Re: [eman] feedback on the eman-ietf-eman-requirements-04

["John Parello (jparello)" <[e-mail]>]

HI Benoit,

 

We have the notion of relationships setup in the framework. I sent a
note to Chris on perhaps using this scheme for modeling gangs.

 

Jp

 

From: [e-mail] [mailto:[e-mail]] On Behalf Of
Benoit Claise (bclaise)
Sent: Monday, July 25, 2011 11:19 PM
To: eman mailing list
Subject: [eman] feedback on the eman-ietf-eman-requirements-04

 

Dear all,

Here is my feedback regarding the EMAN requirement, as a contributor.
Note that some points might have been made on the mailing list already.

A couple of big points
- the outlet gang was mentioned by Chris Verges as a requirement. I
don't think I've seen it mentioned.
    Note: this could be solved by a specificEnergy Managed Object
Relationships  (Metering, Power Source, Proxy, Dependency)
- we would need some requirements about producer and/or consumer
- I've been thinking about the following requirement some more

7.3.  Reporting quantities accumulated over multiple powered entities 

   For powered entities reporting single values that are accumulated 
   over multiple powered entities, the energy management standard must 
   provide means for reporting the list of all powered entities from 
   which contributions are included in the accumulated value. 

And I wonder if we're not trying to make EMAN too complex by adding this
aggregation function.
Note: I've been involved in aggregation scheme (See RFC 5982, RFC 6183,
and http://tools.ietf.org/html/draft-trammell-ipfix-a9n-03) and this is
not straight forward to list all powered entities for which there is an
aggregation.
My point is that there is some debate whether or not a switch should
aggregate all values for children, or if this is a NMS issue.
Feedback?

See inline



Network Working Group                                    J. Quittek, Ed.

Internet-Draft                                                 R. Winter

Intended status: Informational                                  T. Dietz

Expires: January 12, 2012                                NEC Europe Ltd.

                                                               B. Claise

                                                         M. Chandramouli

                                                     Cisco Systems, Inc.

                                                           July 11, 2011



                   Requirements for Energy Management 
                    draft-ietf-eman-requirements-04 

Abstract 

   This document defines requirements for standards specifications for 
   energy management.  Defined requirements concern monitoring functions

   as well as control functions.  Covered functions include 
   identification of powered entities, monitoring of their power state, 
   power inlets, power outlets, actual power, consumed energy, and 
   contained batteries.  Further included is control of powered 
   entities' power supply and power state.  This document does not 
   specify the features that must be implemented by compliant 
   implementations but rather features that must be supported by 
   standards for energy management. 

This misses the power quality, or whatever name we want to call it.
For example "power characteristics)"




Status of this Memo 

   This Internet-Draft is submitted in full conformance with the 
   provisions of BCP 78 and BCP 79. 

   Internet-Drafts are working documents of the Internet Engineering 
   Task Force (IETF).  Note that other groups may also distribute 
   working documents as Internet-Drafts.  The list of current Internet- 
   Drafts is at http://datatracker.ietf.org/drafts/current/. 

   Internet-Drafts are draft documents valid for a maximum of six months

   and may be updated, replaced, or obsoleted by other documents at any 
   time.  It is inappropriate to use Internet-Drafts as reference 
   material or to cite them other than as "work in progress." 

   This Internet-Draft will expire on January 12, 2012. 

Copyright Notice 

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




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   This document is subject to BCP 78 and the IETF Trust's Legal 
   Provisions Relating to IETF Documents 
   (http://trustee.ietf.org/license-info) in effect on the date of 
   publication of this document.  Please review these documents 
   carefully, as they describe your rights and restrictions with respect

   to this document.  Code Components extracted from this document must 
   include Simplified BSD License text as described in Section 4.e of 
   the Trust Legal Provisions and are provided without warranty as 
   described in the Simplified BSD License. 


Table of Contents 

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4

     1.1.   Conventional requirements for energy management . . . . .  4

     1.2.   Specific requirements for energy management . . . . . . .  5


   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  6


   3.  General Objectives of Energy Management  . . . . . . . . . . .  8

     3.1.   Power states  . . . . . . . . . . . . . . . . . . . . . .  8

     3.2.   Trade-offs  . . . . . . . . . . . . . . . . . . . . . . .  8

     3.3.   Local and network-wide energy management  . . . . . . . .  8

     3.4.   Energy monitoring . . . . . . . . . . . . . . . . . . . .  9

     3.5.   Overview of energy management requirements  . . . . . . . 10


   4.  Identification of Powered Entities . . . . . . . . . . . . . . 10


   5.  Information on Powered Entities  . . . . . . . . . . . . . . . 11

     5.1.   General information on powered entities . . . . . . . . . 11

     5.2.   Power state . . . . . . . . . . . . . . . . . . . . . . . 12

     5.3.   Power inlet and power outlet  . . . . . . . . . . . . . . 14

     5.4.   Power . . . . . . . . . . . . . . . . . . . . . . . . . . 16

     5.5.   Energy  . . . . . . . . . . . . . . . . . . . . . . . . . 18

     5.6.   Battery State . . . . . . . . . . . . . . . . . . . . . . 19


   6.  Control of Powered Entities  . . . . . . . . . . . . . . . . . 21


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


   8.  Controlling Other Powered Entities . . . . . . . . . . . . . . 23

     8.1.   Controlling power states of other powered entities  . . . 23

     8.2.   Controlling power supply of other powered entities  . . . 24


   9.  Security Considerations  . . . . . . . . . . . . . . . . . . . 25


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





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


   12. Open issues  . . . . . . . . . . . . . . . . . . . . . . . . . 26

     12.1.  Revise security considerations  . . . . . . . . . . . . . 26

     12.2.  High/Low power notifications  . . . . . . . . . . . . . . 26

     12.3.  Power and energy time series? . . . . . . . . . . . . . . 26

     12.4.  Inlet/outlet combinations . . . . . . . . . . . . . . . . 26

     12.5.  Aggregation functions . . . . . . . . . . . . . . . . . . 27

     12.6.  Add a definition of 'demand'  . . . . . . . . . . . . . . 27

     12.7.  IEC references  . . . . . . . . . . . . . . . . . . . . . 27

     12.8.  Standard references for BACNET or MODBUS  . . . . . . . . 27

     12.9.  IEEE 1621 and 802.3az references  . . . . . . . . . . . . 27

     12.10. DC power quality covered by IEC standard? . . . . . . . . 27

     12.11. Introduce 'disconnected from power' as power state  . . . 27

     12.12. Need for basic state 'reduced power'? . . . . . . . . . . 27

     12.13. Local and network-wide energy management  . . . . . . . . 28

     12.14. Do we need entity types?  . . . . . . . . . . . . . . . . 28

     12.15. Power availability mode 'minimum' or 'ready'? . . . . . . 28

     12.16. Is there a need for metering power supply inpedance?  . . 28

     12.17. Confidence in power values  . . . . . . . . . . . . . . . 28

     12.18. Terminology for reporting on other entitites  . . . . . . 28


   13. Informative References . . . . . . . . . . . . . . . . . . . . 29


   Appendix A.  Existing Standards  . . . . . . . . . . . . . . . . . 30

     A.1.   Existing IETF Standards . . . . . . . . . . . . . . . . . 30

       A.1.1.  ENTITY MIB . . . . . . . . . . . . . . . . . . . . . . 30

       A.1.2.  ENTITY STATE MIB . . . . . . . . . . . . . . . . . . . 31

       A.1.3.  ENTITY SENSOR MIB  . . . . . . . . . . . . . . . . . . 31

       A.1.4.  UPS MIB  . . . . . . . . . . . . . . . . . . . . . . . 32

       A.1.5.  POWER ETHERNET MIB . . . . . . . . . . . . . . . . . . 32

       A.1.6.  LLDP MED MIB . . . . . . . . . . . . . . . . . . . . . 33

     A.2.   Existing standards of other bodies  . . . . . . . . . . . 33

       A.2.1.  DMTF . . . . . . . . . . . . . . . . . . . . . . . . . 33

       A.2.2.  OVDA . . . . . . . . . . . . . . . . . . . . . . . . . 33

       A.2.3.  IEEE-ISTO Printer WG . . . . . . . . . . . . . . . . . 33


   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 34














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1.  Introduction 

   With rising energy cost and with an increasing awareness of the 
   ecological impact of running IT and networking equipment, energy 
   management is becoming an additional basic requirement for network 
   management systems and frameworks. 

   This document defines requirements for standards specifications for 
   energy management.  Defined requirements concern monitoring functions

   as well as control functions.  Covered functions include 
   identification of powered entities, monitoring of their power state, 
   power inlets, power outlets, actual power, consumed energy, and 
   contained batteries.  Further included is control of powered 
   entities' power supply and power state.  Note that this document does

   not specify the features that must be implemented by compliant 
   implementations but rather features that must be supported by 
   standards for energy management. 

Same remark about power quality




   The main subject of energy management are powered entities that 
   consume electric energy.  Powered entities include devices that have 
   an IP address and can be addressed directly, such as hosts, routers, 
   and middleboxes, as well as devices indirectly connected to an IP 
   network, for which a proxy with an IP address provides a management 
   interface, for example, devices in a building management 
   infrastructure using BACNET or MODBUS protocols. 

   The requirements specified in this document explicitly concern the 
   standards specification process and not the implementation of 
   specified standards.  All requirements in this document must be 
   reflected by standards specifications to be developed.  But which of 
   the features specified by these standards will be mandatory, 
   recommended, or optional for compliant implementations is to be 
   defined by the concrete standards track document(s) and not in this 
   document. 

   This document first discusses general objectives of energy management

   in Section 3.  Requirements for an energy management standard are 
   specified in Sections 4 to 8. 

1.1.  Conventional requirements for energy management 

I don't know what "conventional" is supposed to mean.




   The specification of requirements for an energy management standard 
   starts with Section 4 addressing the identification of powered 
   entities and the granularity of reporting of energy-related 
   information.  

I don't understand why we have that sentence here and not in the
identifier in section 4.



A standard must support unique identification of 
   powered entities.  Furthermore, it must support more than just 
   reporting per powered device.  Support is required for also reporting

   energy-related information on individual components of a device or 



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   subtended devices.  This is why this draft uses the more general term

   "powered entity" rather than "powered device".  A powered entity may 
   be a device or a component of a device. 

   Section 5 specifies requirements related to monitoring of powered 
   entities.  This includes general (type, context) information and 
   specific information on power states, power inlets, power outlets, 
   power, energy, and batteries.  Control power state and power supply 
   of powered entities is covered by requirements specified in 
   Section 6. 

1.2.  Specific requirements for energy management 

   At first glance the rather conventional requirements summarized above

   seem to be all that would be needed for energy management.  But it 
   turns out that there are some significant differences between energy 
   management and most of the well known conventional network management

   functions.  The most significant difference from many other 
   management functions is the need for some devices to report on other 
   entities.  There are three major reasons for this. 
   o  For monitoring and controlling a particular powered entity in 
      general it is not sufficient to communicate with the powered 

"sufficient" is not the right wording.
In some cases, this is just impossible to communicate with the powered
entity.
Example: proxy.




      entity only, but in many cases also communication with other 
      powered entities along the power distribution path may be 
      necessary, for example, with power switches and power meters. 
      Indeed, there are situations where a power or energy meter is not 
      located in the powered entity, but in a different physical 
      location.  For example, a Power Distribution Unit (PDU), which 
      supplies power for a server connected to a PDU socket, would meter

      the power supplied, while the server may not have the capability 
      to measure its power consumption.  

new text: In specific cases, the monitoring and controlling of powered
entities must be done by another entity along the power distribution
domain. For example. 
And you remove "a second example" below



A second example is a Power 
      over Ethernet port, which provides power to the attached device, 
      and which can meter how much power/energy it delivers to the 
      attached device. 
   o  Energy management often extends its scope beyond powered entities 
      with IP network interfaces, for example toward non-IP building 
      networks, that are accessed via an IP gateway.  Requirements in 
      this document do not fully cover all these networks, but they 
      cover means for opening IP network management towards them. 
   o  For monitoring of particular powered entities, it is sometimes not

      a scalable approach to communicate directly with all the powered 
      entities directly from a central energy management system as the 
      number of powered entities keeps increasing. 

   This specific issue of energy management and a set of further ones 
   are covered by requirements specified in Sections 7 and 8. 





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2.  Terminology 

2.1.  Energy 

   the definition of the term energy is to be agreed on in the EMAN WG. 

   The term 'energy consumption' is commonly used for both, for 
   referring to the amount of consumed energy and also for referring to 
   the rate of consuming energy.  In the first case it addresses 
   consumed energy measured by joule, watthour, or another energy unit, 
   in the second one it addresses power, typically an average power 
   measured by watt. 

   However, in this document the term "consumed energy" always refers to

   an energy quantity (measured in joule, watthour, etc.) and not to a 
   power quantity (measured in watt, etc.). 

2.2.  Power 

   the definition of the term power is to be agreed on in the EMAN WG. 

2.3.  Powered entity 

   A powered entity is a consumer of energy that is subject to energy 
   management.  In general, all managed physical entities in a 
   communication network consume electric energy and thus are subject to

   energy management including particularly energy monitoring and energy

   control. 

   A powered entity can be a managed device or a component of a managed 
   device, which is monitored or controlled individually. 

2.4.  Power state 

   Power state of a powered entitiy is defined as a specific settings of

   a powered entitiy that influences its power.  Examples of power 
   states of a powered entitiy are on, off, and sleep. 

2.5.  Power monitor 

   Energy management requires retrieving energy-related information on 
   powered entities.  In many cases this information is not available at

   the powered entities themselves, but at other powered entities.  For 
   example measurement of power and energy consumption can be conducted 
   by power meters at other locations along the power distribution tree 
   for the powered entity. 

   A power monitor is a module that reports energy-related information 



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   on powered entities.  A power monitor may be integrated into a 
   powered entity or located remotely of the powered entity.  Instances 
   of power monitors may report information on, for example, power 
   supply, power, and power state of a powered entity.  There may be 
   multiple power monitors reporting information on the same powered 
   entity. 

2.6.  Power inlet 

   Powered entities receive power at their power inlets.  Powered 
   entities may have multiple inlets, for example, servers with 
   redundant power supply.  Examples for power inlets are AC power cords

   of a powered entity or an Ethernet port at which the powered entity 
   receives DC Power over Ethernet (PoE). 

2.7.  Power outlet 

   Powered entities may have means to supply others with electrical 
   power.  Power is delivered to other powered entities through power 
   outlets.  Power sourcing entities often have more than one power 
   outlet.  Examples for power outlets are AC power sockets at a Power 
   Distribution Unit (PDU) and Ethernet ports at a Power over Ethernet 
   (PoE) Power Sourcing Equipment (PSE), that can supply powered 
   entities with DC power using the Ethernet cable. 

2.8.  Energy management 

   the definition of the term power is to be agreed on in the EMAN WG. 

2.9.  Energy management standard 

This doesn't look like a definition. At least, the first paragraph
should be removed.




   This document specifies requirements for an energy management 
   standard.  This term refers to a collections of documents specifying 
   standards for energy-related monitoring and control.  The energy 
   management standard specifies means for building energy management 
   systems. 

   Requirements specified in this document concern the means that an 
   energy management standard must provide.  It does not imply that all 
   required means must be implemented in all energy standard scenarios. 
   Which means and features must be implemented by compliant 
   implementations is to be specified by the energy management standard 
   itself, not by this requirements document. 

   Note that for meeting individual requirements specified in this 
   document, new standards are not necessarily required.  It is 
   recommended to rather use existing standards than specify new ones. 









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3.  General Objectives of Energy Management 

Rename to "general considerations related to energy management"




   The basic objective of energy management is operating communication 
   networks and other equipment with minimal amount of energy, while 
   maintaining a certain level of service.  A set of use cases for 
   energy management can be found in 
   [I-D.tychon-eman-applicability-statement]. 

It would read better if the content of section about trade-offs was next
in this introduction (without having a specific section)
Then 
    3.1. Power States
    3.2 Energy Monitoring versus Energy Savings
    3.3 Local versus network-wide energy management
    3.4. Overview of the energy management requirements





3.1.  Power states 

   One approach to achieve this goal is by setting all powered entities 
   to an operational state that results in lower energy consumption, but

   still meets the service level performance objectives.  The sufficient

   performance level may vary over time and can depend on several 
   factors.  In principle, there are four basic types of power states 
   for a powered entity or for a whole system: 
   o  full power state 
   o  reduced power states (lower clock rate for processor, lower data 
      rate on a link, etc.) 
   o  sleep state (not functional, but immediately available) 
   o  off state (may imply requiring significant time for becoming 
      operational) 
   In actual implementations the number of power states and their 
   properties vary a lot.  Very simple powered entities may just have 
   only the extreme states, full power and off state.  Some 
   implementations might use IEEE1621 model of three states on, off, and

   sleep.  However, more granular power states can be implemented with 
   many levels of off, sleep, and reduced power states. 

3.2.  Trade-offs 

   While the general objective of energy management is quite clear, the 
   way to attain that goal is often difficult.  In many cases there is 
   no way of reducing power consumption without the consequence of a 
   potential performance, service, or capacity degradation.  Then a 
   trade-off needs to be dealt with between service level objectives and

   energy efficiency.  In other cases a reduction of energy consumption 
   can easily be achieved while still maintaining sufficient service 
   level performance, for example, by switching powered entities to 
   lower power states when higher performance is not needed. 

3.3.  Local and network-wide energy management 

   Many energy saving functions can be executed locally by a powered 
   entitiy.  The basic principle is that a powered entitiy monitors its 
   usage and dynamically adapts its energy consumption according to the 
   required performance.  It may switch to a sleep state when it is not 
   in use at all.  

Well, not only when it's not in use.
It could be based on the time of day, or any other energy saving
policies.



Potential interactions with an energy management 



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   system for such an entity include the observation of the entity's 
   power state and the configuration of power saving policies, for 
   example, by setting thresholds for power state changes. 

   Energy savings can also be achieved with policies implemented by a 
   network management system that controls power states of managed 
   entities.  In order to make policy decisions properly, information 
   about the energy consumption of powered entities in different power 
   states is required.  Often this information is acquired best through 
   monitoring. 

   Both methods, network-wide and local energy management, have 
   advantages and disadvantages.  Most buildings use both of them.  In 
   some cases for example, significant energy savings can be achieved by

   simply setting all powered entities in a network to sleep, when the 
   network is not needed.  However, in general it is dangerous to set 
   all powered entities of a group to the same state, because there is a

   risk that such actions ignore specifics of individual powered 
   entities or violate local service level agreements. 

Can you please expand the previous sentence.
I'm not sure that I agree.




3.4.  Energy monitoring 

rename to "energy monitoring versus energy savings"




   It should be noted that only monitoring energy consumption and power 
   states is obviously not a means to reduce the energy consumption of a

   powered entitiy.  In fact, it is likely to increase the power 
   consumption of a powered entitiy slightly because monitoring energy 
   may require instrumentation that consumes energy when in use.  And 
   also reporting of measured quantities over the network consumes 
   energy.  However, the acquired energy consumption and power state 
   information is essential for defining energy saving policies and can 
   be used as input to power state control loops that in total can lead 
   to energy savings. 

   Monitoring operational power states and energy consumption can also 
   be required for other energy management purposes including but not 
   limited to: 
   o  investigating power saving potential 
   o  evaluating the effectiveness of energy saving policies and 
      measures 
   o  deriving, implementing, and testing power management strategies 
   o  accounting for the total power consumption of a powered entity, a 
      network, or a service 
   o  predicting a powered entitiy's reliability based on power usage 
   o  choosing time of next maintenance cycle for a powered entitiy 







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3.5.  Overview of energy management requirements 

   From the considerations described above the following basic 
   management functions appear to be required for energy management: 
   o  monitoring power states 
   o  monitoring power (energy consumption rate) 
   o  monitoring (accumulated) energy consumption 
   o  setting power states 
   o  setting and enforcing power saving policies 

And again the comment about the power quality




   It should be noted that active power control is complementary (but 

what does the "active" power control mean?



   essential) to other energy savings measures such as low power 
   electronics, energy saving protocols (for example, IEEE 802.3az), 
   energy-efficient device design (for example, sleep and low-power 
   modes for individual components of a device), and energy-efficient 
   network architectures.  Measurement of energy consumption may also 
   provide useful input for developing these technologies. 


4.  Identification of Powered Entities 

   As already stated Section 1.1, powered entities on which energy- 
   related information is provided

add a comma



are identified in a sufficiently 
   unique way.  This holds in particular for powered entities that are 
   components of managed devices and in case that one powered entity 
   reports information on another one, see Section 7.  For powered 
   entities that control other powered entities it is important to 
   identify the powered entities they control, see Section 8. 

   Also stated already in Section 1.1 is the requirement of providing 
   means for reporting energy-related information on components of a 
   managed device.  An entity in this document may be an entire managed 
   device or just a component of it.  Examples of components of interest

   are a hard drive, a battery, or a line card.  For controlling 
   entities it may be required to be able to address individual 
   components in order to save energy.  For example, server blades can 
   be switched off when the overall load is low or line cards at 
   switches may be powered down at night times. 

   Instrumentation for measuring energy consumption of a device is 
   typically more expensive than instrumentation for retrieving the 
   devices power state.  It may be a reasonable compromise in many cases

   to provide power state information for all individually switchable 
   components of a device separately, while the energy consumption is 
   only measured for the entire device. 

   Detailed Requirements: 




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4.1.  Identifying powered entities 

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

   potential receivers of monitored information. 

We want to remove "and persistently" from the sentence, as this is
covered in 4.3

We should have a requirement about a UUID for powered entities.
Let's cover that during the WG.




4.2.  Identifying components of powered devices 

   The energy management standard must provide means for identifying not

   just entire devices as powered entities, but also individual 
   components of powered devices. 

4.3.  Persistency of Identifiers 

   The energy management standard must provide means for indicating 
   whether identifiers of powered entities are persistent across a re- 
   start of the powered entitiy that provides the identifiers. 


5.  Information on Powered Entities 

   This section describes energy-related information on powered entities

   for which an energy management standard must provide means for 
   retrieving and reporting. 

   Note that the fact that an energy management standard provides 
   required means does not imply that all of them must be implemented by

   every compliant implementation.  The concrete specification of 
   standards based on these requirements may label individual features 
   as mandatory, recommended, or optional. 

Remove this paragraph above, as this is already covered before, and this
is not specific to this section 5.




   Required information on powered entities can be structured into six 
   groups.  Section 5.1 specifies requirements for general information 
   on powered entities, such as type of powered entity or context 
   information.  Section 5.2 covers requirements related to entities' 
   power states.  Requirements for information on power inlets and power

   outlets of powered entities are specified in Section 5.3.  Monitoring

   of power and energy is covered by Sections 5.4 and 5.5, respectively.

   Finally, Section 5.6 specified requirements for monitoring batteries.


5.1.  General information on powered entities 

   For energy management it may be required to understand the role and 
   context of a powered entitiy.  When monitoring, it may be helpful to 
   group energy consumption per kind of entity.  When controlling and 
   setting power states it may be helpful to understand the kind and 



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   role of a powered entitiy in a network, for example, in order to 
   avoid switching off vital network components. 

   Detailed Requirements: 

5.1.1.  Type of powered entity 

   The energy management standard must provide means to retrieve and 
   report the type of powered entities according to a standrdized 
   classification scheme. 

see the email thread on the mailing list.




5.1.2.  Context information on powered entities 

   The energy management standard must provide means for retrieving and 
   reporting context information on powered entities, for example tags 
   associated with a powered entity that indicate the powered entitiy's 
   role, or importance. 

5.1.3.  Grouping of powered entities 

   The energy management standard must provide means for grouping 
   powered entities, for example, into energy monitoring domains, energy

   control domains, power supply domains, groups of powered entities of 
   the same type, etc. 

5.2.  Power state 

   Many powered entities have a limited number of discrete power states,

   such as, for example, full power, low power, sleep, and off. 

   Obviously, there is a need to report the actual power state of a 
   powered entitiy.  Beyond that, there is also a requirement for 
   standardizing means for retrieving the list of all supported power 
   states of a powered entitiy. 

   Different standards bodies have already defined their own sets of 
   power states for powered entities.  Further organizations are in the 
   process of adding more of these sets.  In order to support multiple 
   management systems possibly using different power state sets, while 
   simultaneously interfacing with a particular powered entity, the 
   energy management standard must provide means for supporting multiple

   power state sets used simultaneously at a powered entity. 

   Power states have parameters that describe its properties It is 
   required to have standardized means for reporting some key 
   properties, such as mean power and maximum power of a powered entitiy

   in a certain state. 




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   There also is a need to report statistics on power states including 
   the time spent an the energy consumed in a power state. 

   For some network management tasks, it may be desirable to receive 
   notifications from powered entities, for example, when the components

   or the entire entity change their power state. 

   Detailed Requirements: 

5.2.1.  Actual power state 

   The energy management standard must provide means for reporting the 
   actual power state of a powered entitiy. 

5.2.2.  List of supported power states 

	
	   The energy management standard must provide means for
retrieving the 
	   list of all potential power states of a powered entitiy. 
	
	5.2.3.  Multiple power state sets 
	
	   The energy management standard must provide means for
supporting 
	   multiple power state sets simultaneously at a powered entity.

	
	5.2.4.  List of supported power state sets 
	
	   The energy management standard must provide means for
retrieving the 
	   list of all power state sets supported by a powered entitiy. 
	
	5.2.5.  List of supported power states 

5.2.2 has got the same title.
Proposal for 5.2.5 "List of supported power states within power state
set"




   Referring to the "list of supported power state sets" requirement, 
   the energy management standard must provide means for retrieving the 
   list of all potential power states of a powered entitiy that belong 
   to a given power state set. 

new text.
    For the rest of the document, when the Power State term is used, it
implicitly refers to a power state within a power state set.

Note that this comment might be part of the power State definition




5.2.6.  Maximum and average power per power state 

   The energy management standard must provide means for retrieving the 
   maximum power and the average power as a typically static property 
   for each supported power state. 

5.2.7.  Power state statistics 

   The energy management standard must provide means for monitoring 
   statistics per power state including at least the total time spent in

   a power state, the number of times a state was entered and the last 
   time a state was entered.  More power state statistics are addressed 



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   by requirement 5.5.3. 

5.2.8.  Power state changes 

   The energy management standard must provide means for generating a 
   notification when the actual power state of a powered entity changes.


5.3.  Power inlet and power outlet 

   Powered entities have power inlets at which they are supplied with 
   electric power.  Most powered entities just have a single power 
   inlet, while some have multiple ones.  Often different power inlets 
   are connected to separate power distribution trees.  For energy 
   monitoring, it is important information which power inlets a powered 
   entitiy has, 

what do you mean? the type, the number, or something else?



if power is available at an inlet and which of them are 
   actually in use. 

   Some powered entities have power outlets for supplying other powered 
   entities with electric power.  A powered entitiy may have multiple 
   power outlets.  Examples are Power Distribution Units (PDUs) and 
   Power over Ethernet (PoE) Power Sourcing Equipment (PSE). 

Remove the previous sentence, as this is already in the terminology
section.




   For identifying and potentially controlling the source of power 
   received at an inlet, it may be required to identify the power outlet

   of another powered entity at which the received power is provided. 
   Analogously, for each outlet it is of interest to identify the power 
   inlets that receive the power provided at a certain outlet. 

   Static properties of each power inlet and each power outlet are 
   required information for energy management.  Static properties 
   include the kind of electric current (Alternating Current (AC) or 
   Direct Current (DC)), the nominal voltage, the nominal AC frequency, 
   and the number of AC phases. 

So "static properties" is what we called "power quality"?




   Detailed Requirements: 

5.3.1.  List of power inlets and power outlets 

   The energy management standard must provide means for monitoring the 
   list of power inlets and power outlets at a powered entitiy. 

5.3.2.  Corresponding power outlet 

   The energy management standard must provide means for identifying the

   power outlet that provides the power received at a power inlet. 






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5.3.3.  Corresponding power inlets 

   The energy management standard must provide means for identifying the

   list of power inlets that receive the power provided at a power 
   outlet. 

5.3.4.  Availability of power 

   The energy management standard must provide means for monitoring the 
   availability of power at each power inlet and each power outlet. 
   This information indicates whether at a power providing outlet power 
   supply is switched on or off. 

5.3.5.  Use of power 

   The energy management standard must provide means for monitoring for 
   each power inlet and each power outlet if it is in actual use.  For 
   the inlet this means that the powered entitiy actually receives power

   at the inlet.  For the outlet this means that actually power is 
   provided to one or more powered entities at the outlet. 

5.3.6.  Type of current 

   The energy management standard must provide means for reporting the 
   type of current (Alternating Current (AC) or Direct Current (DC)) for

   each power inlet and each power outlet of a powered entity. 

5.3.7.  Nominal voltage 

   The energy management standard must provide means for reporting the 
   nominal voltage for each power inlet and each power outlet of a 
   powered entity. 

5.3.8.  Nominal AC frequency 

   The energy management standard must provide means for reporting the 
   nominal AC frequency for each power inlet and each power outlet of a 
   powered entity. 

5.3.9.  number of AC phases 

number -> Number




   The energy management standard must provide means for reporting the 
   number of AC phases for each power inlet and each power outlet of a 
   powered entity. 







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5.4.  Power 

   Power is a quantity measured as instantaneous power or as average 
   power over a time interval.  In contrast to power state values, this 
   quantity may change continuously. 

   Obtaining highly accurate values for power and energy may be costly. 
   Often dedicated metering hardware is needed for this purpose. 
   Powered entities without the ability to measure their power and 
   energy consumption with high accuracy may just report estimated 
   values, for example based on load monitoring or even just the entity 
   type. 

   Depending on how power and energy consumption values are obtained the

   confidence in the reported value and its accuracy may vary.  Powered 
   entities reporting such values should qualify the confidence in the 
   reported values and quantify the accuracy of measurements.  For 
   reporting accuracy, the accuracy classes specified in IEC 62053-21 
   [IEC.62053-21] and IEC 62053-22 [IEC.62053-22] should be considered. 

   In addition to the plain real power value, also further properties of

   the supplied power are subject to monitoring.  In case of AC power 
   supply, there are more power values beyond the real power to be 
   reported including the apparent power, the reactive power, and the 
   phase angle of the current or the power factor.  For both AC and DC 
   power the power quality is also subject of monitoring. 

So "power quality" is mentioned.



Power quality 
   parameters include the actual voltage, the actual frequency, the 
   Total Harmonic Distortion (THD) of voltage and current, the impedance

   of an AC phase or of the DC supply.  Power quality monitoring should 
   be in line with existing standards, such as [IEC.61850-7-4]. 

   For some network management tasks, it is required to obtain time 
   series of power values (or energy consumption values).  In general 
   these could be obtained in many different ways.  It should be avoided

   that such time series can only be obtained by regular polling by the 
   energy management system.  Means should be provided to either push 
   such values from the place they are available to the management 
   system or to have them stored at the powered entitiy for a 
   sufficiently long period of time such that a management system can 
   retrieve a stored time series of values. 

   Detailed Requirements: 

5.4.1.  Real power 

   The energy management standard must provide means for reporting the 
   real power for each power inlet and each power outlet of a powered 
   entity. 



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5.4.2.  Power measurement interval 

   The energy management standard must provide means for reporting the 
   corresponding time or time interval for which a power value is 
   reported.  The power value can be measured at the corresponding time 
   or averaged over the corresponding time interval. 

5.4.3.  Confidence in power values 

   The energy management standard must provide means for reporting the 
   confidence in reported power values by indicating the way these 
   values have been obtained. for example, by power measurement, by 
   estimation based on performance values, or hard coding average power 
   values for a powered entity. 

5.4.4.  Accuracy of power and energy values 

   The energy management standard must provide means for reporting the 
   accuracy of reported power values. 

5.4.5.  Complex power 

   The energy management standard must provide means for reporting the 
   complex power for each power inlet and each power outlet of a powered

   entity.  Besides the real power, at least two out of the following 
   three quantities need to be reported: apparent power, reactive power,

   phase angle.  The phase angle can be substituted by the power factor.

   In case of AC power supply, means must be provided for reporting the 
   complex power per phase. 

5.4.6.  Actual voltage and current 

   The energy management standard must provide means for reporting the 
   actual voltage and actual current for each power inlet and each power

   outlet of a powered entity.  In case of AC power supply, means must 
   be provided for reporting the actual voltage and actual current per 
   phase. 

5.4.7.  Actual AC frequency 

   The energy management standard must provide means for reporting the 
   actual AC frequency for each power inlet and each power outlet of a 
   powered entity. 

5.4.8.  Total harmonic distortion 

   The energy management standard must provide means for reporting the 
   Total Harmonic Distortion (THD) of voltage and current for each power




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   inlet and each power outlet of a powered entity.  In case of AC power

   supply, means must be provided for reporting the THD per phase. 

5.4.9.  Power supply impedance 

   The energy management standard must provide means for reporting the 
   impedance of power supply for each power inlet and each power outlet 
   of a powered entity.  In case of AC power supply, means must be 
   provided for reporting the impedance per phase. 

5.4.10.  Time series of power values 

   The energy management standard must provide means for collecting time

   series of real power values for each power inlet and for each power 
   outlet of a powered entitiy without requiring to regularly poll the 
   powered entitiy from an energy management station.  A solution for 
   this is that the concerned powered entity or another powered entity 
   closely interacting with the concerned powered entity collect time 
   series of power values and make them available via push or pull 
   mechanisms to receivers of the information. 

5.5.  Energy 

   Monitoring of electrical energy consumed (or converted) at a powered 
   entitiy can be done in various ways.  One is collecting time series 
   of power values for the powered entitiy and calculating the consumed 
   energy from these values.  An alternative is the powered entity 
   itself or another powered entity taking care of energy measurement 
   and reporting energy consumption values for certain time intervals. 
   Time intervals of interest are the time from the last restart of the 
   powered entitiy to the reporting time, the time from another past 
   event to the reporting time, or the last given amount of time before 
   the reporting time. 

   In order to monitor energy consumption in different power states, it 
   is useful if powered entities record their energy consumption per 
   power state and report these quantities. 

   For some network management tasks, it is required to obtain time 
   series of energy values.  In general these could be obtained in many 
   different ways.  It should be avoided that such time series can only 
   be obtained by regular polling by the energy management system. 
   Means should be provided to either push such values from the place 
   they are available to the management system or to have them stored at

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

   Detailed Requirements: 



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5.5.1.  Energy 

   The energy management standard must provide means for reporting the 
   consumed energy received at a power input or provided at a power 
   outlet of a powered entitiy.  Reports must be made for a clearly 
   specified time interval. 

5.5.2.  Time intervals 

   The energy management standard must provide means for reporting the 
   consumed energy of a powered entitiy for certain time intervals. 
   o  Reports must be supported for the time interval starting at the 
      last restart of the powered entitiy and ending at a certain point 
      in time, such as the time when a report was delivered. 
   o  Reports must be supported for a sequence of consecutive non- 
      overlapping time intervals of fixed size (periodic reports). 
   o  Reports must be supported for a sequence of consecutive 
      overlapping time intervals of fixed size (periodic reports). 
   o  Reports must be supported for an interval of given length ending 
      at a certain point in time, such as the time when a report was 
      delivered (sliding window) 

5.5.3.  Energy per power state 

   The energy management standard must provide means for reporting the 
   consumed energy individually for each power state.  This extends the 
   requirement 5.2.7 on power state statistics. 

5.5.4.  Time series of energy values 

   The energy management standard must provide means for collecting time

   series of energy values for each power inlet and for each power 
   outlet of a powered entitiy without requiring to regularly poll the 
   powered entitiy from an energy management station.  A solution for 
   this is that the concerned powered entity or another powered entity 
   closely interacting with the concerned powered entity collect time 
   series of energy values and make them available via push or pull 
   mechanisms to receivers of the information. 

5.6.  Battery State 

   Today more and more powered entities contain batteries that supply 
   them with power when disconnected from electrical power distribution 
   grids.  Common examples are nomadic and mobile devices, such as 
   notebook computers, netbooks, and smart phones.  The status of 
   batteries in such an powered entity, particularly the charging status

   is typically controlled by automatic functions that act locally on 
   the powered entitiy and manually by users of the powered entity.  In 



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   addition to this, there is a need to monitor the battery status of 
   these entities by network management systems. 

   The management requirements discussed above in Sections 5.1 to 5.5 
   concern energy-related information on powered entities.  Powered 
   entities may be powered devices or components of powered devices. 

I  believe that we mentioned that sentence already.



   Devices containing batteries can be modeled in two ways.  The entire 
   device can be modeled as a single powered entity on which energy- 
   related information is reported or the battery can be modeled as an 
   individual powered entity for which energy-related information is 
   monitored individually according to requirements in Sections 5.1 to 
   5.5. 

   In both cases further information on batteries is of interest for 
   energy management, such as the current charge of the battery, the 
   number of completed charging cycles, the charging state of the 
   battery, and further static and dynamic battery properties.  Also 
   desirable is to receive notifications if the charge of a battery 
   becomes very low or if a battery needs to be replaced. 

   Detailed Requirements: 

5.6.1.  Battery charge 

   The energy management standard must provide means for reporting the 
   current charge of a battery. 

5.6.2.  Battery charging state 

   The energy management standard must provide means for reporting the 
   charging state (charged, discharged, etc.) of a battery. 

5.6.3.  Battery charging cycles 

   The energy management standard must provide means for reporting the 
   number of completed charging cycles of a battery. 

5.6.4.  Actual battery capacity 

   The energy management standard must provide means for reporting the 
   actual capacity of a battery. 

5.6.5.  Static battery properties 

   The energy management standard must provide means for reporting 
   static properties of a battery, including the nominal capacity, the 
   number of cells, the nominal voltage, and the battery technology. 




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5.6.6.  Low battery charge notification 

   The energy management standard must provide means for generating a 
   notification when a the charge of a battery decreases below a given 
   threshold. 

remove "a"




5.6.7.  Battery replacement notification 

   The energy management standard must provide means for generating a 
   notification when the number of charging cycles of battery exceeds a 
   given threshold. 

5.6.8.  Multiple batteries 

   The energy management standard must provide means for meeting 
   requirements 5.6.1 to 5.6.7 for each individual battery contained in 
   a single powered entity. 


6.  Control of Powered Entities 

   Many powered entities control their power state locally by self- 
   managed dynamic adaptation to the environment.  But other powered 
   entities without that capability need interfaces for a energy 
   management system to control their power states in order to save 
   energy.  Even for self-managed powered entities such interface may be

   required for overruling local policy decisions by global ones from an

   energy management system. 

   Power supply is typically not self-managed by powered entities.  And 
   controlling power supply is typically not conducted as interaction 
   between energy management system and the powered entity itself.  It 
   is rather an interaction between the management system and an entity 
   providing power at its power outlets.  Still, requirements for power 
   state control apply accordingly to power supply control. 

   Note that shutting down the power supply abruptly may have severe 
   consequences for the powered entity. 

   Detailed Requirements: 

6.1.  Controlling power states 

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






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6.2.  Controlling power supply 

   The energy management standard must provide means for switching power

   supply off or turning power supply on at power outlets providing 
   power to one or more powered entity. 


7.  Reporting on Other Powered Entities 

   As already discussed in the introduction of Section 5, not all 
   energy-related information may be available at the concerned powered 
   entity.  Such information may be provided by other powered entities, 
   such as a Power Distribution Unit (PDU), external power meter, or a 
   Power over Ethernet (PoE) Power Sourcing Equipment (PSE).  Some of 
   these entities (PDU, PSE) can also control the power provided to the 
   other powered entities, while some can just report on the remote 
   powered entities (external power meter).  This section covers 
   reporting of information (monitoring) only.  See Section 8 for 
   requirements on controlling other powered entities. 

   There are cases where a power supply unit switches power for several 
   powered entities by turning power on or off at a single power outlet 
   or where a power meter measures the accumulated power of several 
   powered entities at a single power line.  Consequently, it should be 
   possible to report that a monitored value does not relate to just a 
   single powered entity, but is an accumulated value for a set of 
   powered entities.  All of these powered entities belonging to that 
   set need to be identified. 

   If a powered entity has information about where energy-related 
   information on itself can be retrieved, then it would be very useful 
   if it has a way to communicate this information to an energy 
   management system.  This applies even if the information only 
   provides accumulated quantities for several powered entities. 

   Detailed Requirements: 

7.1.  Reports on other powered entities 

   The energy management standard must provide means for a powered 
   entitiy to report energy-related information on another powered 
   entity. 

7.2.  Identity of other powered entities on which is reported 

   The energy management standard must provide means for reporting the 
   identity of another powered entity on which energy-related 
   information is reported. 



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7.3.  Reporting quantities accumulated over multiple powered entities 

   For powered entities reporting single values that are accumulated 
   over multiple powered entities, the energy management standard must 
   provide means for reporting the list of all powered entities from 
   which contributions are included in the accumulated value. 

See my comments at the beginning of the email




7.4.  List of all powered entities on which is reported 

   The energy management standard must provide means for a powered 
   entitiy to report the list of all other powered entities on which it 
   can report energy-related information. 

7.5.  Content of reports on other powered entities 

   The energy management standard must provide means for a powered 
   entitiy to indicate for each other powered entity on which it can 
   provide energy-related information which energy-related information 
   can be provided for this powered entity. 

7.6.  Indicating source of remote information 

   The energy management standard must provide means for a powered 
   entity to indicate another powered entity at which energy-related 
   information on itself can be retrieved. 

7.7.  Indicating source of remote information 

   For a powered entity that has another powered entity at which energy-

   related information on itself can be retrieved, the energy management

   standard must provide means for indicating the information that is 
   available at other powered entities per other powered entity. 


8.  Controlling Other Powered Entities 

   This section specifies requirements for controlling power states and 
   power supply of powered entities by communicating not with these 
   powered entities themselves, but with other powered entities that 
   have means for controlling power state or power supply of others. 

8.1.  Controlling power states of other powered entities 

   Some powered entities may have control of power states of other 
   powered entities.  For example a gateway to a building network may 
   have means to control the power state of powered entities in the 
   building that do not have an IP interface.  For this and similar 
   cases means are needed to make this control accessible to the energy 



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   management system. 

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

   Detailed Requirements: 

8.1.1.  Control of power states of other powered entities 

   The energy management standard must provide means for an energy 
   management system to send power state control commands to a powered 
   entity that concern the power states of other powered entities than 
   the one the command was send to. 

8.1.2.  Identity of other power state controlled entities 

   The energy management standard must provide means for reporting the 
   identity of another powered entity for which the reporting powered 
   entity has means to control the power state. 

8.1.3.  List of all power state controlled entities 

   The energy management standard must provide means for a powered 
   entitiy to report the list of all powered entities for which it can 
   control the power state. 

8.1.4.  List of all power state controllers 

   The energy management standard must provide means for a powered 
   entitiy that receives commands controlling its power state from other

   powered entities to report the list of all those entities. 

8.2.  Controlling power supply of other powered entities 

   Some powered entities may have control of the power supply of other 
   powered entities, for example, because the other powered entity is 
   supplied via a power outlet of the powered entitiy.  For this and 
   similar cases means are needed to make this control accessible to the

   energy management system. 

   In addition to this, it is very required that a powered entitiy that 

very required -> required



   has its supply controlled by other powered entities has means to 
   report the list of these other powered entities. 

   Detailed Requirements: 





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8.2.1.  Control of power supply of other powered entities 

   The energy management standard must provide means for an energy 
   management system to send power supply control commands to a powered 
   entity that concern the power supply of other powered entities than 
   the one the command was send to. 

8.2.2.  Identity of other power supply controlled powered entities 

   The energy management standard must provide means for reporting the 
   identity of another powered entity for which the reporting powered 
   entity has means to control the power supply. 

8.2.3.  List of all power supply controlled powered entities 

   The energy management standard must provide means for a powered 
   entitiy to report the list of all other powered entities for which it

   can control the power supply. 

8.2.4.  List of all power supply controllers 

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


9.  Security Considerations 

   The typical security threats for the management protocol for energy 
   monitoring are similar to the ones specified in the SNMP security 
   framework.  In other words, from an energy monitoring point of view, 
   no additional security requirements have been imposed. 

   Link layer discovery mechanisms need to ensure that only the trusted 
   powered entities shall be discovered during discovery and detect/ 
   discard powered entities without a trusted relationship to be 
   included among the powered entities for energy monitoring. 

   In terms of monitoring, considering that there can be some network 
   entities which shall be entitled to collect the measured data on 
   behalf of other powered entities, then it is important to 
   authenticate and/or authorize such powered entities.  In addition, in

   the case of control of other powered entities, it would be highly 
   desirable to have some form of an authentication mechanism to ensure 
   that only the designated powered entities shall control the powered 
   entities within its control domain.  It should be possible to prevent

   a powered entity which does not have the appropriate authorization 
   and authority to control or configure powered entities in its control




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   domain/purview.  Secondly, it should be possible to prevent malicious

   powered entities from exercising control over entities. 


10.  IANA Considerations 

   This document has no actions for IANA. 


11.  Acknowledgements 

   The authors would like to thank Ralf Wolter for his first essay on 
   this draft.  Many thanks to William Mielke, John Parello, Bruce 
   Nordman, JinHyeock Choi, Georgios Karagiannis, and Michael Suchoff 
   for helpful comments on the draft. 

I'll address the open issues in separate email threads.

Regards, Benoit.




12.  Open issues 

12.1.  Revise security considerations 

   A discussion of the sensitivity of the content of the monitoring data

   is missing. 

12.2.  High/Low power notifications 

   For some network management tasks it may be desirable to receive 
   notifications from entities when the power of an powered entity 
   exceeds or falls below certain thresholds.  Do we want to make this a

   requirement? 

   Proposal: added "for example" so that we don't restrict the framework

   to only this notification 

12.3.  Power and energy time series? 

   We have requirements for reporting of time series of power and energy

   values.  Do we need both or just one of them?  If just one, then 
   which one? 

12.4.  Inlet/outlet combinations 

   How to model the case that an inlet or outlet changes during 
   operation from one kind to the other.  An example is a battery that 
   receives power at a socket at one time.  Then the socket is an inlet.

   At another time the battery provides power at the same socket.  Then 
   it's an outlet.  The same holds for entities with integrated power 
   generators. 



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   One solution would be to introduce a new kind of hybrid in/outlets. 
   Another one would be to model the same socket as inlet as well as as 
   outlet.  It would appear twice in the list of all inlets and outlets.

   Then received power/energy would be reported under the inlet entry 
   and provided power/energy would be reported under the outlet entry. 

   These would be two solutions.  What would be the concrete requirement

   behind them? 

12.5.  Aggregation functions 

   Aggregation functions are not covered (yet).  Are there requirements 
   on aggregation?  Which are they? 

12.6.  Add a definition of 'demand' 

12.7.  IEC references 

   References to mentioned IEC standards are missing.  Also these 
   references should be double checked. 

12.8.  Standard references for BACNET or MODBUS 

   Section 1 mentions BACNET or MODBUS as examples for building network 
   protocols.  We need references to the standards specifications for 
   these protocols. 

12.9.  IEEE 1621 and 802.3az references 

   A reference to the IEEE 1621 standard is missing in section 3.1 and a

   reference to IEEE 802.3az is missing in section 3.4.  The references 
   should be double checked if they are well applicable in the 
   respective section. 

12.10.  DC power quality covered by IEC standard? 

   Is there an IEC standard on DC power quality? 

12.11.  Introduce 'disconnected from power' as power state 

   We need to introduce the concept of a device being "disconnected" 
   from power.  This is a subset of the Off state.  Shall we do it here 
   or rather in the framework draft? 

12.12.  Need for basic state 'reduced power'? 

   Are "full power" and "reduced power" really different basic types of 
   power states?  Both may be forms of the on state.  Identifying "full"




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   separately is arbitrary.  (For something like a computer, "idle" is 
   the most common state so would be the one to call out separately 
   rather than "full".) 

12.13.  Local and network-wide energy management 

   All but first sentence of the third paragraph in section 3.3 seem to 
   be true not needed here.  Proposal: remove them. 

12.14.  Do we need entity types? 

   Or shall we remove Section 5.1.1? 

12.15.  Power availability mode 'minimum' or 'ready'? 

   Do we need an additional mode for power availability called "minimum"

   or "ready" for power availability in xref target="availability"/>? 
   This would reflect a PoE state at which the PSE is ready to serve the

   PD. 

12.16.  Is there a need for metering power supply inpedance? 



12.17.  Confidence in power values 

   Shall we rename "confidence in power values" to "method for 
   determining power values"? 

12.18.  Terminology for reporting on other entitites 

   In Section 7 we need some additional terms here to streamline the 
   text (and ultimately our thinking).  Nominations include: 
   o  "powered entity" (which may be "self-reporting") 
   o  "reporting entity" (can be "self" or "other") 
   o  "other entity" (a reporting entity reporting not on itself; likely

      a different term would be better for this) 
   o  "controlled entity", "controlling entity" (section 8.1) 
   o  "switched entity", "switching entity" (section 8.2) 

   Also, there are two cases for an "other entity".  One is where the 
   powered entity cannot report the value in question itself (either 
   because it can't report anything, or doesn't know the value in 
   question, e.g. when metering is external). 

   The second is where the powered entity can report, but the other 
   entity is doing the reporting for some convenience.  We need to be 
   aware of both even if the framework does not need to make the 



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   distinction. 

   There may be multiple other reporting entities, not just a single 
   one. 

   Do components of devices ever report, or do only devices do the 
   reporting?  This seems like an important point. 


13.  Informative References 

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

   [RFC3433]  Bierman, A., Romascanu, D., and K. Norseth, "Entity Sensor

              Management Information Base", RFC 3433, December 2002. 

   [RFC3621]  Berger, A. and D. Romascanu, "Power Ethernet MIB", 
              RFC 3621, December 2003. 

   [RFC3805]  Bergman, R., Lewis, H., and I. McDonald, "Printer MIB v2",

              RFC 3805, June 2004. 

   [RFC4133]  Bierman, A. and K. McCloghrie, "Entity MIB (Version 3)", 
              RFC 4133, August 2005. 

   [RFC4268]  Chisholm, S. and D. Perkins, "Entity State MIB", RFC 4268,

              November 2005. 

   [I-D.tychon-eman-applicability-statement] 
              Tychon, E., Silver, L., and M. Chandramouli, "Energy 
              Management (EMAN) Applicability Statement", 
              draft-tychon-eman-applicability-statement-02 (work in 
              progress), June 2011. 

   [ACPI.R30b] 
              Hewlett-Packard Corporation, Intel Corporation, Microsoft 
              Corporation, Phoenix Corporation, and Toshiba Corporation,

              "Advanced Configuration and Power Interface Specification,

              Revision 3.0b", October 2006. 

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

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



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   [IEC.62053-21] 
              International Electrotechnical Commission, "Electricity 
              metering equipment (a.c.) - Particular requirements - Part

              22: Static meters for active energy  (classes 1 and 2)", 
              2003. 

   [IEC.62053-22] 
              International Electrotechnical Commission, "Electricity 
              metering equipment (a.c.) - Particular requirements - Part

              22: Static meters for active energy  (classes 0,2 S and 
              0,5 S)", 2003. 

   [IEC.61850-7-4] 
              International Electrotechnical Commission, "Communication 
              networks and systems for power utility automation - Part 
              7-4: Basic communication structure - Compatible logical 
              node classes and data object classes", 2010. 


Appendix A.  Existing Standards 

   This section analyzes existing standards for energy consumption and 
   power state monitoring.  It shows that there are already several 
   standards that cover only some part of the requirements listed above,

   but even all together they do not cover all of the requirements for 
   energy management. 

A.1.  Existing IETF Standards 

   There are already RFCs available that address a subset of the 
   requirements. 

A.1.1.  ENTITY MIB 

   The ENTITY-MIB module defined in [RFC4133] was designed to model 
   physical and logical entities of a managed system.  A physical entity

   is an identifiable physical component.  A logical entity can use one 
   or more physical entities.  From an energy monitoring perspective of 
   a managed system, the ENTITY-MIB modeling framework can be reused and

   whenever RFC 4133 [RFC4133] has been implemented.  The 
   entPhysicalIndex from entPhysicalTable can be used to identify an 
   entity/component.  However, there are use cases of energy monitoring,

   where the application of the ENTITY-MIB does not seem readily 
   apparent and some of those entities could be beyond the original 
   scope and intent of the ENTITY-MIB. 

   Consider the case of remote devices attached to the network, and the 
   network device could collect the energy measurement and report on 



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   behalf of such attached devices.  Some of the remote devices such as 
   PoE phones attached to a switch port have been considered in the 
   Power-over-Ethernet MIB module [RFC3621].  However, there are many 
   other devices such as a computer, which draw power from a wall outlet

   or building HVAC devices which seem to be beyond the original scope 
   of the ENTITY-MIB. 

   Yet another example, is smart-PDUs, which can report the energy 
   consumption of the device attached to the power outlet of the PDU. 
   In some cases, the device can be attached to multiple to power 
   outlets.  Thus, the energy measured at multiple outlets need to be 
   aggregated to determine the consumption of a single device.  From 
   mapping perspective, between the PDU outlets and the device this is a

   many-to-one mapping.  It is not clear if such a many-to-one mapping 
   is feasible within the ENTITY-MIB framework. 

A.1.2.  ENTITY STATE MIB 

   RFC 4268 [RFC4268] defines the ENTITY STATE MIB module. 
   Implementations of this module provide information on entities 
   including the standby status (hotStandby, coldStandby, 
   providingService), the operational status (disabled, enabled, 
   testing), the alarm status (underRepair, critical, major, minor, 
   warning), and the usage status (idle, active, busy).  This 
   information is already useful as input for policy decisions and for 
   other network management tasks.  However, the number of states would 
   cover only a small subset of the requirements for power state 
   monitoring and it does not provide means for energy consumption 
   monitoring.  For associating the information conveyed by the ENTITY 
   STATE MIB to specific components of a device, the ENTITY STATE MIB 
   module makes use of the means provided by the ENTITY MIB module 
   [RFC4133].  Particularly, it uses the entPhysicalIndex for 
   identifying entities. 

   The standby status provided by the ENTITY STATE MIB module is related

   to power states required for energy management, but the number of 
   states is too restricted for meeting all energy management 
   requirements.  For energy management several more power states are 
   required, such as different sleep and operational states as defined 
   by the Advanced Configuration and Power Interface (ACPI) [ACPI.R30b] 
   or the DMTF Power State Management Profile [DMTF.DSP1027]. 

A.1.3.  ENTITY SENSOR MIB 

   RFC 3433 [RFC3433] defines the ENTITY SENSOR MIB module. 
   Implementations of this module offer a generic way to provide data 
   collected by a sensor.  A sensor could be an energy consumption meter

   delivering measured values in Watt.  This could be used for reporting




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   current power of an entity and its components.  Furthermore, the 
   ENTITY SENSOR MIB can be used to retrieve the accuracy of the used 
   power meter. 

   Similar to the ENTITY STATE MIB module, the ENTITY SENSOR MIB module 
   makes use of the means provided by the ENTITY MIB module [RFC4133] 
   for relating provided information to components of a device. 

   However, there is no unit available for reporting energy quantities, 
   such as, for example, watt seconds or kilowatt hours, and the ENTITY 
   SENSOR MIB module does not support reporting accuracy of measurements

   according to the IEC / ANSI accuracy classes, which are commonly in 
   use for electric power and energy measurements.  The ENTITY SENSOR 
   MIB modules only provides a coarse-grained method for indicating 
   accuracy by stating the number of correct digits of fixed point 
   values. 

A.1.4.  UPS MIB 

   RFC 1628 [RFC1628] defines the UPS MIB module.  Implementations of 
   this module provide information on the current real power of entities

   attached to an uninterruptible power supply (UPS) device.  This 
   application would require identifying which entity is attached to 
   which port of the UPS device. 

   UPS MIB provides information on the state of the UPS network.  The 
   MIB module contains several variables that are used to identify the 
   UPS entity (name, model,..), the battery state, to characterize the 
   input load to the UPS, to characterize the output from the UPS, to 
   indicate the various alarm events.  The measurements of power in UPS 
   MIB are in Volts, Amperes and Watts.  The units of power measurement 
   are RMS volts, RMS Amperes and are not based on Entity-Sensor MIB 
   [RFC3433]. 

A.1.5.  POWER ETHERNET MIB 

   Similar to the UPS MIB, implementations of the POWER ETHERNET MIB 
   module defined in RFC3621 [RFC3621] provide information on the 
   current energy consumption of the entities that receive Power over 
   Ethernet (PoE).  This information can be retrieved at the power 
   sourcing equipment.  Analogous to the UPS MIB, it is required to 
   identify which entities are attached to which port of the power 
   sourcing equipment. 

   The POWER ETHERNET MIB does not report power and energy consumption 
   on a per port basis, but can report aggregated values for groups of 
   ports.  It does not use objects of the ENTITY MIB module for 
   identifying entities, although this module existed already when the 



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   POWER ETHERNET MIB modules was standardized. 

A.1.6.  LLDP MED MIB 

   The Link Layer Discovery Protocol (LLDP) defined in IEEE 802.1ab is a

   data link layer protocol used by network devices for advertising of 
   their identities, capabilities, and interconnections on a LAN 
   network.  The Media Endpoint Discovery (MED) (ANSI/TIA-1057) is an 
   enhancement of LLDP known as LLDP-MED.  The LLDP-MED enhancements 
   specifically address voice applications.  LLDP-MED covers 6 basic 
   areas: capabilities discovery, LAN speed and duplex discovery, 
   network policy discovery, location identification discovery, 
   inventory discovery, and power discovery. 

A.2.  Existing standards of other bodies 

A.2.1.  DMTF 

   The DMTF has defined a power state management profile [DMTF.DSP1027] 
   that is targeted at computer systems.  It is based on the DMTF's 
   Common Information Model (CIM) and rather an entity profile than an 
   actual energy consumption monitoring standard. 

   The power state management profile is used to describe and to manage 
   the power state of computer systems.  This includes e.g. means to 
   change the power state of an entity (e.g. to shutdown the entity) 
   which is an aspect of but not sufficient for active energy 
   management. 

A.2.2.  OVDA 

   ODVA is an association consisting of members from industrial 
   automation companies.  ODVA supports standardization of network 
   technologies based on the Common Industrial Protocol (CIP).  Within 
   ODVA, there is a special interest group focused on energy and 
   standardization and inter-operability of energy aware entities. 

A.2.3.  IEEE-ISTO Printer WG 

   The charter of the IEEE-ISTO Printer Working Group is for open 
   standards that define printer related protocols, that printer 
   manufacturers and related software vendors shall benefit from the 
   interoperability provided by conformance to these standards.  One 
   particular aspect the Printer WG is focused on is power monitoring 
   and management of network printers and imaging systems PWG Power 
   Management Model for Imaging Systems [IEEE-ISTO].  Clearly, these 
   devices are within the scope of energy management since these devices

   consume power and are attached to the network.  In addition, there is




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   ample scope of power management since printers and imaging systems 
   are not used that often.  IEEE-ISTO Printer working group has defined

   MIB modules for monitoring the power consumption and power state 
   series that can be useful for power management of printers.  The 
   energy management framework should also take into account the 
   standards defined in the Printer working group.  In terms of other 
   standards, IETF Printer MIB RFC3805 [RFC3805] has been standardized, 
   however, this MIB module does not address power management of 
   printers. 


Authors' Addresses 

   Juergen Quittek (editor) 
   NEC Europe Ltd. 
   NEC Laboratories Europe 
   Network Research Division 
   Kurfuersten-Anlage 36 
   Heidelberg  69115 
   DE 

   Phone: [phone] 
   Email: [e-mail] 


   Rolf Winter 
   NEC Europe Ltd. 
   NEC Laboratories Europe 
   Network Research Division 
   Kurfuersten-Anlage 36 
   Heidelberg  69115 
   DE 

   Phone: [phone] 
   Email: [e-mail] 


   Thomas Dietz 
   NEC Europe Ltd. 
   NEC Laboratories Europe 
   Network Research Division 
   Kurfuersten-Anlage 36 
   Heidelberg  69115 
   DE 

   Phone: [phone] 
   Email: [e-mail] 




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   Benoit Claise 
   Cisco Systems, Inc. 
   De Kleetlaan 6a b1 
   Degem  1831 
   BE 

   Phone: [phone] 
   Email: [e-mail] 


   Mouli Chandramouli 
   Cisco Systems, Inc. 
   Sarjapur Outer Ring Road 
   Bangalore, 
   IN 

   Phone: [phone] 
   Email: [e-mail] 

































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