draft-various-eimpact-arch-considerations-00.txt   draft-various-eimpact-arch-considerations.txt 
Network Working Group M. Welzl Network Working Group M. Welzl
Internet-Draft University of Oslo Internet-Draft University of Oslo
Intended status: Informational E. Stephan Intended status: Informational E. Stephan
Expires: 4 September 2025 Orange Expires: 8 January 2026 Orange
E. Schooler E. Schooler
University of Oxford University of Oxford
S. Rumley S. Rumley
HES-SO HES-SO
A. Rezaki A. Rezaki
Nokia Nokia
J. Manner J. Manner
Aalto University Aalto University
C. Pignataro C. Pignataro
Blue Fern Consulting Blue Fern Consulting
skipping to change at page 1, line 33 skipping to change at line 32
A. Keränen A. Keränen
Ericsson Ericsson
H. ElBakoury H. ElBakoury
L. M. Contreras L. M. Contreras
Telefonica Telefonica
A. Clemm A. Clemm
Independent Independent
J. Arkko J. Arkko
Ericsson Ericsson
3 March 2025 7 July 2025
Architectural Considerations for Environmentally Sustainable Internet Architectural Considerations for Environmentally Sustainable Internet
Technology Technology
draft-various-eimpact-arch-considerations-00 draft-various-eimpact-arch-considerations-latest
Abstract Abstract
This document discusses protocol and network architecture aspects This document discusses protocol and network architecture aspects
that may have an impact on the sustainability of network technology. that may have an impact on the sustainability of network technology.
The focus is on providing guidelines that can be helpful for protocol The focus is on providing guidelines that can be helpful for protocol
designers and network architects, where such guidelines can be given. designers and network architects, where such guidelines can be given.
About This Document About This Document
skipping to change at page 2, line 29 skipping to change at line 73
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute 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 Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on 4 September 2025. This Internet-Draft will expire on 8 January 2026.
Copyright Notice Copyright Notice
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction
2. Potential Architectural Aspects . . . . . . . . . . . . . . . 5 2. Understanding
2.1. Measurement . . . . . . . . . . . . . . . . . . . . . . . 5 2.1. Measurement and Modeling
2.1.1. Motivation . . . . . . . . . . . . . . . . . . . . . 6 2.1.1. Motivation
2.1.2. Analysis . . . . . . . . . . . . . . . . . . . . . . 6 2.1.2. Analysis
2.1.3. Recommendation . . . . . . . . . . . . . . . . . . . 7 2.1.3. Recommendation
3. Actions
2.2. Modeling . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1. Dynamic Scaling
2.2.1. Motivation . . . . . . . . . . . . . . . . . . . . . 9 3.1.1. Motivation
2.2.2. Analysis . . . . . . . . . . . . . . . . . . . . . . 9 3.1.2. Analysis
2.2.3. Recommendation . . . . . . . . . . . . . . . . . . . 11 3.1.3. Recommendation
2.3. Dynamic Scaling . . . . . . . . . . . . . . . . . . . . . 11 3.2. Transport
2.3.1. Motivation . . . . . . . . . . . . . . . . . . . . . 12 3.2.1. Motivation
2.3.2. Analysis . . . . . . . . . . . . . . . . . . . . . . 13 3.2.2. Analysis
2.3.3. Recommendation . . . . . . . . . . . . . . . . . . . 15 3.2.3. Recommendation
2.4. Transport . . . . . . . . . . . . . . . . . . . . . . . . 15 3.3. Equipment Longevity
2.4.1. Motivation . . . . . . . . . . . . . . . . . . . . . 15 3.3.1. Motivation
2.4.2. Analysis . . . . . . . . . . . . . . . . . . . . . . 16 3.3.2. Analysis
2.4.3. Recommendation . . . . . . . . . . . . . . . . . . . 17 3.3.3. Recommendation
2.5. Equipment Longevity . . . . . . . . . . . . . . . . . . . 17 3.4. Encoding
2.5.1. Motivation . . . . . . . . . . . . . . . . . . . . . 17 3.4.1. Motivation
2.5.2. Analysis . . . . . . . . . . . . . . . . . . . . . . 18 3.4.2. Analysis
2.5.3. Recommendation . . . . . . . . . . . . . . . . . . . 19 3.4.3. Recommendation
2.6. Compact encoding . . . . . . . . . . . . . . . . . . . . 19 3.5. Sustainable by Design: Data Governance Perspective
2.6.1. Motivation . . . . . . . . . . . . . . . . . . . . . 19 3.5.1. Motivation
2.6.2. Analysis . . . . . . . . . . . . . . . . . . . . . . 19 3.5.2. Analysis
2.6.3. Recommendation . . . . . . . . . . . . . . . . . . . 20 3.5.3. Recommendation
2.7. Sustainable by Design: Data Governance Perspective . . . 20 4. Recommendations for Protocol Design
2.7.1. Motivation . . . . . . . . . . . . . . . . . . . . . 20 5. Recommendations for Further Work and Research
2.7.2. Analysis . . . . . . . . . . . . . . . . . . . . . . 20 6. Security Considerations
2.7.3. Recommendation . . . . . . . . . . . . . . . . . . . 21 7. IANA Considerations
3. Recommendations for Further Work and Research . . . . . . . . 21 8. Informative References
4. Security Considerations . . . . . . . . . . . . . . . . . . . 22 Appendix A. Modeling Approaches and Literature
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 A.1. Customer Attribution
6. Informative References . . . . . . . . . . . . . . . . . . . 22 A.2. Baselining and Benchmarking
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 25 Acknowledgments
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 26 Authors' Addresses
1. Introduction 1. Introduction
This document discusses protocol and network architecture aspects
that can have an impact on the environmental sustainability of
network technology. For brevity, we will use the term sustainability
in this document to refer to environmental sustainability. We do
note that sustainability as a term is widely used to refer to
different notions of sustainability, and the most well-known larger
definition of sustainability can be seen from the United Nations
Sustainable Development Goals (UN SDG) [UNSDG].
Environmental sustainability is an important consideration in Environmental sustainability is an important consideration in
networking. Both for ensuring that networking technology can enable society, and in networking, too. Networking technologies enable
societies to operate in an environmentally sustainable manner and societies to operate in an environmentally sustainable manner and
that the networks themselves are environmentally sustainable. thereby have a positive handprint, yet networks themselves must be
environmentally sustainable and attempt to minimise their negative
footprint.
This document discusses protocol and network architecture aspects Fundamentally the question we try to address concerns the resource
that may have an impact on the environmental sustainability of usage and the lifecycle of network equipment. The less devices are
network technology. For brevity, we will use the term sustainability built, and energy is used, the less emissions are created. Networks
to refer to environmental sustainability. We do note that are built with hardware and these in turn use electrical energy to
sustainability as a term is widely used to refer to different notions run. Eventually, the hardware is decommissioned and some amount of
of sustainability, and the most well-known larger definition of the materials are recycled.
sustainability can be seen from the United Nations Sustainable
Development Goals (UN SDG) [UNSDG].
Sustainability impact and emissions from networking comes from three We can divide the lifecycle into three major phases (omitting some
primary categories: hardware manufacturing, direct energy usage and intermittent steps like shipping of products):
construction work. The last category is out of scope of this
document because networking has limited means to impact construction 1. Manufacturing (including the raw material extraction and usage,
work itself. The manufacturing of networking hardware, both for the embedded chips and electronics, casing, and energy needed for
fixed and wireless networks, is a significant source of emissions, these operations, etc.),
and recycling of ICT equipment is still limited. Direct energy usage
of networking and the source of the energy have been the primary 2. Use phase that is focused on the operational energy use and
concerns, but as the world moves towards greener energy production, repairing equipment, and
the relative negative impact of the emissions from manufacturing
becomes more prominent. 3. End of life that can include both direct recycling of some of the
materials or finding a new life and usage for an old product that
still functions, after which it is finally recycled.
Networks also require some amount of physical construction to
realize, and this construction work also creates emissions. This
category of emissions is out of scope of this document because the
Internet community and network engineers have limited means to impact
construction work itself and the associated industry, but we can
impact how networks, protocols and hardware are designed, built and
operated.
All these phases create harmful emissions, into the ground and in the
air, that have a negative impact on our environment and people. As
the type of such emissions vary, they are often standardized as
carbon dioxide equivalent (CO2e) to allow comparing sources and
amounts of emissions. When discussing (carbon) emissions in this
document, we generally refer to CO2e.
The manufacturing of networking hardware, both for fixed and wireless
networks, is a significant source of emissions, and recycling of ICT
equipment is still limited to the casing and some other minor parts.
Direct energy usage of networking and the source of the energy have
often been the primary concerns. There are many reports and
scientific papers discussing carbon emissions of the energy used by
ICT. As of today, and the foreseeable future, the difference in
emissions of the electric grid between countries and regions can vary
significantly. e.g. In the EU, there are 10-fold differences between
countries, and similar differences exist between US states. On a
global level, the differences can be over 50-fold. Yet, as the world
moves towards greener energy production, the relative negative
impacts related to manufacturing becomes more prominent and the
importance of equipment longevity grows.
When good design and architecture can improve the sustainability of When good design and architecture can improve the sustainability of
networks, they should certainly be applied to designing new protocols networks, they should certainly be applied to designing new protocols
and building networks. Intuitively, protocol and network and building networks. Intuitively, protocol and network
architecture choices can have an impact on sustainability. At the architecture choices can have an impact on sustainability. At the
very least the right design and architecture can make it possible to very least the right design and architecture can make it possible to
have a positive impact, but of course the architecture alone is not have a positive impact, but of course the architecture alone is not
enough. The possibilities offered by the architecture need to be enough. The possibilities offered by the architecture need to be
realized by implementations and practical deployments. realized by implementations and practical deployments.
To give an example of an architectural aspect that potentially has a To give an example of an architectural aspect that potentially has a
sustainability impact, enabling the collection of information (e.g., sustainability impact, enabling the collection of information (e.g.,
energy consumption) and then using that information to make smarter energy consumption) and then using that information to make smarter
decisions is one. For instance, understanding power consumption of decisions is one. For instance, understanding power consumption of
individual nodes can be valuable input to future purchasing decisions individual nodes can be valuable input to future purchasing decisions
or development efforts to reduce the power consumption. Yet, as data or development efforts to reduce the power consumption. Yet, as data
collection is often rather easy, we should not overdo it in such a collection is often rather easy, it is easy to overdo it in such a
way that it leads to accumulation of dark data (i.e. data that is way that it leads to accumulation of dark data (i.e. data that is
collected and stored, but never used). All data collection consumes collected and stored but never used). All data collection consumes
processing power, network resources and storage space, and this can processing power, network resources and storage space, and this can
in turn increase the emissions from the network. in turn increase the emissions from the network.
Other architectural examples include making it possible to scale Other architectural examples include making it possible to scale
resources or resource selection processes performed in a resources or resource selection processes performed in a
sustainability-aware fashion. The use of communication primitives sustainability-aware fashion. The use of communication primitives
that maximize utility in a given problem (e.g., using multicast) or that maximize utility in a given problem (e.g., using multicast) or
the use of technologies that reduce the number or size of messages the use of technologies that reduce the number or size of messages
needed for a given task (e.g., binary encoding instead of textual) needed for a given task (e.g., binary encoding instead of textual)
are some further examples. are some further examples.
Of course, some of these aspects may have a major impact on Of course, some of these aspects may have a major impact on
sustainability, where others may only have a minor effect. There are sustainability, where others may only have a minor effect. There are
also tradeoffs, such as side-effects of architectural choices, e.g., also tradeoffs, such as side-effects of architectural choices, e.g.,
dynamic scaling of a router network potentially impacting jitter, or dynamic scaling of a router network potentially impacts jitter;
putting cellular base stations to sleep and activating them as putting cellular base stations to sleep and activating them as
capacity needs grow may introduce a delay in matching the needs of capacity needs grow potentially introduces a delay in matching the
the data flows. needs of the data flows.
The document is intended to help engineering efforts in the IETF, The document is intended to help engineering efforts in the IETF,
provide operational guidance in the operator community, as well as to provide operational guidance in the operator community, as well as to
point to potential research directions in the IRTF. point to potential research directions in the IRTF.
The scope of the document is advice on Internet and protocol The scope of the document is advice on Internet and protocol
architecture, such as what architecture or capabilities new protocol architecture, such as what architecture or capabilities new protocol
designs or features should have, what kind of operational network designs or features should have, what kind of operational network
architectures should be deployed, and how all of these can be architectures should be deployed, and how all of these can be
designed to best address sustainability concerns. The focus of this designed to best address sustainability concerns.
document is to provide actionable design advice to protocol
designers. This document therefore addresses one aspect in the The focus of this document is to provide actionable design advice to
architecture question, and does not claim to cover the topic protocol designers. This document therefore addresses one aspect in
the architecture question and does not claim to cover the topic
exhaustively. exhaustively.
This document is also not focused on general issues around This document is not focused on general issues around environmental
environmental sustainability, except those that pertain to sustainability, except those that pertain to architecture or
architecture or significant protocol features. significant protocol features.
It is to be noted that networks themselves are a service, a tool, for It is to be noted that networks themselves are a service, a tool, for
all the applications and services on the Internet. Networks connect all the applications and services on the Internet. Networks connect
data, people and services. The increase in networking and size of data, people and services. The increase in networking and size of
the Internet is driven by these applications and the usage. the Internet is driven by these applications and the usage.
Therefore the emissions from networking are tied to the applications Therefore, the emissions from networking are tied to the applications
and the data they consume; with less applications or data, the and the data they consume; with less applications or data, the
Internet would have less hardware and less energy usage. The goals Internet would have less hardware and less energy usage. The goals
of this document are not to instruct application and service of this document are not to instruct application and service
developers to choose what applications are worthwhile or how much developers to choose what applications are worthwhile or how much
content is sent. There are many forums and parties whose mission is content is sent. There are many forums and parties whose mission is
to help these developers to implement more sustainable services, such to help these developers to implement more sustainable services, such
as, the Green Software Foundation, the Green Web Foundation, Greening as, the Green Software Foundation, the Green Web Foundation, Greening
of Streaming, to name a few. of Streaming, to name a few.
2. Potential Architectural Aspects The next two sections present architectural and protocol design
aspects that can have an impact on the sustainability of networking.
Section 2 discusses those foundations that are required to prepare
for sustainability improvements, and Section 3 discusses actions that
can be taken to make the actual improvements. For each topic in
these sections, we provide an overview, the motivation for why it
would be important to consider for more sustainable networking, an
analysis and recommendations for future networking professionals.
This section presents architectural and protocol design aspects that Recommendations for protocol designers are discussed throughout the
can have an impact on the sustainability of networking. For each document and summarized in Section 4. Finally, Section 5 discusses
topic, we provide an overview, the motivation for why it would be further work that is needed to make further concrete recommendations
important to consider for more sustainable networking, an analysis for the designers.
and recommendations for future networking professionals.
2.1. Measurement 2. Understanding
It is essential to understand the current state of affairs before any 2.1. Measurement and Modeling
improvements can be made. i.e. Some levels of measurements are
necessary for starting to improve sustainability. This is
particularly the case when looking at the systems as a whole in post-
analysis. As discussed earlier, this level of measurements is useful
input for further actions, such as deciding what parts of the network
need to be targeted for further improvement.
But measurements may also be useful for some dynamic situations where It is essential to understand the current state of affairs before any
power-saving decisions, for instance, depend on knowing the relative improvements can be made. Thus, some levels of measurements are
power consumption of different activities, such as when a power-off necessary for starting to improve sustainability. In some cases
decision involves understanding the relative savings during the measurements may be complemented by modeling.
shutdown period vs. the power cost of shutdown and startup
procedures, or the possible need to reconfigure other nodes in the
network due to the shutdown.
2.1.1. Motivation 2.1.1. Motivation
Measurements are a necessary mechanism for both post-analysis and
potentially for some of the dynamic decisions taken by systems.
Without measurements of any kind, it is impossible to assess if the Without measurements of any kind, it is impossible to assess if the
networks are functioning correctly. It is impossible to know if the networks are functioning correctly. It is impossible to know if the
system is efficient by comparing it against a baseline model. It is system is efficient by comparing it against a baseline model. It is
also impossible to check that changes aiming at optimizing something also impossible to check that changes aiming at optimizing something
are indeed valuable. are indeed valuable.
For instance, while electricity providers can make information about This is particularly the case when looking at the systems as a whole
power usage available, this is only done at the aggregate level. in post-analysis. As discussed earlier, some level of measurements
Without per-device data about power usage, there would be limited is useful input for further actions, such as deciding what parts of
basis for deciding where power is actually consumed and consequently, the network need to be targeted for further improvement.
what improvements are most useful.
But measurements may also be useful for some dynamic situations where
power-saving decisions, for instance, depend on knowing the relative
power consumption of different activities, such as when a power-off
decision involves understanding the relative savings during the
shutdown period vs. the power cost of shutdown and startup
procedures, or the possible need to reconfigure other nodes in the
network due to the shutdown.
At the same time, it is not possible to measure everything. At the same time, it is not possible to measure everything.
Furthermore, any measurement must be validated. Relevance of Furthermore, any measurement must be validated. Relevance of
measurements must be periodically assessed, e.g., with comparisons measurements must be periodically assessed, e.g., with comparisons
between measurements within a network and the aggregate numbers from between measurements within a network and the aggregate numbers from
the electricity provider. the electricity provider.
Finally, measurements made in the field must be collected and Finally, measurements made in the field must be collected and
organized to allow later retrieval. structured to allow later retrieval. And measurements are
counterproductive if they are endlessly accumulated without being
consulted.
2.1.2. Analysis 2.1.2. Analysis
While the simplest forms of sustainability-related measurements are This section discusses how measurements relate to the fabrication and
about power, there's clearly room for other measurements and other usage phases and how efficiency can be measured.
information as well. To begin with, power consumption by itself may
not be what matters most for sustainability, as the source of the
power may be equally important in terms of determining the actual
carbon footprint.
Secondly, for many classes of devices the embedded carbon aspects or 2.1.2.1. Measuring impacts of fabrication and usage phases
use of raw materials may be a significant sustainability issue. See
also Section 2.2.
Third, power or energy measurements alone are of meager use if the Network infrastructure generates negative impacts principally during
cause of the consumption is not measured as well. Any power/energy fabrication and usage phases. Measuring negative impacts related to
measurement should occur alongside other measurements that can be fabrication falls in the activity of lifecycle analysis (LCA). LCAs
used to determine energy efficiency. Hence a sound measurement is typically realized per device, either by the equipment vendor
architecture implies that a prior existence of an energy efficiency itself, or by third-party analysts. LCA involves modeling (see
framework of some kind. Section 2.1.3.6). The analysis can be done in terms of climate
change (CC) but can be extended to other criteria as abiotic resource
depletion (ARD), ecotoxicity (ET) or water usage (WU). LCA also
involves information systems keeping an inventory of the devices
uses. For many classes of devices, the embedded carbon aspects or
use of raw materials are significant sustainability issues. As these
measurements and inventories are external to the network
architecture, they are considered out of this document scope.
But when it comes to energy consumption, as noted the aggregate Measuring negative impacts related to the usage phase falls in the
information is often typically available, and it's not particularly scope of monitoring. In this phase, the most obvious sustainability-
hard to measure the energy consumption of individual network devices related measurement is power monitoring to measure the energy
either. Still, there are a number of desirable use cases where the consumption and estimate the related negative impacts.
measurement situation needs to improve.
2.1.2.1. Measuring Power Efficiency 2.1.2.2. Measuring efficiency
When assessing the power consumption (Scope 2) of an IT-organization, Power (in Watts, that is, in Joule/s) or energy (in Joules)
emission accountants are generally looking for a metric of the measurements alone are of meager use if the cause of the consumption
delivered value per unit of energy. is not measured as well. Any power/energy measurement should occur
alongside other measurements that can be used to determine energy
efficiency. Hence a sound measurement architecture implies the
existence of an energy efficiency framework of some kind.
A commonly used method is to equate the delivered value with the In the context of carbon accounting, emission accountants are
number of bits sent or received, or to the communication capacity generally looking for a metric of the delivered value per unit of
made available when there's a need for it. The latter is important, carbon. In networking, the most obvious delivered value is number of
as often communication networks have requirements to be able to send bits sent or received (traffic), or to the communication capacity
messages when there's a need for it, e.g., for emergency made available during unit of time. In both case, the unit is the
communications, not that those messages are always being sent. bit, but the two metrics have very different meanings. In one case,
one spends a Joule to send a bit. In the other case, one spends a
Joule to offer a bandwidth capacity of 1 bit/s during a second. The
latter is important, as often communication networks have
requirements to be able to send messages when there's a need for it,
e.g., for emergency communications, even when those messages may not
always be sent.
The measurement of efficiency is not restricted to energy. Traffic
or offered bandwidth can be related to the carbon emitted by the
device traversed by this traffic. This carbon should include the
part associated with electricity, but also the part associated with
fabricating the device (pro rata temporis) [LCAandUsage].
Sustainable efficiency can also be expressed in water used per
traffic, for example.
2.1.3. Recommendation 2.1.3. Recommendation
Ongoing work at the IETF's GREEN working group is already targeted at Ongoing work at the IETF's GREEN working group is already targeted at
improving existing energy consumption metrics and frameworks but some improving existing energy consumption metrics and frameworks but some
further considerations may apply. In order to meet the needs further considerations may apply. While the Sustainable Internet
discussed above, the following architectural design principles are Architecture addresses broader lifecycle aspects such as
proposed. manufacturing, reuse, and recycling—essential to circular economy
goals the GREEN framework provides a foundational model for
monitoring and optimizing energy consumption across networked devices
and components. Therefore, extending the measurements defined in the
Sustainable Internet Architecture to integrate energy related data
from the GREEN framework, such as power states, consumption patterns,
and efficiency ratios will enable a more holistic approach to
environmental impact assessment. Harmonizing these efforts will
support the development of composite metrics that connect operational
energy use with manufacturing and end-of-life considerations,
establishing a coherent basis for sustainable digital infrastructure
management.
2.1.3.1. Generality In order to meet the needs discussed above, the following
architectural design principles are proposed.
2.1.3.1. Future Proof Metrics
We recommend that any measurement framework or sustainability-related We recommend that any measurement framework or sustainability-related
information sharing mechanism be designed to share different types of information sharing mechanism be designed to share different types of
information and not limited to a single metric such as power information and not limited to a single metric such as power
consumption. Similarly, the granularity of data collection needs to consumption. Requirements, units, granularity and collection method
be configurable so that the metrics collected can be as fine-grained specifications are sure to shift over time.
or as aggregated as needed in order to identify potential areas of
improvement.
2.1.3.2. Collect Metrics from Existing Equipment 2.1.3.2. Plug-in Architecture for Collection and Control
Since the need to deliver on the use cases described is urgent, the Since the need to deliver on the use cases described is urgent, the
industry has to accomodate the capabilities (and limitations) of industry has to accommodate the capabilities (and limitations) of
existing equipment in the field for collecting metrics. existing equipment in the field for collecting metrics. It is
recommended to apply a plug-in architecture with modules that can
It is recommended to have a plug-in architecture with modules that work with (read from and control) devices of any kind, including
can work with (read from and control) devices of any kind, including
traditional networking hardware devices, cooling systems, software traditional networking hardware devices, cooling systems, software
stacks, and occasionally static datasheets. stacks, and occasionally static data sheets.
2.1.3.3. Content Declaration for all Collected Metrics
A warehouse filled with data collected from diverse sources is 2.1.3.3. Data with Content Declaration
useless without proper labeling. Hence, these is a need to create
metadata that describes the collected data. (e.g. What are the
source(s)? What measurement units are used? Precision? What is
included/excluded in these numbers?)
The metadata itself must also have a formal description. e.g. Use To make sense of the collected data, it must be possible to see
YANG for the metadata schema. Keep the metadata attached to the exactly where all data is coming from, what it means, its precision
dataflow it describes, so that the relation is clear to each and how it has been processed. The metadata itself must also have a
component that has anything to do with it, including components added formal description. YANG might be suitable for modeling the metadata
by other organizations at a later point in time. schema. Keep the metadata attached to the dataflow it describes, so
that the relation is clear even when components are added by other
organizations at a later point in time.
2.1.3.4. Collection, Aggregation, Processing, Display, Decisions 2.1.3.4. Processing Flexibility and Audit Trails
The collected data passes through a pipeline from collection to The collected data passes through a pipeline from collection to
decisions. By processing we mean steps to reshape the data to match decisions. By processing we mean steps to reshape the data to match
further aggregation and processing steps, such as unit conversions, further aggregation and processing steps, such as unit conversions,
sample frequency alignment, filtering, etc. sample frequency alignment, filtering, etc.
Separate these architectural roles into separate modules in order to Separate these pipeline stages into separate modules and use
enable reuse, modular development and a transparent, configurable configuration to construct the pipeline. This gives flexibility,
pipeline. reuse and enables a full audit trail. It is essential that every
data processing step can be reviewed in an audit situation without
2.1.3.5. Configurable Pipeline for Reuse and Transparency looking at code.
Let the pipeline connections between the components be driven by
configuration rather than hard coded. This enables reconfiguration
of the processing pipeline over time, and perhaps more importantly,
transparency into what stages the data pass through, even without
access to or understanding of the source code of the entire system.
2.1.3.6. Design Together with the Users 2.1.3.5. Aligned with Reporting Frameworks
Every system should be designed involving some of its target users. Ensure that the system output is aligned with the measurement
In order for delivered metrics to be of any value, the target requirements set forth by relevant legal frameworks, e.g. ESRS
audience needs to be aware of their existence, be able to interpret (Europe), TCFD and IFRS (US, Japan), BRSR (India), etc. The
them and understand how they can be used in their professional responsible corporate bodies producing the corporate reports are
context. unlikely to use any technical collection system that isn't well
aligned.
There are many target user groups for the information produced. Some 2.1.3.6. Modeling
examples are network designers/engineers, scientists, operations
teams and IT-development organizations. One critical group that is
often overlooked is the sustainability assessment experts. If they
are not aware, don't understand or don't care about the produced
sustainability metrics, the value of this work would be greatly
diminished.
2.2. Modeling Where power optimization choices are made, accurate information is
required to decide the right choice.
The paucity of up-to-date information on equipment and system The paucity of up-to-date information on equipment and system
parameters, especially power consumption and maximum throughput, parameters, especially power consumption and maximum throughput,
makes estimating the power consumption and energy efficiency of these makes estimating the power consumption and energy efficiency of these
systems extremely challenging. In addition the rapid evolution of systems extremely challenging. In addition, the rapid evolution of
technology and products in ICT makes the estimation quickly outdated technology and products in ICT makes the estimation quickly outdated
and possibly inaccurate. In almost all cases physical measurement and possibly inaccurate. In some cases, physical measurements have
has to be replaced by partial measurement and mathematical modeling. to be replaced by partial measurements and mathematical modeling.
2.2.1. Motivation
Where power optimization choices are made, accurate information is
required to decide the right choice. Modeling instead of
measurements may have to be used in some cases.
2.2.2. Analysis 2.1.3.6.1. Power modeling
To date, two approaches to network power modeling are accepted as To date, two approaches to network power modeling are accepted as
providing a realistic estimate of network power consumption. These providing a realistic estimate of network power consumption. These
approaches are referred to as "bottom-up" and "top-down". The paper approaches are referred to as "bottom-up" and "top-down". The paper
[Unifying] surveys both approaches and provide a new approach which [Unifying] surveys both approaches and provide a new approach which
unifies both of them. The unified approach is used to estimate the unifies both of them. The unified approach is used to estimate the
power consumption of access, aggregation and core networks. power consumption of access, aggregation and core networks.
The paper [Modeling] provides a model for IP Routers and the routers Modeling can also help address attribution aspects, such as those
of other future Internet architectures (FIA) such as SCION and involved in an effort of an organization to calculate its Scope 3
NEBULA. They use a generic model which captures the commonalities of emissions. Modeling can also be used to assist in establishing a
IP router as well as the peculiarities of FIA routers. They conduct baseline energy consumption, and enable later comparisons to that
a large-scale simulation based on this router model to estimate the baseline.
power consumption for different network architectures.
Since routers and other network devices and functions can be
virtualized, this article (1) provides comprehensive "graphical,
analytical survey of the literature, over the period 2010–2020, on
the measurement of power consumption and relevant power models of
virtual entities as they apply to the telco cloud." This paper A
Methodology and Testbed to Develop an Energy Model for 5G Virtualized
RANs IEEE Conference Publication IEEE Xplore got best paper award for
GreenNet 2024, but I am not sure if we are interested to model 5G
vRAN.
There is a plethora of publications on modeling communication
networks and DC computing.
2.2.2.1. Customer Attribution
When organizations assess their Scope 3 emissions, they need to sum
up their share of emissions from all their suppliers, one of which
for example, might be a cloud hosting service. In order for the
supplier to provide an emission share value back to the customer, the
provider needs to develop a mechanism for attribution.
A significant challenge in accurately assessing Scope 3 emissions is
avoiding Double Counting, where the same emission is reported by
multiple entities. According to the GHG Protocol best practices, it
is crucial to establish clear guidelines and agreements between
suppliers and customers to ensure that emissions are attributed
correctly and not counted multiple times. This requires transparent
communication and precise emission reporting standards to ensure that
all parties involved have a consistent understanding of which
emissions belong to which organization.
By addressing the Double Counting issue, companies can achieve more
accurate and reliable Scope 3 emissions assessments, thereby
contributing to better overall sustainability reporting and
improvement efforts.
2.2.2.2. Baselining and Benchmarking
Establishing a baseline is a fundamental step in the process of
improving energy efficiency and sustainability of network technology.
Baselining involves establishing a reference point of typical energy
usage, which is crucial for identifying inefficiencies and measuring
improvements over time. In this step, the controller uses only the
collected data from datasheets and other reliable sources.
By establishing a baseline and using benchmarking, organizations can
determine if their networking equipment is performing normally or if
it is deviating from expected performance. This is the first step in
identifying and guiding necessary improvements. Benchmarking
involves collecting performance measurements of networking equipment
under controlled conditions. This process helps establish
standardized performance metrics, allowing for comparison against
baselines collected during regular operational conditions.
The initial measurement of networking equipment's energy efficiency
and performance, known as Baselining, should be coordinated with
vendor specifications and industry standards to understand what is
considered normal or optimal performance. For example, if the
baseline indicates that your switches operate at 5 Gbps per watt,
while vendor specifications suggest 8 Gbps per watt and the industry
standard is 10 Gbps per watt, actions should be taken to implement
energy-saving measures and upgrades. Continuously tracking
subsequent measurements can reveal if efficiency improves towards the
benchmark of 8-10 Gbps per watt.
This practice ensures that any improvements can be quantifiably
tracked over time, providing a clear measure of the effectiveness of
the implemented changes and guiding further enhancements in network
sustainability.
See also [Baseline] and [BenchmarkingFramework].
2.2.3. Recommendation Additional discussion of modeling can be found in Appendix A.
Even though baselining is essential in identifying potential areas of 3. Actions
improvement and tracking progress, it is still to be determined to
what extent we need to work on modeling networks and devices in the
architecture.
2.3. Dynamic Scaling 3.1. Dynamic Scaling
Dynamic scaling is the ability to adjust resources according to Dynamic scaling is the ability to adjust resources according to
demand, and possibly turn some of them off during periods of low demand and possibly turn some of them off during periods of low
usage. Examples include the set of servers needed for a service, how usage. Examples include the set of servers needed for a service, how
many duplicate links are needed to carry high-volume traffic, whether many duplicate links are needed to carry high-volume traffic, whether
one needs all base stations with overlapping coverage areas to be on, one needs all base stations with overlapping coverage areas to be on,
etc. etc.
Networks and communications are also critical functions of the modern Networks and communications are also critical functions of the modern
digital society. The reliability of individual networking links or digital society. The reliability of individual networking links or
devices cannot always be guaranteed. As a result, various levels and devices cannot always be guaranteed. As a result, various levels and
forms of resiliency are often needed, for instance through forms of resiliency are often needed, for instance through
redundancy. Yet, there is a question on how much redundancy is redundancy. Yet, there is a question on how much redundancy is
needed and how quickly a backup or resource increase can be activated needed and how quickly a backup or resource increase can be activated
due to increased demand. due to increased demand.
2.3.1. Motivation Scaling can be pulled up and down by data consumption variations and
more rarely by power shortage. In such situation dynamic scaling is
the ability to adjust demand resources according to resources. When
operating on limited backup energy sources such as batteries or
generators, the architecture must support graceful adaptation before
power runs out. In such situations, networks must minimize
consumption to extend operational time.
3.1.1. Motivation
Outside of implementation improvements, dynamic scaling is Outside of implementation improvements, dynamic scaling is
potentially the most promising method for reducing power consumption potentially the most promising method for reducing power consumption
related environmental impacts. Scaling can happen on a device-level related environmental impacts. Scaling can happen on a device-level
(increasing performance as traffic levels grow) or a network segment (increasing performance as traffic levels grow) or a network segment
level (increasing the number of active links or cellular base level (increasing the number of active links or cellular base
stations). stations).
Considering current fixed networking hardware, dynamic scaling might Considering current fixed networking hardware, dynamic scaling might
not have an impact in situations where there's only a single router not have an impact in situations where there's only a single router
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hardware can be fully operational at all times and used to serve the hardware can be fully operational at all times and used to serve the
traffic, while other links may be in hot or cold standby depending on traffic, while other links may be in hot or cold standby depending on
the use case. the use case.
Cellular networks are typically built with significant overlap in Cellular networks are typically built with significant overlap in
coverage areas of multiple base stations. Demand and business coverage areas of multiple base stations. Demand and business
reasons dictate the design of the coverage, and regulations might reasons dictate the design of the coverage, and regulations might
dictate how reliable the cellular service should be. There is dictate how reliable the cellular service should be. There is
extensive work world-wide to optimize the operation of this extensive work world-wide to optimize the operation of this
overlapping coverage, e.g. by turning down some sites at night time overlapping coverage, e.g. by turning down some sites at night time
when traffic volumes are low. A cellular basestation site can when traffic volumes are low. A cellular base station site can
consume anything from a few kWh to ten or more kWh per provider. consume anything from a few kWh to ten or more kWh per provider.
Modern cellular base stations do implement numerous features to scale Modern cellular base stations do implement numerous features to scale
the energy consumption. In general, cellular base stations have a the energy consumption. In general, cellular base stations have a
base energy consumption and traffic-dependent consumption, a somewhat base energy consumption and traffic-dependent consumption, a somewhat
similar behavior to what we can observe in modern CPUs. similar behavior to what we can observe in modern CPUs.
On the network level, most large systems have significant amount of On the network level, most large systems have significant amount of
redundancy and spare capacity. Where such capacity can be turned on redundancy and spare capacity. Where such capacity can be turned on
or off to match the actual need at a given time, significant or off to match the actual need at a given time, significant
reductions in power consumption can be achieved. reductions in power consumption can be achieved.
2.3.2. Analysis Whereas scaling down under normal conditions seeks to reduce
consumption while maintaining full capabilities, power-constrained
operations accept degraded performance or functionality. Operating
in power backup mode introduces a shift in network behavior as it
differs from network-driven auto scaling:
* Network, devices and components must reduce power usage, possibly
sacrificing performance, feature sets, or redundancy.
* Each network domain (RAN, edge, and core network segments) faces
its own constraints and policies in power-limited operation.
3.1.2. Analysis
Dynamic scaling could be seen as either an alternative or Dynamic scaling could be seen as either an alternative or
complementary to load stabilization, e.g., via "peak shaving". complementary to load stabilization, e.g., via "peak shaving".
Perhaps the most realistic angle is that both are likely needed. Perhaps the most realistic view is that both are likely needed.
The most rudimentary approach to dynamic scaling is just turning some The most rudimentary approach to dynamic scaling is just turning some
resources off. However this may not be sufficient, and a more resources off. However this may not be sufficient, and a more
graceful/engineered approach potentially yields better results. graceful/engineered approach potentially yields better results.
Network architects need to understand the impacts of scaling changes Network architects need to understand the impacts of scaling changes
on users and traffic. These may include the fate of ongoing on users and traffic. These may include the fate of ongoing
sessions, latency/jitter, packets in flight, or running processes, sessions, latency/jitter, packets in flight, or running processes,
attempts to contact resources that are no longer present, and the attempts to contact resources that are no longer present, and the
time it takes for the network to converge to its new state. time it takes for the network to converge to its new state.
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[I-D.ietf-tvr-requirements] [I-D.ietf-tvr-schedule-yang] [I-D.ietf-tvr-requirements] [I-D.ietf-tvr-schedule-yang]
[I-D.ietf-tvr-alto-exposure]. [I-D.ietf-tvr-alto-exposure].
* Efficient propagation of changes of new routes, new set of * Efficient propagation of changes of new routes, new set of
servers, etc. as to reduce the amount of time where state is not servers, etc. as to reduce the amount of time where state is not
synchronized across the network. The needs for the propagation synchronized across the network. The needs for the propagation
solution needs to be driven by dynamic scaling and sustainability solution needs to be driven by dynamic scaling and sustainability
as well as other aspects, such as recovery from failures. as well as other aspects, such as recovery from failures.
* Build mechanisms to deal with dynamic changes: Plan for dynamic * Build mechanisms to deal with dynamic changes: Plan for dynamic
set of resources, and not expect to work with a fixed set of set of resources and not expect to work with a fixed set of
resources. resources.
* Dynamic scaling requires automation in most cases, e.g., to turn * Dynamic scaling requires automation in most cases, e.g., to turn
on new service instances. See again on new service instances. See again
[I-D.pignataro-enviro-sustainability-architecture] for a [I-D.pignataro-enviro-sustainability-architecture] for a
discussion of automation. discussion of automation.
* Interaction with the energy grid can enable dynamic load shifting. * Interaction with the energy grid can enable dynamic load shifting.
For instance, a demand-response technique can be used where the For instance, a demand-response technique can be used where the
system temporarily reduces its energy usage in response to pricing system temporarily reduces its energy usage in response to pricing
signals from a smart grid. The proposed demand-response technique signals from a smart grid. The proposed demand-response technique
involves deferring the load from elastic requests to later time involves deferring the load from elastic requests to later time
periods in order to reduce the server demand and the current periods in order to reduce the server demand and the current
energy usage, and hence, energy costs [LoadShifting]. energy usage, and hence, energy costs [LoadShifting].
* Energy-aware routing. This generally aims at aggregating traffic * Energy-aware routing. This generally aims at aggregating traffic
flows over a subset of the network devices and links, allowing flows over a subset of the network devices and links, allowing
other links and interconnection devices to be switched off. These other links and interconnection devices to be switched off. These
solutions shall preserve connectivity and QoS, for instance by solutions shall preserve connectivity and QoS, for instance by
limiting the maximum utilization over any link, or ensuring a limiting the maximum utilization over any link or ensuring a
minimum level of path diversity. There are also algorithms for minimum level of path diversity. There are also algorithms for
Green Traffic engineering. For instance [Segment] employs segment Green Traffic engineering. For instance, [Segment] employs
routing. Experimental analysis results [Experiment] show that the segment routing. Experimental analysis results [Experiment] show
resource usage for SRv6 could be more than 70% lower than that of that the resource usage for SRv6 could be more than 70% lower than
the SPF-based forwarding, depending on the network topology. that of the SPF-based forwarding, depending on the network
topology.
2.3.3. Recommendation 3.1.3. Recommendation
The guidelines above need to be considered specifically for each The guidelines above need to be considered specifically for each
protocol and system design. Further work in detailing this guidance protocol and system design. Further work in detailing this guidance
would also be useful. would also be useful.
It is likely that there is increased attention to resiliency in the It is likely that there is increased attention to resiliency in the
future, given for instance the increased importance of the tasks future, given for instance the increased importance of the tasks
supported by networks or the potentially increasing frequency of supported by networks or the potentially increasing frequency of
natural disasters as a result of global warming. natural disasters as a result of global warming.
2.4. Transport Scaling steps during power shortage differ from network dynamic
scaling and depend on the network domain and the events: grid
outages, deployment in remote or mobile environments, extreme weather
events, or any sort of enforced reductions in power usage like
monthly battery testing. Nevertheless, there is a gain to have a
common dynamic scaling approach that includes network-driven scaling
and power-shortage scaling.
Transport protocols are the flexible tools that make it possible for 3.2. Transport
communication flows between parties to adjust themselves to the
dynamic conditions that exist in the network at any given time:
available bandwidth, delays, congestion, the ability of a peer to
send or receive traffic, and so on. Depending on the conditions, an
individual flow may carry traffic at widely different rates, may
pause for some time, etc. Various higher-level transport solutions
may also cache or pre-fetch information.
This behavior has an effect on sustainability as well, e.g., in what Transport protocols make it possible for communication flows to
periods the endpoint and network systems are active or when they adjust themselves to the dynamic conditions that exist in the network
could be in reduced activity or sleep states. at any given time: available bandwidth, delays, congestion, the
ability of a peer to send or receive traffic, and so on. Depending
on the conditions, an individual flow may carry traffic at widely
different rates, may pause for some time, etc.
Cellular networks and mobile links can scale their energy usage based This behavior has an effect on sustainability, e.g., in what periods
on load and enter a low-power state when a traffic flow ends. Thus, the endpoint and network systems are active or when they could be in
in theory, the faster the data is transferred, the faster the device reduced activity or sleep states. Cellular networks and mobile links
transmission/reception functions can enter a low-power state. can scale their energy usage based on load and enter a low-power
state when a traffic flow ends. Thus, in theory, the faster the data
is transferred, the faster the device transmission/reception
functions can enter a low-power state.
2.4.1. Motivation 3.2.1. Motivation
Transport behavior would have a possibility of impacting how much Transport behavior would have a possibility of impacting how much
downtime or sleep can be had in the communication system, either on downtime or sleep can be had in the communication system, either on
the end systems or routers or other equipment in between. The the end systems or routers or other equipment in between. The
savings can be significant, at least in wireless systems. savings can be significant, at least in wireless systems.
Improvements through transport behavior are only useful if the Improvements through transport behavior are only useful if the
involved systems have power proportionality. involved systems have power proportionality.
2.4.2. Analysis 3.2.2. Analysis
A critical issue is the tradeoff involved in sending traffic. As Various higher-level transport solutions may also cache or pre-fetch
argued in [NotTradeOff], reducing the amount of time the endpoints information. For instance, [I-D.irtf-nmrg-green-ps] lifts CDNs as
and the network are active can sometimes help save energy, e.g. in one example of technology that has reduced energy consumption, by
case the receiver is connected over a WiFi link. Similar logic moving the needed endpoints closer to each other.
applies for any technology that has a certain degree of energy
proportionality, e.g. cellular communication. As a result, in On a given set of endpoints, application behavior can impact
environmental costs. For instance,
[I-D.pignataro-enviro-sustainability-consid] observes the effect of
protocol chattiness. Does the protocol rely on periodic updates or
heartbeat messages? Could such message patterns result in preventing
links or nodes from going to sleep (absent other communications), and
in such a case, would an alternative pattern be feasible?
Transport layer protocol behavior also has an impact. A critical
issue is the tradeoff involved in sending traffic. As argued in
[NotTradeOff], reducing the amount of time the endpoints and the
network are active can sometimes help save energy. As a result, in
general, delivering information as rapidly as possible would appear general, delivering information as rapidly as possible would appear
to be desirable. to be desirable.
On the other hand, bandwidth-intensive applications can influence On the other hand, would such as rapid transmission impact peak
other applications or users by presenting a significant load on the traffic, and as such, contribute to a need to dimension networks for
higher traffic volumes? And in this case the need could be only a
perceived one as a less rapid transmission would not have impacted,
for instance, a user's ability to view a video if the transmission
was merely for the buffering of the rest of the video.
Furthermore, bandwidth-intensive applications can influence other
applications or users by presenting a significant load on the
network, and consequently reducing capacity available for others, or network, and consequently reducing capacity available for others, or
increasing buffering (and with it, latency) across the network path. increasing buffering (and with it, latency) across the network path.
For an application with intermittent data transfers, such as For an application with intermittent data transfers, such as
streaming video, this would seem to speak in favor of sustained but streaming video, this would seem to speak in favor of sustained but
lower-rate delivery instead of transmitting short high-rate bursts lower-rate delivery instead of transmitting short high-rate bursts
[Sammy]. However, this is in contradiction with the energy-saving [Sammy]. However, this is in contradiction with the energy-saving
approach above. Thus, the tradeoff is: should data be sent in a way approach above. Thus, the tradeoff is: should data be sent in a way
that is "friendly" to others (avoiding bad interference), or should that is "friendly" to others (avoiding bad interference), or should
it save energy by sending fast, increasing the chance for equipment it save energy by sending fast, increasing the chance for equipment
to enter a "sleep" state? to enter a "sleep" state?
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expense of other traffic. For non-urgent data transfers, the IETF- expense of other traffic. For non-urgent data transfers, the IETF-
recommended default approach is the opposite: the LEDBAT congestion recommended default approach is the opposite: the LEDBAT congestion
control mechanism [RFC6817], which is designed for such use, will control mechanism [RFC6817], which is designed for such use, will
always "step out of the way" of other traffic, giving it a low rate always "step out of the way" of other traffic, giving it a low rate
when it competes with any other traffic. Alternatively, if the goal when it competes with any other traffic. Alternatively, if the goal
is to reduce energy, such traffic could be sent at a high rate, at a is to reduce energy, such traffic could be sent at a high rate, at a
strategically good moment within a longer time interval; this would strategically good moment within a longer time interval; this would
give network equipment an opportunity to enter a sleep state in the give network equipment an opportunity to enter a sleep state in the
remaining time period within the interval. remaining time period within the interval.
Perhaps the issue is that the transport behavior (as with many other A hypothesis could be made that transport protocols should take
things) needs to take into account multiple parameters. For example, energy into account in addition to the many other inputs they decide
it is possible that a balanced transport algorithm would be able to upon. For example, it is possible that a non-urgent data transfer
send as much as possible as soon as possible, while tracking buffer would send as much as possible as soon as possible when at least one
growth from transmission delays and scaling back if there's any of the links along the path is known to be power proportional (e.g.,
buffer growth. This remains to be confirmed with experiments, a cellular link), while tracking buffer growth from transmission
however. delays to scale back if delay should occur.
Similarly, caching and pre-fetching designs need to take into account Such ideas remain to be confirmed with experiments, however.
not only the likelihood of having acquired the right content in
memory, but also the sustainability cost of possibly fetching too Similarly, caching and pre-fetching designs need to consider not only
much or the timing of those fetching operations. the likelihood of having acquired the right content in memory, but
also the sustainability cost of possibly fetching too much or the
timing of those fetching operations.
In general, information about the impacts of loading or not loading In general, information about the impacts of loading or not loading
the network with additional traffic, and whether a certain sending the network with additional traffic, and whether a certain sending
pattern enables power savings through sleep modes, would be pattern enables power savings through sleep modes, would be
beneficial for the communicating endpoints. Mechanisms for making beneficial for the communicating endpoints. Mechanisms for making
such information available to the endpoints would be useful. such information available to the endpoints would be useful.
2.4.3. Recommendation 3.2.3. Recommendation
The techniques described above have been based on theoretical As can be seen from the above, there are a number of complex
analysis. There is a need for further simulations and experiments to tradeoffs merely for transport protocol behavior on a given
confirm what strategies would provide the best end-user and energy connection.
performance. This may be work that fits within the IRTF SUSTAIN
research group.
2.5. Equipment Longevity This prompts us to give two types of advice. The first type of
advice is for protocol designers: simple models are unlikely to
guarantee optimal results, but as long as normal precautions such as
congestion control, monitoring queue build-up, and avoiding
unnecessary messages are employed, systems will operate reasonably
well.
The second type of advice is for further work in the research
community to better understand what strategies would actually provide
the best end-user and energy performance, and whether the choice of
strategy depends on other factors, such as whether sleep modes are
implemented in network nodes. There is a clear need for simulations
and experiments to understand this better. This may be work that
fits within the IRTF SUSTAIN research group. Also, new standards may
be need if information sharing about the sustainability and sleep
mode characteristics of network systems is needed for applications to
make the best transport decisions.
3.3. Equipment Longevity
This section discusses the ability to extend the useful life of This section discusses the ability to extend the useful life of
protocols and/or network equipment in order to amortize the embedded protocols and/or network equipment in order to amortize the embedded
energy costs over a longer period, even though it may mean that the energy costs over a longer period, even though it may mean that the
protocols/equipment may not be fully optimized for the present use. protocols/equipment may not be fully optimized for the present use.
This includes devising tools to inform network administrators and This includes devising tools to inform network administrators and
their users of the potential benefits of network equipment upgrades, their users of the potential benefits of network equipment upgrades,
so that they can make better choices on what upgrades are necessary so that they can make better choices on what upgrades are necessary
and when. and when.
It should be noted that from an environmental sustainability It should be noted that from an environmental sustainability
perspective, it may not always be the best choice to upgrade network perspective, it may not always be the best choice to upgrade network
equipment whenever slightly less power-hungry and "greener" equipment whenever slightly less power-hungry and "greener"
alternatives become available. The environmental cost of amortizing alternatives become available. The environmental cost of amortizing
the carbon embedded inside equipment over its lifetime, including the the carbon embedded inside equipment over its lifetime, including the
carbon associated with the manufacturing of the equipment that is to carbon associated with the manufacturing of the equipment that is to
be replaced, should be taken into consideration as well. be replaced, should be taken into consideration as well.
2.5.1. Motivation 3.3.1. Motivation
Embedded carbon and raw materials can be a significant part of the Embedded carbon and raw materials can be a significant part of the
overall environmental impact of systems. If this can be improved for overall environmental impact of systems. If this can be improved for
devices that are manufactured in large quantities, the improvements devices that are manufactured in large quantities, the improvements
can be significant. can be significant.
The more the world moves toward low-carbon energy sources, the more The more the world moves toward low-carbon energy sources, the more
the manufacturing matters in the holistic view. Today there can be the manufacturing matters in the holistic view. Today there can be
an order of magnitude difference in average emissions for a kWh of an order of magnitude difference in average emissions for a kWh of
electricity between two countries. Thus, any estimates that seek to electricity between two countries. Thus, any estimates that seek to
compare the manufacturing and use phase emissions of a network compare the manufacturing and use phase emissions of a network
equipment would have to be calculated per country or region, and equipment would have to be calculated per country or region, and
there is no universal standard for the whole planet. there is no universal standard for the whole planet.
Long equipment lifetimes are only useful if the longer lifetimes can Long equipment lifetimes are only useful if the longer lifetimes can
be achieved without compromising other aspects of sustainability, be achieved without compromising other aspects of sustainability,
such as when using a high-end and power-hungry router in place of such as when using a high-end and power-hungry router in place of
small routers. The exact moment when a hardware change is warranted small routers. The exact moment when a hardware change is warranted
for sustainability differs between countries and regions. for sustainability differs between countries and regions.
2.5.2. Analysis 3.3.2. Analysis
When we engineer protocols and network equipment, we are inclined to When we engineer protocols and network equipment, we are inclined to
design them in a highly optimized manner for a very specific set of design them in a highly optimized manner for a very specific set of
requirements, use cases and context. While this is necessary in requirements, use cases and context. While this is necessary in
certain cases (e.g. constrained nodes with limits on processing certain cases (e.g. constrained nodes with limits on processing
capacity or long lived battery powered devices), there are certainly capacity or long-lived battery powered devices), there are certainly
cases where such optimized equipment is not absolutely required. cases where such optimized equipment is not absolutely required.
Most infrastucture network nodes on the Internet utilize only a Most infrastructure network nodes on the Internet utilize only a
fraction of their design capacity most of the time. fraction of their design capacity most of the time.
Designing the equipment with an eye on longevity comes with a set of Designing the equipment with an eye on longevity comes with a set of
advantages: advantages:
* It allows the same equipment and protocols be reused in a * It allows the same equipment and protocols be reused in a
different context in the future. e.g. A core router of today can different context in the future. e.g. A core router of today can
become an edge router in a near future and an access router in the become an edge router in a near future and an access router in the
further future if the protocol implementations are adaptable. further future if the protocol implementations are adaptable.
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Another aspect that can play an important role in extending the Another aspect that can play an important role in extending the
longevity of equipment concerns software-defined networking, in the longevity of equipment concerns software-defined networking, in the
sense of designing networking equipment in such a way that new sense of designing networking equipment in such a way that new
equipment capabilities and features can be introduced via software equipment capabilities and features can be introduced via software
upgrades as opposed to requiring hardware replacement. This requires upgrades as opposed to requiring hardware replacement. This requires
system architectures that incorporate the necessary infrastructure to system architectures that incorporate the necessary infrastructure to
support such upgrades in a secure manner that does not compromise support such upgrades in a secure manner that does not compromise
equipment integrity. equipment integrity.
2.5.3. Recommendation On the other hand, it is very much possible that there could be new
equipment available that is significantly more sustainable in its
operation. The longevity of the existing equipment and the
amortization of its embedded sustainability costs, needs to be
balanced against the potential operational savings to be realized by
upgrading to newer equipment over the intended lifecycle of the newer
equipment.
3.3.3. Recommendation
The guidelines above should be considered for any new system design. The guidelines above should be considered for any new system design.
If some aspect of protocol or network equipment design choice could If some aspect of protocol or network equipment design choice could
be made more generic and flexible without a significant performance be made more generic and flexible without a significant performance
and sustainability impact, it needs to be studied in further detail. and sustainability impact, it needs to be studied in further detail.
Specifically, the potential additional sustainability costs due to Specifically, the potential additional sustainability costs due to
forgoing optimization need to be weighed against the potential forgoing optimization need to be weighed against the potential
savings in embedded carbon and raw material costs brought about by savings in embedded carbon and raw material costs brought about by
premature upgrades. There are also cases where equipment upgrades premature upgrades.
are done to provide better peak performance characteristics (e.g.
higher advertised speeds towards consumers) and these need to be
viewed as well with the same tradeoffs in mind. Finally, when
designing networks it is recommended to consider whether it is
possible to reuse retiring equipment in a different location or for a
different function (e.g. move it to lower traffic geographies, core
routers become edge/access routers etc.)
2.6. Compact encoding There are also cases where equipment upgrades are done to provide
better peak performance characteristics (e.g. higher advertised
speeds towards consumers) and these need to be viewed as well with
the same tradeoffs in mind. Also, when newer more sustainable
equipment is available there needs to be a cost benefit analysis made
to decide whether to keep current equipment running for longer or
upgrade to realize the benefits of newer equipment even though it
incurs new embedded costs.
Finally, when designing networks, it is recommended to consider
whether it is possible to reuse retiring equipment in a different
location or for a different function (e.g. move it to lower traffic
geographies, core routers become edge/access routers etc.)
3.4. Encoding
This is about considering the effects encoding methods on This is about considering the effects encoding methods on
sustainability, such as the use of binary encodings instead of text. sustainability, such as the use of binary encodings instead of text.
2.6.1. Motivation 3.4.1. Motivation
Better encoding can obviously reduce the length of messages sent. It Better encoding can obviously reduce the length of messages sent or
remains a question mark how big overall impact this is, however. It reduce the amount of computing required for the encoding and decoding
should only be performed if it gives a measurable overall impact. operations. It remains a question mark how big overall impact this
is, however. It should only be performed if it gives a measurable
overall impact.
2.6.2. Analysis 3.4.2. Analysis
Better encoding methods are clearly beneficial for improving the Better encoding methods are clearly beneficial for improving the
detailed-level effectiveness of communications. detailed-level effectiveness of communications.
The main questions are, however: The main questions are, however:
* Is the effect of this is at a magnitude comparable to the other * How large are the potential remaining savings in this area, and
things, or if it is just absolutely tiny? Particularly how do they compare to other things? Particularly considering
considering that much of the traffic on the Internet is video, and that much of the traffic on the Internet is video, which is
much of that is other content than, e.g., HTTP headers. Moran et already highly optimized and constantly updated with better
al. argued in their 2022 paper [CBORGreener] [RFC9547] that that encoding methods. Moran et al. argued in their 2022 paper
for a weather data example from [RFC8428] [RFC9193] there are [CBORGreener] [RFC9547] that that for a weather data example from
significant savings. However, this needs more research in terms [RFC8428] [RFC9193] there are significant savings. However, this
of the overall impact across different examples and the general needs more research in terms of the overall impact across
make up of Internet traffic. different examples and the general make up of Internet traffic.
* At what layer is the compactness achieved? Are link, IP, or * At what layer is the compactness achieved? Are link, IP, or
transport layer mechanisms that can compact some of the verbose transport layer mechanisms that can compact some of the verbose
messaging useful, or should each protocol have optimal compacting? messaging useful, or should each protocol have optimal compacting?
* Tradeoffs related to compressing (particularly if AI-based * Tradeoffs related to compute required to do encoding and decoding
computationally expensive methods are used). operations. These can be relatively heavy operations,
particularly if compression is performed, particularly if AI-based
computationally expensive methods are used.
2.6.3. Recommendation 3.4.3. Recommendation
More research is needed to quantify the likely sources of measurable More research is needed to quantify the likely sources of measurable
impacts. impacts.
Of course, new protocols can generally be designed to work with Of course, new protocols can generally be designed to work with
compact encoding, unless there is a significant reason not to. But compact encoding, unless there is a significant reason not to. But
efforts to modify existing protocols for the sake of encoding efforts to modify existing protocols for the sake of encoding
efficiency should be further investigated by the above mentioned efficiency should be further investigated by the above-mentioned
quantification results. quantification results.
2.7. Sustainable by Design: Data Governance Perspective One particular area of interest is the impact of AI-based compression
methods and their computational and energy costs vs. achieved savings
in communication efficiencies.
3.5. Sustainable by Design: Data Governance Perspective
Incorporating sustainability into the design phase of network Incorporating sustainability into the design phase of network
architecture is critical for ensuring long-term environmental and architecture is critical for ensuring long-term environmental and
operational benefits. From a Data Governance point of view, operational benefits. From a Data Governance point of view,
"Sustainable by Design" involves embedding sustainability principles "Sustainable by Design" involves embedding sustainability principles
and practices into the data management frameworks and processes from and practices into the data management frameworks and processes from
the outset. the outset.
2.7.1. Motivation 3.5.1. Motivation
Data governance plays a pivotal role in shaping how data is Data governance plays a pivotal role in shaping how data is
collected, stored, processed, and used. By integrating collected, stored, processed, and used. By integrating
sustainability into these processes, organizations can ensure that sustainability into these processes, organizations can ensure that
their data practices contribute to environmental goals, such as their data practices contribute to environmental goals, such as
reducing carbon footprints, optimizing resource usage, and minimizing reducing carbon footprints, optimizing resource usage, and minimizing
waste. waste.
2.7.2. Analysis 3.5.2. Analysis
Key elements of Sustainable by Design in data governance include: Key elements of Sustainable by Design in data governance include:
* Data Minimization: Collecting only the data that is necessary and * Data Minimization: Collecting only the data that is necessary and
useful, reducing storage and processing requirements, which in useful, reducing storage and processing requirements, which in
turn lowers energy consumption. turn lowers energy consumption.
* Efficient Data Storage Solutions: Implementing energy-efficient * Efficient Data Storage Solutions: Implementing energy-efficient
data storage technologies and practices that prioritize reduced data storage technologies and practices that prioritize reduced
power usage and cooling needs. power usage and cooling needs.
* Lifecycle Management: Ensuring that data is managed throughout its * Lifecycle Management: Ensuring that data is managed throughout its
lifecycle in a way that minimizes environmental impact, including lifecycle in a way that minimizes environmental impact, including
secure and sustainable data disposal practices. secure and sustainable data disposal practices.
* Transparency and Accountability: Establishing clear data * Transparency and Accountability: Establishing clear data
governance policies that promote transparency in data usage and governance policies that promote transparency in data usage and
accountability for sustainability objectives. accountability for sustainability objectives.
2.7.3. Recommendation 3.5.3. Recommendation
Organizations should adopt data governance frameworks that Organizations should adopt data governance frameworks that
incorporate sustainability as a core principle. This includes incorporate sustainability as a core principle. This includes
setting clear sustainability goals, measuring progress towards these setting clear sustainability goals, measuring progress towards these
goals, and continuously improving data management practices to goals, and continuously improving data management practices to
enhance sustainability. By doing so, organizations can ensure that enhance sustainability. By doing so, organizations can ensure that
their data operations are not only effective but also environmentally their data operations are not only effective but also environmentally
responsible. responsible.
3. Recommendations for Further Work and Research There is a protocol designer angle in this as well. Protocol
designers should consider at least the data minimization aspects from
Section 3.5.2, and may additionally consider providing mechanisms for
the lifecycle management and transparency aspects.
Dynamic scaling, i.e., the ability to respond to demand variations 4. Recommendations for Protocol Design
and resiliency requirements while optimizing energy consumption
clearly has significant potential for savings. Past and ongoing work
in various systems and protocols has looked at this, of course, but
we believe work also remains. Any large scale system likely benefits
from further analysis, unless already ongoing. Guidance in
{dynscale} simple, and further work in detailing this guidance would
also be useful.
Transport-related optimizations (see {transport}) that enable devices The recommendations that can be applied by protocol designers and
to consume less power by sleeping more appear to have potential for architects have been listed in Section 2 and Section 3.
significant savings, but confirming this requires further research. Specifically:
Such research could be performed in the context of the recently
chartered SUSTAIN research group.
More research is needed to quantify the likely sources of measurable * Measurement and modeling are a necessary foundation to understand
impacts when it comes to efficient protocol message encoding where environmental impacts are generated, and to quantify any
discussed in {encoding}. Again, this is work that the research group improvements. The recommendations related to this topic were
could take on. listed in Section 2.1.3. These are primarily about ensuring that
the measurement frameworks are generic enough to support data
collection for an evolving set of metrics, and to prepare for the
possibility that mathematical modeling may have to replace
measurements in some cases.
TBD * Dynamic scaling is the ability to respond to demand variations and
resiliency requirements while optimizing energy consumption
clearly has significant potential for savings. Recommendations
related to this were listed in Section 3.1.3. These are about
some basic techniques for being able to scale systems up and down
while avoiding negative effects from these operations.
... * Transport-related recommendations were listed in Section 3.2.
These are about tradeoffs associated with different transport
strategies.
4. Security Considerations * Longevity-related recommendations were listed in Section 3.3.3.
These are primarily about how equipment can fulfill evolving roles
over its lifetime, and associated tradeoffs.
* Encoding-related recommendations were listed in Section 3.4.3.
These are about the effects of encoding size in protocols, and the
associated compression computing impacts.
* Data governance-related recommendations were listed in
Section 3.5.3. These are primarily about ensuring the right
amount of data is collected, stored, and processed, in view of the
effort required to do so.
5. Recommendations for Further Work and Research
There are several areas where concrete advice for protocol designers
could not be given, or additional advice would be useful, but we do
not understand the situation well enough to give practical advice.
These include:
* Past and ongoing work in various systems and protocols has looked
at dynamic scaling extensively, but we believe work also remains.
Any large-scale system likely benefits from further analysis,
unless already ongoing. Guidance in Section 3.1 simple, and
further work in detailing this guidance would also be useful.
* Transport-related optimizations (see Section 3.2) that enable
devices to consume less power by sleeping more appear to have
potential for significant savings but confirming this requires
further research. Such research could be performed in the context
of the recently chartered SUSTAIN research group.
* More research is needed to quantify the likely sources of
measurable impacts when it comes to efficient protocol message
encoding discussed in Section 3.4. Also, the tradeoffs involving
the use AI-based compression methods deserve further study.
Again, these are topics that the research group could take on.
6. Security Considerations
It is possible that the introduction of features and architectural It is possible that the introduction of features and architectural
properties to facilitate environmentally sustainable Internet properties to facilitate environmentally sustainable Internet
technology introduces new attack vectors or other security technology introduces new attack vectors or other security
ramifications. ramifications.
For example, the introduction of measurements and metrics for the For example, the introduction of measurements and metrics for the
purpose of saving energy could be misused for the opposite effect purpose of saving energy could be misused for the opposite effect
when compromised. For example, measurements might be tampered with when compromised. For example, measurements might be tampered with
in order to cause an operator to waste energy. Energy measurements, in order to cause an operator to waste energy. Energy measurements,
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by allowing to infer usage profiles. They could also be abused to by allowing to infer usage profiles. They could also be abused to
implement a covert communications channel in which information is implement a covert communications channel in which information is
leaked via tampered measurement values that are being reported. leaked via tampered measurement values that are being reported.
Networking features and technology choices may have security Networking features and technology choices may have security
implications regardless of why they are introduced, including for implications regardless of why they are introduced, including for
reasons of environmental sustainability. The possibility of this reasons of environmental sustainability. The possibility of this
needs to be taken into consideration, understood, and communicated to needs to be taken into consideration, understood, and communicated to
allow for their mitigation. allow for their mitigation.
5. IANA Considerations 7. IANA Considerations
This document has no IANA actions. This document has no IANA actions.
6. Informative References 8. Informative References
[Baseline] Livieratos, S., Panetsos, S., Fotopoulos, A., and M. [Baseline] Livieratos, S., Panetsos, S., Fotopoulos, A., and M.
Karagiorgas, "A New Proposed Energy Baseline Model for a Karagiorgas, "A New Proposed Energy Baseline Model for a
Data Center as a Tool for Energy Efficiency Evaluation", Data Center as a Tool for Energy Efficiency Evaluation",
International Journal of Power and Energy Research, Vol. International Journal of Power and Energy Research, Vol.
3, No. 1 , April 2019. 3, No. 1 , April 2019.
[BenchmarkingFramework] [BenchmarkingFramework]
Mahadevan, P., Sharma, P., Banerjee, S., and P. Mahadevan, P., Sharma, P., Banerjee, S., and P.
Ranganathan, "A Power Benchmarking Framework for Network Ranganathan, "A Power Benchmarking Framework for Network
skipping to change at page 23, line 26 skipping to change at line 1155
[I-D.cparsk-eimpact-sustainability-considerations] [I-D.cparsk-eimpact-sustainability-considerations]
Pignataro, C., Rezaki, A., Krishnan, S., ElBakoury, H., Pignataro, C., Rezaki, A., Krishnan, S., ElBakoury, H.,
and A. Clemm, "Sustainability Considerations for and A. Clemm, "Sustainability Considerations for
Internetworking", Work in Progress, Internet-Draft, draft- Internetworking", Work in Progress, Internet-Draft, draft-
cparsk-eimpact-sustainability-considerations-07, 24 cparsk-eimpact-sustainability-considerations-07, 24
January 2024, <https://datatracker.ietf.org/doc/html/ January 2024, <https://datatracker.ietf.org/doc/html/
draft-cparsk-eimpact-sustainability-considerations-07>. draft-cparsk-eimpact-sustainability-considerations-07>.
[I-D.ietf-tvr-alto-exposure] [I-D.ietf-tvr-alto-exposure]
Contreras, L. M., "Using ALTO for exposing Time-Variant Contreras, L. M., "Using off-path mechanisms for exposing
Routing information", Work in Progress, Internet-Draft, Time-Variant Routing information", Work in Progress,
draft-ietf-tvr-alto-exposure-00, 23 December 2024, Internet-Draft, draft-ietf-tvr-alto-exposure-02, 5 July
<https://datatracker.ietf.org/doc/html/draft-ietf-tvr- 2025, <https://datatracker.ietf.org/doc/html/draft-ietf-
alto-exposure-00>. tvr-alto-exposure-02>.
[I-D.ietf-tvr-requirements] [I-D.ietf-tvr-requirements]
King, D., Contreras, L. M., Sipos, B., and L. Zhang, "TVR King, D., Contreras, L. M., Sipos, B., and L. Zhang, "TVR
(Time-Variant Routing) Requirements", Work in Progress, (Time-Variant Routing) Requirements", Work in Progress,
Internet-Draft, draft-ietf-tvr-requirements-05, 3 March Internet-Draft, draft-ietf-tvr-requirements-05, 3 March
2025, <https://datatracker.ietf.org/doc/html/draft-ietf- 2025, <https://datatracker.ietf.org/doc/html/draft-ietf-
tvr-requirements-05>. tvr-requirements-05>.
[I-D.ietf-tvr-schedule-yang] [I-D.ietf-tvr-schedule-yang]
Qu, Y., Lindem, A., Kinzie, E., Fedyk, D., and M. Qu, Y., Lindem, A., Kinzie, E., Fedyk, D., and M.
Blanchet, "YANG Data Model for Scheduled Attributes", Work Blanchet, "YANG Data Model for Scheduled Attributes", Work
in Progress, Internet-Draft, draft-ietf-tvr-schedule-yang- in Progress, Internet-Draft, draft-ietf-tvr-schedule-yang-
03, 20 October 2024, 05, 4 July 2025, <https://datatracker.ietf.org/doc/html/
<https://datatracker.ietf.org/doc/html/draft-ietf-tvr- draft-ietf-tvr-schedule-yang-05>.
schedule-yang-03>.
[I-D.irtf-nmrg-green-ps]
Clemm, A., Pignataro, C., Westphal, C., Ciavaglia, L.,
Tantsura, J., and M. Odini, "Challenges and Opportunities
in Management for Green Networking", Work in Progress,
Internet-Draft, draft-irtf-nmrg-green-ps-06, 15 March
2025, <https://datatracker.ietf.org/doc/html/draft-irtf-
nmrg-green-ps-06>.
[I-D.pignataro-enviro-sustainability-architecture] [I-D.pignataro-enviro-sustainability-architecture]
Pignataro, C., Rezaki, A., Krishnan, S., Arkko, J., Clemm, Pignataro, C., Rezaki, A., Krishnan, S., Arkko, J., Clemm,
A., and H. ElBakoury, "Architectural Considerations for A., ElBakoury, H., and S. Prabhu, "Architectural
Environmental Sustainability", Work in Progress, Internet- Considerations for Environmental Sustainability", Work in
Draft, draft-pignataro-enviro-sustainability-architecture- Progress, Internet-Draft, draft-pignataro-enviro-
01, 27 December 2024, sustainability-architecture-02, 12 May 2025,
<https://datatracker.ietf.org/doc/html/draft-pignataro- <https://datatracker.ietf.org/doc/html/draft-pignataro-
enviro-sustainability-architecture-01>. enviro-sustainability-architecture-02>.
[I-D.pignataro-enviro-sustainability-consid]
Pignataro, C., Rezaki, A., Arkko, J., Clemm, A.,
ElBakoury, H., and S. Prabhu, "Sustainability
Considerations for Networking Protocols and Applications",
Work in Progress, Internet-Draft, draft-pignataro-enviro-
sustainability-consid-02, 12 May 2025,
<https://datatracker.ietf.org/doc/html/draft-pignataro-
enviro-sustainability-consid-02>.
[LCAandUsage]
Weppe, O., Bekri, D., Guibert, L., Aubet, L., Prévotet,
J., Pelcat, M., and S. Rumley, "Carbon Topography
Representation: Improving Impacts of Data Center
Lifecycle", Proceedings of the 4th Workshop on Sustainable
Computer Systems (HotCarbon'25) , 2025.
[LinkAggregation] [LinkAggregation]
"IEEE Standard for Local and Metropolitan Area Networks-- "IEEE Standard for Local and Metropolitan Area Networks--
Link Aggregation", IEEE STD 802.1AX-2020 (Revision of IEEE Link Aggregation", IEEE STD 802.1AX-2020 (Revision of IEEE
STD 802.1AX-2014): 1–333. doi:10.1109/ STD 802.1AX-2014): 1–333. doi:10.1109/
IEEESTD.2020.9105034. ISBN 978-1-5044-6428-4 , May 2020. IEEESTD.2020.9105034. ISBN 978-1-5044-6428-4 , May 2020.
[LoadShifting] [LoadShifting]
Mathew, V., Sitaraman, R. K., and P. Shenoy, "Reducing Mathew, V., Sitaraman, R. K., and P. Shenoy, "Reducing
energy costs in Internet-scale distributed systems using energy costs in Internet-scale distributed systems using
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[Unifying] Ishii, K., Kurumida, J., K.-i Sato, Kudoh, T., and S. [Unifying] Ishii, K., Kurumida, J., K.-i Sato, Kudoh, T., and S.
Namiki, "Unifying Top-Down and Bottom-Up Approaches to Namiki, "Unifying Top-Down and Bottom-Up Approaches to
Evaluate Network Energy Consumption", In Journal of Evaluate Network Energy Consumption", In Journal of
Lightwave Technology, vol. 33, no. 21, pp. 4395-4405, doi: Lightwave Technology, vol. 33, no. 21, pp. 4395-4405, doi:
10.1109/JLT.2015.2469145 , November 2015. 10.1109/JLT.2015.2469145 , November 2015.
[UNSDG] "United Nations Sustainable Development Goals", [UNSDG] "United Nations Sustainable Development Goals",
https://unstats.un.org/sdgs , 2017. https://unstats.un.org/sdgs , 2017.
Appendix A. Modeling Approaches and Literature
The paper [Modeling] provides a model for IP Routers and the routers
of other future Internet architectures (FIA) such as SCION and
NEBULA. They use a generic model which captures the commonalities of
IP router as well as the peculiarities of FIA routers. They conduct
a large-scale simulation based on this router model to estimate the
power consumption for different network architectures.
Since routers and other network devices and functions can be
virtualized, this article (1) provides comprehensive "graphical,
analytical survey of the literature, over the period 2010–2020, on
the measurement of power consumption and relevant power models of
virtual entities as they apply to the telco cloud." This paper A
Methodology and Testbed to Develop an Energy Model for 5G Virtualized
RANs IEEE Conference Publication IEEE Xplore got best paper award for
GreenNet 2024, but I am not sure if we are interested to model 5G
vRAN.
There is a plethora of publications on modeling communication
networks and DC computing.
A.1. Customer Attribution
When organizations assess their Scope 3 emissions, they need to sum
up their share of emissions from all their suppliers, one of which
for example, might be a cloud hosting service. In order for the
supplier to provide an emission share value back to the customer, the
provider needs to develop a mechanism for attribution.
A significant challenge in accurately assessing Scope 3 emissions is
avoiding Double Counting, where the same emission is reported by
multiple entities. According to the GHG Protocol best practices, it
is crucial to establish clear guidelines and agreements between
suppliers and customers to ensure that emissions are attributed
correctly and not counted multiple times. This requires transparent
communication and precise emission reporting standards to ensure that
all parties involved have a consistent understanding of which
emissions belong to which organization.
By addressing the Double Counting issue, companies can achieve more
accurate and reliable Scope 3 emissions assessments, thereby
contributing to better overall sustainability reporting and
improvement efforts.
A.2. Baselining and Benchmarking
Establishing a baseline is a fundamental step in the process of
improving energy efficiency and sustainability of network technology.
Baselining involves establishing a reference point of typical energy
usage, which is crucial for identifying inefficiencies and measuring
improvements over time. In this step, the controller uses only the
collected data from datasheets and other reliable sources.
By establishing a baseline and using benchmarking, organizations can
determine if their networking equipment is performing normally or if
it is deviating from expected performance. This is the first step in
identifying and guiding necessary improvements. Benchmarking
involves collecting performance measurements of networking equipment
under controlled conditions. This process helps establish
standardized performance metrics, allowing for comparison against
baselines collected during regular operational conditions.
The initial measurement of networking equipment's energy efficiency
and performance, known as Baselining, should be coordinated with
vendor specifications and industry standards to understand what is
considered normal or optimal performance. For example, if the
baseline indicates that your switches operate at 5 Gbps per watt,
while vendor specifications suggest 8 Gbps per watt and the industry
standard is 10 Gbps per watt, actions should be taken to implement
energy-saving measures and upgrades. Continuously tracking
subsequent measurements can reveal if efficiency improves towards the
benchmark of 8-10 Gbps per watt.
This practice ensures that any improvements can be quantifiably
tracked over time, providing a clear measure of the effectiveness of
the implemented changes and guiding further enhancements in network
sustainability.
See also [Baseline] and [BenchmarkingFramework].
Acknowledgments Acknowledgments
Everyone on the author section has contributed to the document in Everyone on the author section has contributed to the document in
significant ways. The author list has been ordered in (reverse) significant ways. The author list has been ordered in (reverse)
alphabethical order. alphabethical order.
Parts of this document extensively leverage ideas and text from Parts of this document extensively leverage ideas and text from
[I-D.cparsk-eimpact-sustainability-considerations] and [I-D.cparsk-eimpact-sustainability-considerations] and
[I-D.pignataro-enviro-sustainability-architecture] and associated [I-D.pignataro-enviro-sustainability-architecture] and associated
discussions in the IETF, IRTF, and IAB groups. We acknowledge and discussions in the IETF, IRTF, and IAB groups. We acknowledge and
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