| Internet-Draft | Peer-Mount | November 2023 |
| Pignataro, et al. | Expires 11 May 2024 | [Page] |
Abstract Here...¶
By definition, an Internet-Draft is a work in progress. An impactful Abstract and Introduction will be added to this working draft pending an initial set of reviews of this -00, and after the main sections are stable.¶
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/.¶
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 11 May 2024.¶
Copyright (c) 2023 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.¶
Introduction Here...¶
By definition, an Internet-Draft is a work in progress. An impactful Abstract and Introduction will be added to this working draft pending an initial set of reviews of this -00, and after the main sections are stable.¶
This section defines sustainability-specific terms as they are used in the document, and as they pertain to environmental impacts. The goal is to provide a common sustainability considerations lexicon for network equipment vendors, operators, and designers. The terms are alphabetically organized.¶
Every technology solution, system or process has sustainability impacts, as it uses energy and resources and operates in a given context to provide a [perceived] useful output. These impacts could be both negative and positive w.r.t sustainability outcomes. With a simplistic view, the negative impact is termed as footprint and the positive impact is handprint, as defined in the terms section above. Again, generally speaking, footprint considerations of a technology are grouped under “Sustainable X” and the handprint considerations are covered under “X for Sustainability”.¶
Additionally, when sustainability impacts are considered, not only environmental but also societal and economic perspectives need to be taken into account, both for footprint and handprint domains. A systems perspective ensures that the interactions and feedback loops are not forgotten among different sub-areas of sustainability.¶
Another fundamental sustainability impact assessment requirement is to cover the complete impact of a product, service or process over its full lifetime. Life Cycle Assessment (LCA) starts from the raw materials extraction & acquisition phases, and continues with design, manufacturing, distribution, deployment, use, maintenance, decommissioning, refurbishment/reuse, and ends with end-of-life treatment (recycling & waste). It is imperative that we consider not only the design and build stages of our technologies but also its use and end-of-life phases. An equally essential way of ensuring a holistic perspective is the supply-chain dimension. When we consider the footprint impact of a technology we are building, we need to consider the full supply chain that the technology is part of, both upstream, what it inherits from the materials, components and services used, to downstream for wherever the technology is used and then decommissioned. What this implies is that we are responsible for the direct and indirect impacts of our activity, both on demand and supply directions.¶
Below, we cover the “Sustainable Internetworking” and “Internetworking for Sustainability” perspectives in more detail.¶
Sustainable internetworking is about ensuring that the negative impacts of internetworking are minimized as much as possible.¶
In the environmental / ecological sustainability domain, the sub-areas to be considered are:¶
Climate change,¶
materials efficiency, circularity, preservation of geodiversity, and¶
biodiversity preservation.¶
Climate change considerations in internetworking by and large translate to energy sourcing, consumption, savings and efficiency as this impacts the GHGs of the internetworking systems directly, when mostly non-renewable energy sources are used for the operations of the networks. When the carbon intensity of the energy supply used in operations decreases (more renewable energy in the supply mix), then the use phase GHGs also proportionally decrease. This might put the GHG emissions of the manufacturing and materials extraction and acquisition phases ahead of the use phase. These are called the embodied emissions.¶
However, energy is not the only aspect to consider: materials efficiency and circularity are key actions to limit the resource use of our technologies, thereby reducing the scarcity of materials but also the destruction of many ecosystems during their extraction and manufacturing, polluting water and land with waste, which might also impact directly or indirectly the abundance and health of the species on the planet, namely biodiversity. While it is significantly more difficult to quantify and measure the impact of our technologies in these domains, the planetary boundaries framework provides helpful guidance.¶
For the societal and economic footprint of our technologies, we need to be mindful about the potential negative effects of our technologies w.r.t. the social boundaries, as depicted in the so-called doughnut economics model, that includes education, health, incomes, housing, gender equality, social equity, inclusiveness, justice and more. What we need to realize is that our technology has direct and indirect impacts in these aspects and the challenge is not only to meet environmental sustainability targets but social and economic ones as well. There are very practical considerations for example: does centralization/concentration in internetworking affect empowerment and inclusion, or the relationship of automation and AI use with bias or job creation. More technology doesn’t always mean better outcomes for all and can we mitigate this impact? Admittedly, a quantitative approach to the societal and economical aspects is more challenging but the KV/KVI approach described below brings some relief.¶
When it comes to the positive impact of internetworking in tackling the sustainability challenges faced, we are in the “internetworking for sustainability” realm. This is a very diverse topic covering innumerable industrial and societal verticals and use cases. Essentially, we are asking how our technology can help other sectors and users to decarbonize, and to reduce their own footprints and to increase their handprints in environmental, societal and economic dimensions. These are induced or enablement effects. Examples are how internetworking is being used in smart energy grids or smart cities, transport, health care, education, agriculture, manufacturing and other verticals. While efficiency gains are usually a basis, there are also other impacts through ubiquitous network coverage, sensing, affordability, ease of maintenance and operation, decentralization, to name a few.¶
Climate change mitigation and climate change adaptation, as defined in the terms section above, are particular focus areas where internetworking could help create more resilience in our societies and economies along with sustainability.¶
Essentially, handprint considerations are asking us to think about how our technology could be used to tackle sustainability challenges at first, and second, to generate feedback on how to create enablers and improvements in our technology for it to be more impactful. The usual KPIs related to technical system parameters would be largely insufficient for this purpose. Supporting this effort, Key Values (KV) and Key Value Indicators (KVIs) concepts have been developed, to be used in conjunction with use cases to develop impactful solutions. KV and KVIs are the subject of the nxt section below.¶
TBC.¶
In the context of sustainability, key values are what matters to societies and to people when it comes to direct and indirect outcomes of the use of our technology. While KPIs help us to build, monitor and improve the design and implementation of our technologies, key values and their qualitative and quantitative indicators tell us about their usefulness and value to society and people. As we want our technology to help tackle the grand challenges of our planet, their likelihood of usefulness and impact is a paramount consideration. KVs and KVIs help set our bearings right and also demonstrate the impact we could create.¶
While key values could be universal, like for example the United Nations Sustainable Development Goals (UN SDGs), how they are measured, or perceived (KVIs) could be context dependent, that is, use case specific. To give a simplified example, UN SDG 3, “good health and well-being” is a key value for any society and individual. Then, when we consider the use case of providing health care and wellness services in a remote, rural community which doesn’t have any hospitals or specialist doctors, a key value indicator could be how fast a patient could access health care services without having to travel out of town, or the successful medical interventions that could be carried out remotely. Then the next step is to identify which parts of our technology could help enable this and design our technology to create impact for the KVs as per KVIs. In this case, universal network coverage, capacity and features to integrate multitude of sensors, low-latency and jitter communication services could all be enablers with their own design targets and KPIs defined. Subsequently, we would track the KVIs and the KPIs together for successful outcomes.¶
Admittedly, this might not be a straightforward task to carry out for each protocol design. Yet, such analyses could be included in design processes along with use case development, covering a group of technology design activities (protocols) together. There are ongoing efforts in mobile networking research to use KVs/KVIs efficiently [M6G-KVI] [M6G-VP].¶
While we find ourselves trying to optimize seemingly contradicting parameters or aspects such as reducing latency and jitter and increasing bandwidth and reach targets with sustainability ones like reduced energy consumption and increased energy efficiency, key values and key value indicators would help keep our eyes on the targets that matter for the end users and communities and societies. Considerations for such potential design trade-offs, which are at the heart of our engineering innovations, is the topic of the next section.¶
Traditionally, digital communication networks are optimized for a specific set of criteria that proxies for business metrics. A network operator providing services to their customers intends to maximize profits, by increasing top-line revenue and decreasing bottom-line associated costs. This directly translates to goals of optimizing performance and availability, while reducing various costs.¶
Most recently, as explained above, various forces elevate the need for sustainability in networking technologies and architectures, to quantify and minimize negative environmental impact.¶
A first approximation to this conundrum indicates that optimizing network availability (e.g., by having excess capacity and backup paths) or optimizing performance (e.g., by increasing speeds selecting paths based on delays only) can be in opposition to optimizing sustainability objectives. As such, network architects and designers are presented with a set of new design tradeoffs: a multi-objective optimization that satisfies border requirements and global optima for availability, performance, and sustainability simultaneously. This is not unlike the doughnut economics model concept introduced in the Terms above.¶
To understand this new model, we can analyze a simplified example. Assume the following topology, passing traffic from A to B:¶
A
|
+----------+
| Router 1 |------------+
+----------+ |
| | | | | +----------+
| | | | | | Router 3 |
| | | | | +----------+
+----------+ |
| Router 2 |------------+
+----------+
|
B
Router 1 is connected to Router 2 with five parallel links, of 10 Gbps each. Router 1 can also reach Router 2 through Router 3 with 40 Gbps links. Let’s assume that the capacity-planned traffic between A and B equals 15 Gbps.¶
In this scenario, a topology optimized for performance and availability/resiliency would have all links and routers on, and would likely forward traffic using two of the parallel links. Utilizing the path through Router 3 might lower performance, but it serves as a backup path.¶
On the other hand, when we add sustainability as a consideration, different options are presented. One of them is to remove from the topology Router 3 and associated links, and shutdown links and optics in two or three of the parallel links. Another option is to completely shutdown all the parallel links and route traffic through Router 3 (i.e., not maximizing performance alone, but maximizing at the time performance, availability and resiliency, and sustainability.) The choice between these two options will depend on the aggregate sustainability metrics of network elements in each of the two topologies.¶
When we add sustainability considerations, resiliency is not the single objective to optimize. And while the graphs of resiliency and sustainability might be impractical to approximate with formulas, there are ratios that can give a sense of border conditions.¶
For example, consider the overall network capacity over the used capacity, and let’s call it “Resiliency Index”. If this number is one, there’s no resiliency; and as the ratio grows, so potentially unused capacity that could be utilized in a failure event. Similarly, consider the values os sustainability metrics for when the Resiliency Index is one and for when it is two. These borders points might give an indication of the slope for each objective.¶
The fields of performance and quality of experience have the benefit of significant study and standardization of metrics. In a similar way than with resiliency, a degradation of performance and Quality of Service parameters, such as bandwidth, latency, jitter, etc., can very well be observed and measured, as a variation of sustainability metrics. The relative slopes of improvement of each goal would hint as to where the balance lies.¶
The networking industry is in the starting phases of addressing this objective. We are seeing a sprinkling of sustainability features across the networking stack and components of devices, whether it is on forwarding chips, power supplies, optics, or compute. Many of those optimizations and features are typically local in nature, and widely scattered across different elements of a network architecture. An opportunity for maximizing the positive environmental impact of these technologies calls for a more cohesive and complementary view that spans the complete product lifecycle for hardware and software, as well as how some of these features work in unison.¶
For example, features that provide energy saving modes for devices can be dynamically utilized when the network utilization is such that performance would not significantly suffer. Or consider a core router of today that becomes more usable as an edge/access router of the future due to the need for higher throughput in the core. This section explores the benefits of macro-optimizations by clustering in specific phases, versus micro-optimizing locally without awareness of the network context.¶
The sustainability considerations described above and the associated goals cannot always be achieved at the same time and we expect the following high level phases:¶
Visibility: In this phase we focus on the measurement and collection of metrics.¶
Insights and Recommendations: In this phase we focus on deriving insights and providing recommendations that can be acted upon manually over large time scales.¶
Self-Optimization via Automation: In this phase we build awareness into the systems to automatically recognize opportunities for improvement and implement them.¶
Visibility represents collecting and organizing data in a standard vendor agnostic manner. The first step in improving our environmental impact is to actually measure it in a clear and consistent manner. The IETF, IRTF and the IAB have a long history of work in this field, and this has greatly helped with the instrumentation of network equipment in collecting metrics for network management, performance, and troubleshooting. On the environmental-impact side though, there has been a proliferation of a wide variety of vendor extensions based on these standards. Without a common definition of metrics across the industry and widespread adoption we will be left with ill-defined, potentially redundant, proprietary, or even contradicting metrics. Similarly, we also need to work on standard telemetry for collecting these metrics so that interoperability can be achieved in multi-vendor networks.¶
Once the metrics have been collected, categorized, and aggregated in a common format, it would be straightforward to visualize these metrics and allow consumers to draw insights into their GHG and energy impact. The visualizations would take the form of high-level dashboards that provide aggregate metrics and potentially some form of maturity continuum. We think this can be accomplished using reference implementations of the standards developed in phase 1. We do expect vendors and other open projects to customize this and incorporate specific features. This will allow identifying sources of environmental impact and address any potential issues through operational changes, creation of best-practices, and changes towards a greener, more environmentally friendly equipment, software, platforms, applications, and protocols.¶
Manually making changes as mentioned in Phase 2 works for changes needed on large timescales but does not scale to improvements on smaller scales (i.e., it is impractical in many levels for an operator to be looking at a dashboard monitoring usage and making changes in real-time 24x7). There is a need to provision some amount of self-awareness into the network itself, at various layers, so that it can recognize opportunities for improvement and make those changes and measure the effects by closing the loop. The goals of the consumers can be stated in a declarative fashion, and the networks can continually use mechanisms such as ML/DL/AI with an additional goal to optimize for improvements in the environmental impact. These include, for example:¶
Discovery and advertisement of networking characteristics that have either direct or indirect environmental impact,¶
greener networking protocols that can move traffic on to more energy efficient paths, directing topological graphs to optimize environmental impacts, and¶
protocols that can instruct equipment to move under-utilized links and devices into low-energy modes.¶
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 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 less-traditionally and non-Internet technologies as well as non-technologies. E.g., use our technologies to choose greener and more efficient sources of power, control HVAC systems efficiently, etc. We are looking forward to our efforts that will positively impact the environment using Internet technologies and protocols.¶
INSERT specific call to action here.¶
TBC.¶
TBC.¶