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Sustainability Insights
draft-almprs-sustainability-insights-03

Document Type Active Internet-Draft (individual)
Authors Per Andersson , Jan Lindblad , Snezana Mitrovic , Marisol Palmero , Esther Roure , Gonzalo Salgueiro , Emile Stephan
Last updated 2024-05-07
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draft-almprs-sustainability-insights-03
Network Working Group                                       P. Andersson
Internet-Draft                                               J. Lindblad
Intended status: Informational                               S. Mitrovic
Expires: 8 November 2024                                      M. Palmero
                                                                E. Roure
                                                            G. Salgueiro
                                                           Cisco Systems
                                                              E. Stephan
                                                                  Orange
                                                              7 May 2024

                        Sustainability Insights
                draft-almprs-sustainability-insights-03

Abstract

   Internet and the ICT industry is consuming a sizable portion of the
   electricity available in the world today, and the fraction has been
   growing significantly over time.  Data shows that the power draw of
   internet is relatively constant over the day and week, even though
   the “load” and delivered services vary greatly over this time span.
   This seems to suggest that there is room for optimizations.

   This document provides some definitions, some proposed principles for
   a solution, and then paints a picture of what a solution based on
   existing standards and some current internet drafts might look like.

   The first step of an optimization loop is to measure.  This document
   proposes a mechanism to collect energy related telemetry data from
   the extremely diverse set of devices found in networks today, without
   necessarily updating the network elements.  Once the collection is
   done, it’s also very relevant to be able to control the devices, and
   turn them into low power modes when the service demand is lower.

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 https://datatracker.ietf.org/drafts/current/.

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

   This Internet-Draft will expire on 8 November 2024.

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 (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.  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  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  The Sustainability Telemetry Standard Specification . . .   5
     1.2.  Requirements language . . . . . . . . . . . . . . . . . .   7
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   7
   3.  Motivation  . . . . . . . . . . . . . . . . . . . . . . . . .   8
   4.  Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . .   9
     4.1.  Use Case I  . . . . . . . . . . . . . . . . . . . . . . .   9
       4.1.1.  Scenario ‘monitoring power’ . . . . . . . . . . . . .   9
       4.1.2.  Sustainability Insights Added Value . . . . . . . . .   9
     4.2.  Use Case II . . . . . . . . . . . . . . . . . . . . . . .   9
       4.2.1.  Scenario ‘migration’  . . . . . . . . . . . . . . . .   9
       4.2.2.  Sustainability Insights Added Value . . . . . . . . .  10
     4.3.  Use Case III  . . . . . . . . . . . . . . . . . . . . . .  10
       4.3.1.  Scenario ‘recycling’  . . . . . . . . . . . . . . . .  10
       4.3.2.  Sustainability Insights Added Value . . . . . . . . .  10
     4.4.  Use Case IV . . . . . . . . . . . . . . . . . . . . . . .  10
       4.4.1.  Scenario ‘power optimization’ . . . . . . . . . . . .  10
       4.4.2.  Sustainability Insights Added Value . . . . . . . . .  11
     4.5.  Use Case V  . . . . . . . . . . . . . . . . . . . . . . .  11
       4.5.1.  Scenario ‘sustainability cost’  . . . . . . . . . . .  11
       4.5.2.  Sustainability Insights Added Value . . . . . . . . .  11
     4.6.  Use Case VI . . . . . . . . . . . . . . . . . . . . . . .  12
       4.6.1.  Scenario ‘switch off’ . . . . . . . . . . . . . . . .  12
       4.6.2.  Sustainability Insights Added Value . . . . . . . . .  12
   5.  Proposals for a Solution  . . . . . . . . . . . . . . . . . .  13

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     5.1.  Basic Principles  . . . . . . . . . . . . . . . . . . . .  13
       5.1.1.  Describe the Collected Data using YANG  . . . . . . .  13
       5.1.2.  Work with Existing Equipment  . . . . . . . . . . . .  13
       5.1.3.  New Systems that want to be Helpful . . . . . . . . .  13
       5.1.4.  Time Series Database (TSDB) Storage . . . . . . . . .  13
       5.1.5.  Define Telemetry Component Roles: Providers,
               Collectors, Aggregators, Processors . . . . . . . . .  14
       5.1.6.  Add YANG and Metadata where missing, and keep the
               Metadata with the Data  . . . . . . . . . . . . . . .  14
       5.1.7.  Transparency: Solid YANG to Time Series Database (TSDB)
               Mapping . . . . . . . . . . . . . . . . . . . . . . .  14
     5.2.  The Sustainability Framework  . . . . . . . . . . . . . .  15
     5.3.  The Framework Architecture  . . . . . . . . . . . . . . .  15
   6.  Next Steps  . . . . . . . . . . . . . . . . . . . . . . . . .  17
     6.1.  Reaching Methodological Agreement . . . . . . . . . . . .  18
       6.1.1.  Need to Agree on What and How to Measure  . . . . . .  18
       6.1.2.  Need to Agree on What and How to Aggregate  . . . . .  18
       6.1.3.  Let’s bring in the Economists from SBTi, GHGP,
               etc.  . . . . . . . . . . . . . . . . . . . . . . . .  18
     6.2.  Expanding the Scope . . . . . . . . . . . . . . . . . . .  18
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  19
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  19
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  19
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  19
   Change log  . . . . . . . . . . . . . . . . . . . . . . . . . . .  20
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .  21
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  21

1.  Introduction

   To answer questions about how sustainable equipment and operational
   practices are, various key performance indicators (KPIs) produced by
   network devices, management systems, and networking solutions are
   necessary.  While such KPIs are abundantly produced and collected
   today there are quite a few issues with their usability and
   commonality.  Without a common definition of metrics across the
   industry and widespread adoption, we will be left with ill-defined,
   potentially redundant, and proprietary metrics.

   An aspect lacking today is the precise definitions of the collected
   metrics.  This leads to KPIs that are not comparable to each other,
   as it is unknown what is included in the outcomes and what is not.
   It makes it challenging to sum or compare numbers from different
   manufacturers and organizations without investing in data
   normalization and a high number of assumptions.

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   To produce aggregate data, it is also important to consider how the
   component inputs are combined.  Different vendors and operators might
   do this aggregation differently, yet again producing values that are
   hard to combine or compare when also using different units of
   measurement.  In many cases, one might suspect the actual numbers are
   underestimated, since there is competitive pressure to produce small
   numbers to report on the environmental impact of Internet
   communications and applications in contrast with the benefit of using
   it.  The aim shall not be to “produce the numbers” but to find
   quantitative measures, when possible, that give a fair assessment of
   Sustainability related metrics vs. useful work.

   It may be tempting to define the useful work in networking equipment
   as simply as the number of bits that are passing through the device.
   For some types of equipment, that might be appropriate, but clearly a
   video system that is sending a video stream with better video
   compression is not necessarily less sustainable just because it sends
   fewer bits per Joule.  There are also many kinds of networking
   equipment where measuring the end user value in number of passed bits
   is obviously ridiculous, and other metrics have to be defined.
   Monitoring or management systems are examples of this.

   Another important and key aspect, when referring to environmental
   impact metrics is what needs to be considered as part of the
   lifecycle.  Life cycle assessment, also known as LCA, of networks and
   services, is defined by ISO 14040 as the compilation and evaluation
   of the inputs, outputs, and potential environmental impacts
   throughout its lifecycle.

   LCA is based on four main phases:

   *  Goal and Scope

   *  Inventory Analysis

   *  Impact Assessment

   *  Interpretation

   This document is setting up the stage to identify data quality
   requirements, under the information and communications technology
   (ICT) category.  Following product Lifecycle Accounting (LCA), this
   document focuses on using the five product lifecycle stages defined
   by the GHG Protocol Accounting and Reporting Standard, which is in
   accordance with the ISO 14040:44 standards:

   1.  Use

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   2.  Manufacturing

   3.  Material Acquisition / Processing

   4.  Transport

   5.  End of Life

   Impact and interpretation will be briefly covered under the
   document’s motivation and use cases sections.

   There is reason to suspect that nebulous definitions combined with
   the competitive pressure might produce greenwashing.  Greenwashing
   involves making an unsubstantiated claim to deceive consumers into
   believing that a vendor’s product or solution is environmentally
   friendly or has a greater positive environmental impact than it does.
   This document proposes the following initiative to counter these
   effects.

1.1.  The Sustainability Telemetry Standard Specification

   As an industry, we need to cooperate and agree on a set of core KPIs
   that are measured, including the definition of terms, units, and
   measurement procedures.  What is included, and what is not included.

   Sustainability metrics require a broad diversity of data sources that
   need to be combined.

   *  Static information.  Data coming from manufacturing, including
      reference values on how the assets have been designed if they
      enable reuse and recycling, and which materials have been used
      during manufacturing and packaging; normally this information is
      defined once and it is part of data sheets provided by the
      vendors.

   *  Dynamic data.  Information measured in real-time or close to real-
      time from the networking equipment or application.  For instance,
      metrics should consider current inventory and current source and
      amount of consumed power, as well as what hardware and software
      features are enabled and used by the specific network equipment.

   *  Best practices.  Recommendations for optimizing the use of the
      network equipment, throughout its complete lifecycle.

   *  Local context.  Country-specific regulations, corporate policy,
      and social aspects.

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   To enable the exchange of sustainability data among all interested
   parties, deployment considerations that are out of the scope of this
   document will need to include:

   *  Data models.  The model definition can be implemented in different
      forms.  This document proposes YANG as part of the Specification
      Data Model.  YANG can be used independently of the transport and
      can be converted into any encoding format supported by the network
      configuration protocol.  YANG models are decoupled from the
      management protocol layer.

   *  Sustainability framework.  To drive adoption, we propose an open-
      source aggregation framework for sustainability data.  This
      framework should be seen as a reference architecture for a
      sustainability monitoring mechanism.  While each implementation
      may be (and will be) different, the basic framework shall remain
      constant.  The framework must account for vendor-specific
      calculations and enhancements in a plug-in architecture.

   YANG data models as part of the Sustainability Telemetry
   Specification, which will follow this document, have been classified
   as follows:

   *  Identification of the assets.  Assets include hardware (physical
      as well as virtual), software, applications, and services.  The
      asset concept is defined in the Data Model for Lifecycle
      Management and Operations (DMLMO)
      [I-D.draft-palmero-ivy-dmalmo-01] IETF draft.

   *  Power and Efficiency.  To measure power consumption and energy
      efficiency, common methods, attributes, and units are needed to
      define metrics.  The approach needs to cover the different
      networking domains, starting with hardware focus, but including
      software and protocols attributes and metrics.

   *  Circular Economy attributes.  Collecting circularity data (such as
      materials used, or the embedded emissions footprint) is expensive
      and difficult because of confidentiality and the non-standardized
      approach to reporting and exchanging circularity data.  The flow
      of circularity data is typically lost at each step throughout the
      supply chain, as goods are passed through suppliers,
      manufacturers, system integrators, distributors, customers, and
      consumers into reuse and recycling.

   *  Context metrics.  Without understanding the context of the use,
      none of the metrics listed above will provide much value.  The
      carbon intensity of the power used, for example, is key to
      assessing the sustainability of a given application.  An

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      efficiency number needs to be interpreted differently at peak
      hours and night.  A given usage may be considered less sustainable
      if someone demonstrates the ability to deliver the same end-user
      value with a smaller footprint.  A system that is transported a
      shorter distance or using a more sustainable mode of
      transportation from the factory to the installation site may also
      be assessed more positively.  Or if it has a longer economic life
      or comes with less single-use packaging.

   The model definition can be implemented in different forms.  We would
   like to propose a specific YANG model for the sustainability metrics,
   which intrinsically allows for a variety of collection protocols.
   YANG can be used independently of the transport protocol, and lends
   itself well to be converted into a variety of encoding formats
   supported by popular network configuration protocols.

   The rest of this document is organized as follows.  Section 2
   establishes the terminology and abbreviations.  Section 3 outlines
   the goals and motivation of Sustainability metrics.  Section 4
   discusses Use Cases that lay out the groundwork for the
   Sustainability Telemetry Specification, to address new business needs
   introduced by the Circular Economy and to avoid excessive climate
   change.  Section 5 proposes principles for and a solution based on
   existing standards and current internet drafts.  Section 6 lists
   ideas for future development of this work.

1.2.  Requirements language

   The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”,
   “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “NOT RECOMMENDED”, “MAY”, and
   “OPTIONAL” in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

2.  Terminology

   Terminology and abbreviations used in this document:

   Asset  Hardware, software, applications, or services.  An asset can
      be physical or virtual.

   Greenwashing  Marketing (intentionally or not) an asset as being
      green (i.e. fitting well into the circular economy) by selectively
      omitting less green aspects of the asset.

   Circular economy  An economic paradigm in which the full lifecycle
      cost of resource use and emissions are included.

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   Climate change  The disruption of ecological processes caused by
      excessive resource use or emissions.

3.  Motivation

   Aside from the need for consistency on metrics to be considered as
   part of the ICT sector, to reduce environmental impact and increase
   benefit; this document and future work related, aim to support the
   Digital Product Passport initiative under the European Union’s (EU’s)
   Circular Economy Action Plan (CEAP) and the Ecodesign for Sustainable
   Products Regulation (ESPR).  There is not much time for businesses to
   prepare and for IETF work to influence this development.

   The Digital Product Passport (DPP) is key to the EU’s transition to a
   circular economy and will provide information about assets’
   environmental sustainability.  It aims to improve traceability and
   transparency along the entire value chain of an asset and to improve
   the management and sharing of product-related data which are critical
   to ensuring their sustainable use, prolonged life, and circularity.

   There is a need to:

   *  Track raw materials extraction/production, supporting due
      diligence efforts

   *  Enable manufacturers to increase transparency in the value chain,
      better compliance, increased circularity, and sustainability

   *  Enabling services related to its remanufacturing, reparability,
      second-life, and recyclability, enabling sustainable business
      models.

   In the case of upgrading, repairing, repurposing, or remanufacturing
   a product, it should be clear the responsibility to update the
   information is transferred to the installer, repairer, or
   remanufacturer who will be putting the product into service or
   placing it on the EU market.

   The three main target groups of the passport are:

   *  Public authorities and policymakers: reliable information on
      compliance of products with EU legislation

   *  Economic operators (such as recyclers): information on proper
      dismantling and waste treatment of products; the presence of
      Substances of Very High Concern (SVHCs) through a link to the SCIP
      database; etc.

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   *  Consumers: instructions for use, information on repair centers,
      sorting instructions, and other information as required by
      existing EU legislation (e.g.  CLP regulations), more information
      about products would be made available to consumers and customers
      to enable informed choices.

   The DPP will help business planners and consumers make informed
   choices when purchasing assets, and should also help local and public
   authorities to better perform checks and controls.

4.  Use Cases

4.1.  Use Case I

4.1.1.  Scenario ‘monitoring power’

   An organization is running a large and complex network with many
   types of devices.  By looking at the utility bills, it is clear that
   the organization is consuming rather more energy per transported bit
   than many other organizations.  Exactly which devices or network
   functions are at the root of the situation is unclear, however.

   The product LCA in this scenario applies to the stage of “Use”.

4.1.2.  Sustainability Insights Added Value

   By providing near-real-time data that is broken down at least to an
   individual hardware device, and ideally considerably deeper than
   that, it will be possible to attribute energy and environmental
   footprint costs to different device types, service types, and
   individual customers.

   If one customer is altering its behavior or load on the network, a
   monitoring application could detect this quickly.  It would also be
   possible to try several implementations or configurations for a given
   service and get quick feedback on the operations cost of that change.

4.2.  Use Case II

4.2.1.  Scenario ‘migration’

   An organization is running a network with a variety of managed
   services and applications.  Some of the devices are getting old, and
   have lower energy efficiency than more modern devices.  Replacing old
   devices with new ones might improve efficiency, but has an economical
   as well as environmental cost.  Without specific performance data, it
   is difficult to make informed decisions about upgrades.

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   The product LCA stage applies to “Use”.

4.2.2.  Sustainability Insights Added Value

   By providing KPIs for reading sustainability parameters that pertain
   to actual usage, rather than numbers from data sheets, the accuracy
   of upgrade decisions is enhanced.  Such data can make the case for an
   upgrade very clear and easy to make, or it may show that it’s not a
   good idea at this time.  In both cases improving the sustainability
   of the operations.

4.3.  Use Case III

4.3.1.  Scenario ‘recycling’

   Recycling and reuse are major drivers of the circular economy.
   Companies must put high efforts in this direction and transparency.
   This is a qualitative KPI, passed if percentages of recycled and
   reused goods given the manufacturing options, as well as reports
   listing how many units have been recycled.

   The product LCA applies to the stage of “Material Acquisition /
   Processing”.

4.3.2.  Sustainability Insights Added Value

   The trend seems to be to report on the percentage of recycled user
   devices and the eco-design and refurbishment efforts.  Sustainability
   Insights can enable the data sources to report comprehensive
   reporting of recycling efforts.

4.4.  Use Case IV

4.4.1.  Scenario ‘power optimization’

   An organization is running a network with a variety of managed
   services and applications.  The network and application performance
   is continuously monitored, and there are even some automatic
   remediation actions that may trigger when certain conditions are
   detected.

   In this scenario, the product LCA applies to the stage of “Use”.

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4.4.2.  Sustainability Insights Added Value

   By providing KPIs for sustainability parameters such as power
   consumption and power efficiency, the monitoring system can access
   relevant data and perform actions that reduce the power consumption
   or sustainability footprint of the delivered services.

   For example, some overlay redundant links or systems may be powered
   off at non-pick hours, or enter into a low-power mode.  A highly
   available application may be configured to take more load in the data
   center with a lower price of energy, lower outside temperatures, or
   an environmentally superior energy mix.

4.5.  Use Case V

4.5.1.  Scenario ‘sustainability cost’

   IT solutions are currently analyzed from two main perspectives:
   technological and economical.  When looking at environmental, social,
   and corporate governance (ESG) impact topics, sustainability metrics
   in the context of digital transformation, deliver insights into
   opportunities and risks that emerge from a rapidly growing
   stakeholder demand for sustainable, digitally advanced products and
   services.

   The product LCA applies to all stages under its lifecycle.

4.5.2.  Sustainability Insights Added Value

   From an application point of view, this use case proposes to include
   Sustainability factors in the Total Cost of Ownership (TCO)
   calculation, where there is a need to add Environmental, Social, and
   Governmental Key Performance Indicators (KPIs) to the analysis.
   However, adding Sustainability metrics comes with challenges and
   trades-off.  Future work considers a model to calculate the Total
   Sustainability Cost of Ownership (TSCO) for network solutions based
   on the ESG Materiality Matrix.  This model is open to adding any
   implementation that takes into consideration Sustainability
   objectives at a point in time, but it also evolves with the needs of
   the business and the stakeholders.  The initial scope proposes to
   investigate the top four most important ESG Materiality issues as a
   base to grow the TCO to a TSCO that matches the Company’s priorities
   and issues.

   Future work might include use cases that will cover “Manufacturing”,
   “Transport” and “End of Life” examples.

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4.6.  Use Case VI

4.6.1.  Scenario ‘switch off’

   WIFI is deployed in any famous stadiums around the world.  It is
   common for such networks to rely on several thousands of Access
   Points (APs).

   Such networks are very dense and designed to separate finely fans
   connections from business operations (ticketing, …).

   Such WIFI network activity varies in time and follow a well-known
   calendaring (but not as trivial as the match calendar).  It is
   obvious that the bigger part of a stadium WIFI network footprint is
   most of the time unused at all.

   Current WIFI management tools are not designed to stop and restart
   the APs automatically following a schedule.  In 2022 Orange and Cisco
   implemented practical actions to lower the power consumption of the
   WIFI APs of the Orange velodrome of Marseille.  The experimentation
   was able to save 20% of the APs power consumption without modifying
   the infrastructure.  The experimentation shown that the current
   design of network operation tools need to be updated to save up to
   50%.

   Stadium and arenas WIFI network are made of a very limited number of
   clusters.  There are WIFI networks similar in size which are by far
   more constraint in term of calendaring and capillarity.  In France,
   banks have thousands of branches.  See Number of bank branches in
   France (https://www.statista.com/statistics/744109/french-banks-
   branches-number/).

   NB: APs are not per designed build to support numerous cold restarts.
   This may impacts TSCO

4.6.2.  Sustainability Insights Added Value

   Being able to stop and restart WIFI APs with the right time, space
   and service granularity.

   From an operation point of view, this use case proposes to save power
   consumption during periods the APs are not in-used.

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5.  Proposals for a Solution

5.1.  Basic Principles

5.1.1.  Describe the Collected Data using YANG

   There are many data/info modeling languages out there, but we are not
   aware of any that comes close to YANG in its ability to concretely
   and extensibly describe data structures and with a tools eco system
   to render functionality from that.

5.1.2.  Work with Existing Equipment

   Network devices as well as servers and cooling systems are providing
   metrics in various formats today.  We could standardize how they
   should report their information, and require them to follow certain
   principles for accounting.  We could then watch as these new systems
   spread across the industry.  Optimistically, this would take a few
   years to standardize and another few to be implemented in devices.
   Then yet another few years before it is widely deployed in production
   networks.  These are years that must not be lost in our efforts to
   achieve reasonably sustainable networks.  Therefore, we propose that
   focusing on retrieving the data we need from the systems out there,
   without inventing new reporting APIs/mechanisms on the equipment
   level.  The interfaces on existing devices are sometimes YANG-based
   (e.g.  YANG-push), but most are probably not (e.g.  CLI scraping,
   SNMP, homegrown REST, …)

5.1.3.  New Systems that want to be Helpful

   While we can’t expect all systems out there to adopt any new APIs or
   reporting mechanisms, some system implementors may be interested to
   help out as much as possible.  In such cases, we think the best thing
   a system implementor can do is to provide a catalog of the existing
   sensors/measurement points the system provides, along with all the
   metadata that the higher layers will need.  We can standardize what
   such an (optional) catalog would look like.  This will make it easier
   to integrate with the rest of the metrics collection system.
   Implementing it may give a system a competitive advantage over
   systems that don’t.

5.1.4.  Time Series Database (TSDB) Storage

   The already established industry norm seems to be storing any
   collected and aggregated telemetry data in a Time Series Database
   (TSDB).

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5.1.5.  Define Telemetry Component Roles: Providers, Collectors,
        Aggregators, Processors

   We need to agree on some terms.  We have used the term “provider” to
   mean any system that is reporting (sustainability) telemetry.  This
   could be a router, blade server or a building’s cooling system.

   The telemetry data flow is initiated by a “collector”.  The aim of
   the collector is to ensure that data from a provider ends up in a
   time series database, along with relevant metadata.  How it
   accomplishes this is outside the scope our efforts (could use e.g.
   polling, subscriptions, YANG-push, …).

   “Aggregators” and “processors” take telemetry data flow(s) from a
   time series database and apply some sort transformation/aggregation
   operation on them, and deliver the result to a time series database.
   That could very well be a different partition/table/bucket in the
   same time series database.

5.1.6.  Add YANG and Metadata where missing, and keep the Metadata with
        the Data

   There are of course plenty of systems and telemetry data flows that
   has no YANG description, but that can be solved.  We, who are
   building the telemetry stack, can add YANG descriptions to any data
   flow we care about, if the system implementor doesn’t.  Similarly,
   aggregators and processors describe their outgoing data flows using
   YANG models.

   Both the YANG descriptions of the data flows and the corresponding
   metadata descriptions of the flows should be kept close to the data
   it pertains to.  Preferably in or linked to the same database.

5.1.7.  Transparency: Solid YANG to Time Series Database (TSDB) Mapping

   Since all the data stored in the TSDB has a YANG description, we can
   define an algorithm that maps any YANG defined data to the flat,
   tagged, naming structure suitable for use in a TSDB.  This makes it
   easy to trace the origins of all the data in the TSDB.  It is key to
   be able to answer questions about the origins of the collected data
   without looking into code.  All the sources, and which processing
   steps are applied, should be visible and editable as configuration
   data, not deeply hidden in code created elsewhere.

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5.2.  The Sustainability Framework

   To drive quick adoption, we propose to build an open-source
   aggregation framework for sustainability data.  This framework should
   be seen as a reference architecture for a sustainability monitoring
   mechanism.  The reference implementation will be based on the
   specifications mentioned in this document.  The architecture would
   supply a few base components, but otherwise, allow vendors or
   standards bodies to plugin their applications that fit in the general
   framework.

   One example of such an application that we would like to propose is a
   model to calculate the Total Sustainability Cost of Ownership (TSCO)
   for network solutions based on the Environmental, Social, and
   Governance (ESG) Materiality Matrix.  This matrix model is open to
   adding any implementation that takes into consideration
   Sustainability objectives at a point in time, but it also evolves
   with the needs of the business and the stakeholders.  The initial
   scope proposes to investigate the top four most important ESG
   Materiality issues as a base to grow the TCO to a TSCO that matches
   the Company’s priorities and issues.

5.3.  The Framework Architecture

   Even though the end-goal with the architecture is to enable fully
   automated network management which is taking the sustainability
   insights that comes out of the network into account, we envision the
   top layer of the architecture would also contain a human consumable
   graphs showing how well our network is operating with respect to
   energy and emissions.  We live in a demo-or-die world, after all.
   Such graphs typically take their input from one or more Time-Series
   Databases (TSDB).  The mapping from YANG to TSDB is described in
   [I-D.draft-kll-yang-label-tsdb-00].  The graphing technology already
   exists, and many mature commercial and open source tools are
   available.  This operator user interface would also do well to have a
   section for recommendations from the system, based on potential
   savings the system has discovered.

   An aggregation framework that collects information about, and to a
   large extent directly from, the network elements and subsystems in
   the network, and delivers it into a TSDB.  Sometimes, the best
   available data about some of the properties of some nework elements
   is found in the datasheets for the network element.  In such cases,
   the information about a network element may be read from a web server
   or file with structured information about the network element, rather
   than reading it in (near) real-time from the system itself.  We
   propose that the aggregation system is built on the framework
   described in the [I-D.draft-lindblad-tlm-philatelist-01].

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   In the figure below, many lines are drawn between components in the
   aggregation framework.  In general, those lines represent telemetry
   data flows in and out of one or more TSDB buckets/topics.  This state
   of affairs is depicted in the diagram with a TSDB symbol “hanging in
   the air” next to these lines.

   Besides aggregating the collected telemetry data, the Philatelist
   framework can also be used to associate selected points in the
   collection tree with specific assets defined in the network
   inventory, as defined in [I-D.draft-palmero-ivy-dmalmo-01].

   Lower down in the stack, the aggregation framework needs to access
   the actual devices, or other data sources standing in for them.  The
   variety in types of sensors and collection protocols to use here is
   great.  It is hard to know what sensors are available from a device,
   and using which protocols.  It is even harder to know more about what
   the delivered metrics mean.  What unit of measuremnt is used?  Is the
   power reported true RMS power, or something else?  What is included
   and not in this number, e.g. is the cooling cost included?  What is
   the precision?  This metadata information SHOULD come from the device
   vendor, either declared directly by the device itself, or by
   providing a structured data manifest.  The YANG interface and file
   format for the manifest is described in [I-D.draft-opsawg-poweff-01].

   A concrete device YANG model that provides some functionality for
   reading power telemetry as well as some power control functionality
   on the device level is found in [I-D.draft-li-ivy-power-01].

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                         +-----------------+
                         | USER INTERFACE  |       ________
                         |      Graphs     |      /        \
                         |                 |     (   TSDB   )
                         +-----------------+     |\________/|
                                  |              |          |
                                 ...              \________/
                                  |
          +---------------+-------+-------+--------------+
          |               |               |              |
   +------------+  +------------+  +------------+  +------------+
   | PROCESSOR  |  | AGGREGATOR |  | AGGREGATOR |  | AGGREGATOR |
   | Normalizer |  |  Network   |  |  Storage   |  |  Compute   |
   +------------+  +------------+  +------------+  +------------+
          |           |                   |\             |\
         ...         ...                  ...            ...
          |           |                   |              |
          |- YANG     |-YANG              |-YANG         |-YANG
          |- Metadata |-Metadata          |-Metadata     |-Metadata
          |           |                   |              |
   +------------+  +------------+  +------------+  +------------+
   | COLLECTOR  |  | COLLECTOR  |  | COLLECTOR  |  | COLLECTOR  |
   +------------+  +------------+  +------------+  +------------+
          |           |                   |\             |\
         ...         ...                  ...            ...
          |           |                   |              |
          +- YANG     |                   +- some YANG   +- YANG
          +- Metadata +- Metadata         +- Metadata    +- Metadata
          |           |                   |              |
   +----------+  +-----------+  +--------------+  +----------------+
   | NETCONF  |  | CLI       |  | Device       |  | Device with    |
   | device   |  | and SNMP  |  | with REDFISH |  | POWEFF models  |
   |          |  | device    |  | and RESTCONF |  | over NETCONF   |
   +----------+  +-----------+  +--------------+  +----------------+

       Figure 1: Example component diagram sketch of a Sustainability
                            Insights deployment.

6.  Next Steps

   To enable the exchange of sustainability data among all interested
   parties at each step of the value supply chain, a technical
   sustainability framework for how this data is queried, transported,
   and visualized will be required.

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6.1.  Reaching Methodological Agreement

6.1.1.  Need to Agree on What and How to Measure

   Once we agree on the principles of how a collection framework should
   be structured, we also need to agree on what data is meaningful to
   measure from the systems, and how that measurement is done.  What
   units to convert to, what sample frequencies and how (im)precision is
   conveyed.  What about missing data points?

6.1.2.  Need to Agree on What and How to Aggregate

   Once we agree on what and how to measure, we also need to agree on
   how we aggregate the data.  Is linear interpolation of time series
   data a good approach?  Should we work with averages, and if so over
   which time spans?  Filter out outliers?  How deep into the device
   subsystems/interfaces etc should we drill?  How should we add cost of
   cooling, buildings, operations teams, etc?

6.1.3.  Let’s bring in the Economists from SBTi, GHGP, etc.

   On the e-impact mailing list, we have identified a number of hairy
   questions when it comes to attribution/allocation of energy or co2eq-
   cost, that are more of policy nature than hard science.  E.g. who is
   “responsible” for the idle power consumption of a system?  Does it
   matter if users pay a flat monthly fee for services, or per byte or
   per cat video?  All the above is about computing a cost-metric for
   running the system.  It may be equally important to compute a value
   metric (e.g. based on what users pay for the service) to put in
   relation to the cost.  Just cost alone will be pretty much a useless
   number.

   To sort out questions on this level, it may be wise to involve “the
   economists”. By that we mean the folks that are already assessing
   many of our organizations when it comes to co2-reduction targets etc.
   Folks from Science Based Targets initiative (SBTi), or Green House
   Gas Protocol (GHGP), for example.  They are used to construct
   economic models where the right incentives show up.

6.2.  Expanding the Scope

   Items that are not in the scope of this edition of this document, but
   could be addressed in future revisions, include:

   *  How to relate Sustainability Telemetry Specification to
      sustainability Scopes 1, 2, and 3,

   *  Circular Economy Business models,

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   *  Recommendations,

   *  Scope 4, i.e. metrics for avoided footprints (sometimes called
      handprint).  For instance, to reduce GHG emissions, automation
      activities like Zero Touch, or certain technologies like Routed
      Optical Networking, can replace other higher emitting activities.
      Another example would be the positive impact arising from video
      conferencing as opposed to international travel by airplane.

7.  Security Considerations

   The security considerations mentioned in section 17 of [RFC7950]
   apply.

   Sustainability Insights brings several security and privacy
   implications because of the various components and attributes of the
   information model.  For example, each functional component can be
   tampered with to give manipulated data.  Sustainability Insights when
   used alone or with other relevant data, can identify an individual,
   revealing Personal Identifiable Information (PII).  Misconfigurations
   can lead to data being accessed by unauthorized entities.

   Methods exist to secure the communication of management information.
   The transport entity of the functional model MUST implement methods
   for secure transport.  This document also contains an Information
   model and Data-Model in which none of the objects defined are
   writable.  If the objects are deemed sensitive in a particular
   environment, access to them MUST be restricted using appropriately
   configured security and access control rights.  The information model
   contains several optional elements which can be enabled or disabled
   for the sake of privacy and security.  Proper authentication and
   audit trail MUST be included for all the users/processes that access
   Sustainability Insights Telemetry Data.

8.  References

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

8.2.  Informative References

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   [I-D.draft-kll-yang-label-tsdb-00]
              Larsson, K., "Mapping YANG Data to Label-Set Time Series",
              Work in Progress, Internet-Draft, draft-kll-yang-label-
              tsdb-00, 18 October 2023,
              <https://datatracker.ietf.org/doc/html/draft-kll-yang-
              label-tsdb-00>.

   [I-D.draft-li-ivy-power-01]
              Li, T. and R. Bonica, "A YANG model for Power Management",
              Work in Progress, Internet-Draft, draft-li-ivy-power-01,
              17 October 2023, <https://datatracker.ietf.org/doc/html/
              draft-li-ivy-power-01>.

   [I-D.draft-lindblad-tlm-philatelist-01]
              Lindblad, J., "Philatelist, YANG-based Network Controller
              collection and aggregation framework integrating Telemetry
              data and Time Series Databases", Work in Progress,
              Internet-Draft, draft-lindblad-tlm-philatelist-01, 7 May
              2024, <https://datatracker.ietf.org/api/v1/doc/document/
              draft-lindblad-tlm-philatelist/>.

   [I-D.draft-opsawg-poweff-01]
              Lindblad, J., Mitrovic, S., Palmero, M., and G. Salgueiro,
              "Power and Energy Efficiency", Work in Progress, Internet-
              Draft, draft-opsawg-poweff-01, 7 May 2024,
              <https://datatracker.ietf.org/api/v1/doc/document/draft-
              opsawg-poweff/>.

   [I-D.draft-palmero-ivy-dmalmo-01]
              Palmero, M., Brockners, F., Kumar, S., Cardona, C., and D.
              Lopez, "Data Model for Asset Lifecycle Management and
              Operations", Work in Progress, Internet-Draft, draft-
              palmero-ivy-dmalmo-01, 24 April 2024,
              <https://datatracker.ietf.org/doc/html/draft-palmero-ivy-
              dmalmo-01>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

Change log

   RFC Editor Note: This section is to be removed during the final
   publication of the document.

   *  From version -02 to -03

      -  Rewrote the abstract

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      -  Added a solution principles section

      -  Rewrote the architecture framework section to take a more
         holistic view

      -  Removed the deployment considerations section

      -  Added methodological agreement section under next steps

      -  Many minor word changes and language fixes

      -  Updated list of normative references

   *  From version -01 to -02

      -  Includes explanation and new diagram for the architecture
         framework

      -  Added Use Case VI

   *  From version -00 to -01

      -  Added an architecture framework section.

   *  Version -00

      -  Initial version.

Acknowledgments

   This document was created by meaningful contributions from Jeff
   Apcar, Klaus Verschure and Suresh Krishnan.

   The authors wish to thank them and many others for their helpful
   comments and suggestions.

Authors' Addresses

   Per Andersson
   Cisco Systems
   Email: perander@cisco.com

   Jan Lindblad
   Cisco Systems
   Email: jlindbla@cisco.com

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   Snezana Mitrovic
   Cisco Systems
   Email: snmitrov@cisco.com

   Marisol Palmero
   Cisco Systems
   Email: mpalmero@cisco.com

   Esther Roure
   Cisco Systems
   Email: erourevi@cisco.com

   Gonzalo Salgueiro
   Cisco Systems
   Email: gsalguei@cisco.com

   Emile Stephan
   Orange
   Email: emile.stephan@orange.com

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