wdiff rfc9547v1.txt rfc9547.txt

Internet Architecture Board (IAB) J. Arkko
Request for Comments: 9547 Ericsson
Category: Informational C. S. Perkins
ISSN: 2070-1721 University of Glasgow
Category: Informational S. Krishnan
Cisco
ISSN: 2070-1721 February 2024

Report from the IAB Workshop on Environmental Impact of Internet
Applications and Systems, 2022

Abstract

Internet communications and applications have both environmental
costs and benefits. The IAB ran an online workshop in December 2022
to explore and understand these impacts.

The role of the workshop was to discuss the impacts and the evolving
industry needs, and to identify areas for improvements and future
work. A key goal of the workshop was to call further attention to
the topic and bring together a diverse stakeholder community to
discuss these issues.

This

Note that this document is a report summarizes on the proceedings of the
workshop. The views and positions documented in this report are
those of the workshop inputs participants and discussions. do not necessarily reflect IAB
views and positions.

Status of This Memo

This document is not an Internet Standards Track specification; it is
published for informational purposes.

This document is a product of the Internet Architecture Board (IAB)
and represents information that the IAB has deemed valuable to
provide for permanent record. It represents the consensus of the
Internet Architecture Board (IAB). Documents approved for
publication by the IAB are not candidates for any level of Internet
Standard; see Section 2 of RFC 7841.

Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9547.

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

Table of Contents

1. Introduction
1.1. About the Contents of This Workshop Report
2. Scope
2.1. Practical Arrangements
3. Workshop Topics and Discussion
3.1. The Big Picture
3.2. Understanding the Impacts
3.3. Improvements
3.4. Next Steps
3.4.1. Overall Strategy
3.4.2. Improvements
3.4.3. Actions
4. Feedback
5. Security Considerations
6. IANA Considerations
7. Position Papers
8. Program Committee
9. Informative References
Appendix A. Workshop Participants
IAB Members at the Time of Approval
Acknowledgments
Authors' Addresses

1. Introduction

The IAB ran an online workshop in December 2022 to explore and
understand the environmental impacts of the Internet.

The background context for the workshop was that Internet communications and
applications have both environmental costs and benefits. In the
positive direction, they can reduce the environmental impact of our
society, for instance, by allowing virtual interaction to replace
physical travel. On the other hand, the Internet can just as equally well
act as an enabler for increasing the consumption of physical goods, goods consumption, for
instance, by facilitating commerce.

Beyond the effects associated with its use, Internet applications do
not come for free either. The Internet runs on systems that require
energy and raw materials to manufacture and operate. While the
environmental benefits of the Internet may certainly outweigh this
use of resources in many cases, it is incumbent on the Internet
industry to ensure that this use of resources is minimized and
optimized. In many cases, this is already an economic necessity due
to operational costs. And because many consumers, businesses, and
civil societies care deeply about the environmental impact of the
services and technologies they use, there is also a clear demand for
providing Internet services with minimal environmental impact.

The role of the workshop was to discuss the Internet's environmental
impact and the evolving industry needs, and to identify areas for
improvements and future work. A key goal of the workshop was to call
further attention to the topic and bring together a diverse
stakeholder community to discuss these issues. This report
summarizes the workshop inputs and discussions.

The workshop drew many position paper submissions. Of these, 26 were
accepted and published to stimulate discussion. There were active
discussions both in the meeting and on the workshop mailing list with
73 participants altogether.

Perhaps the main overriding observation is how much interest and
urgency there is on this topic, among engineers, researchers, and
businesses.

The workshop discussions and conclusions are covered in Section 3.
The position papers and links to recordings of workshop sessions can
be found at <https://www.iab.org/activities/workshops/e-impact/>.
Presentations held during and related materials from the discussions can be found in workshop are available
from the IETF Datatracker at <https://datatracker.ietf.org/group/eimpactws/
meetings/>.

Discussion at
<https://datatracker.ietf.org/group/eimpactws/meetings/>.

After the workshop, the IETF will continue after the workshop, both around to discuss general topics
and specific proposals as well as general discussion on a new mailing list, the e-impact list
(e-impact@ietf.org). You can subscribe to this list at
<https://www.ietf.org/mailman/listinfo/e-impact>.

Some

The IETF is discussing improvements addressing for some specific situations are being discussed
at the IETF, situations,
such as the Time Variant Time-Variant Routing (TVR) proposal, which can help
optimize connectivity with systems that are periodically on or
reachable (such as satellites). We expect more proposals in the
future.

1.1. About the Contents of This Workshop Report

This document is a report on the proceedings of the workshop.

The
views Internet Architecture Board (IAB) holds occasional workshops
designed to consider long-term issues and positions documented in this report are those expressed
during strategies for the workshop by participants
Internet, and do not necessarily reflect to suggest future directions for the Internet
architecture. This long-term planning function of the IAB views and positions. is
complementary to the ongoing engineering efforts performed by working
groups of the Internet Engineering Task Force (IETF).

Furthermore, the content of this report comes from presentations
given by workshop participants and notes taken during the
discussions, without interpretation or validation. Thus, the content
of this report follows the flow and dialog of the workshop and
documents a few next steps and actions, but it does not attempt to
determine or record consensus on these.

2. Scope

Environmental impact assessments and improvements are broad topics,
ranging from technical questions to economics, business decisions,
and policies.

The technical, standards, and research communities can help ensure
that we have a sufficient understanding of the environmental impact
of the Internet and its applications. They can also help to design
the right tools to continue to build and improve all aspects of the
Internet, such as addressing new functional needs, easing of
operations, improving performance and/or efficiency, or reducing
environmental impacts in other ways.

The following topics were expected to be discussed at the workshop:

* The direct environmental impacts of the Internet, including but
not limited to energy usage by Internet systems themselves (the
network equipment along with the associated power and cooling
infrastructure), energy usage of the relevant end-user devices,
resources needed for manufacturing the associated devices, or the
environmental impacts throughout the life cycle of Internet
systems. This included discussion about the breakdown of those
impacts across different system components and operations and
predictions about the potential future trends for these impacts
based on changed usage patterns and emerging technologies.

* The indirect environmental impacts of the Internet, i.e., its
effects on society through enabling communications, virtual
services, or global commerce.

* Sharing information about relevant measurement metrics and data
and identifying the need for additional metrics or measurements.

* The need for improvements or new associated functionality.

* Sharing information about the societal, business, and regulatory
situation to help identify areas of opportunity.

* Identifying areas where further technical work would be most
impactful.

* Specific improvement proposals.

* Past work in the IETF, IRTF, and IAB in this area and the status
of such work.

* Observed user behaviors as they relate to environmental impacts.

We expected the workshop discussions to connect analysis of the
issues (e.g., scale of energy consumption or carbon footprint) to
industry needs (e.g., deployment opportunities) and solutions.

Business and societal policy questions were in scope only insofar as
they informed the workshop participants about the context we are in,
but what those policies should be was not for the workshop to decide
or even extensively discuss. The scope also excluded how the
technical community works and meets, such as the question of in-
person or hybrid meetings (although it should be noted that the
workshop itself was run as an online meeting).

2.1. Practical Arrangements

The IAB discussed a potential workshop in this area during its May
2022 retreat. A call for position papers went out in August 2022.
Position papers were to be submitted by end of October, a deadline
that was later extended by one week.

As noted, the workshop itself was run as an online meeting, with four
half-day sessions complemented by email discussions and the position
papers submitted by the participants.

All in all, 73 people participated in at least one session in the
workshop. Participation was by invitation only, based on the
position paper submissions.

Every submission was read by at least three members of the program
committee, and acceptance decisions were communicated back to the
authors. Review comments were provided to authors for information,
and some of the papers were revised before the workshop.

The program committee decided that due to interest and differing
areas of expertise, all co-authors were to be invited; most of them
attended. The program committee also invited a handful of additional
participants that were seen as providing valuable input. Similarly,
as is traditional has been done in previous IAB workshops, the program committee
members and members of the IAB and IESG were offered an opportunity
to participate, even in cases where they did not submit a position
paper.

The IETF Secretariat and communications staff provided practical
support during the process, sending announcements, maintaining the
workshop web page with position papers, setting up mailing lists,
tracking submissions, helping with blog article submissions, and so
on.

3. Workshop Topics and Discussion

The meeting part of the workshop was divided into four sessions:

* The first session was about the big picture and relationships
between different aspects of sustainability (see Section 3.1).

* The second session focused on what we know and do not know and how
we can measure environmental impacts (see Section 3.2).

* The third session was about potential improvements (see
Section 3.3).

* The final fourth session was about conclusions and next steps (see
Section 3.4).

3.1. The Big Picture

This session was about the big picture and how the Internet
influences the rest of the society. We also spoke about the goals of
the workshop.

The session began with a discussion about what is overall involved in
this topic. We also looked at how the IETF has approached this topic
in the past.

The discussions also expressed the urgency of action and the
importance of continuous improvement, i.e., an incremental change
every year is needed for larger savings at the end of the decade. We
continued to talk about the need to recognize how climate change
impacts different communities in the world, often unfairly. Finally,
we focused on the need to be aware of carbon footprint rather than
pure energy consumption -- carbon intensity of energy sources varies.

The starting observation from this session was that the issue is much
bigger than Internet technology alone. The issue influences all
parts of society, even matters such as (in)equality, externalized
costs, and justice. Another key observation was that improvements
come in many forms; there is no silver bullet. The opportunity to
bring people with different backgrounds together helped us see how we
approach the topic from different angles -- none of them wrong, but
also none of them are the sole angle to focus on either. Only the
combined effects of complementary efforts can provide the required
level of changes.

Some of the useful tools for approaching the issue of course included
technical solutions but also solidarity, aiming for sufficiency, and
awareness. It is important to not stand still waiting for the
perfect solution. Renewable energy and carbon awareness were seen as
a part of the solution but not sufficient by themselves.

As an example demonstration of the diversity of angles and
improvements relating to environmental issues, the figure below
classifies the areas that workshop position papers fell on:

Figure 1: Position Paper Submission Topics

Some of the goals for the IETF should include:

* Connecting the IETF with others. Given that the issue is broad,
it is difficult for one Standards Development Organization (SDO)
alone to make a significant impact or even have the full picture.
Working in collaboration with others is necessary, and
understanding the situation beyond technology will be needed.

* Continuous improvement. It is important that the IETF (among
others) set itself on a continuous improvement cycle. No single
improvement will change the overall situation sufficiently, but
over a longer period of time, even smaller changes every year will
result in larger improvements.

* Finding the right targets for improvements in the Internet. These
should perhaps not be solely defined by larger speeds or bigger
capacity but rather increased usefulness to society and declining
emissions from the Information and Communications Technology (ICT)
sector.

* Specifying what research needs to be done, i.e., where additional
knowledge would allow us to find better improvements. For
instance, not enough is known about environmental impacts beyond
energy, such as natural resources used for manufacturing or the
use of water. Carbon awareness and measurements across domains
are also poorly understood today. And business model impacts --
such as the role of advertising on the Internet's carbon footprint
-- deserve more study.

3.2. Understanding the Impacts

The second session focused on what we know and do not know and how we
can measure environmental impacts.

The initial presentation focused on narrowing down the lower and
upper limits of the energy use of the Internet and putting some
common but erroneous claims into context. There was also discussion
regarding the energy consumption of the ICT sector and how it
compares to some other selected industries, such as aviation.

Dwelling deeper into the energy consumption and the carbon footprint
of the ICT sector, there was discussion regarding how the impact was
split amongst the networks, data centers, and user devices (with the
user devices appearing to contribute to the largest fraction of
impact). Also, while a lot of the energy-consumption-related studies
and discussions have been focused on data centers, some studies
suggested that data center energy usage is still a small fraction of
energy use as compared to residential and commercial buildings.

There were also further discussions during both the presentations and
in the hallway chats regarding the press and media coverage of the
potential environment technologies. The overall sense of the
participants seemed to be that there was a lot of sensational
headlines, but they were not really backed by measurements done by
the industry and academia and were fraught with errors. Some of
these media reports were off by quite a bit, sometimes even by an
order of magnitude (e.g., confusing MBps vs. Mbps in calculations).
The potential harm of having widely circulating misinformation was
noted; it can hinder realistic efforts to reduce carbon emissions.

In the rest of the session, we looked at both additional data
collected from the operators as well as factors that -- depending on
circumstances -- may drive energy consumption. For instance, these
include peak capacity and energy proportionality.

If energy consumption is minimally affected by an offered load, the
ratio of peak capacity to typical usage becomes a critical factor in
energy consumption. On the other hand, systems with energy
proportionality scale their resource and energy consumption more
dynamically based on the offered load. The lack of energy
proportionality in many parts of the network infrastructure was
noted, along with the potential gains if it can be improved.

There were also observations that showed that the energy consumption
grew as a step function when the peak capacity was reached (even
instantaneously), and additional capacity was built up by performing
network upgrades to handle these new peaks. This resulted in an
overall higher baseline energy consumption, even when the average
demand did not change that much. Thus, the ability to shift load to
reduce peak demand was highlighted as a potential way to delay
increases in consumption when energy proportionality is lacking.

3.3. Improvements

The third session was about potential improvements.

As noted earlier, there are many different types of improvements. In
the discussion, we focused mostly on protocol aspects and looked at
metrics, telemetry, routing, multicast, and data encoding formats.

The two initial presentations focused on metrics and telemetry with
the premise that visibility is a very important first step
(paraphrasing Peter Drucker's mantra of "You cannot improve what you
don't measure"). There was a discussion of the scopes of emissions,
and it seemed that, from a networking vendor perspective, while
directly controlled emissions and emissions from purchased energy are
easily measurable, emissions from across the entire value chain can
be much larger. Thus, it seemed important that networking vendors
put effort into helping their customers measure and mitigate their
environmental impact as well. The need for standardized metrics was
very clear, as it helps avoid proprietary, redundant, and even
contradictory metrics across vendors.

The initial and the near-term focus was related to metrics and
techniques related to energy consumption of the networking devices
themselves, while the longer term focus can go into topics much
further removed from the IETF circular design, such as packaging, in
order to form a more holistic picture. The overall feeling was that
the topics of metrics, telemetry, and management are quite specific
and could be targets to be worked on in the IETF in the near term.

The next part of the discussion highlighted the need to understand
the trade-offs involved in changing forwarding decisions -- such as
increased jitter and stretch. Jitter is about delay fluctuation
between packets in a stream [RFC4689]. Stretch is defined as the
difference between the absolute shortest path traffic could take
through the network and the path the traffic actually takes
[RFC7980]. Impacts on jitter and stretch point to the need for
careful design and analysis of improvements from a system perspective
to ensure that the intended effect is indeed reached across the
entire system and is not only a local optimum.

We also talked about the potentially significant impact, provided the
network exhibits energy proportionality, of using efficient binary
formats instead of textual representations when carrying data in
protocols. This is something that can be adopted relatively easily
in new protocols as they are developed. Indeed, some recently
finished protocols, such as HTTP/2, have already chosen to use this
technique [RFC9113]. General-purpose binary formats, such as Concise
Binary Object Representation (CBOR) [RFC8949], are also available for
use.

There were also some interesting discussions regarding the use of
multicast and whether it would help or hurt on the energy efficiency
of communications. There were some studies and simulations that
showed the potential gains to be had, but they were to be balanced
against some of the well-known barriers to deployment of multicast.
We also heard from a leading Content Delivery Network (CDN) operator
regarding their views on multicast and how it relates to media usage
and consumption models. The potential negative effects of multicast
in wireless and constrained networks were also discussed in hallway
conversations. Overall, the conclusion was that the use of multicast
can potentially provide some savings but only in some specific
scenarios.

For all improvements, the importance of metrics was frequently
highlighted to ensure changes lead to a meaningful reduction in the
overall system carbon footprint. footprint of systems.

3.4. Next Steps

The fourth and final session was about conclusions and next steps.
This section highlights some of these conclusions.

3.4.1. Overall Strategy

While only a few things are easy, the road ahead for making
improvements seems clear: we need to continue to improve our
understanding of the environmental impact and have a continuous cycle
of improvements that lead not just to better energy efficiency but to
reduced overall carbon emissions. The IETF can play an important
part in this process, but of course there are other aspects beyond
protocols.

On understanding our environmental impact, the first step is better
awareness of sustainability issues in general, which helps us better
understand where our issues are. The second step is willingness to
understand in detail what the causes and relationships are within our
issues. What parts, components, or behaviors in the network cause
what kinds of impacts? An overall drive in the society to report and
improve environmental impacts can be helpful in creating a
willingness to get to this information.

On establishing a continuous cycle of improvements, the ability to
understand where we are, making improvements, and then seeing the
impact of those improvements is of course central. But obviously the
key questions are what are the potential improvements and how can we
accelerate them? It should be noted that quick, large changes are
not likely. But a continuous stream of smaller changes can create a
large impact over a longer period of time.

One of the key realizations from this workshop was that the problem
to be solved is very large and complex; therefore, there is no single
solution that fixes everything. There are some solutions that could
help in the near term and others that would only show benefits over
longer periods, but they are both necessary.

One further challenge is that due to the size and complexity of the
problem, there are likely varying opinions on what Key Performance
Indicators (KPIs) need to be measured and improved.

3.4.2. Improvements

In looking at potential improvements, it is essential that any
associated trade-offs be understood (note that not all improvements
do indeed entail a trade-off).

Importantly, the role of the Internet in improving other areas of
society must not be diminished. Understanding the costs and benefits
requires taking a holistic view of energy consumption, focusing not
just on the carbon footprint of the Internet but of the broader
systems in which it is used. For instance, discussion in session
three revealed how some changes might impact latency and jitter.
Given that these characteristics are important factors in how virtual
meetings are perceived by potential participants, it is important
that the performance of networks satisfy these participants at a
level such that they are willing to use them over other potentially
more environmentally harmful methods, such as travel. Focusing
solely on the carbon footprint of the Internet, or solely on the
carbon footprint of travel, risks missing the bigger picture
potential savings.

Note that, while shifting to virtual meetings are is a common example, example of
how the carbon footprint could be decreased, it is important to
consider different use cases, some of which may not be as obvious to
us human users as meetings are. Improvements may bring different or
even larger impacts in other situations, e.g., Internet-
connected Internet-connected
electronics might benefit from different characteristics than human
users, e.g., with regards to support for intermittent connectivity.

The relationships between different system components and the impact
of various detailed design choices in networks are not always
apparent. A local change in one node may have an impact in other
nodes. When considering environmental sustainability, in most cases,
the overall system impact is what counts more than local impacts. Of
course, other factors, such as device battery life and availability
of power, may result in other preferences, such as optimizing for
low-power usage of end-user devices, even at the cost of increases
elsewhere.

In terms of useful tools for building improvements, the following
were highlighted in discussions:

* Measures beyond protocol design, such as implementations or
renewable energy use. Not everything is about protocols.

* Metrics, measurements, and data are very beneficial. Carbon-aware
metrics in particular would be very useful. All additional
information makes us more aware of what the environmental impacts
are, and it also enables optimization, adjustments based on
Artificial Intelligence (AI), carbon-directed computing and
networking tools, and so on.

* It would be beneficial to be able to provide various systems a
more dynamic ability to slow down and sleep. Awareness of energy
availability and type would also allow us to employ time and place
shifting for reducing carbon impacts.

* When we design systems, paying attention to the used data formats
may pay off significantly, as argued in [Moran].

* There's a new possible opportunity for deploying multicast as well
[Navarre].

* Designing systems for energy-constrained situations may actually
make the resulting systems work well in several environments.

3.4.3. Actions

The workshop discussed a number of possible actions. These actions
are not about how to take specific technical solutions forward but
rather about how to discuss the topic going forward or what technical
areas to focus on:

* We need to continue the discussion -- not all questions are
answered. Additional discussion within the IETF will be needed.
Continuing to connect the IETF with others in society and other
SDOs around this topic is also useful.

* It is useful to find a role and a scope for IETF work in this
area. The IETF will not develop alternative energy sources, work
on social issues, or have detailed discussions about
implementation strategies or electronics design. However, the
IETF has a role in measurement mechanisms, protocol design, and
standards -- but of course, activities in this role need to be
aware of other aspects, such as implementation strategies.

* Increase our understanding of the environmental impacts of
Internet technologies. One discussion topic that arose during the
workshop was whether each new RFC should dedicate a section to
discuss these impacts. No conclusion was drawn about the way to
document these in RFCs, but it is clear that the IETF community
will need to understand the environmental issues better. (Perhaps
in addition to learning about the actual issues, guidelines for
analyzing protocols with regards to their impacts could be
useful.)

* IETF activities on specific technologies are already ongoing or
starting, such as metrics discussed,
starting; for instance, at example, metrics are being discussed in the Network
Management Research Group [NMRG], the Operations and Management
Area Working Group [OPSAWG], or and the new Time-Variant Routing
Working Group [TVRWG]. It may also be useful to start with the
low-hanging fruits, such as:

- Focusing on improving energy proportionality and the consequent
use of efficient data formats.

- Avoiding crypto assets -- such as Non-Fungible Tokens (NFTs)
and cryptocurrencies.

- Being able to carry information that needs to be shared for the
purposes of enabling load and time shifting.

* Help initiate research activities that address some of the issues,
such as broader gathering and sharing of measurement data,
analysis of this data, and examination of business-related issues,
such as how peering or advertising impacts sustainability. In
addition, there may be a need to look at research for specific
areas of improvements that are promising but not ready for
standards discussion.

In summary, the goals that the IETF should have include:

* Full understanding of the Internet's environmental impact.

* Continuous improvement of our technology.

* Launching research-relevant activities.

To support these goals, the IAB has created the e-impact program
[E-IMPACT] as a venue for further discussions concerning
environmental impacts and sustainability of Internet technology.

4. Feedback

The organizers received generally positive feedback about the
workshop.

One practical issue from the organizer's point of view was that, due
to the extension of the deadline, the final submissions and paper
reviews collided in part with the IETF 115 meeting. This led to it
being very difficult for the program committee and practical
organization staff to find time for the activity. We recommend
avoiding such collisions in the future.

5. Security Considerations

The workshop itself did not address specific security topics. Of
course, individual changes in Internet technology or operations that
influence environmental impacts may also influence security aspects.
These need to be looked at for every proposed change.

Such influence on security may come in different forms. For
instance:

* A mechanism that makes, for instance, makes energy consumption information available
may be susceptible to tampering or providing false information.
For example, in [McDaniel], the author argues that economics and
history show that different players will attempt to cheat if a
benefit can be accrued by doing so, e.g., by misreporting. As a
result, sustainability measures and systems must be modeled as
systems under threat.

* A mechanism that allows control of network elements for
optimization purposes may be misused to cause denial-of-service or
other types of attacks.

* Avoiding the use of crypto assets where other mechanisms suffice.

* Streamlining what data is sent may improve privacy if less
information is shared.

6. IANA Considerations

This document has no IANA actions.

7. Position Papers

The following position papers were submitted to the workshop:

* Chris Adams, Stefano Salsano, Hesham ElBakoury: "Extending IPv6 to
support Carbon Aware Networking" [Adams]

* Per Anderson, Suresh Krishnan, Jan Lindblad, Snezana Mitrovic,
Marisol Palmero, Esther Roure, Gonzalo Salgueiro: "Sustainability
Telemetry" [Anderson]

* Jari Arkko, Nina Lövehagen, Pernilla Bergmark: "Environmental
Impacts of the Internet: Scope, Improvements, and Challenges"
[Arkko]

* R. Bolla, R. Bruschi, F. Davoli, C. Lombardo, Beatrice Siccardi:
"6Green: Green Technologies for 5/6G Service-Based Architectures"
[Bolla]

* Alexander Clemm, Lijun Dong, Greg Mirsky, Laurent Ciavaglia, Jeff
Tantsura, Marie-Paule Odini: "Green Networking Metrics" [ClemmA]

* Alexander Clemm, Cedric Westphal, Jeff Tantsura, Laurent
Ciavaglia, Marie-Paule Odini, Michael Welzl: "Challenges and
Opportunities in Green Networking" [ClemmB]

* Toerless Eckert, Mohamed Boucadair, Pascal Thubert, Jeff Tantsura:
"IETF and Energy - An Overview" [Eckert]

* Greening of Streaming: "Tune In. Turn On. Cut Back. Finding the
optimal streaming 'default' mode to increase energy efficiency,
shift consumer expectations, and safeguard choice" [GOS]

* Romain Jacob: "Towards a power-proportional Internet" [Jacob]

* Fieke Jansen and Maya Richman: "Environment, internet
infrastructure, and digital rights" [Jansen]

* Michael King, Suresh Krishnan, Carlos Pignataro, Pascal Thubert,
Eric Voit: "On Principles for a Sustainability Stack" [King]

* Suresh Krishnan, Carlos Pignataro: "Sustainability considerations
for networking equipment" [Krishnan]

* Jukka Manner: "Sustainability Considerations" [Manner]

* Vesna Manojlovic: "Internet Infrastructure and Climate Justice"
[Manojlovic]

* Mike Mattera: "Understanding the Full Emissions Impact from
Internet Traffic" [Mattera]

* John Preuß Mattsson: "Environmental Impact of Crypto-Assets"
[Mattsson]

* Brendan Moran, Henk Birkholz, Carsten Bormann: "CBOR is Greener
than JSON" [Moran]

* Louis Navarre, Franoçis Michel, Olivier Bonaventure: "It Is Time
to Reconsider Multicast" [Navarre]

* Bruce Nordman: "Applying Internet Architecture to Energy Systems"
[Nordman]

* Alvaro Retana, Russ White, Manuel Paul: "A Framework and
Requirements for Energy Aware Control Planes" [Retana]

* Shayna Robinson, Remy Hellstern, Mariana Diaz: "Sea Change:
Prioritizing the Environment in Internet Architecture" [Robinson]

* Daniel Schien, Paul Shabajee, Chris Preist: "Rethinking Allocation
in High-Baseload Systems: A Demand-Proportional Network
Electricity Intensity Metric" [Schien]

* Eve M. Schooler, Rick Taylor, Noa Zilberman, Robert Soulé, Dawn
Nafus, Rajit Manohar, Uri Cummings: "A Perspective on Carbon-aware
Networking" [Schooler]

* Selome Kostentinos Tesfatsion, Xuejun Cai, Arif Ahmed: "End-to-end
Energy Efficiency at Service-level in Edge Cloud" [Kostentinos]

* Pascal Thubert: "Digital Twin and Automation" [Thubert]

* Wim Vanderbauwhede: "Frugal Computing" [Vanderbauwhede]

* Michael Welzl, Ozgu Alay, Peyman Teymoori, Safiqul Islam:
"Reducing Green House Gas Emissions With Congestion Control"
[Welzl]

8. Program Committee

The program committee members were:

* Jari Arkko, Ericsson (program committee co-chair)

* Lars Eggert, Netapp (program committee co-chair)

* Colin Perkins, University of Glasgow (program committee co-chair)

* Luis M. Contreras, Telefónica

* Toerless Eckert, Futurewei

* Martin Flack, Akamai

* Mike Mattera, Akamai

* Colin Perkins, University of Glasgow

* Barath Raghavan, USC

* Daniel Schien,University Schien, University of Bristol

* Eve M. Schooler, Intel

* Rick Taylor, Ori Industries

* Jiankang Yao, CNNIC

9. Informative References

[Adams] Adams, C., Salsano, S., and H. ElBakoury, "Extending IPv6
to support Carbon Aware Networking", Position paper in the
IAB Workshop on Environmental Impacts of Internet
Applications and Systems, December 2022.

[Anderson] Anderson, P., Krishnan, S., Lindblad, J., Mitrovic, S.,
Palmero, M., Roure, E., and G. Salgueiro, "Sustainability
Telemetry", Position paper in the IAB Workshop on
Environmental Impacts of Internet Applications and
Systems, December 2022.

[Arkko] Arkko, J., Lövehagen, N., and P. Bergmark, "Environmental
Impacts of the Internet: Scope, Improvements, and
Challenges", Position paper in the IAB Workshop on
Environmental Impacts of Internet Applications and
Systems, December 2022.

[Bolla] Bolla, R., Bruschi, R., Davoli, F., Lombardo, C., and B.
Siccardi, "6Green: Green Technologies for 5/6G Service-
Based Architectures", Position paper in the IAB Workshop
on Environmental Impacts of Internet Applications and
Systems, December 2022.

[ClemmA] Clemm, A., Dong, L., Mirsky, G., Ciavaglia, L., Tantsura,
J., and M. Odini, "Green Networking Metrics", Position
paper in the IAB Workshop on Environmental Impacts of
Internet Applications and Systems, December 2022.

[ClemmB] Clemm, A., Westphal, C., Tantsura, J., Ciavaglia, L.,
Odini, M., and M. Welzl, "Challenges and Opportunities in
Green Networking", Position paper in the IAB Workshop on
Environmental Impacts of Internet Applications and
Systems, December 2022.

[E-IMPACT] IAB, "Environmental Impacts of Internet Technology", IAB
Program, <https://datatracker.ietf.org/group/eimpact>.

[Eckert] Eckert, T., Ed., Boucadair, M., Ed., Thubert, P.,
Tantsura, J., and C. Pignataro, "An Overview of Energy-related Energy-
related Effort within the IETF", Work in Progress,
Internet-Draft, draft-eckert-
ietf-and-energy-overview-06, 5 draft-eckert-ietf-and-energy-overview-06,
6 January 2024,
<https://datatracker.ietf.org/doc/html/draft-eckert-ietf-
and-energy-overview-06>. <https://datatracker.ietf.org/doc/html/
draft-eckert-ietf-and-energy-overview-06>.

[GOS] Greening of Streaming, "Tune In. Turn On. Cut Back.
Finding the optimal streaming 'default' mode to increase
energy efficiency, shift consumer expectations, and
safeguard choice", Position paper in the IAB Workshop on
Environmental Impacts of Internet Applications and
Systems, December 2022.

[Jacob] Jacob, R., "Towards a power-proportional Internet",
Position paper in the IAB Workshop on Environmental
Impacts of Internet Applications and Systems, December
2022.

[Jansen] Jansen, F. and M. Richman, "Environment, internet
infrastructure, and digital rights", Position paper in the
IAB Workshop on Environmental Impacts of Internet
Applications and Systems, December 2022.

[King] King, M., Krishnan, S., Pignataro, C., Thubert, P., and E.
Voit, "On Principles for a Sustainability Stack", Position
paper in the IAB Workshop on Environmental Impacts of
Internet Applications and Systems, October 2022.

[Kostentinos]
Tesfatsion, S., Cai, X., and A. Ahmed, "End-to-end Energy
Efficiency at Service-level in Edge Cloud", Position paper
in the IAB Workshop on Environmental Impacts of Internet
Applications and Systems, December 2022.

[Krishnan] Krishnan, S. and C. Pignataro, "Sustainability
considerations for networking equipment", Position paper
in the IAB Workshop on Environmental Impacts of Internet
Applications and Systems, December 2022.

[Manner] Manner, J., "Sustainability Considerations", Position
paper in the IAB Workshop on Environmental Impacts of
Internet Applications and Systems, December 2022.

[Manojlovic]
Manojlovic, V., "Internet Infrastructure and Climate
Justice", Position paper in the IAB Workshop on
Environmental Impacts of Internet Applications and
Systems, October 2022.

[Mattera] Mattera, M., "Understanding the Full Emissions Impact from
Internet Traffic", Position paper in the IAB Workshop on
Environmental Impacts of Internet Applications and
Systems, October 2022.

[Mattsson] Preuß Mattsson, J., "Environmental Impact of Crypto-
Assets", Position paper in the IAB Workshop on
Environmental Impacts of Internet Applications and
Systems, December 2022.

[McDaniel] McDaniel, P., "Sustainability is a Security Problem", ACM
SIGSAC Conference on Computer and Communications Security
(CCS), November 2022.

[Moran] Moran, B., Birkholz, H., and C. Bormann, "CBOR is Greener
than JSON", Position paper in the IAB Workshop on
Environmental Impacts of Internet Applications and
Systems, October 2022.

[Navarre] Navarre, L., Michel, F., and O. Bonaventure, "It Is Time
to Reconsider Multicast", Position paper in the IAB
Workshop on Environmental Impacts of Internet Applications
and Systems, December 2022.

[NMRG] IRTF, "Network Management Research Group NMRG", IRTF
Research Group, March 1999,
<https://www.irtf.org/nmrg.html>.

[Nordman] Nordman, B., "Applying Internet Architecture to Energy
Systems", Position paper in the IAB Workshop on
Environmental Impacts of Internet Applications and
Systems, December 2022.

[OPSAWG] IETF, "Operations and Management Area Working Group
(opsawg)", IETF Working Group,
<https://datatracker.ietf.org/wg/opsawg/about/>.

[Retana] Retana, A., White, R., and M. Paul, "A Framework for
Energy Aware Control Planes", Work in Progress, Internet-
Draft, draft-retana-rtgwg-eacp-07, 24 August 2023,
<https://datatracker.ietf.org/doc/html/draft-retana-rtgwg-
eacp-07>.

[RFC4689] Poretsky, S., Perser, J., Erramilli, S., and S. Khurana,
"Terminology for Benchmarking Network-layer Traffic
Control Mechanisms", RFC 4689, DOI 10.17487/RFC4689,
October 2006, <https://www.rfc-editor.org/info/rfc4689>.

[RFC7980] Behringer, M., Retana, A., White, R., and G. Huston, "A
Framework for Defining Network Complexity", RFC 7980,
DOI 10.17487/RFC7980, October 2016,
<https://www.rfc-editor.org/info/rfc7980>.

[RFC8949] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", STD 94, RFC 8949,
DOI 10.17487/RFC8949, December 2020,
<https://www.rfc-editor.org/info/rfc8949>.

[RFC9113] Thomson, M., Ed. and C. Benfield, Ed., "HTTP/2", RFC 9113,
DOI 10.17487/RFC9113, June 2022,
<https://www.rfc-editor.org/info/rfc9113>.

[Robinson] Robinson, S., Hellstern, R., and M. Diaz, "Sea Change:
Prioritizing the Environment in Internet Architecture",
Position paper in the IAB Workshop on Environmental
Impacts of Internet Applications and Systems, December
2022.

[Schien] Schien, D., Shabajee, P., and C. Preist, "Rethinking
Allocation in High-Baseload Systems: A Demand-Proportional
Network Electricity Intensity Metric", Position paper in
the IAB Workshop on Environmental Impacts of Internet
Applications and Systems, December 2022.

[Schooler] Schooler, E., Taylor, R., Zilberman, N., Soulé, R., Nafus,
D., Manohar, R., and U. Cummings, "A Perspective on
Carbon-aware Networking", Position paper in the IAB
Workshop on Environmental Impacts of Internet Applications
and Systems, October 2022.

[Thubert] Thubert, P., "Digital Twin and Automation", Position paper
in the IAB Workshop on Environmental Impacts of Internet
Applications and Systems, December 2022.

[TVRWG] IESG, "Time-Variant Routing (tvr)", IETF Working Group,
<https://datatracker.ietf.org/group/tvr/about/>.

[Vanderbauwhede]
Vanderbauwhede, W., "Frugal Computing", Position paper in
the IAB Workshop on Environmental Impacts of Internet
Applications and Systems, December 2022.

[Welzl] Welzl, M., Alay, O., Teymoori, P., and S. Islam, "Reducing
Green House Gas Emissions With Congestion Control",
Position paper in the IAB Workshop on Environmental
Impacts of Internet Applications and Systems, October
2022.

Appendix A. Workshop Participants

The participants who attended at least one of the four sessions were:

* Alex Clemm

* Ali Rezaki

* Arif Ahmed

* Beatrice Siccardi

* Brendan Moran

* Bruce Nordman

* Carlos Pignataro

* Carsten Bormann

* Cedric Westphal

* Chiara Lombardo

* Chris Adams

* Colin Perkins

* Daniel Schien

* Dawn Nafus

* Dom Robinson

* Eric Voit

* Éric Vyncke

* Esther Roure Vila

* Eve M. Schooler

* Fieke Jansen

* Franco Davoli

* Gonzalo Salgueiro

* Greg Mirsky

* Henk Birkholz

* Hesham ElBakoury

* Hosein Badran

* Iankang Yao

* Jan Lindblad

* Jari Arkko

* Jens Malmodin

* Jiankang Yao

* John Preuß Mattsson

* Jukka Manner

* Julien Maisonneuve

* Kristin Moyer

* Lars Eggert

* Laurent Ciavaglia

* Lijun Dong

* Louis Navarre

* Louise Krug

* Luis M. Contreras

* Marisol Palmero Amador

* Martin Flack

* Maya Richman

* Michael Welzl

* Mike Mattera

* Mohamed Boucadair

* Nina Lövehagen

* Noa Zilberman

* Olivier Bonaventure

* Pascal Thubert

* Paul Shabajee

* Per Andersson

* Pernilla Bergmark

* Peyman Teymoori

* Qin Wu

* Remy Hellstern

* Rick Taylor

* Rob WIlton

* Rob Wilton

* Romain Jacob

* Russ White

* Safiqul Islam

* Selome Kostentinos Tesfatsion

* Shayna Robinson

* Snezana Mitrovic

* Stefano Salsano

* Suresh Krishnan

* Tirumaleswar Reddy.K

* Toerless Eckert

* Uri Cummings

* Vesna Manojlovic

* Wim Vanderbauwhede

IAB Members at the Time of Approval

Internet Architecture Board members at the time this document was
approved for publication were:

Dhruv Dhody
Lars Eggert
Wes Hardaker
Cullen Jennings
Mallory Knodel
Suresh Krishnan
Mirja Kühlewind
Tommy Pauly
Alvaro Retana
David Schinazi
Christopher Wood
Qin Wu
Jiankang Yao

Acknowledgments

Naturally, most of the credit goes to the workshop participants.

The organizers wish to thank Cindy Morgan and Greg Wood for their
work on the practical arrangements and communications relating to the
workshop. This report was greatly enhanced by the feedback provided
on it. Thanks to Michael Welzl in particular for his detailed
review.

Authors' Addresses

Jari Arkko
Ericsson
Email: jari.arkko@ericsson.com

Colin S. Perkins
University of Glasgow
Email: csp@csperkins.org

Suresh Krishnan
Cisco
Email: suresh.krishnan@gmail.com