Requirements for Energy Management
draft-ietf-eman-requirements-05
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 6988.
|
|
|---|---|---|---|
| Authors | Juergen Quittek , Rolf Winter , Thomas Dietz , Benoît Claise , Mouli Chandramouli | ||
| Last updated | 2011-11-01 (Latest revision 2011-07-11) | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
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| Stream | WG state | WG Document | |
| Document shepherd | Dan Romascanu | ||
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draft-ietf-eman-requirements-05
Network Working Group J. Quittek, Ed.
Internet-Draft R. Winter
Intended status: Informational T. Dietz
Expires: May 4, 2012 NEC Europe Ltd.
B. Claise
M. Chandramouli
Cisco Systems, Inc.
November 1, 2011
Requirements for Energy Management
draft-ietf-eman-requirements-05
Abstract
This document defines requirements for standards specifications for
energy management. The requirements presented in this document
include monitoring functions as well as control functions. In
detail, the focus of the requirements is on the following features:
identification of powered entities, monitoring of their power state,
power inlets, power outlets, actual power, power quality, consumed
energy, and contained batteries. Further, requirements are included
to enable control of powered entities' power supply and power state.
This document does not specify the features that must be implemented
by compliant implementations but rather features that must be
supported by standards for energy management.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 4, 2012.
Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
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include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1. Conventional requirements for energy management . . . . . 6
1.2. Specific requirements for energy management . . . . . . . 6
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 7
3. General Considerations Related to Energy Management . . . . . 7
3.1. Power states . . . . . . . . . . . . . . . . . . . . . . . 7
3.2. Saving energy versus maintaining service level
agreements . . . . . . . . . . . . . . . . . . . . . . . . 8
3.3. Local versus network-wide energy management . . . . . . . 8
3.4. Energy monitoring versus energy saving . . . . . . . . . . 9
3.5. Overview of energy management requirements . . . . . . . . 9
4. Identification of Powered Entities . . . . . . . . . . . . . . 10
5. Information on Powered Entities . . . . . . . . . . . . . . . 11
5.1. General information on powered entities . . . . . . . . . 11
5.2. Power state . . . . . . . . . . . . . . . . . . . . . . . 12
5.3. Power inlet and power outlet . . . . . . . . . . . . . . . 14
5.4. Power . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.5. Energy . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.6. Battery state . . . . . . . . . . . . . . . . . . . . . . 20
5.7. Notifications . . . . . . . . . . . . . . . . . . . . . . 21
6. Control of Powered Entities . . . . . . . . . . . . . . . . . 22
7. Reporting on Other Powered Entities . . . . . . . . . . . . . 22
8. Controlling Other Powered Entities . . . . . . . . . . . . . . 24
8.1. Controlling power states of other powered entities . . . . 24
8.2. Controlling power supply of other powered entities . . . . 25
9. Security Considerations . . . . . . . . . . . . . . . . . . . 26
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 26
12. Open issues . . . . . . . . . . . . . . . . . . . . . . . . . 27
12.1. Improve references . . . . . . . . . . . . . . . . . . . . 27
12.2. Do we need entity types? . . . . . . . . . . . . . . . . . 27
13. Informative References . . . . . . . . . . . . . . . . . . . . 27
Appendix A. Existing Standards . . . . . . . . . . . . . . . . . 29
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A.1. Existing IETF Standards . . . . . . . . . . . . . . . . . 29
A.1.1. ENTITY MIB . . . . . . . . . . . . . . . . . . . . . . 29
A.1.2. ENTITY STATE MIB . . . . . . . . . . . . . . . . . . . 30
A.1.3. ENTITY SENSOR MIB . . . . . . . . . . . . . . . . . . 31
A.1.4. UPS MIB . . . . . . . . . . . . . . . . . . . . . . . 31
A.1.5. POWER ETHERNET MIB . . . . . . . . . . . . . . . . . . 31
A.1.6. LLDP MED MIB . . . . . . . . . . . . . . . . . . . . . 32
A.2. Existing standards of other bodies . . . . . . . . . . . . 32
A.2.1. DMTF . . . . . . . . . . . . . . . . . . . . . . . . . 32
A.2.2. OVDA . . . . . . . . . . . . . . . . . . . . . . . . . 32
A.2.3. IEEE-ISTO Printer WG . . . . . . . . . . . . . . . . . 32
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 33
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1. Introduction
With rising energy cost and with an increasing awareness of the
ecological impact of running IT and networking equipment, energy
management is becoming an additional basic requirement for the
network devices and the associated network management systems.
This document defines requirements for standards specifications for
energy management. This doccument contains the requirements that
concern monitoring functions as well as control functions. In
detail, the requirements listed are focussed on the following
features: identification of powered entities, monitoring of their
power state, power inlets, power outlets, actual power, power
quality, consumed energy, and contained batteries. Further included
is control of powered entities' power supply and power state.
The main subject of energy management are powered entities that
consume electric energy. Powered entities include devices that have
an IP address and can be addressed directly, such as hosts, routers,
and middleboxes, as well as devices indirectly connected to an IP
network, for which a proxy with an IP address provides a management
interface, for example, devices in a building management
infrastructure using the BACnet [ANSI/ASHRAE-135-2010] or MODBUS
[MODBUS-Protocol] protocols.
The requirements specified in this document explicitly concern the
standards specification process and not the implementation of
specified standards. All requirements in this document must be
reflected by standards specifications to be developed. But which of
the features specified by these standards will be mandatory,
recommended, or optional for compliant implementations is to be
defined by the concrete standards track document(s) and not in this
document.
This document first elaborates a set of general considerations
related to energy management in Section 3. Requirements for an
energy management standard are specified in Sections 4 to 8.
Sections 4 to 6 contain rather conventional requirements specifying
which information on powered entities needs to be covered by an
energy management standard, and which control functions are needed.
Sections 7 and 8 contain requirements that are very specific to
energy management. They result from the fact that due to the nature
of power supply, some of the monitoring and control functions are not
conducted by interacting with the powered entity of interest, but
with other entities, for example, with entities upstream in the power
distribution tree.
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1.1. Conventional requirements for energy management
The specification of requirements for an energy management standard
starts with Section 4 addressing the identification of powered
entities and the granularity of reporting of energy-related
information. A standard must support unique identification of
powered entities. Furthermore, it must support more than just
reporting per powered device. Support is required for also reporting
energy-related information on individual components of a device or
subtended devices. This is why this draft uses the more general term
"powered entity" rather than "powered device". A powered entity may
be a device or a component of a device.
Section 5 specifies requirements related to monitoring of powered
entities. This includes general (type, context) information and
specific information on power states, power inlets, power outlets,
power, energy, and batteries. Control power state and power supply
of powered entities is covered by requirements specified in
Section 6.
1.2. Specific requirements for energy management
At first glance the rather conventional requirements summarized above
seem to be all that would be needed for energy management. But it
turns out that there are some significant differences between energy
management and most of the well known conventional network management
functions. The most significant difference from many other
management functions is the need for some devices to report on other
entities. There are three major reasons for this.
o For monitoring a particular powered entity in general it is not
sufficient to communicate with the powered entity only,
particularly if the powered entity has no instrumentation for
measuring power. In such cases it might still be possible to
obtain power values for the entity by communication with other
entities in the same power distribution tree.
A very simple example would be retrieving power values from a
dedicated power meter at the power line of the powered entity.
More common examples are a Power Distribution Unit (PDU) and a
Power over Ethernet (PoE) switch. Both supply power to other
entities at sockets or ports, respectively, and are often
instrumented to measure power per socket or port.
o Similar considerations apply to controlling power supply of a
powered entity which often needs direct or indirect communication
with another entity upstream in the power distribution tree.
Again, a PDU and a PoE switch are common examples, if they have
the capability to switch on or off power at their sockets or
ports, respectively.
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o Energy management often extends its scope beyond powered entities
with IP network interfaces, for example toward non-IP building
networks, that are accessed via an IP gateway. Requirements in
this document do not fully cover all these networks, but they
cover means for opening IP network management towards them.
o For monitoring of particular powered entities, it is sometimes not
a scalable approach to communicate directly with all the powered
entities directly from a central energy management system as the
number of powered entities keeps increasing.
This specific issue of energy management and a set of further ones
are covered by requirements specified in Sections 7 and 8.
For meeting the requirements specified in these sections first a new
energy management framework needs to be specified that gives
directions on how to deal with the specific nature of energy
management. Based on such a framework, energy management standards
can be specified that meet the requirements below. The actual
standards documents, such as, for example, MIB module specifications,
will address conformance issues by specifying which feature must,
should, or may to be implemented by compliant implementations.
2. Terminology
Terminology to be used by the eman WG is currently discussed in
[I-D.parello-eman-definitions]. After final definitions of terms
have been agreed, they will be listed here.
3. General Considerations Related to Energy Management
The basic objective of energy management is operating sets of devices
with minimal amount of energy, while maintaining a certain level of
service. A set of use cases and the target devices for the
application of energy management can be found in
[I-D.tychon-eman-applicability-statement].
3.1. Power states
One approach to achieve this goal is by setting all powered entities
to an operational state that results in lower energy consumption, but
still meets the service level performance objectives. The sufficient
performance level may vary over time and can depend on several
factors. In principle, there are four basic types of power states
for a powered entity or for a whole system:
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o full power state
o reduced power states (lower clock rate for processor, lower data
rate on a link, etc.)
o sleep state (not functional, but immediately available)
o off state (may imply requiring significant time for becoming
operational)
In actual implementations the number of power states and their
properties vary a lot. Very simple powered entities may just have
only the extreme states, full power and off state. Some
implementations might use the IEEE 1621 [IEEE-1621] model of three
states on, off, and sleep. However, more finely grained power states
can be implemented with many levels of off, sleep, and reduced power
states.
3.2. Saving energy versus maintaining service level agreements
While the general objective of energy management is quite clear, the
way to attain that goal is often difficult. In many cases there is
no way of reducing power consumption without the consequence of a
potential performance, service, or capacity degradation. Then a
trade-off needs to be dealt with between service level objectives and
energy efficiency. In other cases a reduction of energy consumption
can easily be achieved while still maintaining sufficient service
level performance, for example, by switching powered entities to
lower power states when higher performance is not needed.
3.3. Local versus network-wide energy management
Many energy saving functions can be executed locally by a powered
entity. The basic principle is that a powered entity monitors its
usage and dynamically adapts its energy consumption according to the
required performance. It may, for example, switch to a sleep state
when it is not in use or out of scheduled business hours. Potential
interactions with an energy management system for such an entity
include the observation of the entity's power state and the
configuration of power saving policies, for example, by setting
thresholds or schedules for power state changes.
Energy savings can also be achieved with policies implemented by a
network management system that controls power states of managed
entities. In order to make policy decisions properly, information
about the energy consumption of powered entities in different power
states is required. Often this information is acquired best through
monitoring.
Both methods, network-wide and local energy management, have
advantages and disadvantages and often it is a good choice to combine
them. Central management is often favorable for setting power states
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of a large number of entities at the same time, for example, at
beginning and end of business hours in a building. Local management
appears often to be preferable for dynamic power saving measures
based on local observations, such as high or low load of an entity.
3.4. Energy monitoring versus energy saving
It should be noted that only monitoring energy consumption and power
states is obviously not a means to reduce the energy consumption of a
powered entity. In fact, it is likely to increase the power
consumption of a powered entity slightly because monitoring energy
may require instrumentation that consumes energy when in use. And
also reporting of measured quantities over the network consumes
energy. However, the acquired energy consumption and power state
information is essential for defining energy saving policies and can
be used as input to power state control loops that in total can lead
to energy savings.
Monitoring operational power states and energy consumption can also
be required for other energy management purposes including but not
limited to:
o investigating power saving potential
o evaluating the effectiveness of energy saving policies and
measures
o deriving, implementing, and testing power management strategies
o accounting for the total power consumption of a powered entity, a
network, or a service
o predicting a powered entity's reliability based on power usage
o choosing time of next maintenance cycle for a powered entity
3.5. Overview of energy management requirements
From the considerations described above the following basic
management functions appear to be required for energy management:
o monitoring power states
o monitoring power (energy consumption rate)
o monitoring (accumulated) energy consumption
o monitoring power quality
o setting power states
o setting and enforcing power saving policies
It should be noted that power control is complementary (but
essential) to other energy savings measures such as low power
electronics, energy saving protocols (for example, Energy-Efficient
Ethernet [IEEE-802.3az]), energy-efficient device design (for
example, sleep and low-power modes for individual components of a
device), and energy-efficient network architectures. Measurement of
energy consumption may also provide useful input for developing these
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technologies.
4. Identification of Powered Entities
As already stated in Section 1.1, powered entities on which energy-
related information is provided, are identified in a sufficiently
unique way. This holds in particular for powered entities that are
components of managed devices and in case that one powered entity
reports information on another one, see Section 7. For powered
entities that control other powered entities it is important to
identify the powered entities they control, see Section 8.
Also stated already in Section 1.1 is the requirement of providing
means for reporting energy-related information on components of a
managed device. An entity in this document may be an entire managed
device or just a component of it. Examples of components of interest
are a hard drive, a battery, or a line card. For controlling
entities it may be required to be able to address individual
components in order to save energy. For example, server blades can
be switched off when the overall load is low or line cards at
switches may be powered down at night times.
Identifiers to other devices and to components of devices are already
defined in standard MIB modules, such as the LLDP MIB module
[IEEE-802.1AB] and the LLDP-MED MIB module [ANSI/TIA-1057] for
devices and the Entity MIB module [RFC4133] and the Power Ethernet
MIB [RFC3621] for components of devices. For energy management it is
necessary to have means for linking energy-related information to
such identifiers.
Instrumentation for measuring energy consumption of a device is
typically more expensive than instrumentation for retrieving the
devices power state. It may be a reasonable compromise in many cases
to provide power state information for all individually switchable
components of a device separately, while the energy consumption is
only measured for the entire device.
Detailed Requirements:
4.1. Identifying powered entities
The energy management standard must provide means for uniquely
identifying powered entities that are monitored or controlled by an
energy management system. Uniqueness must be preserved in a domain
that is large enough to avoid collisions of identities at potential
receivers of monitored information.
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4.2. Identifying components of powered devices
The energy management standard must provide means for identifying
individual sub-components of powered devices.
4.3. Persistency of identifiers
The energy management standard must provide means for indicating
whether identifiers of powered entities are persistent across a re-
start of the powered entity.
4.4. Using entity identifiers of other MIB modules
The energy management standard must provide means for re-using entity
identifiers from other standards including at least the following:
o the LldpPortNumber in the LLDP MIB module [IEEE-802.1AB]and in the
LLDP-MED MIB module [ANSI/TIA-1057]
o the entPhysicalIndex in the Entity MIB module [RFC4133]
o the pethPsePortIndex and the pethPsePortGroupIndex in the Power
Ethernet MIB [RFC3621]
Additionally, generic means for re-using further entity identifiers
must be provided.
5. Information on Powered Entities
This section describes energy-related information on powered entities
for which an energy management standard must provide means for
retrieving and reporting.
Required information on powered entities can be structured into six
groups. Section 5.1 specifies requirements for general information
on powered entities, such as type of powered entity or context
information. Section 5.2 covers requirements related to entities'
power states. Requirements for information on power inlets and power
outlets of powered entities are specified in Section 5.3. Monitoring
of power and energy is covered by Sections 5.4 and 5.5, respectively.
Finally, Section 5.6 specified requirements for monitoring batteries.
5.1. General information on powered entities
For energy management it may be required to understand the role and
context of a powered entity. From the point of view of monitoring
and management of a large network perspective, it may be helpful to
aggregate the energy consumption according to a defined grouping of
entities. When controlling and setting power states it may be
helpful to understand the the grouping of the entity and role of a
powered entity in a network, for example, in order to avoid switching
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off vital network components.
Detailed Requirements:
5.1.1. Type of powered entity
The energy management standard must provide means to retrieve and
report the type of powered entities according to a standardized
classification scheme.
YCM --- This issue has been discussed and the feeling was that type
may not be needed and thus it is better to drop this requirement. ---
YCM
The energy management standard must provide means to configure,
retrieve and report a textual name or a description of a powered
entity. In addition to the unique identity, such a textual
description shall be useful.
5.1.2. Context information on powered entities
The energy management standard must provide means for retrieving and
reporting context information on powered entities, for example, tags
associated with a powered entity that indicate the powered entity's
role, or importance.
5.1.3. Grouping of powered entities
The energy management standard must provide means for grouping
powered entities, for example, into energy monitoring domains, energy
control domains, power supply domains, groups of powered entities of
the same type, etc.
5.2. Power state
Many powered entities have a limited number of discrete power states,
such as, for example, full power, low power, sleep, and off.
Obviously, there is a need to report the actual power state of a
powered entity. Beyond that, there is also a requirement for
standardizing means for retrieving the list of all supported power
states of a powered entity.
Presently, different standards bodies have already defined their own
sets of power states for some powered entities. Beyond those, other
standards organizations are in the process of adding more of these
power state sets for the devices considered in their scope. Given
this context, it is desirable that the energy management standard
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shall be interoperable across these multiple power state standards.
In order to support multiple management systems possibly using
different power state sets, while simultaneously interfacing with a
particular powered entity, the energy management standard must
provide means for supporting multiple power state sets used
simultaneously at a powered entity.
Power states have parameters that describe its properties. It is
required to have standardized means for reporting some key
properties, such as average power and maximum power of a powered
entity in a certain state.
There also is a need to report statistics on power states including
the time spent and the energy consumed in a power state.
For some network management tasks, it may be desirable to receive
notifications from powered entities, for example, when the entire
entity or some of the components of the entity change their power
state.
Detailed Requirements:
5.2.1. Actual power state
The energy management standard must provide means for reporting the
actual power state of a powered entity.
5.2.2. List of supported power states
The energy management standard must provide means for retrieving the
list of all potential power states of a powered entity.
5.2.3. Multiple power state sets
The energy management standard must provide means for supporting
multiple power state sets simultaneously at a powered entity.
5.2.4. List of supported power state sets
The energy management standard must provide means for retrieving the
list of all power state sets supported by a powered entity.
5.2.5. List of supported power states within a set
Referring to the "list of supported power state sets" requirement,
the energy management standard must provide means for retrieving the
list of all potential power states of a powered entity that belong to
a given power state set.
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5.2.6. Maximum and average power per power state
The energy management standard must provide means for retrieving the
maximum power and the average power as a for each supported power
state. These values may be static properties of a power state.
5.2.7. Power state statistics
The energy management standard must provide means for monitoring
statistics per power state including at least the total time spent in
a power state, the number of times a state was entered and the last
time a state was entered. More power state statistics are addressed
by requirement 5.5.3.
5.2.8. Power state changes
The energy management standard must provide means for generating a
notification when the actual power state of a powered entity changes.
5.3. Power inlet and power outlet
Powered entities have power inlets at which they are supplied with
electric power. Most powered entities just have a single power
inlet, while some have multiple ones. Often different power inlets
are connected to separate power distribution trees. For energy
monitoring, it is useful to retrieve information on the number of
inlets of a powered entity, the availability of power at inlets and
which of them are actually in use.
Some powered entities have power outlets for supplying other powered
entities with electric power. A powered entity may have multiple
power outlets.
For identifying and potentially controlling the source of power
received at an inlet, it may be required to identify the power outlet
of another powered entity at which the received power is provided.
Analogously, for each outlet it is of interest to identify the power
inlets that receive the power provided at a certain outlet.
Static properties of each power inlet and each power outlet are
required information for energy management. Static properties
include the kind of electric current (Alternating Current (AC) or
Direct Current (DC)), the nominal voltage, the nominal AC frequency,
and the number of AC phases.
Detailed Requirements:
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5.3.1. List of power inlets and power outlets
The energy management standard must provide means for monitoring the
list of power inlets and power outlets at a powered entity.
5.3.2. Corresponding power outlet
The energy management standard must provide means for identifying the
power outlet that provides the power received at a power inlet.
5.3.3. Corresponding power inlets
The energy management standard must provide means for identifying the
list of power inlets that receive the power provided at a power
outlet.
5.3.4. Availability of power
The energy management standard must provide means for monitoring the
availability of power at each power inlet and at each power outlet.
This information indicates whether at a power providing outlet power
supply is switched on or off.
5.3.5. Use of power
The energy management standard must provide means for monitoring for
each power inlet and each power outlet if it is in actual use. For
the inlet this means that the powered entity actually receives power
at the inlet. For the outlet this means that power is actually
provided to one or more powered entities at the outlet.
5.3.6. Type of current
The energy management standard must provide means for reporting the
type of current (Alternating Current (AC) or Direct Current (DC)) for
each power inlet and each power outlet of a powered entity.
5.3.7. Nominal voltage
The energy management standard must provide means for reporting the
nominal voltage for each power inlet and each power outlet of a
powered entity.
5.3.8. Nominal AC frequency
The energy management standard must provide means for reporting the
nominal AC frequency for each power inlet and each power outlet of a
powered entity.
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5.3.9. Number of AC phases
The energy management standard must provide means for reporting the
number of AC phases for each power inlet and each power outlet of a
powered entity.
5.4. Power
Power is a quantity measured as instantaneous power or as average
power over a time interval. In contrast to power state values, this
quantity may change continuously.
Obtaining highly accurate values for power and energy may be costly.
Often dedicated metering hardware is needed for this purpose.
Powered entities without the ability to measure their power and
energy consumption with high accuracy may just report estimated
values, for example based on load monitoring or even just the entity
type. Measuring and estimating power must be sensitive to detect and
report if the energy is consumed or produced.
Depending on how power and energy consumption values are obtained the
confidence in the reported value and its accuracy may vary. Powered
entities reporting such values should qualify the confidence in the
reported values and quantify the accuracy of measurements. For
reporting accuracy, the accuracy classes specified in IEC 62053-21
[IEC.62053-21] and IEC 62053-22 [IEC.62053-22] should be considered.
In addition to the plain real power measurements, qualitative
properties of the supplied power are of interest from a monitoring
point of view. In case of AC power supply, there are more power
values beyond the real power to be reported including the apparent
power, the reactive power, and the phase angle of the current or the
power factor. For both AC and DC power the power quality is also
subject of monitoring. Power quality parameters include the actual
voltage, the actual frequency, the Total Harmonic Distortion (THD) of
voltage and current, the impedance of an AC phase or of the DC
supply. Power quality monitoring should be in line with existing
standards, such as [IEC.61850-7-4].
For some network management tasks, it is required to obtain time
series of power values (or energy consumption values). In general
these could be obtained in many different ways. It should be avoided
that such time series can only be obtained by regular polling by the
energy management system. Means should be provided to either push
such values from the place they are available to the management
system or to have them stored at the powered entity for a
sufficiently long period of time such that a management system can
retrieve a stored time series of values.
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Detailed Requirements:
5.4.1. Real power
The energy management standard must provide means for reporting the
real power for each power inlet and each power outlet of a powered
entity, including whether the energy is produced or consumed.
5.4.2. Power measurement interval
The energy management standard must provide means for reporting the
corresponding time or time interval for which a power value is
reported. The power value can be measured at the corresponding time
or averaged over the corresponding time interval.
5.4.3. Power measurement method
The energy management standard must provide means to indicating the
method how these values have been obtained. Based on how the
measurement was obtained, it is possible to associate a certain
degree of confidence on the reported power value. For example, there
are methods of measurement such as direct power measurement, or by
estimation based on performance values, or hard coding average power
values for a powered entity.
5.4.4. Accuracy of power and energy values
The energy management standard must provide means for reporting the
accuracy of reported power values.
5.4.5. Complex power
The energy management standard must provide means for reporting the
complex power for each power inlet and each power outlet of a powered
entity. Besides the real power, at least two out of the following
three quantities need to be reported: apparent power, reactive power,
phase angle. The phase angle can be substituted by the power factor.
In case of AC power supply, means must be provided for reporting the
complex power per phase.
5.4.6. Actual voltage and current
The energy management standard must provide means for reporting the
actual voltage and actual current for each power inlet and each power
outlet of a powered entity. In case of AC power supply, means must
be provided for reporting the actual voltage and actual current per
phase.
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5.4.7. Actual AC frequency
The energy management standard must provide means for reporting the
actual AC frequency for each power inlet and each power outlet of a
powered entity.
5.4.8. Total harmonic distortion
The energy management standard must provide means for reporting the
Total Harmonic Distortion (THD) of voltage and current for each power
inlet and each power outlet of a powered entity. In case of AC power
supply, means must be provided for reporting the THD per phase.
5.4.9. Power supply impedance
The energy management standard must provide means for reporting the
impedance of power supply for each power inlet and each power outlet
of a powered entity. In case of AC power supply, means must be
provided for reporting the impedance per phase.
5.4.10. Time series of power values
The energy management standard must provide means for collecting time
series of real power values for each power inlet and for each power
outlet of a powered entity without requiring to regularly poll the
powered entity from an energy management station. A solution for
this is that the concerned powered entity or another powered entity
closely interacting with the concerned powered entity collect time
series of power values and make them available via push or pull
mechanisms to receivers of the information.
5.5. Energy
Monitoring of electrical energy consumed (or converted) at a powered
entity can be done in various ways. One is collecting time series of
power values for the powered entity and calculating the consumed
energy from these values. An alternative is the powered entity
itself or another powered entity taking care of energy measurement
and reporting energy consumption values for certain time intervals.
Time intervals of interest are the time from the last restart of the
powered entity to the reporting time, the time from another past
event to the reporting time, or the last given amount of time before
the reporting time.
In order to monitor energy consumption in different power states, it
is useful if powered entities record their energy consumption per
power state and report these quantities.
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For some network management tasks, it is required to obtain time
series of energy values. In general these could be obtained in many
different ways. It should be avoided that such time series can only
be obtained by regular polling by the energy management system.
Means should be provided to either push such values from the place
they are available to the management system or to have them stored at
the powered entity for a sufficiently long period of time such that a
management system can retrieve a stored time series of values.
Detailed Requirements:
5.5.1. Energy
The energy management standard must provide means for reporting the
consumed energy received at a power input or provided at a power
outlet of a powered entity. Reports must be made for a clearly
specified time interval.
5.5.2. Time intervals
The energy management standard must provide means for reporting the
consumed energy of a powered entity for certain time intervals.
o Reports must be supported for the time interval starting at the
last restart of the powered entity and ending at a certain point
in time, such as the time when a report was delivered.
o Reports must be supported for a sequence of consecutive non-
overlapping time intervals of fixed size (periodic reports).
o Reports must be supported for a sequence of consecutive
overlapping time intervals of fixed size (periodic reports).
o Reports must be supported for an interval of given length ending
at a certain point in time, such as the time when a report was
delivered (sliding window)
5.5.3. Energy per power state
The energy management standard must provide means for reporting the
consumed energy individually for each power state. This extends the
requirement 5.2.7 on power state statistics.
5.5.4. Time series of energy values
The energy management standard must provide means for collecting time
series of energy values for each power inlet and for each power
outlet of a powered entity without requiring to regularly poll the
powered entity from an energy management station. A solution for
this is that the concerned powered entity or another powered entity
closely interacting with the concerned powered entity collect time
series of energy values and make them available via push or pull
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mechanisms to receivers of the information.
5.6. Battery state
Today more and more powered entities contain batteries that supply
them with power when disconnected from electrical power distribution
grids. Common examples are nomadic and mobile devices, such as
notebook computers, netbooks, and smart phones. The status of
batteries in such a powered entity, particularly the charging status
is typically controlled by automatic functions that act locally on
the powered entity and manually by users of the powered entity. In
addition to this, there is a need to monitor the battery status of
these entities by network management systems.
The management requirements discussed above in Sections 5.1 to 5.5
concern energy-related information on powered entities. Devices
containing batteries can be modeled in two ways. The entire device
can be modeled as a single powered entity on which energy-related
information is reported or the battery can be modeled as an
individual powered entity for which energy-related information is
monitored individually according to requirements in Sections 5.1 to
5.5.
In both cases further information on batteries is of interest for
energy management, such as the current charge of the battery, the
number of completed charging cycles, the charging state of the
battery, and further static and dynamic battery properties. Also
desirable is to receive notifications if the charge of a battery
becomes very low or if a battery needs to be replaced.
Detailed Requirements:
5.6.1. Battery charge
The energy management standard must provide means for reporting the
current charge of a battery.
5.6.2. Battery charging state
The energy management standard must provide means for reporting the
charging state (charging, discharging, etc.) of a battery.
5.6.3. Battery charging cycles
The energy management standard must provide means for reporting the
number of completed charging cycles of a battery.
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5.6.4. Actual battery capacity
The energy management standard must provide means for reporting the
actual capacity of a battery.
5.6.5. Static battery properties
The energy management standard must provide means for reporting
static properties of a battery, including the nominal capacity, the
number of cells, the nominal voltage, and the battery technology.
5.6.6. Low battery charge notification
The energy management standard must provide means for generating a
notification when the charge of a battery decreases below a given
threshold.
5.6.7. Battery replacement notification
The energy management standard must provide means for generating a
notification when the number of charging cycles of battery exceeds a
given threshold.
5.6.8. Multiple batteries
The energy management standard must provide means for meeting
requirements 5.6.1 to 5.6.7 for each individual battery contained in
a single powered entity.
5.7. Notifications
Often it is needed to check if values of monitored energy-related
quantities rise or fall above or below certain thresholds. In such
cases, polling these values is a very inefficient way. Preferable,
values should be checked locally and notifications should be send
when thresholds get exceeded. This can be achieved by using generic
mechanism that are not specific to energy management.
Detailed Requirement:
5.7.1. High/low value notifications
The energy management standard must provide means for creating
notifications if values of measured quantities are above or below
given thresholds.
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6. Control of Powered Entities
Many powered entities control their power state locally by self-
managed dynamic adaptation to the environment. But other powered
entities without that capability need interfaces for a energy
management system to control their power states in order to save
energy. Even for self-managed powered entities such interfaces may
be required for configuring local policy parameters and for
overruling local policy decisions by global ones from an energy
management system.
Power supply is typically not self-managed by powered entities. And
controlling power supply is typically not conducted as interaction
between energy management system and the powered entity itself. It
is rather an interaction between the management system and an entity
providing power at its power outlets. Similar to power state
control, power supply control may be policy driven. Note that
shutting down the power supply abruptly may have severe consequences
for the powered entity.
Detailed Requirement:
6.1. Controlling power states
The energy management standard must provide means for setting power
states of powered entities.
6.2. Controlling power supply
The energy management standard must provide means for switching power
supply off or turning power supply on at power outlets providing
power to one or more powered entity.
7. Reporting on Other Powered Entities
As already discussed in the introduction of Section 5, not all
energy-related information may be available at the concerned powered
entity. Such information may be provided by other powered entities,
such as a Power Distribution Unit (PDU), external power meter, or a
Power over Ethernet (PoE) Power Sourcing Equipment (PSE). Some of
these entities (PDU, PSE) can also control the power provided to the
other powered entities, while some can just report on the remote
powered entities (external power meter). This section covers
reporting of information (monitoring) only. See Section 8 for
requirements on controlling other powered entities.
There are cases where a power supply unit switches power for several
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powered entities by turning power on or off at a single power outlet
or where a power meter measures the accumulated power of several
powered entities at a single power line. Consequently, it should be
possible to report that a monitored value does not relate to just a
single powered entity, but is an accumulated value for a set of
powered entities. All of these powered entities belonging to that
set need to be identified.
If a powered entity has information about where energy-related
information on itself can be retrieved, then it would be very useful
if it has a way to communicate this information to an energy
management system. This applies even if the information only
provides accumulated quantities for several powered entities.
Detailed Requirements:
7.1. Reports on other powered entities
The energy management standard must provide means for a powered
entity to report energy-related information on another powered
entity.
7.2. Identity of other powered entities on which is reported
For entities that report on one or more other entities, the energy
management standard must provide means for reporting the identity of
another powered entity on which energy-related information is
reported.
7.3. Reporting quantities accumulated over multiple powered entities
For entities that report quantities accumulated over multiple powered
entities, the energy management standard must provide means for
reporting the list of all powered entities from which contributions
are included in an accumulated value.
7.4. List of all powered entities on which is reported
For entities that report on other entities, the energy management
standard must provide means for reporting the complete list of those
powered entities on which energy-related information can be reported.
7.5. Content of reports on other powered entities
For entities that report on other entities, the energy management
standard must provide means for indicating which energy-related
information it can reported for which of those powered entities.
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7.6. Indicating source of remote information
For an entity that has one or more other entities reporting on it,
the energy management standard must provide means for the entity to
indicate which information is available at which other entities.
7.7. Indicating content of remote information
For an entity that has one or more other entities reporting on it,
the energy management standard must provide means for indicating the
content that other designated entities can report on it.
8. Controlling Other Powered Entities
This section specifies requirements for controlling power states and
power supply of powered entities by communicating not with these
powered entities themselves, but with other powered entities that
have means for controlling power state or power supply of others.
8.1. Controlling power states of other powered entities
Some powered entities may have control of power states of other
powered entities. For example a gateway to a building network may
have means to control the power state of powered entities in the
building that do not have an IP interface. For this scenario and
other similar cases means are needed to make this control accessible
to the energy management system.
In addition to this, it is required that a powered entity that has
its state controlled by other powered entities has means to report
the list of these other powered entities.
Detailed Requirements:
8.1.1. Control of power states of other powered entities
The energy management standard must provide means for an energy
management system to send power state control commands to a powered
entity that concern the power states of other powered entities than
the one the command was sent to.
8.1.2. Identity of other power state controlled entities
The energy management standard must provide means for reporting the
identities of the powered entities for which the reporting powered
entity has means to control their power states.
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8.1.3. List of all power state controlled entities
The energy management standard must provide means for a powered
entity to report the list of all powered entities for which it can
control the power state.
8.1.4. List of all power state controllers
The energy management standard must provide means for a powered
entity that receives commands controlling its power state from other
powered entities to report the list of all those entities.
8.2. Controlling power supply of other powered entities
Some powered entities may have control of the power supply of other
powered entities, for example, because the other powered entity is
supplied via a power outlet of the powered entity. For this and
similar cases means are needed to make this control accessible to the
energy management system.
In addition to this, it is required that a powered entity that has
its supply controlled by other powered entities has means to report
the list of these other powered entities.
Detailed Requirements:
8.2.1. Control of power supply of other powered entities
The energy management standard must provide means for an energy
management system to send power supply control commands to a powered
entity that concern the power supply of other powered entities than
the one the command was sent to.
8.2.2. Identity of other power supply controlled powered entities
The energy management standard must provide means for reporting the
identity of another powered entity for which the reporting powered
entity has means to control the power supply.
8.2.3. List of all power supply controlled powered entities
The energy management standard must provide means for a powered
entity to report the list of all other powered entities for which it
can control the power supply.
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8.2.4. List of all power supply controllers
The energy management standard must provide means for a powered
entity that has other powered entities controlling its power supply
to report the list of all those powered entities.
9. Security Considerations
Controlling power state and power supply of powered entities are
highly sensitive actions since they can significantly affect the
operation of directly and indirectly affected devices. Therefore all
control actions addressed in Sections Section 6 and Section 8 must be
sufficiently protected through authentication, authorization, and
integrity protection mechanisms.
Monitoring energy-related quantities of a powered entity addressed in
Sections Section 5 - Section 8 can be used to derive more information
than just the consumed power. Therefore, monitored data requires
privacy protection. Since the monitored data may be used as input to
control, accounting, and other actions, integrity of transmitted
information and authentication of the origin may be needed.
Detailed Requirements:
9.1. Secure energy management
The energy management standard must provide privacy, integrity, and
authentication mechanisms for all actions addressed in Sections
Section 5 - Section 8. The security mechanisms must address all
threats listed in Section 1.4 of [RFC3411].
10. IANA Considerations
This document has no actions for IANA.
11. Acknowledgements
The authors would like to thank Ralf Wolter for his first essay on
this draft. Many thanks to William Mielke, John Parello, Bruce
Nordman, JinHyeock Choi, Georgios Karagiannis, and Michael Suchoff
for helpful comments on the draft.
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12. Open issues
12.1. Improve references
DC power quality covered by IEC standard?
Is there an IEC standard on DC power quality?
12.2. Do we need entity types?
Or shall we remove Section 5.1.1? The issue is unsolved on the
mailing list.
13. Informative References
[RFC1628] Case, J., "UPS Management Information Base", RFC 1628,
May 1994.
[RFC3411] Harrington, D., Presuhn, R., and B. Wijnen, "An
Architecture for Describing Simple Network Management
Protocol (SNMP) Management Frameworks", STD 62, RFC 3411,
December 2002.
[RFC3433] Bierman, A., Romascanu, D., and K. Norseth, "Entity Sensor
Management Information Base", RFC 3433, December 2002.
[RFC3621] Berger, A. and D. Romascanu, "Power Ethernet MIB",
RFC 3621, December 2003.
[RFC3805] Bergman, R., Lewis, H., and I. McDonald, "Printer MIB v2",
RFC 3805, June 2004.
[RFC4133] Bierman, A. and K. McCloghrie, "Entity MIB (Version 3)",
RFC 4133, August 2005.
[RFC4268] Chisholm, S. and D. Perkins, "Entity State MIB", RFC 4268,
November 2005.
[I-D.parello-eman-definitions]
Parello, J., "Energy Management Terminology",
draft-parello-eman-definitions-03 (work in progress),
October 2011.
[I-D.tychon-eman-applicability-statement]
Tychon, E., Silver, L., and B. Nordman, "Energy Management
(EMAN) Applicability Statement",
draft-tychon-eman-applicability-statement-05 (work in
progress), October 2011.
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[ACPI.R30b]
Hewlett-Packard Corporation, Intel Corporation, Microsoft
Corporation, Phoenix Corporation, and Toshiba Corporation,
"Advanced Configuration and Power Interface Specification,
Revision 3.0b", October 2006.
[ANSI/TIA-1057]
Telecommunications Industry Association, "ANSI/
TIA-1057-2006 - TIA Standard - Telecommunications - IP
Telephony Infrastructure - Link Layer Discovery Protocol
for Media Endpoint Devices", April 2006.
[ANSI/ASHRAE-135-2010]
American Society of Heating, Refrigerating and Air-
Conditioning Engineers, "Standard 135-2010 - BACnet A Data
Communication Protocol for Building Automation and
Control Networks (ANSI Approved) - SSPC 135 and TC 1.4,
Control Theory and Application", 2011.
[DMTF.DSP1027]
Dasari (ed.), R., Davis (ed.), J., and J. Hilland (ed.),
"Power State Management Profile", September 2008.
[IEC.61850-7-4]
International Electrotechnical Commission, "Communication
networks and systems for power utility automation - Part
7-4: Basic communication structure - Compatible logical
node classes and data object classes", 2010.
[IEC.62053-21]
International Electrotechnical Commission, "Electricity
metering equipment (a.c.) - Particular requirements -
Part 22: Static meters for active energy (classes 1 and
2)", 2003.
[IEC.62053-22]
International Electrotechnical Commission, "Electricity
metering equipment (a.c.) - Particular requirements -
Part 22: Static meters for active energy (classes 0,2 S
and 0,5 S)", 2003.
[IEEE-1621]
Institute of Electrical and Electronics Engineers, "IEEE
P1621-2004 -Draft Standard for User Interface Elements in
Power Control of Electronic Devices Employed in Office/
Consumer Environments", June 2005.
[IEEE-802.1AB]
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IEEE Computer Society, "IEEE Std 802.1AB-2009 - IEEE
Standard for Local and metropolitan area networks -
Station and Media Access Control Discovery",
September 2009.
[IEEE-802.3az]
IEEE Computer Society, "IEEE-802.3az-2010 - IEEE Standard
for Local and Metropolitan Area Networks - Specific
requirements Part 3: Carrier Sense Multiple Access with
Collision Detection (CSMA/CD) Access Method and Physical
Layer Specifications - Amendment 5: Media Access Control
Parameters, Physical Layers, and Management Parameters
for Energy-Efficient Ethernet", October 2010.
[IEEE-ISTO]
Printer Working Group, "PWG 5106.4 - PWG Power Management
Model for Imaging Systems 1.0:", February 2011.
[MODBUS-Protocol]
Modbus-IDA, "MODBUS Application Protocol Specification
V1.1b", December 2006.
Appendix A. Existing Standards
This section analyzes existing standards for energy consumption and
power state monitoring. It shows that there are already several
standards that cover only some part of the requirements listed above,
but even all together they do not cover all of the requirements for
energy management.
A.1. Existing IETF Standards
There are already RFCs available that address a subset of the
requirements.
A.1.1. ENTITY MIB
The ENTITY-MIB module defined in [RFC4133] was designed to model
physical and logical entities of a managed system. A physical entity
is an identifiable physical component. A logical entity can use one
or more physical entities. From an energy monitoring perspective of
a managed system, the ENTITY-MIB modeling framework can be reused and
whenever RFC 4133 [RFC4133] has been implemented. The
entPhysicalIndex from entPhysicalTable can be used to identify an
entity/component. However, there are use cases of energy monitoring,
where the application of the ENTITY-MIB does not seem readily
apparent and some of those entities could be beyond the original
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scope and intent of the ENTITY-MIB.
Consider the case of remote devices attached to the network, and the
network device could collect the energy measurement and report on
behalf of such attached devices. Some of the remote devices such as
PoE phones attached to a switch port have been considered in the
Power-over-Ethernet MIB module [RFC3621]. However, there are many
other devices such as a computer, which draw power from a wall outlet
or building HVAC devices which seem to be beyond the original scope
of the ENTITY-MIB.
Yet another example, is smart-PDUs, which can report the energy
consumption of the device attached to the power outlet of the PDU.
In some cases, the device can be attached to multiple to power
outlets. Thus, the energy measured at multiple outlets need to be
aggregated to determine the consumption of a single device. From
mapping perspective, between the PDU outlets and the device this is a
many-to-one mapping. It is not clear if such a many-to-one mapping
is feasible within the ENTITY-MIB framework.
A.1.2. ENTITY STATE MIB
RFC 4268 [RFC4268] defines the ENTITY STATE MIB module.
Implementations of this module provide information on entities
including the standby status (hotStandby, coldStandby,
providingService), the operational status (disabled, enabled,
testing), the alarm status (underRepair, critical, major, minor,
warning), and the usage status (idle, active, busy). This
information is already useful as input for policy decisions and for
other network management tasks. However, the number of states would
cover only a small subset of the requirements for power state
monitoring and it does not provide means for energy consumption
monitoring. For associating the information conveyed by the ENTITY
STATE MIB to specific components of a device, the ENTITY STATE MIB
module makes use of the means provided by the ENTITY MIB module
[RFC4133]. Particularly, it uses the entPhysicalIndex for
identifying entities.
The standby status provided by the ENTITY STATE MIB module is related
to power states required for energy management, but the number of
states is too restricted for meeting all energy management
requirements. For energy management several more power states are
required, such as different sleep and operational states as defined
by the Advanced Configuration and Power Interface (ACPI) [ACPI.R30b]
or the DMTF Power State Management Profile [DMTF.DSP1027].
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A.1.3. ENTITY SENSOR MIB
RFC 3433 [RFC3433] defines the ENTITY SENSOR MIB module.
Implementations of this module offer a generic way to provide data
collected by a sensor. A sensor could be an energy consumption meter
delivering measured values in Watt. This could be used for reporting
current power of an entity and its components. Furthermore, the
ENTITY SENSOR MIB can be used to retrieve the accuracy of the used
power meter.
Similar to the ENTITY STATE MIB module, the ENTITY SENSOR MIB module
makes use of the means provided by the ENTITY MIB module [RFC4133]
for relating provided information to components of a device.
However, there is no unit available for reporting energy quantities,
such as, for example, watt seconds or kilowatt hours, and the ENTITY
SENSOR MIB module does not support reporting accuracy of measurements
according to the IEC / ANSI accuracy classes, which are commonly in
use for electric power and energy measurements. The ENTITY SENSOR
MIB modules only provides a coarse-grained method for indicating
accuracy by stating the number of correct digits of fixed point
values.
A.1.4. UPS MIB
RFC 1628 [RFC1628] defines the UPS MIB module. Implementations of
this module provide information on the current real power of entities
attached to an uninterruptible power supply (UPS) device. This
application would require identifying which entity is attached to
which port of the UPS device.
UPS MIB provides information on the state of the UPS network. The
MIB module contains several variables that are used to identify the
UPS entity (name, model,..), the battery state, to characterize the
input load to the UPS, to characterize the output from the UPS, to
indicate the various alarm events. The measurements of power in UPS
MIB are in Volts, Amperes and Watts. The units of power measurement
are RMS volts, RMS Amperes and are not based on Entity-Sensor MIB
[RFC3433].
A.1.5. POWER ETHERNET MIB
Similar to the UPS MIB, implementations of the POWER ETHERNET MIB
module defined in RFC3621 [RFC3621] provide information on the
current energy consumption of the entities that receive Power over
Ethernet (PoE). This information can be retrieved at the power
sourcing equipment. Analogous to the UPS MIB, it is required to
identify which entities are attached to which port of the power
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sourcing equipment.
The POWER ETHERNET MIB does not report power and energy consumption
on a per port basis, but can report aggregated values for groups of
ports. It does not use objects of the ENTITY MIB module for
identifying entities, although this module existed already when the
POWER ETHERNET MIB modules was standardized.
A.1.6. LLDP MED MIB
The Link Layer Discovery Protocol (LLDP) defined in IEEE 802.1AB
[IEEE-802.1AB] is a data link layer protocol used by network devices
for advertising of their identities, capabilities, and
interconnections on a LAN network. The Media Endpoint Discovery
(MED) is an enhancement of LLDP known as LLDP-MED [ANSI/TIA-1057].
The LLDP-MED enhancements specifically address voice applications.
LLDP-MED covers 6 basic areas: capabilities discovery, LAN speed and
duplex discovery, network policy discovery, location identification
discovery, inventory discovery, and power discovery.
A.2. Existing standards of other bodies
A.2.1. DMTF
The DMTF has defined a power state management profile [DMTF.DSP1027]
that is targeted at computer systems. It is based on the DMTF's
Common Information Model (CIM) and it is rather an entity profile
than an actual energy consumption monitoring standard.
The power state management profile is used to describe and to manage
the power state of computer systems. This includes e.g. means to
change the power state of an entity (e.g. to shutdown the entity)
which is an aspect of but not sufficient for active energy
management.
A.2.2. OVDA
ODVA is an association consisting of members from industrial
automation companies. ODVA supports standardization of network
technologies based on the Common Industrial Protocol (CIP). Within
ODVA, there is a special interest group focused on energy and
standardization and inter-operability of energy aware entities.
A.2.3. IEEE-ISTO Printer WG
The charter of the IEEE-ISTO Printer Working Group is for open
standards that define printer related protocols, that printer
manufacturers and related software vendors shall benefit from the
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interoperability provided by conformance to these standards. One
particular aspect the Printer WG is focused on is power monitoring
and management of network printers and imaging systems PWG Power
Management Model for Imaging Systems [IEEE-ISTO]. Clearly, these
devices are within the scope of energy management since these devices
consume power and are attached to the network. In addition, there is
ample scope of power management since printers and imaging systems
are not used that often. IEEE-ISTO Printer working group has defined
MIB modules for monitoring the power consumption and power state
series that can be useful for power management of printers. The
energy management framework should also take into account the
standards defined in the Printer working group. In terms of other
standards, IETF Printer MIB RFC3805 [RFC3805] has been standardized,
however, this MIB module does not address power management of
printers.
Authors' Addresses
Juergen Quittek (editor)
NEC Europe Ltd.
NEC Laboratories Europe
Network Research Division
Kurfuersten-Anlage 36
Heidelberg 69115
DE
Phone: +49 6221 4342-115
Email: quittek@neclab.eu
Rolf Winter
NEC Europe Ltd.
NEC Laboratories Europe
Network Research Division
Kurfuersten-Anlage 36
Heidelberg 69115
DE
Phone: +49 6221 4342-121
Email: Rolf.Winter@neclab.eu
Quittek, et al. Expires May 4, 2012 [Page 33]
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Thomas Dietz
NEC Europe Ltd.
NEC Laboratories Europe
Network Research Division
Kurfuersten-Anlage 36
Heidelberg 69115
DE
Phone: +49 6221 4342-128
Email: Thomas.Dietz@neclab.eu
Benoit Claise
Cisco Systems, Inc.
De Kleetlaan 6a b1
Degem 1831
BE
Phone: +32 2 704 5622
Email: bclaise@cisco.com
Mouli Chandramouli
Cisco Systems, Inc.
Sarjapur Outer Ring Road
Bangalore,
IN
Phone: +91 80 4426 3947
Email: moulchan@cisco.com
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