Terminology for Energy Efficiency Network Management

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/.¶

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 January 2026.¶

Copyright Notice

Copyright (c) 2025 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

With rising energy costs and increasing awareness of the environmental impact of running networks, servers, and various equipment, Energy Efficiency is considered by operators as a critical component to be integrated in the overall Network Management systems. Such integration is ambitioned to feed strategies for committing environmental objectives but also mastering related operational cost. Energy Efficiency management is thus complementing conventional network management.¶

Section 3 defines a set of terms used within the IETF when discussing Energy-efficiency networks. The purpose is to (1) ensure consistent use of a set of terms in this area, (2) help with the characterization of Energy Efficiency (and relevant aspects), (3) assist in the development of the YANG data models at the different levels in the IETF, and (4) bring clarity to the Energy Efficiency related discussions between different groups within IETF, in particular.¶

This document does not intend to define a comprehensive list of energy-related terms. Only key terms are defined. Some of these terms are extracted from existing IETF documents and beyond.¶

Also, Section 4 provides an inventory of currently used metrics to assess/compute energy-related consumption, efficiency ratio, etc.¶

Appendix A provides a list of SDOs where relevant energy efficiency effort is ongoing.¶

2. Abbreviations

The following abbreviations are used in the document:¶

CLEE:

Component Level Energy Efficiency¶

DLEE:

Device Level Energy Efficiency¶

DSLAM:

Digital Subscriber Line Access Multiplexer¶

EER

Energy Efficiency Ratio¶

GEPON:

Gigabit Ethernet Passive Optical Network¶

GPON:

Gigabit-capable Passive Optical Network¶

MSAN:

Multiservice Access Node¶

NDR:

None-Drop Rate¶

NLEE:

Network Level Energy Efficiency¶

PUE:

Power Usage Effectiveness¶

3. Definitions

Terms are listed so that terms that are needed to understand other terms are listed first.¶

Energy:

Is generally a reference to electrical energy and is measured in kilowatt-hours (kWh) ([RFC7326]).¶

Power:

Refers the time rate at which energy is emitted, transferred, or received; power is usually expressed in watts (joules per second) ([RFC7326]).¶

Energy Management:

Is a set of functions for measuring, modeling, planning, and optimizing networks to ensure that the network and network-attached devices use energy efficiently and appropriately for the nature of the application and the cost constraints of the organization ([RFC7326]).¶

Energy Monitoring:

Is a part of Energy Management that deals with collecting or reading information from devices to aid in Energy Management ([RFC7326]).¶

Energy Control:

Is a part of Energy Management that deals with directing influence over devices ([RFC7326]).¶

This control can span a network or a subset of it.¶

Energy Efficiency:

Refers to optimize energy usage in network components, devices, and across the network to minimize energy use as possible, eliminating thus energy waste. Examples to improve Energy efficiency include, but not limited to, deactivation of some or all components of network nodes during specific periods (e.g., periods with low-traffic) or adjusting interface speed of an interface based on network traffic load change, or switching to more efficient power supplies and silicon or developing more efficient transmission or signal processing algorithms.¶

Energy Efficiency Management:

Refers to a set of processes used to maintain an inventory of capabilities, use specific metrics to measure, report and assess energy consumption of the network, and control the use of available energy in an optimized manner. The overall goal is to ensure that the network and underlying devices use energy in a resource conserved manner and at low cost for the nature of the the services it provides and the cost constraints while achieving the network’s functional and performance requirements (e.g., improving overall network utilization).¶

Energy Efficiency Observability:

Is part of Energy Efficiency Management that deals with collecting, reporting, and reading metrics information from devices and evaluating the effectiveness of energy-aware policies to aid in Energy Efficiency Management.¶

Energy Efficiency Control:

Is part of Energy Efficiency Management that deals with directing influence over devices.¶

Energy Efficiency Capabilities:

Network Capabilities to optimize energy usage in network components, devices, and across the network through configurable static attributes (e.g., power saving capable attribute which can be applied to both component level and device level, or power setting attributes which specify absolute power, relative power, who provide power, who consume, who is the meter, measurement frequency, or temperature setting, voltage, ampere setting).¶

Energy Efficiency Metric:

Refers to a metric that is used for the assessment of energy consumption of a network, device, or component. One or more metrics can be defined. These metrics are also used for network performance purposes to characterize the effectiveness of an Energy Efficiency management strategy. Developing energy efficiency metrics for internetworking and associated measurement methodologies and conditions as well as consistently collecting this data over time are essential to demonstrating Energy Efficiency improvements. An example of a common outcome-oriented metric is energy consumption per data volume or traffic unit.¶

Energy Proportionality

Is the correlation between energy used and the associated useful output. For internetworking this is generally interpreted as the proportionality of traffic or traffic throughput and energy used. This concept is broadly applicable to networking infrastructure, data center, and other communication architectures. There might not a one-to-one correlation between traffic and energy use, notably due to the materially significant idle power use by devices, as well as the overall network capacity being allocated to serve at times of highest traffic utilization.¶

Energy Efficiency/Energy Efficiency Ratio (EER):

The energy efficiency is expressed as the ratio between the useful output and input of an energy conversion process of a network, device, or component.¶

For instance, in relation with a networking device, it can be stated as the ratio of total throughput (e.g., of a network element capacity) to the total power consumed (bits/Joule).¶

This ratio (i.e., Energy Efficiency Ratio, EER) is the throughput forwarded by 1 watt (e.g., [I-D.cprjgf-bmwg-powerbench]).¶

A higher EER indicates a better energy efficiency.¶

Power Usage Effectiveness (PUE):

Refer to the metric used to measure the energy efficiency of an infrastructure.¶

This metric is calculated as the ratio between the total energy consumed by an infrastructure and the energy needed for a network element/component.¶

Network Level Energy Efficiency (NLEE):

Denotes the Energy Efficiency of an entire network or a subset part of it (e.g., access network).¶

Device Level Energy Efficiency (DLEE):

Denotes the Energy Efficiency of a network element. It can be used, e.g., to compare network elements providing the same functionality or a target to optiize the configuration of a network element.¶

Component Level Energy Efficiency (CLEE):

Denotes the Energy Efficiency of a component of a network element. It can be used in the design, development, and manufacturing of energy efficient a network elements.¶

Is useful to evaluate the energy efficiency performance of individual components of a network element.¶

Measuring and understanding the energy efficiency or energy consumption of each component within a network element may be used to identify key components in a system with regard to energy saving.¶

4. Sample Energy Efficiency Metrics and Measurement Methods

This section lists some metrics that are adopted by other SDOs.¶

• DISCUSS: Should we maintain this section?¶

                      Pport = Peq/Nports[W/port]

                     EErfu = Eoutput/Erfu

                    EER = Ti/Pw [Mbit/s/W]

                    Pw = a*Pu1 + b*Pu2 + c*Pu3

                   EER = Ti/Pw [Mbit/s/W]

                  Ti = 0.35T_idle+0.5T_lowpower+0.15T_maximum
                  Pw = 0.35P_idle+0.5P_lowpower+0.15P_maximum

                           δ = Po/Pi

                          η = Qt/Pi

5. Operations and Manageability Considerations

This document defines terminolgy that is meant to ensure consistency among various efforts and deployment levels. No other operations or manageability requirements are introduced by this document.¶

6. Security Considerations

Security is not discussed in this document.¶

7. Informative References

[ETSI-ES-203-136]

"Environmental Engineering (EE); Measurement methods for energy efficiency of router and switch equipment", 2017, <https://www.etsi.org/deliver/etsi_es/203100_203199/203136/01.02.00_50/es_203136v010200m.pdf>.

[I-D.cprjgf-bmwg-powerbench]

Pignataro, C., Jacob, R., Fioccola, G., and Q. Wu, "Characterization and Benchmarking Methodology for Power in Networking Devices", Work in Progress, Internet-Draft, draft-cprjgf-bmwg-powerbench-05, 7 July 2025, <https://datatracker.ietf.org/doc/html/draft-cprjgf-bmwg-powerbench-05>.

[L.1310]

"Energy efficiency metrics and measurement methods for telecommunication equipment", 2024, <https://www.itu.int/rec/T-REC-L.1310-202409-P>.

[L.1315]

"Standardization terms and trends in energy efficiency", 2017, <https://www.itu.int/rec/T-REC-L.1315-201705-I>.

[L.1316]

"Energy efficiency framework", 2019, <https://www.itu.int/rec/T-REC-L.1316-201911-I>.

[L.1320]

"Energy efficiency metrics and measurement for power and cooling equipment for telecommunications and data centres", 2014, <https://www.itu.int/rec/T-REC-L.1320-201403-I>.

[L.1331]

"Assessment of mobile network energy efficiency", 2020, <https://www.itu.int/rec/T-REC-L.1331-202009-S>.

[L.1333]

"Carbon data intensity for network energy performance monitoring", 2022, <https://handle.itu.int/11.1002/1000/15028>.

[L.1410]

"Methodology for environmental life cycle assessments of information and communication technology goods, networks and services", 2014, <https://www.itu.int/rec/T-REC-L.1410-201412-I>.

[RFC7326]

Parello, J., Claise, B., Schoening, B., and J. Quittek, "Energy Management Framework", RFC 7326, DOI 10.17487/RFC7326, September 2014, <https://www.rfc-editor.org/rfc/rfc7326>.

[TS28.554]

"Management and orchestration; 5G end to end Key Performance Indicators (KPI)", 2024, <https://www.3gpp.org/ftp/Specs/archive/28_series/28.554/28554-i70.zip>.

Appendix A. Standards Bodies and Standards

This appendix provides a list of SDOs where relevant energy efficiency effort is ongoing. This appendix does not aim to be comprehensive. The appendix may be removed in future versions of the document.¶

Appendix B. Changes between Revisions

v01 - v02¶

• Add one new section on Operations and Manageability Considerations;¶

• Add three new energy efficiency related terms based on comments raised during the interim meeting;¶

• Update 4 existing terms such as energy efficiency defintion, energy efficiency metric, energy efficiency capabilities energy proportionality based on comments raised on the list.¶

Appendix C. Acknowledgments

TODO acknowledge.¶

Authors' Addresses