Subject: [eman] FW: comments on draft-ietf-eman-framework-02, part 1

From: "John Parello (jparello)" <[email-masked]>
Date: Mon, 31 Oct 2011 17:36:43 -0700

Hi Juergen,

We have addressed your points

1. in http://tools.ietf.org/html/draft-parello-eman-definitions-03 for
the terminology

2. in the latest version of the EMAN framework draft

3. Any open issue has been inserted in the EMAN framework draft

Jp

-------- Original Message -------- 

Subject: 

[eman] comments on draft-ietf-eman-framework-02, part 1

Date: 

Mon, 25 Jul 2011 00:11:27 -0400

From: 

Juergen Quittek <[email-masked]> <mailto:[email-masked]> 

To: 

[email-masked] list <[email-masked]> <mailto:[email-masked]> 

Dear all, 

Attached please find my comments on sections 1-3 of the framework draft
version -02. 

Comments on the remaining sections will follow in separate emails.

 [snip]

	                         Energy Management Framework 

	                        draft-ietf-eman-framework-02 

 [snip]

     Abstract 

        This document defines a framework for providing Energy 

        Management for devices within or connected to communication 

        networks.  The framework defines a domain of Energy Management 

        devices that is a logical unit of Energy Management. Within a 

This is difficult to parse: "A domain of devices is a unit of energy
management"?

        domain each device is identified, classified and given context.

        Devices can be monitored and/or controlled with respect to 

        power, power state, energy, demand, electrical quality, and 

        battery.  Additionally the framework models relationships and 

        capabilities between devices in a domain.   

        TO DO/OPEN ISSUE 

        - IPFIX or not? Initially IPFIX was mentioned in [EMAN-REQ], 

        then we see now: "A solution for this is that the concerned 

        entity or another entity closely interacting with the concerned 

        entity collect time series of power values and make them 

        available via push or pull mechanisms to receivers of the 

        information.". So, the questions are: Is IPFIX a requirement?  

        What other mechanism do we have to PUSH time series of power 

        values (no, SNMP notifications are not suitable)? So should we 

        or not include IPFIX in this document? 

PUSH mode is a requirement for time series of measurements. 

Whether IPFIX is the only protocol that can do so in the right way

is not a question of requirements. If the framework brings arguments

why IPFIX is the best choice, it should include IPFIX as solution. 

Otherwise, it still may include IPFIX as candidate protocol for PUSH
mode.

        - Power Monitor has been renamed to Energy Managed Object. Get

I don't think that this is a good choice.

"Managed Object" is the term specified to be used for objects defined in
MIB modules.

"Energy Managed Objects" sounds like a kind of MIB objects.

          consensus on the terminology. Another example is Power 

          Quality 

I think the term power quality is the right term and we should easily
find an agreed definition. 

We just should avoid applying it to things that are not related to power
quality.

	     1. Introduction 

	        Network management is divided into the five main areas
defined 

	        in the ISO Telecommunications Management Network model:
Fault, 

	        Configuration, Accounting, Performance, and Security
Management 

	        (FCAPS).   Absent from this management model is any 

I would add ITU X.700 as reference for FCAPS.

        consideration of Energy Management, which is now becoming a 

        critical area of concern worldwide as seen in [ISO50001].  

        This document defines a framework for providing Energy 

        Management for devices within or connected to communication 

        networks.  The framework describes how to identity, classify and

identity -> identify

        provide context for a device in a communications network from 

        the point of view of Energy Management.   

        The identified device can then be monitored for Energy 

        Management by obtaining measurements for power, energy, demand 

        and electrical quality.  If a device contains a battery(s) the 

        characteristics and performance of the battery(s) can also be 

        managed.  A device's state can be monitored or controlled by 

        providing an interface expressed as one or more Power State 

        Sets.  The most basic example of energy management is a single 

        device reporting information about itself.  However, in many 

        cases, energy is not measured by the device itself, but by a 

        meter located upstream in the power distribution tree.  An 

        example is a power distribution unit (PDU) that measures energy 

        consumption of attached devices and may report this to an Energy

        Management System.  Therefore, devices are recognized as having 

        relationships to other devices in the network from the point of 

        view of Energy Management.  These relationships include 

        Aggregation, Metering, Power Source(s), Proxy, and Dependency.  

     1.1. Energy Management Document Overview 

        The EMAN standard provides a set of specifications that together

        provide Energy Management.  This document specifies the 

Specifications do no never provide energy management.

        framework, per the Energy Management requirements specified in 

        [EMAN-REQ] 

        The applicability statement document [EMAN-AS] provides a list 

        of use cases, cross-reference between existing standards and the

        EMAN standard, and shows how the this relates to other 

        frameworks. 

        The [EMAN-AWARE-MIB] provides objects for addressing 

provides -> specifies or defines

        identification, classification, context information, and 

        relationships form the point of view of Energy Management. 

        The Power and Energy Monitoring MIB [EMAN-MON-MIB] contains  

        objects for monitoring of Power, Energy, Demand, Electrical 

        Quality and Power State Sets. 

        Definition of Managed Objects for Battery Monitoring [EMAN-

        BATTERY-MIB] defines managed objects that provide information on

        the status of batteries in managed devices. 

        EDITOR'S NOTE: [EMAN-MON-MIB] and [EMAN-AS] are not EMAN working

        group documents.  Hence, these references will be changed in the

        future. 

     2. Requirements & Use Cases  

        Requirements for power and energy monitoring for networking 

        devices are specified in [EMAN-REQ].  The Energy Management use 

        cases covered by this framework are covered in the EMAN 

        applicability statement document in [EMAN-AS].  Typically 

        requirements and use cases for communication networks cover the 

        devices that make up the communication network and endpoints.  

        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.  

        For example, target devices for this specification can include 

        (but are not limited to): 

I am not sure it makes sure having this list. 

It is always incomplete. I would rather state that

"Target devices for the energy management framework are all devices that
can directly or indirectly be monitored or controlled by an energy
management system using the Internet protocol."

            - Simple electrical appliances / fixtures  

            - Hosts, such as a PC or a datacenter server 

"a PC or a datacenter server"

--> a PC, a datacenter server, or a printer"

            - Routers  

            - Switches 

            - Switches with line card components  

            - Power over Ethernet (PoE) endpoints, 

            - Power Distribution Units (PDU)  

            - Protocol gateways devices for Building Management Systems 

        (BMS) 

            - Electrical Meters 

            - Sensor controllers with subtended sensors 

        There may also exist varying protocols deployed among these 

        parallel networks.  

To what does "these parallel networks" refer?

        For an Energy Management framework to be useful, it should also 

        apply to these types of separate networks as they connect and 

        interact with a communications network.  

     3. Terminology 

There is a section 4 titled "Energy Management Reference Model". But
actually, most of the model's fundamentals are only explained in this
terminology section. I don't think this is a good structure and I don't
think this is sufficient. Basic concepts, such as the Energy Managed
Object, the EMO relationships should be elaborated in section 4.

        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]. 

        This section contains definitions of terms used throughout this 

        specification. Defined terms have their first letter 

        capitalized.  Entities, relationships and or capabilities are 

I am not in favor of the capitalization of terms.

Particularly for terms such as "energy", "power", "demand" which we are
using fully in line with their common meaning it appears to be very
confusing for a reader when (s)he needs to think: "Is capitalized
"Energy" anyhow different from lower case "energy"?

        defined with respect to well known software patterns as 

        described in [GAMMA] and [EIPATT] 

Why this? IMHO definitions for entities and relationships are better
taken from standards (for example UML) than from books written by
individual authors. The books referred to above may be useful when
design patterns are used. But I do not see any of their design patterns
being relevant for a standards on energy management, at least not more
that for standards for IP traffic management and control where these
books hardly appear as references in standards documents.

        Energy Management System (EnMS) 

        An 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 EnMS allows organizations to improve 

        energy performance and demonstrate conformity to requirements, 

        standards and/or legal requirements.  This definition is in line

        with the definition of "Energy management systems - Requirements

        with guidance for use" [ISO50001]. 

Wouldn't it be better to explicitly mention monitoring and control of
energy consumption?

        With respect to communication networks these same goals will 

        apply to the communications networks and attached devices within

        an organization. 

I would remove this paragraph. Either the first paragraph obviously
applies already to communications networks or we need to change it.

        Energy Management 

        Energy Management is a set of functions for measuring, modeling,

        planning, and optimizing networks to ensure that the network 

        elements and attached devices use energy efficiently and is 

I disagree. Even if I don't like it, I would not limit energy management
systems to the ones that ensure energy efficiency. Energy management
deals with assessing and influencing the consumption of energy. This is
independent from an objective of ensuring energy efficiency.

        appropriate for the nature of the application and the cost 

        Management is a system congruent to any of FCAPS area of 

        management in the ISO/OSI Network Management Model [TMN] Energy 

        Management for communication networks and attached devices is a 

"is a" --> "may be"

        subset or part of an organization's greater EnMS. 

This is confusing, because it is completely different from the
definition of EnMS

Why is energy management not

    "developing and implementing an energy policy, 

     setting targets, action plans and taking into account 

     legal requirements related to energy use."

?

This would be consistent with the EnMS definition above.

	        Energy Management Systems  

This is confusing. The same term with different acronym was already
defined above. 

	        An Energy Management System (EMS) is congruent to a
Network 

EMS --> EnMS

        Management System (NMS) and is a combination of hardware and 

        software used to administer a network with the primarily purpose

        being Energy Management. 

This paragraph needs to be merged with the previous definition of the
term. 

        Energy Monitoring 

        Energy Monitoring is a part of Energy Management that deals with

        collecting or reading measurements from devices to aid in Energy

        Management.  This could include Energy, Power, Demand, Quality, 

        Context and/or Battery information. 

        Energy 

line to be deleted

        Energy  

        Energy is the capacity of a system to produce external activity 

        or perform work and can be electricity, fuels, steam, heat, 

        compressed air, and other like media. Energy is typically 

This is certainly not taken from an IEEE or IEC dictionary: 

Energy is not steam, it is not fuel, it is not compressed air.

Let's take text from a dictionary.

        expressed in watt hours or joules.  

can we restrict EMAN to electrical energy and power?

	        Power 

	        Power is a rate of energy conversion.  As the unit of
time 

	        approaches zero a power measurement is called an
instantaneous 

	        power reading.  Typically when implementing Power
monitoring in 

	        hardware, a measuring device may have to compute an
average 

	        value per some unit of time to express a reading to
approximate 

	        an instantaneous power measurement. 

This contradicts the definition of instantaneous power in the IEEE
dictionary of standards terms where active power is "The time average of
the instantaneous power over one period of the wave." This implies that
the instantaneous power changes from zero to a maximum and back two
times of a period, i.e. 100 or 120 times a second for common AC power.
Typical meter implementations measure power over at least half a period.
The result of their approximation is not called instantaneous power. It
is the power over a (short) interval of time.

	        Demand 

	        Demand is an average of Power measurements over an
interval(s) 

I disagree. Demand is a power measurement over a long time interval.
There is no need for having multiple power measurements and averaging
them. Of course I agree that this would be a way to implement demand
measurements. But the definition of a term should not falsely restrict
it to a certain implementation.

Please let's take IEEE or other bodies dictionary terms.

"an interval(s)" --> "an interval"

        of time and typically expressed in kilowatt hours.  This 

        measurement is significant because some utilities or energy 

remove "This measurement is significant because"

        providers bill by Demand measurements as well as for maximum 

	        Demand per billing periods.  Power values may spike
during 

	        short-terms by devices, but Demand measurements
recognize that 

	        maximum Demand does not equal maximum Power during an
interval. 

	        Power Quality 

	        EDITOR'S NOTE: This may be rephrased as Electrical 

	        Characteristics. 

Electrical characteristics seems to better match what the term has been
used for in some drafts.

But the term power quality should still be here to refer to properties
that are usually called so.

        Power Quality is defined as a set of values to describe the 

        electrical characteristics of Power as provided by an electrical

        source as seen by the Energy Managed Object.  For example: AC 

        phase, apparent and reactive power, etc. 

Yes. Phase, apparent and reactive power are not typical power quality
issues. Power quality issues include the deviation of actual voltage
from nominal/design voltage, the deviation of AC frequency from the
nominal frequency, harmonic distortions, etc.

	        Energy Control 

	        Energy Control is a part of Energy Management that deals
with 

	        modifying or setting the state of an Energy Managed
Object in 

	        order to optimize or ensure its efficiency. 

I disagree. Energy Control is not limited to optimization of efficiency.
"in order to optimize or ensure its efficiency" should be removed. A
function that increases energy consumption needs also to be covered by
the term energy control.

What woud be the difference between modifying and setting a state? I
don't make a suggestion for an alternative here. We should put ALL terms
on the mailing list and discuss them until we reach something that comes
closer to a reasonable definition.

	        Energy Managed Object  

	        An Energy Managed Object (EMO) is a device that is part
of or 

	        attached to a communications network that is monitored, 

	        controlled, or aids in the management of another device
for 

	        Energy Management.  

Two issues: 

1. the term "managed object" is already in common use for the objects
defined in a MIB module. Since we are also defining MIB modules, we will
run into ambiguities and risk confusion of readers if we re-use the term
here.

2. The attribute "managed" is confusing, because the term refers also to
"unmanaged" objects that are neither monitored or controlled, but just
"aid" in the management of other devices. These seem to be rather
"managing" objects than "managed" objects.

	        Energy Aware Object  

	        An Energy Managed Object may not have the capability to
provide 

	        information necessary for Energy Management itself. If
an Energy 

	        Managed Object can provide Energy Management Context,
Energy 

	        Monitor and optionally Energy Control values for itself
then the 

Monitor --> Monitoring

        Energy Managed Object is said to be an Energy Aware Object 

I don't see good reasons for using the term energy awareness. IPFIX did
all its specifications well without ever needing the term flow-awareness
and the SNMP Interface MIB module never needed the term packet-awareness
for interfaces that meter bytes and packets.

BTW, I wonder why a device that only reports its energy consumption is
not called energy-aware.

It is only called energy-aware if it can also report its energy context.
Why is this so?

My strongest concern is the following. What I would call energy aware
would be a device that not just reports on its energy consumption, but
rather tries to optimize its energy consumption by its own control
logic, for example a TV sets that switches of the screen when its
sensors indicates that the last watchers has left the room. If this TV
should be called energy-aware even if it does not report anything to any
management system.

I strongly suggest either to replace the term "energy aware" by "energy
reporting" or something similar, or better, not to use the term at all.
We don't need it.

        For example: as the most simplistic example, a set of light 

        bulbs where all values are provided by an EMS through estimation

        and or catalogue information are not Energy Aware. In contrast a

        set of network switches that can report the same information 

        based upon hardware sensing is said to be Energy Aware. 

Would you also call it energy aware if the device can report its energy
information only using a non-IP protocol?

	        Energy Managed Object Identification 

	        Energy Managed Object Identification is a set of
attributes that 

	        enable an Energy Managed Object to be: uniquely
identified among 

	        all Energy Management Domains; linked to other systems; 

Among all domains? 

This means globally unique. 

Do you really mean this? 

Do we need this?

What means "linked to other systems"? 

	        classified as to type model and or manufacturer. 

I do think it is impossible to invent a type of identifier that enables
all kinds of energy managed objects to derive their type model and
manufacturer from it. This is particularly difficult for devices that do
not have a particular or model type model or manufacturer that is
registered somewhere.

	        RFC EDITOR'S: the uniqueness must be clarified in
[EMAN-REQ] 

	        Energy Managed Object Context 

	        Energy Managed Object Context is a set of attributes
that allow 

	        an Energy Management system to classify the use of the
Energy 

	        Managed Object within an organization.  The
classification 

	        contains use and/or ranking of the Energy Managed Object
as 

	        compared to other Energy Managed Objects in the Energy 

	        Management Domain. 

Just questions: 

Are there already standards defining contexts of devices?

Or is this something new? 

Is IANA maintaining a list of standardized contexts?

Are we planning to establish one? 

Or is a context just a string with arbitrary content?

        Energy Management Domain 

        An Energy Management Domain is a name or name space that 

If a domain were a name, we could call it name.

A domain is not a name. It may have one.

        logically groups Energy Managed Objects into a zone of Energy 

        Management.  Typically, this zone will have as members all 

What is a zone of energy management? 

Is it different in any way from a domain?

        Energy Managed Objects that are powered from the same electrical

        panel(s) for which there is a meter or sub meter. 

What is a sub meter? 

What would be the difference between having a meter or a sub meter at a
panel?

        For example: All Energy Managed Objects drawing power from the 

        same distribution panel with the same AC voltage within a 

        building, or all Energy Managed Objects in a building for which 

        there is one main meter, would comprise an Energy Management 

        Domain.  

I would not use this example over five lines of text in the definition.
It should be rather mentioned when the trem is explained in the
description of the reference model.

        From the standpoint of Energy Management, it is useful to report

        Energy as the sum of the Energy of all the Energy Managed 

        Objects within an Energy Management Domain and then correlate 

        that value with metered values.  

The same for this use case: It belongs to the description of the
reference model.

        Energy Managed Object Relationships 

        Energy Managed Objects may have functional relationships to each

        other within an Energy Management Domain.  The functional 

Can't this be cross domain?

In our company, we have fuse cabinets equipped with power meters that
have up to eight current claps and measure power for up to eight power
distribution trees. Is the meter than member of all eight domains

at the same time because it measures in them. Note that the meter is
powered by just one of the distribution trees or be neither of them.

Another case would be an energy management system that uses different
domains for servers, PCs, phones, and switches. Still, a switch should
be able to power a phone cross domain using PoE.

        relationships include Aggregation, Metering, Power Source(s), 

        Proxy, and Dependency.  One device will provide a capability or 

        functional value in the relationship and another will be the 

        receiver of the capability.  These capabilities include

I do not understand why a PDU metering its output provides a capability?

Even less do I understand why a device (host, switch, light bulb) for
which power is measured would receive any capability when this is done.

        Aggregation, Metering, Power Source, Proxy and Dependency.  

Which capability is provided in the dependency relationship?

        Aggregation Relationship 

        An Energy Managed Object may aggregate the Energy Management 

        information of one or more Energy Managed Objects and is 

        referred to as an Aggregation Relationship.  An Energy Managed 

The previous paragraph stated that objects may HAVE relations ships.
This paragraph states that an object IS REFERRED TO  as relationship.
This is not consistent.

        Object may be aggregated by another Energy Managed Object(s).  

        Aggregate values are obtained by reading values from multiple 

        Energy Managed Objects and producing a single value of more 

I think it does not need to be just a single value. It can be multiple.

The definition should not focus on the number of values. A good
indicator for an aggregation action is the presence of operations on
multiple given values. Whether the operation(s) produce one or more
values is not highly relevant for the definition.

        significant meaning such as average, count, maximum, median, 

I would not limit aggregation to operations generating values with more
significant meanings. Even if the meaning is less significant, it still
should be called aggregation.

        minimum, mode and most commonly sum.  

        Metering Relationship 

        An Energy Managed Object may measure the Energy of another 

        Energy Managed Object(s) and is referred to as a Metering 

I think it is important for the EnMS to distinguish two cases: A meter
measures the energy of individual EMOs separately, or it measures just
the accumulated energy and power for these devices, for example in the
fuse cabinet.In the latter case, information on individual EMOs would
not be available. This is a significant qualitative difference and
should be modeled.

        Relationship.  An Energy Managed Object may be metered by 

Again, "the EMO is referred to as metering relationship" does not seem
to be what is intended to b said.

        another Energy Managed Object(s).  Example: a PoE port on a 

Remove second sentence. It is redundant. Or use the following
replacement:

"another Energy Managed Object(s)" --> "multiple Energy Management
Objects and a single EMO may meter multiple other EMOs."

        switch measure the Power it provides to the connected Energy 

        Managed Object. 

Why is this "providing a service to the powered EMO"?

It is providing a service to the EnMS and obviously not to the EMO that
may not even have an information on whether or not the measurement is
performed. The powered EMO does not ask for such a service. The EnMS
does. In my view. The PoE switch measures at its output and provides
this information to the EnMS. The EMS is the free to use this
information also as power information for the powered EMO.

	        Power Source Relationship 

	        An Energy Managed Object may be the source of or
distributor of 

	        power to another Energy Managed Object(s) and is
referred to as 

	        a Power Source Relationship.  An Energy Managed Object
may be 

	        powered by another Energy Managed Object(s).  Example: a
PDU 

"another Energy Managed Object(s)" --> "multiple Energy Management
Objects and a single EMO may power multiple other EMOs."

        provides power for a connected host. 

        Proxy Relationship 

        An Energy Managed Object that provides Energy Management 

        capabilities on behalf of another Energy Managed Object so that 

        is appears to be Energy Aware is referred to a Proxy 

What sense would it make to have another object appear to be energy
aware? Fooling the EnMS?

Whether or not an EMO is energy aware should be completely independent
from whether or not there is a proxy for it. And it should be possible
to have a proxy relationship without pretending an unaware device to be
aware.

        Relationship.  An Energy Managed Object may be proxied by 

        another Energy Managed Object(s).  Example: a protocol gateways 

"another Energy Managed Object(s)" --> "multiple Energy Management
Objects and a single EMO may proxy multiple other EMOs."

	        device for Building Management Systems (BMS) with
subtended 

	        devices.  

	        Dependency Relationship 

	        An Energy Managed Object may be a component of or rely 

	        completely upon another Energy Managed Object to operate
and is 

	        referred to as a Dependency Relationship.  An Energy
Managed 

	        Object may be dependent on another Energy Managed
Object(s).  

	        Example: A Switch chassis with multiple line cards 

This is very foggy. 

What is the meaning of "rely completely upon another EMO to operate"?

Is a server in a datacenter completely dependent on the firewall(s) that
connect the datacenter with the Internet? With a switched off firewall,
the server cannot provide any service thus not operate.

How shall we detect all those dependencies. Wouldn't they be subject to
dynamic changes?

	        Energy Managed Object Parent 

	        An Energy Managed Object Parent is an Energy Managed
Object that 

	        provides one or more of the Energy Managed Object
Relationships 

	        capabilities. 

I don't think that in the case of dependency, a capability is provided
to a EMO. 

Neither in the case of metering.

        Energy Managed Object Child 

        An Energy Managed Object Child is an Energy Managed Object that 

        has at least one Energy Managed Object Relationship capability 

        provided by another Energy Managed Object.   

see previous comment.

        Power State 

        A Power State is a way to classify a Power setting on an Energy 

A power state is not a way.

        Managed Object (e.g., on, off, or sleep).  A Power State can be 

        viewed as a method for Energy Control 

A power state should not be viewed as a method for power control. It is
a state, not a method.

	        Manufacturer Power State 

	        A Manufacturer Power State is a device-specific way to
classify 

	        a Power setting implemented on an Energy Managed Object.

See power state.

        Power State Set 

        A collection of Power States that comprise one named or logical 

        grouping of control is a Power State Set.  For example, the 

        states {on, off, and sleep} as defined in [IEEE1621], or the 16 

        power states as defined by the [DMTF] can be considered two 

        different Power State Sets. 

We should add that a power state set implemented on a device MUST at all
times have exactly one 

state that the device is in.

        Nameplate Power 

        The Nameplate Power is the maximal (nominal) Power that a device

        can support.  This is typically determined via load testing and 

remove "specified via load testing and is"

        is specified by the manufacturer as the maximum value required 

        to operate the device.  This is sometimes referred to as the 

        worst-case Power.  The actual or average Power may be lower.  

        The Nameplate Power is typically used for provisioning and 

        capacity planning. 

Thanks,

    Juergen