9) usage.
     
                 mediumMinus(9): Indicates all Energy Object features
        are available but the Energy Object has taken measures or
        selected options to provide less than medium(10) usage.
     
                 medium(10)  : Indicates all Energy Object features
        are available but the Energy Object has taken measures or
        selected options to provide less than highMinus(11) usage.
     
                 highMinus(11): Indicates all Energy Object features
        are available and power usage is less than high(12).
     
     
     
     
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                 high(12)    : Indicates all Energy Object features
        are available and the Energy Object is consuming the highest
        power.
     
     
     
        4.6 Power State Sets Comparison
     
        A comparison of Power States from different Power State Sets
        can be seen in the following table:
     
     
     
          IEEE1621  DMTF         ACPI           EMAN
     
          Non-operational states
     
          off       Off-Hard     G3, S5         MechOff(1)
     
          off       Off-Soft     G2, S5         SoftOff(2)
     
          sleep     Hibernate    G1, S4         Hibernate(3)
     
          sleep     Sleep-Deep   G1, S3         Sleep(4)
     
          sleep     Sleep-Light  G1, S2         Standby(5)
     
          sleep     Sleep-Light  G1, S1         Ready(6)
     
     
     
          Operational states:
     
          on        on           G0, S0, P5     LowMinus(7)
     
          on        on           G0, S0, P4     Low(8)
     
          on        on           G0, S0, P3     MediumMinus(9)
     
          on        on           G0, S0, P2     Medium(10)
     
          on        on           G0, S0, P1     HighMinus(11)
     
          on        on           G0, S0, P0     High(12)
     
     
     
                     Figure 6: Comparison of Power States
     
     
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        4.7 Relationships
     
        Two Energy Objects can establish an Energy Object
        Relationship.
     
        Relationships are modeled with a Relationship class that
        contains the UUID of the participants in the relationship and
        a description of the type of relationship. The types of
        relationships are:  power source. metering, and aggregations.
     
        The Power Source Relationship gives a view of the wiring
        topology.  For example: a data center server receiving power
        from two specific Power Interfaces from two different PDUs.
     
        Note: A power source relationship may or may not change as the
        direction of power changes between two Energy Objects. The
        relationship may remain to indicate the change of power
        direction was unintended or an error condition.
     
        The Metering Relationship gives the view of the metering
        topology.  Standalone meters can be placed anywhere in a power
        distribution tree.  For example, utility meters monitor and
        report accumulated power consumption of the entire building.
        Logically, the metering topology overlaps with the wiring
        topology, as meters are connected to the wiring topology.  A
        typical example is meters that clamp onto the existing wiring.
     
        The Aggregation Relationship gives a model of devices that may
        aggregate (sum, average, etc) values for other devices.  The
        Aggregation Relationship is slightly different compared to the
        other relationships as this refers more to a management
        function.
     
        In some situations, it is not possible to discover the Energy
        Object Relationships, and they must be set by an EnMS or
        administrator.  Given that relationships can be assigned
        manually, the following sections describes guidelines for use.
     
        4.8 Energy Object Relationship Conventions and Guidelines
     
        This Energy Management framework does not impose many "MUST"
        rules related to Energy Object Relationships. There are always
        corner cases that could be excluded with too strict
        specifications of relationships. However, this Energy
        Management framework proposes a series of guidelines,
        indicated with "SHOULD" and "MAY".
     
     
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        4.8.1 Guidelines: Power Source
     
        Power Source relationships are intended to identify the
        connections between Power Interfaces. This is analogous to a
        Layer 2 connection in networking devices (a "one-hop
        connection").
     
        The preferred modeling would be for Power Interfaces to
        participate in Power Source Relationships.
     
        It may happen that some Energy Objects may not have the
        capability to model Power Interfaces.  Therefore, it may
        happen that a Power Source Relationship is established between
        two Energy Objects or two non-connected Power Interfaces.
     
        While strictly speaking Components and Power Interfaces on the
        same device do provide or receive energy from each other, the
        Power Source relationship is intended to show energy transfer
        between Devices. Therefore the relationship is implied on the
        same Device.
     
        -  An Energy Object SHOULD NOT establish a Power Source
        Relationship with a Component.
     
        -  A Power Source Relationship SHOULD be established with next
        known Power Interface in the wiring topology.
     
        o  The next known Power Interface in the wiring topology would
        be the next device implementing the framework. In some cases
        the domain of devices under management may include some
        devices that do not implement the framework. In these cases,
        the Power Source relationship can be established with the next
        device in the topology that implements the framework and
        logically shows the Power Source of the device.
     
        -  Transitive Power Source relationships SHOULD NOT be
        established.  For example, if an Energy Object A has a Power
        Source Relationship "Poweredby" with the Energy Object B, and
        if the Energy Object B has a Power Source Relationship
        "Poweredby" with the Energy Object C, then the Energy Object A
        SHOULD NOT have a Power Source Relationship "Poweredby" with
        the Energy Object C.
     
     
     
        4.8.2 Guidelines: Metering Relationship
     
     
     
     
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        Metering Relationships are intended to show when one Device is
        measuring the power or energy at a point in a power
        distribution system. Since one point of a power distribution
        system may cover many Devices with a complex wiring topology,
        this relationship type can be seen as an arbitrary set.
     
        Devices may include metering hardware for components and Power
        Interfaces or for the entire Device. For example, some PDUs
        may have the ability to measure Power for each Power Interface
        (metered by outlet). Others may be able to control power at
        each Power Interface but can only measure Power at the Power
        Inlet and a total for all Power Interfaces (metered by
        device).
     
        In such cases a Device SHOULD be modeled as an Energy Object
        that meters all of its Power Outlets and each Power Outlet MAY
        be metered by the Energy Object representing the Device.
     
        -  A Metering Relationship MAY be established with any other
        Energy Object, Component, or Power Interface.
     
        -  Transitive Metering relationships MAY be used.
     
        -  When there is a series of meters for one Energy Object, the
        Energy Object MAY establish a Metering relationship with one
        or more of the meters.
     
     
     
        4.8.3 Guidelines: Aggregation
     
        Aggregation relationships are intended to identify when one
        device is used to accumulate values from other devices.
        Typically this is for energy or power values among devices and
        not for Components or Power Interfaces on the same device.
     
        The intent of Aggregation relationships is to indicate when
        one device is providing aggregate values for a set of other
        devices when it is not obvious from the power source or simple
        containment within a device.
     
        Establishing aggregation relationships within the same device
        would make modeling more complex and the aggregated values can
        be implied from the use of Power Inlets, outlet and Energy
        Object values on the same device.
     
        Since an EnMS is naturally a point of aggregation it is not
        necessary to model aggregation for Energy Management Systems.
     
     
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        Aggregation SHOULD be used for power and energy. It MAY be
        used for aggregation of other values from the information
        model, but the rules and logical ability to aggregate each
        attribute is out of scope for this document.
     
        -  A Device SHOULD NOT establish an Aggregation Relationship
        with a Component.
     
        -  A Device SHOULD NOT establish an Aggregation Relationship
        with the Power Interfaces contained on the same device.
     
        -  A Device SHOULD NOT establish an Aggregation Relationship
        with an EnMS.
     
        -  Aggregators SHOULD log or provide notification in the case
        of errors or missing values while performing aggregation.
     
        4.9 Energy Object Relationship Extensions
     
        This framework for Energy Management is based on three
        relationship types: Aggregation , Metering, and Power Source.
     
        This framework is defined with possible future extension of
        new Energy Object Relationships in mind.  For example, a Power
        Distribution Unit (PDU) that allows physical entities like
        outlets to be "ganged" together as a logical entity for
        simplified management purposes, could be modeled with an
        extension called a "gang relationship", whose semantics would
        specify the Energy Objects' grouping.
     
     5. Energy Management Information Model
     
        The following basic UML represents an information model
        expression of the concepts in this framework.  This
        information model, provided as a reference for implementers,
        is represented as a MIB in the different related IETF Energy
        Monitoring documents.  However, other programming structures
        with different data models could be used as well.
     
        Data modeling specifications of this information model may
        where needed specify which attributes are required or
        optional.
     
        The notation use here is shorthand UML with lowercase types
        considered platform or atomic types (i.e., int, string,
        collection). Uppercase types denote classes described further.
        Collections and cardinality are expressed via qualifier
        notation.  Attributes labeled static are considered class
     
     
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        variables and global to the class.  Arrows indicate
        inheritance. Algorithms for class variable initialization,
        constructors, or destructors are not shown. Attributes and
        structures are considered readable and writeable unless
        prefixed by a dash (-) that indicates read-only.
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
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        EDITOR's NOTE:  Pseudo-code used until consensus then UML
        diagram will be substituted
     
        class EnergyObject {
     
           // identification / classification
           index        : int
           identifier   : uuid
           alternatekey : string
     
           // context
           domainName      : string
           role            : string
           keywords [0..n] : string
           importance      : int
     
           // relationship
     
           relationships [0..n] : Relationship
     
           // measurements
           nameplate    : Nameplate
           power     : PowerMeasurement
           energy    : EnergyMeasurment
           demand    : DemandMeasurement
     
           // control
           powerControl [0..n] : PowerStateSet
     
        }
     
        class Device extends EnergyObject {
              eocategory   : enum { producer, consumer, meter,
        distributor }
        }
     
        class Component extends EnergyObject
              eocategory   : enum { producer, consumer, meter,
        distributor }
        }
     
        classInterface extends EnergyObject{
              eoIfType : enum ( inlet, outlet, both}
        }
     
     
     
     
     
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        class Nameplate {
              nominalPower : PowerMeasurement
              details      : URI
        }
     
     
        class Relationship {
              relationshipType    : enum { meters, meteredby, powers,
        poweredby, aggregates, aggregatedby }
              relationshipObject  : uuid
        }
     
     
        class Measurement {
              multiplier: enum { -24..24}
              caliber   : enum { actual, estimated, trusted, assumed }
              accuracy  : enum { 0..10000} // hundreds of percent
        }
     
     
        class PowerMeasurement extends Measurement {
              value          : long
              units          : "W"
              powerAttribute : PowerAttribute
        }
     
     
        class EnergyMeasurement extends Measurement {
              startTime : time
              units     : "kWh"
              provided  : long
              used      : long
              produced  : long
        }
     
     
        class TimedMeasurement extends Measurement {
              startTime  : timestamp
              value      : Measurement
              maximum    : Measurement
        }
     
     
        class TimeInterval {
              value      : long
              units      : enum { seconds, miliseconds,...}
        }
     
     
     
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        class DemandMeasurement extends Measurement {
              intervalLength : TimeInterval
              interval       : long
              intervalMode   : enum { periodic, sliding, total }
              intervalWindow : TimeInterval
              sampleRate     : TimeInterval
              status         : enum { active, inactive }
              measurements[0..n] : TimedMeasurements
        }
     
     
        class PowerStateSet {
              powerSetIdentifier : int
              name               : string
              powerStates [0..n] : PowerState
              operState          : int
              adminState         : int
              reason             : string
              configuredTime     : timestamp
        }
     
     
        class PowerState {
              powerStateIdentifier  : int
              name             : string
              cardinality      : int
              maximumPower     : PowerMeasurement
              totalTimeInState : time
              entryCount       : long
        }
     
        class PowerAttribute {
     
          // container for attributes
               acQuality      : ACQuality
     
        }
     
     
        class ACQuality {
          acConfiguration : enum {SNGL, DEL,WYE}
          avgVoltage   : long
          avgCurrent   : long
          frequency    : long
          unitMultiplier  : int
          accuracy       : int
          totalActivePower   : long
     
     
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          totalReactivePower : long
          totalApparentPower : long
          totalPowerFactor : long
          phases [0..2]  : ACPhase
     
          // Could have abstract class Phase to be clear it's ACPhase
        or one of the subclasses
     
        }
     
        class ACPhase {
          phaseIndex : long
          avgCurrent : long
          activePower : long
          reactivePower : long
          apparentPower : long
          powerFactor : long
        }
     
        class DelPhase extends ACPhase {
          phaseToNextPhaseVoltage  : long
          thdVoltage : long
          thdCurrent : long
        }
     
     
        class WYEPhase extends ACPhase {
          phaseToNeutralVoltage : long
          thdCurrent : long
          thdVoltage : long
        }
     
     
     
                 Figure 7: Information Model UML Representation
     
     
     
     6. Example Topologies
     
        In this section we give examples of how to use the Energy
        Management framework relationships to model topologies.  In
        each example we show how it can be applied when Devices have
        the capability to model Power Interfaces.  We also show in
        each example how the framework can be applied when devices
        cannot support Power Interfaces but only monitor information
        or control the Device as a whole. For instance, a PDU may only
     
     
     
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        be able to measure power and energy for the entire unit
        without the ability to distinguish among the inlets or outlet.
     
        Together, these examples show how the framework can be adapted
        for Devices with different capabilities (typically hardware)
        for Energy Management.
     
        Given for all Examples:
     
        Device W: A computer with one power supply. Power interface 1
        is an inlet for Device W.
     
        Device X: A computer with two power supplies. Power interface
        1 and power interface 2 are both inlets for Device X.
     
        Device Y: A PDU with multiple Power Interfaces numbered 0..10.
        Power interface 0 is an inlet and power interface 1..10 are
        outlets.
     
        Device Z: A PDU with multiple Power Interfaces numbered 0..10.
        Power interface 0 is an inlet and power interface 1..10 are
        outlets.
     
     
        6.1 Example I: Simple Device with one Source
     
     
        Topology:
          Device W inlet 1 is plugged into Device Y outlet 8.
     
        With Power Interfaces:
     
          Device W has an Energy Object representing the computer
          itself as well as one Power Interface defined as an inlet.
     
          Device Y would have an Energy Object representing the PDU
          itself (the Device), with a Power Interface 0 defined as an
          inlet and Power Interfaces 1..10 defined as outlets.
     
          The interfaces of the devices would have a Power Source
          Relationship such that:
          Device W inlet 1 is powered by Device Y outlet 8.
     
        Without Power Interfaces:
     
          Device W has an Energy Object representing the computer.
          Device Y would have an Energy Object representing the PDU.
     
     
     
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          The devices would have a Power Source Relationship such
          that:
          Device W is powered by Device Y.
     
     
        6.2 Example II: Multiple Inlets
     
     
        Topology:
          Device X inlet 1 is plugged into Device Y outlet 8.
          Device X inlet 2 is plugged into Device Y outlet 9.
     
        With Power Interfaces:
     
          Device X has an Energy Object representing the computer
          itself. It contains two Power Interfaces defined as inlets.
     
          Device Y would have an Energy Object representing the PDU
          itself (the Device), with a Power Interface 0 defined as an
          inlet and Power Interfaces 1..10 defined as outlets.
     
     
          The interfaces of the devices would have a Power Source
          Relationship such that:
          Device X inlet 1 is powered by Device Y outlet 8.
          Device X inlet 2 is powered by Device Y outlet 9.
     
        Without Power Interfaces:
     
          Device X has an Energy Object representing the computer.
          Device Y has an Energy Object representing the PDU.
     
          The devices would have a Power Source Relationship such
          that:
          Device X is powered by Device Y.
     
     
        6.3 Example III: Multiple Sources
     
     
        Topology:
          Device X inlet 1 is plugged into Device Y outlet 8.
          Device X inlet 2 is plugged into Device Z outlet 9.
     
        With Power Interfaces:
     
          Device X has an Energy Object representing the computer
          itself. It contains two Power Interface defined as inlets.
     
     
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          Device Y would have an Energy Object representing the PDU
          itself  (the Device), with a Power Interface 0 defined as an
          inlet and Power Interfaces 1..10 defined as outlets.
     
          Device Z would have an Energy Object representing the PDU
          itself  (the Device), with a Power Interface 0 defined as an
          inlet and Power Interfaces 1..10 defined as outlets.
     
          The interfaces of the devices would have a Power Source
          Relationship such that:
          Device X inlet 1 is powered by Device Y outlet 8.
          Device X inlet 2 is powered by Device Z outlet 9.
     
        Without Power Interfaces:
     
          Device X has an Energy Object representing the computer.
          Device Y and Z would both have respective Energy Objects
          representing each entire PDU.
     
          The devices would have a Power Source Relationship such
          that:
          Device X is powered by Device Y and powered by Device Z.
     
     
     
        6.4 Relationships Between Devices
     
        6.4.1 Power Source Topology
     
        As described in Section 4, the power source(s) of a device is
        important for energy management.  The Energy Management
        reference model addresses this by a Power Source Relationship.
        This is a relationship among devices providing energy and
        devices receiving energy.
     
        A simple example is a PoE PSE, such as an Ethernet switch
        providing power to a PoE PD, such as a desktop phone.  Here
        the switch provides energy and the phone receives energy.
        This relationship can be seen in the figure below.
     
              +----------+   power source  +---------+
     
              |  switch  | <-------------- |  phone  |
     
              +----------+                 +---------+
     
        Figure 8: Simple Power Source
     
     
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        A single power provider can act as power source for multiple
        power receivers.  An example is a power distribution unit
        (PDU) providing AC power for multiple switches.
     
              +-------+   power source  +----------+
     
              |  PDU  | <----------+--- | switch 1 |
     
              +-------+            |    +----------+
     
                                   |
     
                                   |    +----------+
     
                                   +--- | switch 2 |
     
                                   |    +----------+
     
                                   |
     
                                   |    +----------+
     
                                   +--- | switch 3 |
     
                                        +----------+
     
        Figure 10: Multiple Power Source
     
     
     
        This level of modeling is sufficient if there is no need to
        distinguish in monitoring and control between the individual
        receivers at the switch.
     
        However, if there is a need to monitor or control power supply
        for individual receivers at the power provider, then a more
        detailed level of modeling is needed.
     
        Devices receive or provide energy at power interfaces
        connecting them to a transmission medium.  The Power Source
        relationship can be used between power interfaces at the power
        provider side as well as at the power receiver side.  Figure 9
        shows a power-providing device with one power interface (PI)
        per connected receiving device.
     
     
     
     
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              +-------+------+   power source  +----------+
              |       | PI 1 | <-------------- | switch 1 |
              |       +------+                 +----------+
              |       |
              |       +------+   power source  +----------+
              |  PDU  | PI 2 | <-------------- | switch 2 |
              |       +------+                 +----------+
              |       |
              |       +------+   power source  +----------+
              |       | PI 3 | <-------------- | switch 3 |
              +-------+------+                 +----------+
     
        Figure 11: Power Source with Power interfaces
     
        When required for consistency, Power interfaces may also be
        modeled at the receiving device, as shown in Figure 10.
     
              +-------+------+   power source  +----+----------+
              |       | PI 1 | <-------------- | PI | switch 1 |
              |       +------+                 +----+----------+
              |       |
              |       +------+   power source  +----+----------+
              |  PDU  | PI 2 | <-------------- | PI | switch 2 |
              |       +------+                 +----+----------+
              |       |
              |       +------+   power source  +----+----------+
              |       | PI 3 | <-------------- | PI | switch 3 |
              +-------+------+                 +----+----------+
     
        Figure 12: Power Interfaces at Receiving Device
     
     
     
        Power Source relationships are between devices and their
        interfaces.  They are not transitive.  In the examples below
        there is a PDU powering a switch powering a phone.
     
     
              +-------+   power   +--------+   power   +---------+
              |  PDU  | <-------- | switch | <-------- |  phone  |
              +-------+   source  +--------+   source  +---------+
     
        Figure 13: Power Source Non-Transitive
     
     
     
        Power Source Relationships are between the PDU and the switch
        and between the switch and the phone.  Transitively, there
     
     
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        exists a Power Source Relationship between the PDU and the
        phone.  .
     
              +-------+   power   +--------+   power   +---------+
              |  PDU  | <-------- | switch | <-------- |  phone  |
              +-------+   source  +--------+   source  +---------+
                  ^                                          |
                  |              power source                |
                  +------------------------------------------+
     
        Figure 14: Power Source Transitive
     
     
     
        6.4.2 Metering Topology
     
        Case 1: Metering between two devices
     
        The metering topology between two devices is closely related
        to the power source topology.  It is based on the assumption
        that in many cases the power provided and the power received
        is the same for both peers of a power source relationship.
        Then power measured at one end can be taken as the actual
        power value at the other end.  Obviously, the same applies to
        energy at both ends.
     
        We define in this case a Metering Relationship between two
        devices or power interfaces of devices that have a power
        source relationship.  Power and energy values measured at one
        peer of the power source relationship are reported for the
        other peer as well.
     
        The Metering Relationship is independent of the direction of
        the Power Source Relationship.  The more common case is that
        values measured at the power provider are reported for the
        power receiver, but also the reverse case is possible with
        values measured at the power receiver being reported for the
        power provider.
     
                                Power                Power
           +-----+----------+   Source  +--------+   Source +-------+
           | PDU |PI + meter| <-------- | switch | <------- | phone |
           +-----+----------+  Metering +--------+          +-------+
                       ^                                           |
                       |                                           |
                       +-------------------------------------------+
                                       metering
     
     
     
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        Figure 15: Direct and One Hop Metering
     
     
     
        Case 2: Metering at a point in power distribution
     
        A Sub-meter in a power distribution system can logically
        measure the power or energy for all devices downstream from
        the meter in the power distribution system.  As such, a Power
        metering relationship can be seen as a relationship between a
        meter and all of the devices downstream from the meter.
     
        We define in this case a Power Source relationship between a
        metering device and devices downstream from the meter.
     
        In cases where the Power Source topology cannot be discovered
        or derived from the information available in the Energy
        Management Domain, the Metering Topology can be used to relate
        the upstream meter to the downstream devices in the absence of
        specific power source relationships.
     
        A Metering Relationship can occur between devices that are not
        directly connected, as shown in Figure 16.
     
                           +---------------+
                           |   Device 1    |
                           +---------------+
                           |      PI       |
                           +---------------+
                                   |
                           +---------------+
                           |     Meter     |
                           +---------------+
                                   .
                                   .
                                   .
            +----------+   +----------+   +-----------+
            | Device A |   | Device B |   | Device C  |
            +----------+   +----------+   +-----------+
     
        Figure 16: Complex Metering Topology
     
        An analogy to communications networks would be modeling
        connections between servers (meters) and clients (devices)
        when the complete Layer 2 topology between the servers and
        clients is not known.
     
     
     
     
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        6.4.3 Aggregation Topology
     
        Some devices can act as aggregation points for other devices.
        For example, a PDU controller device may contain the summation
        of power and energy readings for many PDU devices.  The PDU
        controller will have aggregate values for power and energy for
        a group of PDU devices.
     
        This aggregation is independent of the physical power or
        communication topology.
     
        An Aggregation Relationship is an Energy Object Relationship
        where one Energy Object (called the Aggregate Energy Object)
        aggregates the Energy Management information of one or more
        other Energy Objects.  These Energy Objects are said to have
        an Aggregation Relationship.
     
        The functions that the aggregation point may perform include
        the calculation of values such as average, count, maximum,
        median, minimum, or the listing (collection) of the
        aggregation values, etc.
     
        Based on the experience gained on aggregations at the IETF
        [draft-ietf-ipfix-a9n-08], the aggregation function in the
        EMAN framework is limited to the summation.
     
        When aggregation occurs across a set of entities, values to be
        aggregated may be missing for some entities.  The EMAN
        framework does not specify how these should be treated, as
        different implementations may have good reason to take
        different approaches.  One common treatment is to define the
        aggregation as missing if any of the constituent elements are
        missing (useful to be most precise). Another is to treat the
        missing value as zero (useful to have continuous data
        streams).
     
        The specifications of aggregation functions are out of scope
        of the EMAN framework, but must be clearly specified by the
        equipment vendor.
     
     7. Relationship with Other Standards
     
     
     
        This energy management framework uses, as much as possible,
        existing standards efforts, especially with respect to
        information modeling and data modeling [RFC3444].
     
     
     
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        The data model for power- and energy-related objects is based
        on IEC 61850.
     
        Specific examples include:
     
        The scaling factor, which represents Energy Object usage
        magnitude, conforms to the IEC 61850 definition of unit
        multiplier for the SI (System International) units of measure.
     
        The electrical characteristic is based on the ANSI and IEC
        Standards, which require that we use an accuracy class for
        power measurement.  ANSI and IEC define the following accuracy
        classes for power measurement:
     
        IEC 62053-22  60044-1 class 0.1, 0.2, 0.5, 1  3.
     
        ANSI C12.20 class 0.2, 0.5
     
        The electrical characteristics and quality adhere closely to
        the IEC 61850 7-2 standard for describing AC measurements.
     
        The power state definitions are based on the DMTF Power State
        Profile and ACPI models, with operational state extensions.
     
     
     8.       Security Considerations
     
        Regarding the data attributes specified here, some or all may
        be considered sensitive or vulnerable in some network
        environments. Reading or writing these attributes without
        proper protection such as encryption or access authorization
        may have negative effects on the network capabilities.
     
        Security Considerations for SNMP
     
        Readable objects in MIB modules (i.e., objects with a MAX-
        ACCESS other than not-accessible) may be considered sensitive
        or vulnerable in some network environments.  It is thus
        important to control GET and/or NOTIFY access to these objects
        and possibly to encrypt the values of these objects when
        sending them over the network via SNMP.
     
     
     
     
     
     
     
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        The support for SET operations in a non-secure environment
        without proper protection can have a negative effect on
        network operations.  For example:
     
        Unauthorized changes to the Energy Management Domain or
        business context of an Energy Object may result in
        misreporting or interruption of power.
     
        Unauthorized changes to a power state may disrupt the power
        settings of the different Energy Objects, and therefore the
        state of functionality of the respective Energy Objects.
     
        Unauthorized changes to the demand history may disrupt proper
        accounting of energy usage.
     
        With respect to data transport, SNMP versions prior to SNMPv3
        did not include adequate security.  Even if the network itself
        is secure (for example, by using IPsec), there is still no
        secure control over who on the secure network is allowed to
        access and GET/SET (read/change/create/delete) the objects in
        these MIB modules.
     
        It is recommended that implementers consider the security
        features as provided by the SNMPv3 framework (see [RFC3410],
        section 8), including full support for the SNMPv3
        cryptographic mechanisms (for authentication and privacy).
     
        Further, deployment of SNMP versions prior to SNMPv3 is not
        recommended.  Instead, it is recommended to deploy SNMPv3 and
        to enable cryptographic security.  It is then a
        customer/operator responsibility to ensure that the SNMP
        entity giving access to an instance of these MIB modules is
        properly configured to give access to the objects only to
        those principals (users) that have legitimate rights to GET or
        SET (change/create/delete) them.
     
     
     
     9.       IANA Considerations
     
     9.1 IANA Registration of new Power State Set
     
        This document specifies an initial set of Power State Sets.
        The list of these Power State Sets with their numeric
        identifiers is given is Section 4. IANA maintains the lists of
        Power State Sets.
     
     
     
     
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        New assignments for Power State Set are administered by IANA
        through Expert Review [RFC5226], i.e., review by one of a
        group of experts designated by an IETF Area Director. The
        group of experts MUST check the requested state for
        completeness and accuracy of the description. A pure vendor
        specific implementation of Power State Set shall not be
        adopted; since it would lead to proliferation of Power State
        Sets.
     
     
     
        Power states in a Power State Set are limited to 255 distinct
        values. New Power State Set must be assigned the next
        available numeric identifier that is a multiple of 256.
     
     
     
     9.1.1 IANA Registration of the IEEE1621 Power State Set
     
        This document specifies a set of values for the IEEE1621 Power
        State Set [IEEE1621].  The list of these values with their
        identifiers is given in Section 4.6.2.  IANA created a new
        registry for IEEE1621 Power State Set identifiers and filled
        it with the initial list of identifiers.
     
        New assignments (or potentially deprecation) for the IEEE1621
        Power State Set is administered by IANA through Expert Review
        [RFC5226], i.e., review by one of a group of experts
        designated by an IETF Area Director.  The group of experts
        must check the requested state for completeness and accuracy
        of the description.
     
     9.1.2 IANA Registration of the DMTF Power State Set
     
        This document specifies a set of values for the DMTF Power
        State Set.  The list of these values with their identifiers is
        given in Section 4. IANA has created a new registry for DMTF
        Power State Set identifiers and filled it with the initial
        list of identifiers
        .
        New assignments (or potentially deprecation) for the DMTF
        Power State Set is administered by IANA through Expert Review
        [RFC5226], i.e., review by one of a group of experts
        designated by an IETF Area Director.  The group of experts
        must check the conformance with the DMTF standard [DMTF], on
        the top of checking for completeness and accuracy of the
        description.
     
     
     
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     9.1.3 IANA Registration of the EMAN Power State Set
     
        This document specifies a set of values for the EMAN Power
        State Set.  The list of these values with their identifiers is
        given in Section 4.6.4.  IANA has created a new registry for
        EMAN Power State Set identifiers and filled it with the
        initial list of identifiers.
     
        New assignments (or potentially deprecation) for the EMAN
        Power State Set is administered by IANA through Expert Review
        [RFC5226], i.e., review by one of a group of experts
        designated by an IETF Area Director.  The group of experts
        must check the requested state for completeness and accuracy
        of the description.
     
     9.1.4 Batteries Power State Set
     
        Batteries have operational and administrational states that
        could be represented as a power state set. Since the work for
        battery management is parallel to this document, we are not
        proposing any Power State Sets for batteries at this time.
     
     
     9.2 Updating the Registration of Existing Power State Sets
     
        With the evolution of standards, over time, it may be
        important to deprecate some of the existing the Power State
        Sets, or to add or deprecate some Power States within a Power
        State Set.
     
     
     
        The registrant shall publish an Internet-draft or an
        individual submission with the clear specification on
        deprecation of Power State Sets or Power States registered
        with IANA.  The deprecation or addition shall be administered
        by IANA through Expert Review [RFC5226], i.e., review by one
        of a group of experts designated by an IETF Area Director. The
        process should also allow for a mechanism for cases where
        others have significant objections to claims on deprecation of
        a registration.
     
     
     
     
     
     
     
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     10.      Acknowledgments
     
        The authors would like to Michael Brown for improving the text
        dramatically, and Rolf Winter for his feedback.  The award for
        the best feedback and reviews goes to Bill Mielke.  Bruce
        Nordman helped a lot in the framework brainstorming with
        numerous conference calls and discussions. Finally, the
        authors would like to thank the EMAN chairs: Nevil Brownlee,
        Bruce Nordman, and Tom Nadeau.
     
     
     11.      References
     
     Normative References
     
     
        [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
                Requirement Levels", BCP 14, RFC 2119, March 1997
     
        [RFC3410]  Case, J., Mundy, R., Partain, D., and B. Stewart,
                "Introduction and Applicability Statements for
                Internet Standard Management Framework ", RFC 3410,
                December 2002
     
        [RFC4122] Leach, P., Mealling, M., and R. Salz," A Universally
                Unique IDentifier (UUID) URN Namespace", RFC 4122,
                July 2005
     
        [RFC5226] Narten, T., and H. Alvestrand, "Guidelines for
                Writing an IANA Considerations Section in RFCs", RFC
                5226, May 2008
     
        [RFC6933]  Bierman, A. and K. McCloghrie, "Entity MIB
                (Version4)", RFC 6933, May 2013
     
     
     Informative References
     
     
        [RFC2578] McCloghrie, K., Perkins, D., and J. Schoenwaelder,
                "Structure of Management Information Version 2
                (SMIv2", RFC 2578, April 1999
     
        [RFC3444] Pras, A., Schoenwaelder, J. "On the Differences
                between Information Models and Data Models", RFC
                3444, January 2003
     
     
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        [RFC5101bis] Claise, B., Ed., and Trammel, T., Ed.,
                "Specification of the IP Flow Information Export
                (IPFIX) Protocol for the Exchange of IP Traffic Flow
                Information ", draft-ietf-ipfix-protocol-rfc5101bis-
                08, (work in progress), June 2013
     
        [RFC6020] M. Bjorklund, Ed., " YANG - A Data Modeling Language
                for the Network Configuration Protocol (NETCONF)",
                RFC 6020, October 2010
     
        [ACPI] "Advanced Configuration and Power Interface
                Specification", http://www.acpi.info/spec30b.htm
     
        [IEEE1621]  "Standard for User Interface Elements in Power
                Control of Electronic Devices Employed in
                Office/Consumer Environments", IEEE 1621, December
                2004
     
        [LLDP]  IEEE Std 802.1AB, "Station and Media Control
                Connectivity Discovery", 2005
     
        [LLDP-MED-MIB]  ANSI/TIA-1057, "The LLDP Management
                Information Base extension module for TIA-TR41.4
                media endpoint discovery information", July 2005
     
        [EMAN-REQ] Quittek, J., Winter, R., Dietz, T., Claise, B., and
                M. Chandramouli, "Requirements for Energy
                Management", draft-ietf-eman-requirements-14, (work
                in progress), May 2013
     
        [EMAN-OBJECT-MIB] Parello, J., and B. Claise, "Energy Object
                Contet MIB", draft-ietf-eman-energy-aware-mib-08,
                (work in progress), April 2013
     
        [EMAN-MON-MIB] Chandramouli, M.,Schoening, B., Quittek, J.,
                Dietz, T., and B. Claise, "Power and Energy
                Monitoring MIB", draft-ietf-eman-energy-monitoring-
                mib-05, (work in progress), April 2013
     
        [EMAN-BATTERY-MIB] Quittek, J., Winter, R., and T. Dietz, "
                Definition of Managed Objects for Battery
                Monitoring", draft-ietf-eman-battery-mib-08, (work in
                progress), February 2013
     
        [EMAN-AS] Schoening, B., Chandramouli, M., and B. Nordman,
                "Energy Management (EMAN) Applicability Statement",
     
     
     
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                draft-ietf-eman-applicability-statement-03, (work in
                progress), April 2013
     
        [ITU-T-M-3400] TMN recommandation on Management Functions
                (M.3400), 1997
     
        [NMF] "Network Management Fundamentals", Alexander Clemm,
                ISBN: 1-58720-137-2, 2007
     
        [TMN] "TMN Management Functions : Performance Management",
                ITU-T M.3400
     
        [1037C] US Department of Commerce, Federal Standard 1037C,
                http://www.its.bldrdoc.gov/fs-1037/fs-1037c.htm
     
        [IEEE100] "The Authoritative Dictionary of IEEE Standards
                Terms"
                http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?pu
                number=4116785
     
        [ISO50001] "ISO 50001:2011 Energy management systems -
                Requirements with guidance for use",
                http://www.iso.org/
     
        [IEC60050] International Electrotechnical Vocabulary
                http://www.electropedia.org/iev/iev.nsf/welcome?openf
                orm
     
        [IEEE-802.3at] IEEE 802.3 Working Group, "IEEE Std 802.3at-
                2009 - IEEE Standard for Information technology -
                Telecommunications and information exchange between
                systems - Local and metropolitan area networks -
                Specific requirements - Part 3: Carrier Sense
                Multiple Access with Collision Detection (CSMA/CD)
                Access Method and Physical Layer Specifications -
                Amendment: Data Terminal Equipment (DTE) -  Power via
                Media Dependent Interface (MDI) Enhancements",
                   October 2009
     
        [DMTF] "Power State Management Profile DMTF  DSP1027  Version
                2.0"  December 2009
                http://www.dmtf.org/sites/default/files/standards/doc
                uments/DSP1027_2.0.0.pdf
     
        [IPENERGY] R. Aldrich, J. Parello "IP-Enabled Energy
                Management", 2010, Wiley Publishing
     
     
     
     
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        [X.700]  CCITT Recommendation X.700 (1992), Management
                framework for Open Systems Interconnection (OSI) for
                CCITT applications
     
        [ASHRAE-201] "ASHRAE Standard Project Committee 201
                        (SPC 201)Facility Smart Grid Information
                        Model", http://spc201.ashraepcs.org
     
        [CHEN] "The Entity-Relationship Model: Toward a Unified View
                of Data",  Peter Pin-shan Chen, ACM Transactions on
                Database Systems, 1976
     
        [CISCO-EW] "Cisco EnergyWise Design Guide",  John Parello,
                Roland Saville, Steve Kramling, Cisco Validated
                Designs, September 2010,
                http://www.cisco.com/en/US/docs/solutions/Enterprise/
                Borderless_Networks/Energy_Management/energywisedg.ht
                ml
     
     
     
     Authors' Addresses
     
     Benoit Claise
     Cisco Systems, Inc.
     De Kleetlaan 6a b1
     Diegem 1813
     BE
     
     Phone: +32 2 704 5622
     Email: bclaise@cisco.com
     
     
     John Parello
     Cisco Systems, Inc.
     3550 Cisco Way
     San Jose, California 95134
     US
     
     Phone: +1 408 525 2339
     Email: jparello@cisco.com
     
     
     Brad Schoening
     44 Rivers Edge Drive
     Little Silver, NJ 07739
     US
     
     
     
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     Phone:
     Email: brad.schoening@verizon.net
     
     
     Juergen Quittek
     NEC Europe Ltd.
     Network Laboratories
     Kurfuersten-Anlage 36
     69115 Heidelberg
     Germany
     
     Phone: +49 6221 90511 15
     EMail: quittek@netlab.nec.de
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
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