NMRG L. M. Contreras, Ed.
Internet-Draft G. Sanchez Illan
Intended status: Informational Telefonica
Expires: 18 September 2025 17 March 2025
Intent for Green Services
draft-contreras-nmrg-green-intent-01
Abstract
There is an increasing interest on incorporating sustainable
dimension to the provision of commnunication services. This document
describes an intent for allowing customers to express their desired
intents in terms of the green service objectives they expect from the
network provider.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Intents Targeting Green Services . . . . . . . . . . . . . . 2
2.1. Intent Structure . . . . . . . . . . . . . . . . . . . . 3
2.2. Relationship among intent attributes . . . . . . . . . . 3
3. Green Intent Lifecycle . . . . . . . . . . . . . . . . . . . 4
4. Implementation Status and Lessons Learned . . . . . . . . . . 6
4.1. Implementation Status . . . . . . . . . . . . . . . . . . 6
4.2. Lessons learned . . . . . . . . . . . . . . . . . . . . . 6
5. Security considerations . . . . . . . . . . . . . . . . . . . 6
6. Informative References . . . . . . . . . . . . . . . . . . . 6
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
Sustainability goals are moving the industry to the objective of
providing services in a more efficient way from the perspective of
energy consumption, which can be referred to as “green services”. The
actual provision of such green services has dependencies on the
challenges identified for the management for green networking
[I-D.irtf-nmrg-green-ps].
In this respect, it is of interest allowing customers to express
their desired intents in terms of the green service objectives they
expect from the network provider. Such objectives can be related not
only to the energy consumption itself, but also to the source of the
energy being consumed for providing the service. The former relates
to the CO2 footprint associated to the service.
The provider could, or could not, honor the customer request
expressed by the intent. It will be then necessary to enable a
framework for negotiation, validation and enforcement of the
objectives subject to the intent.
This document primarily focuses on the structure and attributes of an
intent targeting green services. The discussion on how to assess the
value of the intent attributes is out of scope of this document.
2. Intents Targeting Green Services
For customers it can be of interest to provide descriptive
information about the expected energy and the CO2 intensity of the
service. This information can be processed by the network provider
for determining the way in which the service can be realized, as any
other service constrained. For instance, according to some defined
policies, a service could be provided using resources of a certain
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geographical area.
It should be noted that the concept of service can include not only
connectivity but also Service Functions hosted in different points of
presence. All of them can be subject to different levels of energy
consumption and different sources of energy generation.
2.1. Intent Structure
The following parameters are considered as possible attributes of the
intent:
* _Energy consumption_. This attribute refers to the overall
consumed energy, specifying a threshold value of consumption
(e.g., less than such threshold).
* _Energy efficiency_. This attribute relates to the ratio of energy
per a given unit related to the service (typically such unit
refers to unit of traffic, e.g., bits per Joule), specifying a
threshold value of efficiency (e.g., greater than such threshold).
* _Carbon emissions_. This attribute refers to the overall carbon
intensity of the service (i.e., grams of CO2 per kWh), specifying
a threshold value of emissions (e.g., less than such threshold).
* _Use of renewable energy_ (expressed as a rate). This attribute
relates to ratio of renewable energy used for the service (e.g.,
greater than such threshold), as well as, potentially, the source
of renewable energy.
These attributes do not necessarily be present at the same time in
the green intent. Moreover, the final values of the intent
attributes could be aligned with metrics defined in
[I-D.cx-opsawg-green-metrics]. Finally, the customer can assess the
commitment of the desired intents by the provider by means of APIs as
the one defined in [I-D.petra-path-energy-api].
2.2. Relationship among intent attributes
The attributes mentioned above are interconnected at various levels.
Exploring these relationships helps identify the implications of how
one attribute influences others.
The use of renewable energy (URE) is directly linked to carbon
emissions (CE), as a higher URE generally results in lower CE.
However, the percentage of renewable energy is independent of both
energy consumption (EC) and energy efficiency (EE), showing no direct
correlation with these two factors.
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Conversely, there is a clear relationship between EE and EC. A less
energy-efficient network will require more energy. Consequently, for
a fixed URE value, higher energy consumption leads to increased
carbon emissions. Beyond this evident connection, analyzing the
interplay between EE, EC, and CE enables a deeper understanding of a
system's dynamics concerning these indicators. This is proposed as
for further work.
For example, given a specific energy consumption (EC) value, the
energy efficiency of a network can be improved by increasing its
traffic load, thereby enhancing its performance. This aligns with
current device and network element implementations, where energy
consumption is primarily driven by idle power rather than traffic
volume. As a result, traffic variations have minimal impact on
energy usage.
Achieving a proportional relationship between energy consumption and
traffic requires turning off (or entering into sleep mode) modular
components, such as entire line cards. Additionally, for a fixed
traffic volume, energy consumption can be reduced by adopting more
energy-efficient equipment that consume less energy per unit of
traffic. Consequently, lowering energy consumption also leads to a
reduction in carbon emissions.
3. Green Intent Lifecycle
[RFC9315] defines an intent lifecycle composed of two phases, namely
fulfillment and assurance.
Figure 2 captures the intent procedure for the fulfillment phase.
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User Space : Translation / IBS : Network Ops
: Space : Space
: :
+----------+ : +----------+ +-----------+ : +-----------+
Fulfill |recognize/|---> |translate/|-->| learn/ |-->| configure/|
|generate | | | | plan/ | | provision |
|intent |<--- | refine | | render | : | |
+----------+ : +----------+ +-----------+ : +-----------+
: :
.........................................................................
Customer : Provider
-------- : --------
:
- Generate a green : - Translation of attributes as: - Configuration
intent using one : constraints to check against: of the network
or more of the : pre-defined policies : according to
attributes defined : : policies
in this document : :
Figure 1: Fulfillment phase of the Green Intent
Similarly, Figure 3 sketches the intent procedure for the assurance
phase.
: +--------+ :
: |validate| : +----------+
: +----^---+ <----| monitor/ |
Assure +-------+ : +---------+ +-----+---+ : | observe/ |
|report | <---- |abstract |<---| analyze | <----| |
+-------+ : +---------+ |aggregate| : +----------+
: +---------+ :
.....................................................................
Customer : Provider
-------- : --------
:
- Analysis of the : - Checking of monitored data : - Collection of
reported metrics : for internal closed loops : green metrics
against the intent : to ensure commited SLOs : [I-D.cx-opsawg
request : (inner closed loop) : -green-metrics]
- Trigger of actions : - Exposure of green data by : suitable for
if needed (outer : APIs, e.g. : the intent
closed loop) : [I-D.petra-path-energy-api] : attributes
Figure 2: Assurance phase of the Green Intent
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4. Implementation Status and Lessons Learned
This section will be used to track the status of the implementations
of the model.
4.1. Implementation Status
Current implementation of the green intent can be accessed at:
https://github.com/Telefonica/intent_engine/blob/develop/inputs/
green_v2.yaml
4.2. Lessons learned
At this stage of definition of the intent for green services, the
following lessons can be reported:
* There is yet an ongoing work on definition of metrics which
requires to mature. Such metrics will conidtion the final format
of the intents.
* A service is composed by multiple assets, each of them with their
own way of characterizing energy and power related metrics. A
typical service could be composed of connectivity services,
service functions, control and processing capabilities, etc. Thus
an abstract way of reporting the overall green attributes for a
service is needed, since it can not be expected full knowledge of
the particular aspects of a service by the customer using the
intent.
As long as the work progress, additional lessons will be provided.
5. Security considerations
To be done.
6. Informative References
[I-D.cx-opsawg-green-metrics]
Clemm, A., Dong, L., Mirsky, G., Ciavaglia, L., Tantsura,
J., Odini, M., Schooler, E., Rezaki, A., and C. Pignataro,
"Green Networking Metrics", Work in Progress, Internet-
Draft, draft-cx-opsawg-green-metrics-02, 4 March 2024,
<https://datatracker.ietf.org/doc/html/draft-cx-opsawg-
green-metrics-02>.
[I-D.irtf-nmrg-green-ps]
Clemm, A., Pignataro, C., Westphal, C., Ciavaglia, L.,
Tantsura, J., and M. Odini, "Challenges and Opportunities
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in Management for Green Networking", Work in Progress,
Internet-Draft, draft-irtf-nmrg-green-ps-06, 15 March
2025, <https://datatracker.ietf.org/doc/html/draft-irtf-
nmrg-green-ps-06>.
[I-D.petra-path-energy-api]
Rodriguez-Natal, A., Contreras, L. M., Muniz, A., Palmero,
M., Munoz, F., and J. Lindblad, "Path Energy Traffic Ratio
API (PETRA)", Work in Progress, Internet-Draft, draft-
petra-path-energy-api-02, 8 July 2024,
<https://datatracker.ietf.org/doc/html/draft-petra-path-
energy-api-02>.
[RFC9315] Clemm, A., Ciavaglia, L., Granville, L. Z., and J.
Tantsura, "Intent-Based Networking - Concepts and
Definitions", RFC 9315, DOI 10.17487/RFC9315, October
2022, <https://www.rfc-editor.org/info/rfc9315>.
Acknowledgements
This work has been partially funded by the HORIZON-JU-SNS Research
and Innovation Action projects 6Green (Grant Agreement no. 101096925)
and Exigence (Grant Agreement no. 101139120).
Authors' Addresses
Luis M. Contreras (editor)
Telefonica
Ronda de la Comunicacion, s/n
28050 Madrid
Spain
Email: luismiguel.contrerasmurillo@telefonica.com
URI: http://lmcontreras.com
Guillermo Sanchez Illan
Telefonica
Ronda de la Comunicacion, s/n
28050 Madrid
Spain
Email: guillermo.sanchezillan@telefonica.com
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