#Background and Motivation Energy efficiency gains for communication systems are highly sought after for environmental, business, and technical reasons. Network operators seek tools and solutions to understand and manage the energy consumption of components, devices, and services across their networks, and support a robust and comprehensive energy efficiency strategy. An energy-efficient network involves deploying and managing network infrastructures to optimize energy use on network devices while achieving the network’s functional and performance requirements by improving overall network utilization. This includes adopting management plane technologies to monitor and manage energy consumption, evaluating the effectiveness of energy-aware policies beyond simply reducing consumption, and implementing management strategies that enhance overall energy efficiency in network operations. The EMAN Working Group previously worked on a closely related technology area, but the standards didn’t achieve wide industry adoption, and as illustrated in RFC 9547, the absence of standardized interfaces for measuring, reporting, and managing energy consumption across diverse network setups remains a significant challenge. #Goals and Scope The GREEN Working Group will examine the EMAN work to re-use where applicable but also consider updated operator input and requirements over that previously documented in RFC 6988. Similarly, it will examine the framework previously described in RFC 7326. It will develop new data models, specified in YANG rather than as MIBs. It is necessary to support heterogeneous deployment where energy-related statistics and management may be provided via other models and mechanisms. Guidance will be provided to operators in these heterogeneous environments to cover the incremental deployment of energy-efficient features in both network devices and the management of energy-efficient networks. The GREEN Working Group is chartered to explore use cases, derive requirements, and provide solutions for identifying and characterizing energy efficiency metrics, methods related to energy consumption of network devices, and optimizing energy efficiency across the network. The Working Group will concentrate on the following: - Collecting and updating requirements for the management of energy-efficient networks. - Defining use cases for managing energy-efficient networks. - Defining terms and definitions related to energy efficiency metrics. Where possible, terms and definitions in existing RFCs will be reused. - Developing YANG models to enable measuring and reporting of energy usage through metrics and attributes at component, device, and network levels. - Providing YANG models to allow operators to optimize energy usage in network components, devices, and across the network, via configurable energy efficiency capabilities. - Developing or selecting a framework for energy efficiency monitoring, energy efficiency capability discovery, and management within a network domain. Initially, the GREEN Working Group is expected to focus on simple foundational building blocks for new energy efficiency strategies for operators, such as the work items listed below, striving to illustrate industry implementation and adoption of the working group output before potentially considering more complex aspects of energy-efficient networks in a future charter. #Out of Scope To stay focused, the Working Group will not address energy-related issues in every networking area. Some topics are already covered in other venues while others may not be mature enough or present major shortcomings (e.g., have well-documented but unresolved security threats). The following topics are not currently within the scope of the Working Group: - Regulatory, compliance, and corporate responsibility-related matters. - Routing protocols and algorithms, including those that consider energy factors. - Methodologies for understanding the impact of energy efficiency optimization on service quality. - Methodologies for assessing environmental sustainability and related performance for the network devices. - The carbon accounting and reporting protocol to measure, manage, and report greenhouse gas emissions and other sustainability-related data such as renewable energy data. - Metadata formats for renewable energy or carbon-related data within the energy-efficient network's management system. #Work Items The GREEN Working Group will initially focus on the following deliverables: - Informational document(s) that (1) defines common terminology and metric definitions, (2) categorizes various types of metrics and measurements at component, device, and network levels. - Standard Track definitions of YANG data models at the component level, device level, and network level for energy-efficient network management including energy usage monitoring and energy consumption management. - Informational document(s) that (1) defines a set of architectural components for managing energy-efficient networks and (2) describes incremental deployment considerations for new energy efficiency metrics monitoring and capability discovery, and management within a network domain. #Dependencies and Liaisons **The GREEN Working Group will collaborate with:** - Other IETF Working Groups that address topics related to power consumption observability and energy efficiency management, such as IVY, OPSAWG, NETMOD, TVR, and INTAREA. - Working Groups that might have related work or expertise with defining and standardizing metrics, measurement frameworks, and benchmarking methodology (e.g., IPPM and BMWG). - The IAB e-impact program to identify short-term metrics-related work and propose longer-term problems for further study. **The GREEN Working Group will also liaise with other SDOs on benchmarking methodologies related to power management, mainly:** - The European Telecommunications Standards Institute (ETSI), particularly the Technical Committee of Environment Engineering (TCEE). - The International Telecommunication Union (ITU), specifically with ITU-T-SG-5. - 3GPP, specifically SA-5.