wdiff draft-claise-power-management-arch-01.txt draft-claise-power-management-arch-02.txt

Network Working Group B. Claise
Internet-Draft J. Parello
Intended Status: Informational B. Schoening
Expires: March 17, April 20, 2011 Cisco Systems, Inc.
September 17,
October 20, 2010

Power Management Architecture
draft-claise-power-management-arch-01
draft-claise-power-management-arch-02

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Abstract

This document defines the power management architecture.

Conventions used in this document

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].

Table of Contents

1. Introduction............................................... Introduction.............................................. 4
2. Uses Use Cases & Requirements.................................. 5
3. Terminology................................................ Terminology............................................... 5
4. Energy Management Reference Model......................... 7
5. Architecture High Level Concepts and Scope................. 6
4.1. Scope................ 9
5.1. Power Monitor Information............................. 8
4.2. Information........................... 11
5.2. Power Monitor Meter Domain............................ 8
4.3. Domain.......................... 11
5.3. Power Monitor Parent and Child........................ 9
4.4. Child...................... 11
5.4. Power Monitor Context................................ 10
4.5. Context............................... 12
5.5. Power Monitor Levels................................. 11
4.6. Levels................................ 13
5.6. Power Monitor Usage Measurement...................... 13
4.7. Measurement..................... 16
5.7. Optional Power Usage Quality......................... 14
4.8. Quality........................ 17
5.8. Optional Energy Measurement.......................... 14
4.9. Measurement......................... 18
5.9. Optional Battery Information......................... 15
5. Information........................ 18
6. Power Monitor Children Discovery.......................... 15
6. Configuration............................................. 16 Discovery......................... 18
7. Fault Management.......................................... 16 Configuration............................................ 19
8. Fault Management......................................... 20
9. IPFIX.................................................... 20
10. Relationship with Other Standard Standards Development
Organizations................................................ 17
8.1.
Organizations............................................... 21
10.1. Information Modeling................................. 17
8.2. Modeling............................... 21
10.2. Power Levels......................................... 17
9. Levels....................................... 21
11. Implementation Scenarios.................................. 18 Scenarios................................ 22
Scenario 1: Switch with PoE endpoints..................... 18 endpoints.................... 22
Scenario 2: Switch with PoE endpoints with further connected
device(s)................................................. 18
device(s)................................................ 22
Scenario 3: A switch with Wireless Access Points.......... 18 Points......... 22
Scenario 4: Network connected facilities gateway.......... 19 gateway......... 23
Scenario 5: Data Center Network........................... 19 center network.......................... 23
Scenario 6: Building Gateway Device....................... 19 gateway device...................... 23
Scenario 7: Power Consumption consumption of UPS...................... 19 UPS..................... 23
Scenario 8: Power Consumption consumption of Battery-based Devices.... 20
10. battery-based devices... 24
12. Security Considerations.................................. 20
11. Considerations................................. 24
12.1. Security Considerations for SNMP...................... 24
12.2. Security Considerations for IPFIX..................... 25
13. IANA Considerations...................................... 20
12. References............................................... 20 Considerations..................................... 25
14. Acknowledgments......................................... 25
15. References.............................................. 25
Normative References...................................... 20 References..................................... 25
Informative References.................................... 20
13. Authors' Addresses....................................... 21 References................................... 26

TO DO:

. Since we have DO

- Question for the Working Group: Should the WG consider
IPFIX in this architecture?

- Question for the Working Group: How to specify the notion
of desired versus actual child capabilities, i.e. the capabilities that the
Power
Level, we must deal Monitor Parents have with Power Monitor Children.
For Example:
1. Monitoring (only reporting)
2. Configuration power state
3. Configuration: power
Example: on a PC, we can set power level without knowing
the notion of transition state:

Gracefully versus hard way. Note: power. A solution must be specified in this draft.

- Question for the Working Group: Should transition states are
apparently described in
be tracked when setting a level. Example: The configured
level is set to Off from High. The Actual level will
take time to update as the DMTF model.

. In terms of other SDOs, discuss DMTF?

. Do we need device powers down. Should
there be transitions shown or will the pmIndex persistence?

. Security Considerations two variables
suffice to track the device state.

- Question for working group: Should implementation
scenarios be done incorporated in the architecture draft

- We should have a similar section, for all the drafts,
which includes an overview of all EMAN documents.

1. Introduction

Network management is typically divided into the five main
network management areas of concerns
according to defined in the ISO Telecommunications
Management Network
model. The model defines model: Fault, Configuration, Accounting,
Performance, and Security Management. Notably missing Absent from this model is an
area
any consideration of concern specifically covering energy management at an
equal level to these areas.

With energy management, which is now becoming a more
critical area of concern, this concern worldwide.

This document defines an architecture for power management for use
with
devices in and within or connected to communication networks. This
architecture includes monitoring for power state and energy
consumption of networked elements, taking into account covering the requirements
specified in [POWER-MON-REQ]. However, this
architecture It also goes one a step further, as it includes further in
defining some elements of elements of configuration.

Energy management is applicable to devices that comprise and
that are connected to a in communication network.
networks. Target devices for this specification include (but
are not limited to): routers, switches, Power over Ethernet
(PoE) endpoints, protocol gateways for building management
systems, intelligent meters, home energy gateway, hosts and
servers, sensor proxy, proxies, etc.

Where applicable, monitoring of a device is extended monitoring extends to the individual
components of the device and/or and to any attached dependent device(s). An example of such a case could be when a devices.
For example: A device contains can contain components that are
independent from a power
state power-state point of view (such view, such as line
cards, processor cards, hard
drives) or when a devices has drives. A device can also have
dependent attached devices (such devices, such as a switch with PoE endpoints
or a power distribution unit with attached endpoints). endpoints.

2. Uses Use Cases & Requirements

The requirements

Requirements for power and energy monitoring for networking
devices are specified in [POWER-MON-REQ]. The requirements in
[POWER-MON-REQ] cover devices that typically make up a found in communications network
networks, such as switches, routers, and various connected
endpoints. For a power monitoring architecture to be useful, a
specification it
should also be applicable apply to facility meters, power distribution units,
gateway proxies for commercial building control, home automation devices
devices, and devices that interface with the utility and/or
smart grid. Due to Accordingly, this fact, architecture, the scope of this architecture is
broader than that specified in [POWER-MON-REQ]. Several
scenarios that cover these broader use cases are presented later
in Section 9. 11. - Implementation Scenarios.

3. Terminology

This section contains definitions of major important terms used
throughout this specification.

IPFIX-specific terminology used in
explaining the concepts, examples, and this document is defined in
section 2 of [RFC5101]. For example: Flow Record, Collector ,
etc... As in [RFC5101], these IPFIX-specific terms have the MIB definitions.
first letter of a word capitalized.

Power Monitor

A Power Monitor is a component within a system of one or more components
that
provide provides power, draws power, or reports energy consumption
on behalf of another Power Monitor. It can be independently
managed from a power monitoring power-monitoring and power state power-state configuration
point of view. Examples of Power Monitors are: a router line
card, a motherboard with a CPU, an IP phone connected with a
switch, etc.

Power Monitor Parent

A Power Monitor Parent is a Power Monitor that is the root of
one or multiple more subtending Power Monitors, called Power Monitor
Children. The Power Monitor Parent is able to collect data
about or report on the power state and energy consumption for his of its
Power Monitor Child(ren). Children.

For example, in case of example: A Power-over-Ethernet (PoE) device such (such as an IP
phone or an access point point) is attached to a switch port, the port. The
switch is the source of power for the attached device. In such
a case, device, so the
Power Monitor Parent is the port of the switch,
while and the attached device Power Monitor Child
is the device attached to the switch.

The Power Monitor Parent may report data or implement actions on
behalf of the Power Monitor Child. These capabilities must be
enumerated by the Power Monitor Parent.

The communication between the parent and child for monitoring or
collection of power data is left to the device manufacturer. For
example: A parent switch may use LLDP to communicate with a
connected child, and a parent lighting controller may use BACNET
to communicate with child lighting devices.

Power Monitor Child

A Power Monitor Child is a Power Monitor associated to with a Power
Monitor Parent, and which draws power from its Power Monitor Parent
or reports its power usage and power
state to its Power Monitor Parent. The Power Monitor Child may
or may not draw power from its Power Monitor Parent. .

Power Monitor Meter Domain

A Power Monitor Meter Domain is a name or name space that
logically groups together Power Monitors that comprises into a zone of manageable power
usage. Typically, this zone will comprise have as members all Power
Monitors that are powered from the same electrical panel or
panels for which there is a meter or sub meter. For example,
all example:
All Power Monitors receiving power from the same distribution
panel of a building, or all Power Monitors in a building for
which there is one main meter. meter, would comprise a Power Monitor
Meter Doman. From the point standpoint of monitoring
power use, power-use monitoring, it is
useful to report the total power usage as the sum of power
consumed by all the Power Monitors within a Power Monitor Meter
Domain and then correlate that value to with the metered usage.

Power Level

A Power Level is a uniform way to classify power settings on a
Power Monitor (e.g., shut, hibernate, sleep, high). Power
Levels can be viewed as an interface for interacting with the underlying
device device-
implemented power settings.

Manufacturer Power Level

A device specific Manufacturer Power Level is a device-specific way to classify
power settings implemented on a Power Monitor. For cases where
the implemented power setting settings cannot be directly mapped to a
Power Level(s), Levels, we can use the Manufacturer Power Levels are used to
enumerate and show the relationship between the implemented
power settings and the Power Level interface.

4. Energy Management Reference Model

+---------------+
| NMS | -
+-----+---+-----+ |
| | |
| | | S
+---------+ +-------+ | N
| | | M
| | | P
+---------------+ +------+-------+ |
| Power Monitor | | Power Monitor | |
| Parent 1 | ... | Parent N | -
+---------------+ +---------------+
|||
(protocol |||
out of ||| +-------------+---------+
the scope)|||------| Power Monitor Child 1 |
|| +-----------------------+
||
|| +-------------+---------+
||-------| Power Monitor Child 2 |
| +-----------------------+
|
|
|-------- ...
|
|
| +-------------+---------+
|--------| Power Monitor Child M |
+-----------------------+

Figure 1: Energy Management Pull Reference Model

In this architecture a Network Management Station (NMS) will
poll MIB variables on a Power Monitors via SNMP. The Power
Monitor returns information for itself and for any Power Monitor
Children if applicable. The information returned will contain
business context, energy usage, power quality and other
information as described further.

The protocol between the Power Monitor Parent and Power Monitor
Children is out of scope of this document. The Power Monitor
Parent may speak to a Power Monitor Child using a manufacturer
selected protocol. This protocol may or may not based on IP.
In this way, a Power Monitor Parent acts as a PROXY for protocol
translation between the Power Monitor Parent and Child. The
Power Monitor Parent also acts as an aggregation point for other
subtended Power Monitor Children.

+---------------+
| NMS/Collector | ^ S
+-----+---+-----+ | N
| | | M I
| | | P P
+---------+ +-------+ | & F
| | | N I
| | | O X
+---------------+ +------+-------+ | T
| Power Monitor | | Power Monitor | | .
| Parent 1 | ... | Parent N | -
+---------------+ +---------------+
|||
(protocol |||
out of ||| +-------------+---------+
the scope)|||------| Power Monitor Child 1 |
|| +-----------------------+
||
|| +-------------+---------+
||-------| Power Monitor Child 2 |
| +-----------------------+
|
|
|-------- ...
|
|
| +-------------+---------+
|--------| Power Monitor Child M |
+-----------------------+

Figure 2: Energy Management PUSH Reference Model

The Power Monitor Parents may send SNMP notifications regarding
their own state or the state of their Power Monitor Children.
The Power Monitor Children do not send SNMP notifications on
their own.

As discussed in [POWER-MON-REQ], the Power Monitor Parents may
export IPFIX Flow Records [RFC5101] to a Collector. The IPFIX
protocol is well suited for regular time series export of
similar information, such as the energy consumed by the Power
Monitor Children.

EDITOR'S NOTE: at this point in time, there is no draft
specifying the IPFIX Flow Records.

5. Architecture High Level Concepts and Scope

The scope of this architecture is to enable networking and
network attached
network-attached devices to be managed with respect to their
energy consumption or production. The goal is to make devices
energy aware.
energy-aware.

The architecture describes how to make a device aware of its
consumption or production of energy expressed as usage in watts.
This does not include:

- Manufacturing costs in currency or environmental units
- Embedded carbon or environmental equivalences of the device
itself
- Cost in currency or environmental impact to dismantle or
recycle the device
- Relationship to an electrical or smart grid
- Supply chain analysis
- Conversion of the usage or production of energy to units
expressed from the source of that energy - for example (such as the greenhouse
gas emissions associated with 1000kW from a diesel
source.

This source).

The remainder of this section will go over describes the basic concepts of
the architecture. Each concept is then listed with notable
descriptions examined in detail in
subsequent sections.

Examples will be are provided in a later section to show how these
concepts can be fulfilled in an implementation.

Given a Power Monitor, we can describe the information about the
Power Monitor through various data. A implemented.

The basic concepts are:

The Power Monitor will have basic naming and informational
descriptors to identify it in the network.

A Power Monitor can be part of a Power Monitor Meter Domain. A
Power Monitor Meter Domain is a manageable set of devices that
has a meter or sub-meter attached and typically corresponds to a
power distribution point or panel.

A Power Monitor can be a parent (Power Monitor Parent) or child
(Power Monitor Child) of another Power Monitor. This allows for
devices
Power Monitor Parent to aggregate power reporting and/or and control of
power information.

Each Power Monitor can have information to allow it to be
described in the context of the business or ultimate use. This
is in addition to its networked information. This allows for
tagging, grouping grouping, and differentiation between Power Monitors
for NMS.

For control and universal monitoring monitoring, each Power Monitor will
implement
implements or declare declares a set of known Power Levels. The Power
Levels can be are mapped to Manufacturer Power Levels that indicate the
specific power setting settings for the device implementing the Power
Monitor, in case that Power Monitor doesn't implement yet
Monitor.

When the
standard Power Levels [POWER-MON-MIB].

The desired Power Level variable is set, when setting the Power
Level. If the a Power Monitor is may be busy at the
request time, it
might time. The Power Monitor will set the desired level and
then update the actual Power Level when his the priority task is
finished. This mechanism implies two different Power Level
variables: actual versus desired.

EDITOR'S NOTE: the The transition state will have to be specified.

Each Power Monitor will have usage information that describes
the power information along with how that usage was obtained or
derived.

Optionally

Optionally, a Power Monitor can further describe the power
information with power quality information reflecting the
electrical characteristics of the measurement.

Optionally

Optionally, a Power Monitor can provide power usage over time to
describe energy consumption

If a Power Monitor has one or more batteries, it can provide
optional Battery battery information as well.

4.1.

5.1. Power Monitor Information

Every Power Monitor SHOULD should have a unique printable name, and
MUST
must have a unique Power Monitor index.

Possible naming conventions are: textual DNS name, MAC-address
of the device, interface ifName, or a text string uniquely
identifying the Power Monitor. As an example, in the case of IP
phones, the Power Monitor name can be the device DNS name.

4.2.

5.2. Power Monitor Meter Domain

Each Power Monitor MUST must be a member of a Power Monitor Meter
Domain. The Power Monitor Meter Domain SHOULD should map 1-1 with a
metered or sub-metered portion of the site. The Power Monitor
Meter Domain MUST must be configured on the Power Monitor Parent.
The Power Monitor Children MAY may inherit its their domain value values from
the Power Monitor Parent or the Power Monitor Meter Domain MAY may
be configured directly in a Power Monitor Child.

4.3.

5.3. Power Monitor Parent and Child

A Power Monitor can be connected Child reports its power usage to another its Power
Monitor Parent. A Power Monitor Child has one and
either draw power from that entity or report only one
Power Monitor Parent. If a Power Monitor had two parents there
would be a risk of double-reporting the power usage to that
entity. in the Power
Monitor Meter Domain. Therefore, a Power Monitor cannot be both
a Power Monitor Parent and a Power Monitor Child at the same
time.

A Power Monitor Child can be fully dependent on the Power
Monitor Parent (as in the case of Power Over Ethernet) for its power or independent from the parent
(such as a PC connected to a switch). In the dependent dependently
powered case, the Power Monitor Parent provides power for the
Power Monitor Child (the PoE case). (as in the case of Power Over Ethernet
devices). In the independent independently powered case, the Power Monitor
Child draws power from another source (typically a wall outlet).
Since the Power Monitor Parent is not the source of power
supply, the power usage cannot be measured at the Power Monitor
Parent. However, an independent Power Monitor Child may report reports
Power Monitor information to the Power Monitor Parent. The
Power Monitor Child may listen to the power control settings
from a Power Monitor Parent and could react to the control
messages. Note However, note that the communication between the
Power Monitor Parent and Power Monitor Child is out of scope of for
this document.

A Power Monitor cannot be at the same time a Power Monitor
Parent and a Power Monitor Child. Indeed such configuration
would lead to double counting the energy consumed within a
specific Power Monitor Domain.

A mechanism, outside of the scope of this document, should be in
place to verify the connectivity between the Power Monitor
Parent and its Power Monitor Children. If the a Power Monitor Child
is unavailable, the Power Monitor Parent must follow some rules
to determine how long it should wait before removing the Power
Monitor Child entry, along with all associated statistics, from his
its database. In some situations, such as a connected
building, building
in which the Power Monitor Children are pretty somewhat static, this removal timer might
removal-delay period may be pretty long. The long, and persistence across a Power
Monitor Parent reload could even may make sense. However, in a networking
environment, where endpoints could can come and go, there is not much
sense to configure in configuring a long removal timer. In all cases, the
removal timer or persistence must be clearly specified.

Further examples of Power Monitor Parent and Child
implementations are provided in the Implementation Scenarios
section.

4.4.
section 11.

5.4. Power Monitor Context

Monitored power data will ultimately be collected to by and
reported from a an NMS. In order to aid in the reporting and in
differentiation between Power Monitors, each Power Monitor will
contain information to establish a establishing its business or site context.
A Power Monitor can provide an importance value in the range of
1..100
1 to 100 to help differentiate the a device's use or relative value
to the site. The importance range is from 1 (least important)
to 100 (most important). The default importance value is 1.

For example, a example: A typical office environment has several types of
phones, which can be rated according to the their business impact: a impact.
A public desk phone has a lower importance (for example, 10)
than a business-critical emergency phone (for example, 100). As
another example, a example: A company can consider that a PC and a phone
for a customer-service engineer is more important than a PC and
a phone for lobby use.

Although network managers must establish their own ranking ranking, the
following is a broad recommendation:

. 90 to 100 Emergency response
. 80 to 90 Executive or business critical business-critical
. 70 to 79 General or Average
. 60 to 69 Staff or support
. 40 to 59 Public or guest
. 1 to 39 Decorative or hospitality

A Power Monitor can provide a set of keywords. These keywords
are a list of tags that can be used for grouping and summary
reporting within or between Power Monitor Meter Domains. All
alphanumeric characters and symbols symbols, such as #, (, $, !, and & &,
are allowed. Potential examples are: IT, lobby, HumanResources,
Accounting, StoreRoom, CustomerSpace, router, phone, floor2, or
SoftwareLab. There is no default value for the a keyword.

Multiple keywords can be assigned to a device. In such cases,
the keywords are separated by commas and no spaces between
keywords are allowed. For example, "HR,Bldg1,Private".

Additionally, a Power Monitor can provide a "role description"
string that indicates the purpose the Power Monitor serves in
the network or to for the site/business. This could be a string
describing the context the device fulfils fulfills in deployment. For
example, a lighting fixture in a kitchen area could have a role
of "Hospitality Lighting" to provide context for the use of the
device.

4.5.

5.5. Power Monitor Levels

Power Levels represent universal states of power management of a
Power Monitor. Each Power Level corresponds to a global,
system, and performance state in the ACPI model. model [ACPI].

Level ACPI Global/System Name Power Level
State Name

Non-operational states:

1 G3, S5 Mech Off
2 G2, S5 Soft Off
3 G1, S4 Hibernate
4 G1, S3 Sleep
5 G1, S2 Standby
6 G1, S1 Ready

Operational states:
7 G0, S0, P5 LowMinus
8 G0, S0, P4 Low
9 G0, S0, P3 MediumMinus
10 G0, S0, P2 Medium
11 G0, S0, P1 HighMinus
12 G0, S0, P0 High

Figure 3: ACPI / Power Level Mapping

For example, a Power Monitor with a Power Level of 9 would
indicate an operational state with MediumMinus Power Level.

The Power Levels can be considered as guidelines for an
interface in order to
promote interoperability across device types. Realistically, it is foreseen that
each specific feature requiring Power Levels will require a
complete recommendation of its own. For example, designing IP
phones with consistent Power Levels across vendors requires a
specification for IP phone design, along with the Power Levels
mapping.

In some situation,

Manufacturer Power Levels are required, for
example, required in some situations, such
as when no mappings with the existing Power Levels are
possible possible,
or when more levels than the twelve specified Power Levels are
required.

A first example would be an imaginary device type, with only
five levels: "none", "short", "tall", "grande", and "venti".

Manufacturer Power Level Respective Name
0 none
1 short
2 tall
3 grande
4 venti

Figure 4: Mapping Example 1

In the unlikely event of that there is no possible mapping between
these Manufacturer Power Levels and the proposed Power Monitor
Power Levels, the Power Level will remain 0 throughout the MIB
module, as displayed below.

Power Level / Name Manufacturer Power Level / Name
0 / unknown 0 / none
0 / unknown 1 / short
0 / unknown 2 / tall
0 / unknown 3 / grande
0 / unknown 4 / venti

Figure 5: Mapping Example 2

If a mapping between the Manufacturer Power Levels and the Power
Monitor Power Levels is achievable, both series of levels must
exist in the MIB
module, module in the Power Monitor Parent, allowing
the NMS to understand the mapping between them by correlating
the Power Level with the Manufacturer Power Levels.

Power Level / Name Manufacturer Power Level / Name
1 / Mech Off 0 / none
2 / Soft Off 0 / none
3 / Hibernate 0 / none
4 / Sleep, Save-to-RAM 0 / none
5 / Standby 0 / none
6 / Ready 1 / short
7 / LowMinus 1 / short
8 / Low 1 / short
9 / MediumMinus 2 / tall
10 / Medium 2 / tall
11 / HighMinus 3 / grande
12 / High 4 / venti

Figure 6: Mapping Example 3

How the Power Monitor Levels are then mapped, i.e. assigning the
directly lower or directly higher level, mapped is an
implementation choice. However, its it is recommended that the
Manufacturer Power Levels l maps map to the directly lower lowest applicable Power Level,
Levels, so that setting all Power Meters Monitors to a Power Level
would be conservative in terms of disabled functionality on the
Power Monitor implementing the
Manufacturer Power Levels. Monitor.

A second example would be a device type, such as a dimmer or a
motor, with a high number of operational levels. For the sake
of the example, 100 operational states are assumed.

Power Level / Name Manufacturer Power Level / Name
1 / Mech Off 0 / off
2 / Soft Off 0 / off
3 / Hibernate 0 / off
4 / Sleep, Save-to-RAM 0 / off
5 / Standby 0 1 / off
6 / Ready 0 2 / off
7 / LowMinus 1 11 / 1%
7 / LowMinus 2 12 / 2%
7 / LowMinus 3 13 / 3%
. .
. .
. .
8 / Low 15 / 15%
8 / Low 16 / 16%
8 / Low 17 / 17%
. .
. .
. .
9 / MediumMinus 30 / 30%
9 / MediumMinus 31 / 31%
9 / MediumMinus 32 / 32%
. .
. .
. .
10 / Medium 45 / 45%
10 / Medium 46 / 46%
10 / Medium 47 / 47%
. .
. .
. .
etc...

4.6.

Figure 7: Mapping Example 4

As specified in section 6, this architecture allows the
configuration of the Power Level, while configuring the
Manufacturer Power Level from the MIB directly is not possible.

5.6. Power Monitor Usage Measurement

For a Power Monitor, RMS (Root Mean Square)

The usage or production or RMS equivalent
(for example, after conversion to DC power) power usage must be
reported, including qualified as more than
a value alone. A measurement should be qualified with the magnitude
units, magnitude, direction of measurement, power flow, and by what means the
measurement was made (ex: Root Mean Square versus Nameplate) .

In addition, the Power Monitor should describe how it intends to
measure usage as multiple
scaling factors one of consumer, producer or meter of usage.
Given the intent any readings can be correctly summarized or
analyzed by an NMS. For example metered usage reported by a
meter and consumption usage reported by a device connected to
that meter may naturally measure the same usage. With the two
measurements identified by intent a proper summarization can be used.
made by an NMS.

The power usage measurement should conform to the IEC 61850
definition of unit multiplier for the SI (System International)
units of measure. The power usage measurement is considered an
instantaneous usage value and does not include the usage over
time.

Measured values are represented in SI units obtained by
BaseValue * 10 raised to the power of the scale. For example,
if current power usage of a Power Monitor is 3, it could be 3 W,
3 mW, 3 KW, or 3 MW MW, depending on the value of the scaling
factor (called
pmPowerUnitMultiplier in the MIB module).

In addition to knowing the usage and magnitude magnitude, it is useful to
know how a Power Monitor usage measurement was obtained:
. whether Whether the measurements were made at the device itself or
from a remote source source.
. Description of the method that was used to measure the
power and whether this method can distinguish actual or
estimated values.

An NMS can use this information to account for the accuracy and
nature of the reading between different implementations.

In addition to the power usage usage, the nameplate power rating of a
Power Monitor is typically specified by the vendor as the
capacity required to power the device. Often this label is a
conservative number and is the worst-case power draw. While the
actual utilization of an entity can be lower, the nameplate
power is important for provisioning, capacity planning and
billing.

4.7.

5.7. Optional Power Usage Quality

Given a power measurement of a Power Monitor, it may in certain
circumstances be desirable to know the power quality associated
with that measurement. The information model must adhere to the
IEC 61850 7-2 standard to describe for describing AC measurements. In some
Power Monitor Domains, the power quality may not be needed,
available, nor or relevant to the Power Monitor.

4.8.

5.8. Optional Energy Measurement

In addition to reporting the Power Level, an approach to
characterize
characterizing the energy demand is required. It is well known
in commercial electrical utility rates, rates that demand charges can
be on par with actual power charges. So, charges, so it is useful to
characterize the demand. The demand can be described as the
average energy of an Power Monitor over a time window, window called a
demand interval, typically interval (typically 15 minutes. minutes). The highest peak energy
demand measured over a time horizon, say such as 1 month or 1 year year,
is often the basis for usage charges. A single window of time
of high usage can penalize the consumer with higher energy
consumption charges. However, it is relevant to measure the
demand only when there are actual power measurements from a
Power Monitor, and not when the power measurement is assumed or
predicted.

Several efficiency metrics can be derived and tracked with the
demand usage data.

. For example, per-packet example:

. Per-packet power costs for a networking device (router or
switch) can be calculated by an network
management system. NMS. The packets packet count can
be determined from the traffic usage in the ifTable [RFC2863]
[RFC2863], from the forwarding plane figure, or from the
platform specifications.

. Watt-hour power can be combined with utility energy sources
to estimate carbon footprint and other emission statistics.

4.9.

5.9. Optional Battery Information

Some Power Monitors might may be running on batteries. Therefore
information such as the battery status (charging or
discharging), remaining capacity, etc... and so on, must be available.

6. Power Monitor Children Discovery

There are multiple ways that the Power Monitor Parent can
discover its Power Monitor Children, if they are not present on
the same physical network element. element:

. In case of PoE, the Power Monitor Parent automatically
discovers that a Power Monitor Child when the Child requests some
power.
. The Power Monitor Parent and Children may run the Link
Layer Discovery Protocol [LLDP], or any proprietary similar
protocols other discovery
protocol, such as Cisco Discovery Protocol (CDP). The
Power Monitor Parent might even support the LLDP-MED MIB
[LLDP-MED-MIB], which returns some extra information on the
Power Monitor Children.
. The Power Monitor Parent might may reside on a network connected
facilities gateway. A typical example is a converged
building gateway, monitoring several other devices in the
building, doing the and serving as a proxy between SNMP and a
protocol such as BACNET.

When a Power Monitor Child doesn't support the Power Levels, but supports only its own Manufacturer
Power Levels, the Power Monitor Parent will have to discover
those Manufacturer Power Levels. Note that the communication
specifications between the Power Monitor Parent and Children is
out of the scope of this document. This includes the
Manufacturer Power Levels discovery, which is protocol-specific.

7. Configuration

This power management architecture allows the configuration of a
couple of
the following key parameters:

. Power Monitor name: an A unique printable name for the Power
Monitor.
. Power Monitor Role: an An administratively assigned name to
indicate the purpose a Power Monitor serves in the network.
. Power Monitor Importance: a A ranking of how important the
Power Monitor is is, on a scale of 1 to 100 100, compared to with
other Power Monitors in the same Power Monitor Meter
Domain.
. Power Monitor Keywords: a A list of keywords that can be used
to group Power Monitors for reporting or searching.
. Power Monitor Domain: specifies Specifies the name of a Power Monitor
Meter Domain for the Power Monitor.
. The Power Monitor Level: specifies Specifies the current Power Level
(0..12) for the Power Monitor.
. Manufacturer Power Level and name
. The energy demand parameters: for For example, which interval
length to report the energy on, the number of interval intervals to
keep, etc... etc.

When a Power Monitor requires a mapping with the Manufacturer
Power Level, the Power Monitor configuration is done via the
Power Level settings, and not directly via the Manufacturer
Power Levels, which are read-only. Taking into account Figure
8, where the LowMinus Power Level corresponds to three different
Manufacturer Power Levels (11 for 1%, 12 for 2%, and 13 for 3%),
the implication is that this architecture will not set the
Manufacturer Power Level to one percent granularity without
communicating over or configuring the proprietary protocol for
this Power Monitor.

This architecture uses a Power Level MIB object to set up the
Power Level for a specific Power Monitor. However, the Power
Monitor might be busy executing an important task that requires
the current Power Level for some more time. For example, a PC
might have to finish a backup first, or an IP phone might be
busy with a current phone call. Therefore a second MIB object
contains the actual Power Level. A difference in values between
the two objects indicates that the Power Monitor is currently in
Power Level transition.

Interactions with established open protocols protocols, such as Wake-up-on-
Lan Wake-up-
on-Lan (WoL) and DASH [DASH] [DASH], may require configuration in the
Power Monitor as well, facilitating the communication between
Power Monitor Parent and remote Power Monitor Children.

Note that the communication specifications between the Power
Monitor Parent and Children is out of the scope of this
document. This includes the communication of the power settings and
configuration information information, such as the Power Monitor Domain.

8. Fault Management

[POWER-MON-REQ] specifies some requirements about power states
such as "the current state - the time of the last change", "the
total time spent in each state", "the number of transitions to
each state", etc... etc. Such requirements are fulfilled via the
pmPowerLevelChange NOTIFICATION-TYPE [POWER-MON-MIB]. This SNMP
notification is generated when the value(s) of Power Level has
changed for the Power Monitor.

9. IPFIX

A push based mechanism push-based mechanism, such as IPFIX [RFC5101], might be
required to export
high volume high-volume time series of energy consumption
values, as mentioned in [POWER-MON-REQ].

EDITOR'S NOTE: the Working Group should decide how much of IPFIX
should be described in this document

10. Relationship with Other Standard Standards Development Organizations

8.1.

10.1. Information Modeling

This power management architecture should reuse should, as much as
possible possible,
reuse existing standard efforts and not re-invent something
new, specifically in terms of standards efforts, especially with respect to
information modeling and data modeling [RFC3444].

The data model for power, energy related objects is based on the IEC
61850.

Specific examples include:

. The scaling factor, which represent the magnitude of represents Power Monitor usage, usage
magnitude, conforms to the IEC 61850 definition of unit
multiplier for the SI (System International) units of
measure.

. The power accuracy model is based on the ANSI and IEC
Standards, which require that we use an accuracy class for
power measurement. ANSI and IEC define the following
accuracy classes for power measurement:

. IEC 62053-22 60044-1 class 0.1, 0.2, 0.5, 1 3.

. ANSI C12.20 class 0.2, 0.5

. The powerQualityMIB MIB module adheres closely to the IEC
61850 7-2 standard to describe for describing AC measurements.

8.2.

10.2. Power Levels

There are twelve Power Monitor Levels; divided Levels. They are subdivided into
six operational states, and six non-operational states. The
lowest non-operational state is 1 and the highest is six. Each non-
operational
non-operational state corresponds to an ACPI level [ACPI].

11. Implementation Scenarios

The scope of power and energy monitoring consists of devices
that consume power within and that are connected to a
communications network. These devices include:

- Network devices and sub-components: devices Devices such as routers
and switches and their sub-components.

- Network attached endpoints: devices Devices that use the
communications network network, such as endpoints, PCs, or and facility
gateways that proxy energy monitor and control for commercial
buildings or home automation, automation.

- Network attached meters or supplies: devices Devices that can monitor
the electrical supply supply, such as smart meters or Universal
Power Supplies (UPS) that meter and provide availability.
-
This section provides illustrative examples that model different
scenarios for implementation of the Power Monitor Monitor, including
Power Monitor Parent and Power Monitor Child relationships.

Each of the scenarios below is explained in more details detail in the
Power Monitor MIB document [POWER-MON-MIB], with a mapping to
the MIB Objects.

Scenario 1: Switch with PoE endpoints

Consider a PoE IP phone connected to a switch, as displayed on
figure 1. switch. The IP phone
draws power from the PoE switch.

Scenario 2: Switch with PoE endpoints with further connected
device(s)

Consider the same scenario as example 1 with an IP phone
connected to PoE port of a switch. Now, as in addition, Scenario 1, but with a PC is
also daisy-chained daisy-
chained from the IP phone for LAN connectivity. The phone draws
power from the PoE port of the switch, while the PC draws power
from the wall outlet.

Scenario 3: A switch with Wireless Access Points

Consider a Wireless WAP (Wireless Access Point Point) connected to the PoE port
of a switch. There are several PCs connected to the Wireless
Access Point over Wireless protocols. All PCs draw power from
the wall outlets.

The switch port is the Power Monitor Parent for the Wireless
Access Point (WAP) and all the PCs. There But there is a distinction, between distinction
among the Power Monitor Children, as the WAP draws power from
the PoE port of the switch and the PCs draw power from the wall
outlet.

Scenario 4: Network connected facilities gateway

At the top of the network hierarchy of a building network is a
gateway device that can perform protocol conversion between many
facility management devices, such as BACNET, MODBUS, DALI, LON,
etc. There are power meters associated with power consuming power-consuming
entities (Heating Ventilation & Air Conditioning - HVAC,
lighting, electrical, fire control, elevators, etc). The
proposed MIB can be implemented on the gateway device. The
gateway can be considered as the Power Monitor Parent, while the
power meters associated with the energy consuming entities such can
be considered as its Power Monitor Children.

Scenario 5: Data Center Network center network

A typical data center network consists of a hierarchy of
switches. At the bottom of the hierarchy there are servers
mounted on a rack, and those these are connected to the top of the top-of-the-
rack switches. The top switches are connected to aggregation
switches that are in turn connected to core switches. As an
example, Server 1 and Server 2 are connected to different switch
ports of the top switch.

The proposed MIB can be implemented on the switches. The switch
can be considered as the Power Monitor Parent. The servers can
be considered as the Power Monitor Children.

Scenario 6: Building Gateway Device gateway device

Similar scenario as the scenario 4.

Scenario 7: Power Consumption consumption of UPS

Data centers and commercial buildings can have Uninterruptible
Power Supplies (UPS) connected to the network. The Power Monitor
can be used to model a UPS as a Power Monitor Parent with the
connected devices as Power Monitor Children.

Scenario 8: Power Consumption consumption of Battery-based Devices battery-based devices

A PC is a typical example of a battery-based device.

10.

12. Security Considerations

TO DO

11.

Regarding the data attributes specified here, some or all may be
considered sensitive or vulnerable in some network environments.
Reading or writing these attributes without proper protection
such as encryption or access authorization may have negative
effects on the network capabilities.

12.1. Security Considerations for SNMP

Readable objects in a MIB modules (i.e., objects with a MAX-
ACCESS other than not-accessible) may be considered sensitive or
vulnerable in some network environments. It is thus important
to control GET and/or NOTIFY access to these objects and
possibly to encrypt the values of these objects when sending
them over the network via SNMP.

The support for SET operations in a non-secure environment
without proper protection can have a negative effect on network
operations. For example:

. Unauthorized changes to the Power Domain or business
context of a Power Monitor may result in misreporting or
interruption of power.
. Unauthorized changes to a power level may disrupt the power
settings of the different Power Monitors, and therefore the
level of functionality of the respective Power Monitors.
. Unauthorized changes to the demand history may disrupt
proper accounting of energy usage.

With respect to data transport SNMP versions prior to SNMPv3 did
not include adequate security. Even if the network itself is
secure (for example, by using IPsec), there is still no secure
control over who on the secure network is allowed to access and
GET/SET (read/change/create/delete) the objects in these MIB
modules.

It is recommended that implementers consider the security
features as provided by the SNMPv3 framework (see [RFC3410],
section 8), including full support for the SNMPv3 cryptographic
mechanisms (for authentication and privacy).

Further, deployment of SNMP versions prior to SNMPv3 is not
recommended. Instead, it is recommended to deploy SNMPv3 and to
enable cryptographic security. It is then a customer/operator
responsibility to ensure that the SNMP entity giving access to
an instance of these MIB modules is properly configured to give
access to the objects only to those principals (users) that have
legitimate rights to GET or SET (change/create/delete) them.

12.2. Security Considerations for IPFIX

EDITOR'S NOTE: to be completed if IPFIX is discussed in this
document

13. IANA Considerations

This document has no actions for IANA.

12.

14. Acknowledgments

The authors would like to Michael Brown for improving the text
dramatically.

15. References

Normative References

[RFC2119] S. Bradner, Key words

[RFC3410] Case, J., Mundy, R., Partain, D., and B. Stewart,
"Introduction and Applicability Statements for use in RFCs to Indicate
Requirement Levels, BCP 14, Internet
Standard Management Framework ", RFC 3410, December
2002.

[RFC5101] B. Claise, Ed., Specification of the IP Flow
Information Export (IPFIX) Protocol for the Exchange of
IP Traffic Flow Information, RFC 2119, March 1997. 5101, January 2008.

[POWER-MON-REQ] Quittek, J., Winter, R., Dietz, T., Claise, B.,
and M. Chandramouli, "Requirements for Power
Monitoring", draft-quittek-power-monitoring-
requirements-01 (work in progress), July 2010.

[POWER-MON-MIB] Claise, B., Chandramouli, M., Parello, J., and
Schoening, B., "Power and Energy Monitoring MIB",
draft-claise-energy-monitoring-mib-04,
draft-claise-energy-monitoring-mib-06, (work in
progress), Sept October 2010.

Informative References

[RFC2863] McCloghrie, K., Kastenholz, F., "The Interfaces Group
MIB", RFC 2863, June 2000.

[RFC3444] Pras, A., Schoenwaelder, J. "On the Differences
between Information Models and Data Models", RFC 3444,
January 2003.

[ACPI] "Advanced Configuration and Power Interface
Specification", http://www.acpi.info/spec30b.htm

[LLDP] IEEE Std 802.1AB, "Station and Media Control
Connectivity Discovery", 2005.

[LLDP-MED-MIB] ANSI/TIA-1057, "The LLDP Management Information
Base extension module for TIA-TR41.4 media endpoint
discovery information", July 2005.

[DASH] "Desktop and mobile Architecture for System Hardware",
http://www.dmtf.org/standards/mgmt/dash/

13.

Authors' Addresses

Benoit Claise
Cisco Systems Systems, Inc.
De Kleetlaan 6a b1
Diegem 1813
BE

Phone: +32 2 704 5622
Email: bclaise@cisco.com

John Parello
Cisco Systems Systems, Inc.
3550 Cisco Way
San Jose, California 95134
US
Phone: +1 408 525 2339
Email: jparello@cisco.com

Brad Schoening
Cisco Systems Systems, Inc.
3550 Cisco Way
San Jose, California 95134
US

Phone: +1 408 525 2339
Email: braschoe@cisco.com