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Sustainability Considerations for Networking Protocols and Applications

Document Type Active Internet-Draft (individual)
Authors Carlos Pignataro , Ali Rezaki , Jari Arkko , Alexander Clemm , Hesham ElBakoury
Last updated 2024-06-08
Replaces draft-cparsk-eimpact-sustainability-considerations
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IESG IESG state I-D Exists
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Network Working Group                                  C. Pignataro, Ed.
Internet-Draft                                       NC State University
Intended status: Best Current Practice                         A. Rezaki
Expires: 10 December 2024                                          Nokia
                                                                J. Arkko
                                                                A. Clemm
                                                            H. ElBakoury
                                                  Independent Consultant
                                                             8 June 2024

Sustainability Considerations for Networking Protocols and Applications


   Embedding sustainability considerations at the design of new
   protocols and extensions is more effective than attempting to do so
   after-the-fact.  Consequently, this document also gives network,
   protocol, and application designers and implementors sustainability-
   related advice and guideance.

   This document recommends to authors and reviewers the inclusion of a
   Sustainability Considerations section in IETF Internet-Drafts and

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 10 December 2024.

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Copyright Notice

   Copyright (c) 2024 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (
   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.  Code Components
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Implications to the IETF  . . . . . . . . . . . . . . . . . .   3
   3.  Sustainability Guidelines for Protocol and Network Designers
           and Implementers  . . . . . . . . . . . . . . . . . . . .   3
   4.  Conclusion  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     4.1.  Call to Action  . . . . . . . . . . . . . . . . . . . . .   6
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   7
   7.  Informative References  . . . . . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   The ultimate objective of this document is to detail guidance
   regarding aspects of sustainability and environmental impact that
   authors and reviewers of Internet protocol and architecture documents
   should consider in a "Sustainability Considerations" section.

1.1.  Terminology

   This document leverages the terminology and concepts defined in
   [I-D.pignataro-enviro-sustainability-terminology], and readers are
   expected to be familiar with those.  Specifically, Section 3.1.1 of
   [I-D.pignataro-enviro-sustainability-terminology] describes contepts
   of particular relevance to this draft.

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2.  Implications to the IETF

   This section describes the implications of sustainability to the
   IETF.  Specifically, the high-level relevant areas on which the IETF
   can act upon, and a rough prioritization.  These potentially include
   use cases, protocols, metrics, etc.

   A key area to understand the relevance and implication is regarding
   IETF Protocols.

3.  Sustainability Guidelines for Protocol and Network Designers and

   This section renders the Sustainability Considerations into specific
   guidelines and advice for the design and development of networking

   These specific items are labeled so as to follow and reference as a

   a.  General:
       The section title "Sustainability Considerations" should be used
       to detail the environmental-impact implications of protocols,
       architectures, and Internet technologies.

       a.1.  For each of the items covered, explicitly state the
             "boundary of analysis" considered.  For example, this can
             include a scope, time boundary, or lifecycle phases.

       a.2.  Consider attributional versus consequential analysis
             methods, explaining environmental impact benefits.

       a.3.  Clearly state the units used for each magnitude in every
             analysis (e.g., gCO2e/KWh.)

   b.  Network Management:
       Several areas of network management have direct relationship with

       b.1.  Metrics:
             Instrument equipment, network elements, and networks with a
             set of relevant and meaningful metrics that provide
             visibility into sustainability and environmental-impact
             attributes (e.g., power and energy consumption.)  This is
             the foundation for any mechanisms to improve and optimize

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       b.2.  Managed Elements:
             Facilitate, extend, and enrich the manageability of network
             elements and sub-elements which have environmental impact,
             such as Power Supplies.  For example, provide visibility
             into sourced power, e.g. energy mix, and allow to account
             for the "dirtiness" of power being consumed to obtain a
             truer picture of sustainability than can be gained by
             visibility into power consumption alone.

   c.  Energy Management:
       Minimizing energy consumption is a critical consideration in
       making networks more sustainable.  Minimizing energy consumption
       typically comes also with important economic side benefits
       associated with reducing operational expenses and making network
       providers more competitive.

       To facilitate energy efficiency schemes, designers of networking
       devices and protocols should examine and consider the following

       c.1.  Energy linearity.  In many cases, the amount of power drawn
             by a device is not in linear proportion to the volume of
             traffic that is passed.  Instead, energy consumption when
             idle generally accounts for a very significant percentage
             of the energy consumption when under full load.  The
             implication of this is that the volume of traffic by itself
             is of relative consequence to energy consumption, as long
             as the volume does not get to the point where additional
             equipment needs to be added to the network to handle peak

       c.2.  Power saving modes.  Similarly, many devices and resources
             support power saving modes that can be entered when idled.
             Similarly, during periods of exceedingly low traffic, some
             links may support downspeeding associated with energy
             savings.  As a result, a big opportunity for energy savings
             involves schemes in which resources are temporarily put
             into power saving modes, including almost shut-down, at
             times when they are not needed.

       c.3.  Chattiness of protocols.  For a given protocol, what are
             the message exchange patterns? 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?

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       c.4.  Exploiting burstiness versus smoothening of traffic.  Is it
             feasible to design the protocol in such a way that traffic
             is sent with a smoother traffic pattern with lower traffic
             volumes that are sent continuously, as opposed to a way
             that traffic is bulked up and then sent in one fell swoop?

       c.5.  Rapid discovery and convergence.  Does the protocol involve
             the exchange of state and information about other systems?
             In that case, how can the protocol be designed in such that
             any such information can be discovered quickly and protocol
             synchronization reconverged efficiently?  Does the protocol
             design support stateful schemes that might accelerate this?
             In cases where there is a possibility of nodes going to
             sleep, the associated overhead of going offline and coming
             back online should be minimized.  By shortening the time
             interval needed to go offline and come back online, it
             might be possible to have enter sleep mode in situations
             where it would otherwise not be feasible.

       c.6.  Encoding schemes.  How much computational effort goes into
             encoding and decoding?  Assess the tradeoff between
             encoding efficiency and computational effort, which directs
             into carbon for cycles to perform coding operations.

   d.  Carbon Awareness:

       d.1.  Consider Carbon Intensity (CI) / Emission Factor (EF) as an
             attribute.  For example, CI is used to optimize for lower-
             carbon sources of electrical energy (e.g., using
             renewables.)  Prioritizing electricity use when carbon
             intensity is low is a target, and, for that, this attribute
             needs to be accessed or advertised.

       d.2.  Consider embodied emissions (i.e., embedded carbon) with
             any new product.  For example, a new generation of
             networking device might significantly improve energy
             efficiency, and a replacement migration would include the
             embedded emissions (of producing and transporting the new
             product as well as disposing of the old one), and hence
             there's a break-even point (BEP).

   e.  Beyond Carbon:
       Characterize and note full-spectrum environmental impacts, beyond
       GHG emissions, and into water usage, raw materials usage,
       circularity in supply chain, repurpose, reuse, and recycle, etc.

       e.1.  WIP

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       e.2.  WIP

4.  Conclusion

   The pre-eminent message in this document is to elevate the need and
   sense of urgency of including sustainability considerations in our
   protocol and system design, and to provide editors with a
   sustainability lexicon, definitions, and priorities to carry out that
   task.  As an added benefit, by including sustainability
   considerations, it will be possible to optimize for not only
   performance parameters but also sustainability ones, through
   respective trade-offs in our protocols and systems.

   We also envision that on top of minimizing the environmental impact
   of our technologies and helping consumers identify and reduce the
   environmental impact of their use, we can also make a positive impact
   on other systems.  E.g., use our technologies to choose greener and
   more efficient sources of power, control HVAC systems efficiently,

4.1.  Call to Action

   The intention of this document is multifaceted: establish definitions
   and a lexicon for sustainability, characterize environmental
   implications of internetworking technologies, and provide specific
   guidelines for designers and implementors.

   Making these objectives actionable involves:

   1.  Familiarize yourself with the environmental sustainabilithy

   2.  understand the environmental sustainability implications to
       protocol and architecture, and

   3.  consider, qualify, quantify, and explain the specific guidelines
       in Section 3 as you develop protocols, extensions, and

5.  Security Considerations

   Sustainable practices offer many environmental, economic, and social
   benefits, and security is a route to sustainability rather than a
   hurdle to clear.

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6.  Acknowledgements

   This document is created greatly leveraging ideas and text from
   [I-D.cparsk-eimpact-sustainability-considerations], and consequently
   acknowledges all the many contributions that improved it.

7.  Informative References

              Pignataro, C., Rezaki, A., Krishnan, S., ElBakoury, H.,
              and A. Clemm, "Sustainability Considerations for
              Internetworking", Work in Progress, Internet-Draft, draft-
              cparsk-eimpact-sustainability-considerations-07, 24
              January 2024, <

              Pignataro, C., Rezaki, A., and H. ElBakoury,
              "Environmental Sustainability Terminology and Concepts",
              Work in Progress, Internet-Draft, draft-pignataro-enviro-
              sustainability-terminology-00, 8 June 2024,

Authors' Addresses

   Carlos Pignataro (editor)
   North Carolina State University
   United States of America

   Ali Rezaki

   Jari Arkko

   Alexander Clemm
   2220 Central Expressway
   Santa Clara,  CA 95050
   United States of America

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   Hesham ElBakoury
   Independent Consultant
   United States of America

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