| Internet-Draft | Energy-API | July 2025 |
| Rodriguez-Natal, et al. | Expires 8 January 2026 | [Page] |
This document describes an API to query a network regarding its Energy Traffic Ratio for a given path.¶
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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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This Internet-Draft will expire on 8 January 2026.¶
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.¶
Sustainability is becoming one of the major societal goals for the next decade, and networks are one of the major consumers of energy nowadays. Sustainability of network services is thus one of the forefronts of innovation and action from network service stakeholders, involving manufacturers, operators and customers. In this line, there is a shared goal of achieving better energy awareness.¶
As with any other network metric, the energy traffic ratio could be collected from the underlying network infrastructure. However, there is not a common or single definition of energy metrics towards network consumers so that can be uniformly reported, particularly in heterogeneous network scenarios. This document introduces an API to query networks about Energy Traffic Ratio.¶
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.¶
This documents describes an API to query a network about the Energy Traffic Ratio for a given path. It takes as input the source and destination of a path along with the traffic throughput between and returns energy information related to the traffic on the path. This is energy computed by the infrastructure that is dynamically part of the traffic path. The API is agnostic to the actual hops and underlaying infrastructure that enables a path, which might change transparently to the API. This document only describes the API, the computation of the energy information to return is out of the scope of this document.¶
This API allows to return a number of energy attributes associated with the path and the traffic. Currently the parameters that could be returned as energy information as part of the query are:¶
Some other parameters that could be considered as well as part of the energy information include:¶
The API is envisioned in such a way that could be used recursively. That means, subpaths could report their energy consumption using PETRA and such energy consumption could be aggregated and reported for the overall path also using PETRA.¶
Similarly, this API could be (recursively) used to provide energy information according to the definition of Service Models in an SDN context as described in [RFC8309]. In that case, using Figure 3 in [RFC8309] as reference, PETRA could be used between the Controller(s) and the Network Orchestrator(s), between the Network Orchestrator(s) and the Service Orchestrator, and between the Service Orchestrator and the Customer(s).¶
While considering recursive usage, the aspect of double-counting shall also be taken into consideration. Double counting refers to the fact of counting more than once the same energy consumed. Organizations using PETRA in a recursive manner need to take appropriate measures to ensure no double-counting occurs across recursive calls to the API.¶
This is a posible definition of PETRA as a module following the YANG specification [RFC6020].¶
This section uses the graphical representation of data models defined in [RFC8340].¶
module: ietf-petra
+--rw energy
+---x query
+---w input
| +---w src-ip ietf-inet-types:ip-address
| +---w dst-ip ietf-inet-types:ip-address
| +---w throughput uint32
+--ro output
+--ro (result)?
+--:(success)
| +--ro success
| +--ro watts-per-gigabit? decimal64
| +--ro carbon-intensity? uint32
+--:(invalid-address)
+--ro invalid-address
¶
<CODE BEGINS> file "ietf-petra@2024-07-05.yang"
module ietf-petra {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-petra";
prefix ietf-petra;
import ietf-inet-types {
prefix ietf-inet-types;
}
organization
"";
contact
"";
description
"Initial YANG rendition of the PETRA Energy API, v1.0.1
Copyright (c) 2025 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject to
the license terms contained in, the Revised BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX
(https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself
for full legal notices.
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 (RFC 2119)
(RFC 8174) when, and only when, they appear in all
capitals, as shown here.
";
/*
If you have an implementation of this YANG module, you could
access it like something this over RESTCONF:
$ curl --location --request POST \
'https://localhost:8008/restconf/operations/energy/query' \
--header 'Content-Type: application/yang-data+json' \
--user 'admin:admin' \
--data-raw '{
'input' : {
'src-ip': '10.10.10.10',
'dst-ip': '10.20.20.20',
'throughput': '40'
}
}'
And if all goes well, you might receive (besides all the
HTTP headers) a reply body with something like this:
{
'output': {
'success': {
'watts-per-gigabit': '191.855',
'carbon-intensity': '108'
}
}
}
*/
revision 2025-05-12 {
description
"Initial YANG rendition of the PETRA Energy API, v1.0.1";
reference
"RFC XXXX: ...";
}
grouping energy-metrics-g {
description
"Grouping for query result metrics.";
leaf watts-per-gigabit {
type decimal64 {
fraction-digits 3;
}
units W/Gb;
description
"Watts consumed per Gigabit transmitted";
}
leaf carbon-intensity {
type uint32;
units gCO2e/kWh;
description
"Grams of CO2 per kWh";
}
}
container energy {
description
"PETRA API top level container.";
action query {
description
"Query the network for energy consupmtion";
input {
leaf src-ip {
type ietf-inet-types:ip-address;
mandatory true;
description
"Source IP address";
}
leaf dst-ip {
type ietf-inet-types:ip-address;
mandatory true;
description
"Destination IP address";
}
leaf throughput {
type uint32;
units Gb/s;
mandatory true;
description
"Throughput between source and destination
(in gigabits per second)";
}
}
output {
choice result {
description
"Choice of which kind of result the query gave.";
container success {
description
"Successful operation";
uses energy-metrics-g;
}
container invalid-address {
description
"Invalid source/destination IP address supplied";
}
}
}
}
}
}
<CODE ENDS>¶
Kudos to Elis Lulja for his help with the OpenAPI specification in early versions of this draft. Thanks to Fernando Sanz Garcia and Lori Jakab for their help and support on this work.¶
The contribution of Telefonica to this document has been supported by the Smart Networks and Services Joint Undertaking (SNS JU) under the European Union's Horizon Europe research and innovation projects 6Green (Grant Agreement no. 101096925) and Exigence (Grant Agreement no. 101139120).¶
The IANA is requested to as assign a new namespace URI from the IETF XML registry.¶
This document registers the following namesace URIs in the IETF XML registry [RFC3688]:¶
--------------------------------------------------------------------¶
URI: urn:ietf:params:xml:ns:yang:ietf-petra¶
Registrant Contact: The IESG.¶
XML: N/A, the requested URI is an XML namespace.¶
--------------------------------------------------------------------¶
This document registers the following YANG modules in the "YANG Module Names" registry [RFC6020]:¶
--------------------------------------------------------------------¶
Name: ietf-petra¶
Namespace: urn:ietf:params:xml:ns:yang:ietf-petra¶
Prefix: petra¶
Reference: RFC XXX¶
--------------------------------------------------------------------¶
This section describes some use-cases where this specification might be useful.¶
Software-Defined Wide-Area Networks (SD-WAN) have become a common way for enterprises to provide cost-effective connectivity across their different geographically distributed sites. Typically, SD-WAN deployments operate as an overlay network that is established on top of an existing underlay connectivity network. One aspect to consider is that in many SD-WAN production deployments the operator of the overlay network and the operator of the underlay network are different organizations.¶
This poses an additional challenge when trying to derive sustainability metrics. Even if the underlay network is instrumented to collect energy data, this data is opaque to the operator of the overlay network which has no access to underlay information. While operators of underlay networks offer certain general network metrics to overlay operators, no interface has been defined to allow the overlay operator to query the underlay network for energy information.¶
In this context, the PETRA specification presented in this document enables the operator of the SD-WAN network to coordinate with the underlay operator to capture sustainability data. This in turns opens further use-cases, from observability and reporting to potentially overlay policies based on underlay energy data, further enabling an overall more sustainable operation of the network.¶
The concept of multilayer L3-L1 collection involves integrating data from different network layers to provide a comprehensive view of network operations. The use case of multilayer involves collecting and correlating data from Layer 3 (network layer) down to Layer 1 (physical layer). This multilayer approach allows for better network performance, optimization, and troubleshooting by providing end-to-end visibility.¶
Leveraging PETRA API for multilayer L3-L1 collection use case enhances energy management by providing comprehensive visibility, enabling optimization, and supporting proactive management. This makes PETRA a useful tool for more accurate, efficient and effective energy management in modern networks.¶
The document Framework for Energy Efficiency Management [I-D.belmq-green-framework] describes a framework that comprises a controller element. In that document, the tasks of the controller are defined as "collection, compute and aggregate". In the context of that framework, the controller could also expose PETRA to offer path-related energy information. The figure below updates the one present in [I-D.belmq-green-framework] to add an additional interface (interface 'g') to the controller to represent the Path Traffic Ratio API.¶
+--------------------------------------------------------------------+
| |
| (3) Network Domain Level |
| |
+--------------------------------------------------------------------+
(a) (b) (c)
Inventory Monitor +- DataSheets/DataBase
Of identity Energy | and/or via API
and Capability Efficiency | Metadata and other
^ ^ | device/component/network
| | | related information: (g)
| | | PETRA
| | | .Power/Energy related metrics API
| | | .information ^
| | | .origin of Energy Mix |
| | | .carbon aware based on location |
| | | |
| | v |
+--------------------------------------------------------------------+ |
| | |
| (2) controller (collection, compute and aggregate?) +-+
| |
+--------------------------------------------------------------------+
^ ^ ^ |
(d) | (e) | (f) | |
Inventory | Monitor power | Control | |
Capability | Proportion | (Energy saving | |
| Energy efficiency| Functionality | |
| ratio, power | Localized mgmt/ | |
| consumption, | network wide mgmt) | |
| etc) | | |
| | | v
+--------------------------------------------------------------------+
| |
| (1) Device/Component |
| |
| +---------+ +-----------+ +----------------+ +----------------+ |
| | (I) | | (II) | | (III) | | (IV) | |
| | | | | | Legacy | | 'Attached'(PoE | |
| | Device | | Component | | Device | | end Point) | |
| | | | | | | | | |
| +---------+ +-----------+ +----------------+ +----------------+ |
+--------------------------------------------------------------------+
¶