RFC 3535, 20 Years Later: An Update of Operators Requirements on Network Management Protocols and Modelling
draft-boucadair-nmop-rfc3535-20years-later-06
This document is an Internet-Draft (I-D).
Anyone may submit an I-D to the IETF.
This I-D is not endorsed by the IETF and has no formal standing in the
IETF standards process.
| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Mohamed Boucadair , Luis M. Contreras , Oscar Gonzalez de Dios , Thomas Graf , Reshad Rahman , Lionel Tailhardat | ||
| Last updated | 2024-11-25 | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Additional resources |
GitHub Repository
|
||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | I-D Exists | |
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-boucadair-nmop-rfc3535-20years-later-06
Network Working Group M. Boucadair
Internet-Draft Orange
Intended status: Informational L. M. Contreras
Expires: 29 May 2025 O. G. D. Dios
Telefonica
T. Graf
Swisscom
R. Rahman
Equinix
L. Tailhardat
Orange
25 November 2024
RFC 3535, 20 Years Later: An Update of Operators Requirements on Network
Management Protocols and Modelling
draft-boucadair-nmop-rfc3535-20years-later-06
Abstract
The IAB organized an important workshop to establish a dialog between
network operators and protocol developers, and to guide the IETF
focus on work regarding network management. The outcome of that
workshop was documented in the "IAB Network Management Workshop" (RFC
3535) which was instrumental for developing NETCONF and YANG, in
particular.
20 years later, it is time to evaluate what has been achieved since
then and identify the operational barriers for making these
technologies widely implemented. Also, this document captures new
requirements for network management operations.
Discussion Venues
This note is to be removed before publishing as an RFC.
Source for this draft and an issue tracker can be found at
https://github.com/boucadair/rfc3535-20years-later.
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/.
Boucadair, et al. Expires 29 May 2025 [Page 1]
Internet-Draft RFC 3535, 20 Years Later November 2024
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 29 May 2025.
Copyright Notice
Copyright (c) 2024 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 . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Technology Advances Since RFC 3535 . . . . . . . . . . . . . 4
3. Assessment of RFC 3535 Operator Requirements . . . . . . . . 5
4. Assessment of RFC 3535 Recommendations . . . . . . . . . . . 8
5. Observations and New Requirements . . . . . . . . . . . . . . 10
5.1. On the Importance of Data Models . . . . . . . . . . . . 10
5.2. Fragmented Ecosystem . . . . . . . . . . . . . . . . . . 12
5.3. The Network Becomes Consumable . . . . . . . . . . . . . 12
5.4. Network APIfication . . . . . . . . . . . . . . . . . . . 12
5.5. Lack of Profiling . . . . . . . . . . . . . . . . . . . . 13
5.6. Lack of Agile Process for (The Maintenance of) YANG
Modules . . . . . . . . . . . . . . . . . . . . . . . . 13
5.7. Integration Complexity . . . . . . . . . . . . . . . . . 14
5.8. YANG-formatted Data Manipulation . . . . . . . . . . . . 15
5.9. Translation and Mapping Between Service/Network and Device
Models . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.10. (In)Consistent Data Structures in Network Protocols for
Data Export . . . . . . . . . . . . . . . . . . . . . . 15
5.11. Proprietary YANG Modules, CLI, and Limited Abstraction . 16
5.12. Distinct Networks, Distinct Management Requirements . . . 17
5.13. Implications of External Dependency . . . . . . . . . . . 17
5.14. Too Much Time Between Publication of New Networking
Functionality and the Associated YANG . . . . . . . . . 18
5.15. Lack of Implementation of Proposed Solutions . . . . . . 18
5.16. Tooling & Skills . . . . . . . . . . . . . . . . . . . . 19
Boucadair, et al. Expires 29 May 2025 [Page 2]
Internet-Draft RFC 3535, 20 Years Later November 2024
5.16.1. Integration with "native" IT Tooling . . . . . . . . 19
5.16.2. IETF Support for Better YANG Integration . . . . . . 19
5.16.3. Open-source Tools . . . . . . . . . . . . . . . . . 19
5.16.4. Skills . . . . . . . . . . . . . . . . . . . . . . . 19
5.17. New Service Approaches . . . . . . . . . . . . . . . . . 20
5.18. Many Solutions for the Same Problem, but Lack of Clear
Applicably Guidance . . . . . . . . . . . . . . . . . . 20
6. Security Considerations . . . . . . . . . . . . . . . . . . . 20
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20
8. Informative References . . . . . . . . . . . . . . . . . . . 20
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 29
1. Introduction
The IAB organized a workshop (June 4-June 6, 2002) to establish a
dialog between network operators and protocol developers, and to
guide the IETF to focus on work regarding network management. The
outcome of that workshop was documented in the "IAB Network
Management Workshop" [RFC3535] which was instrumental for developing
NETCONF [RFC6241] and YANG [RFC6020][RFC7950].
More than 20 years later, new requirements on network management
operations are emerging from the operators. This document captures
these requirements that reflect the progress in this area. The
following table lists the new ops requirements; more details are
provided in Section 5.
+===============================+================+
| NEW Ops Requirement Label | Section |
+===============================+================+
| NEW-OPS-REQ-STRENGTHEN-DM | Section 5.1 |
+-------------------------------+----------------+
| NEW -OPS-REQ-DM-RATIONALIZE | Section 5.2 |
+-------------------------------+----------------+
| NEW -OPS-REQ-EASE-EXPOSURE | Section 5.3 |
+-------------------------------+----------------+
| NEW -OPS-REQ-NW-API-DISCOVERY | Section 5.3 |
+-------------------------------+----------------+
| NEW-OPS-REQ-DM-API | Section 5.4 |
+-------------------------------+----------------+
| NEW-OPS-REQ-PROFILING | Section 5.5 |
+-------------------------------+----------------+
| NEW-OPS-REQ-REASSESS | Section 5.5 |
+-------------------------------+----------------+
| NEW-OPS-REQ-AGILE | Section 5.6 |
+-------------------------------+----------------+
| NEW-OPS-REQ-INTEGRATION | Section 5.7 |
Boucadair, et al. Expires 29 May 2025 [Page 3]
Internet-Draft RFC 3535, 20 Years Later November 2024
+-------------------------------+----------------+
| NEW-OPS-REQ-Y2KG | Section 5.8 |
+-------------------------------+----------------+
| NEW-OPS-REQ-SCALE | Section 5.8 |
+-------------------------------+----------------+
| NEW-OPS-REQ-LOSSLESS | Section 5.9 |
+-------------------------------+----------------+
| NEW-OPS-REQ-REUSABILITY | Section 5.10 |
+-------------------------------+----------------+
| NEW-OPS-REQ-NEW-NEED | Section 5.12 |
+-------------------------------+----------------+
| NEW-OPS-REQ-UNSILO | Section 5.13 |
+-------------------------------+----------------+
| NEW-OPS-REQ-TIMELY-DM | Section 5.14 |
+-------------------------------+----------------+
| NEW-OPS-REQ-READILTY-IMPLEM | Section 5.15 |
+-------------------------------+----------------+
| NEW-OPS-REQ-IT-INTEGRATION | Section 5.16.1 |
+-------------------------------+----------------+
| NEW-OPS-REQ-IETF-TOOLS | Section 5.16.2 |
+-------------------------------+----------------+
| NEW-OPS-REQ-CLIENT-TOOLS | Section 5.16.3 |
+-------------------------------+----------------+
| NEW-OPS-REQ-BRIDGE | Section 5.16.4 |
+-------------------------------+----------------+
| NEW-OPS-REQ-GLUE | Section 5.17 |
+-------------------------------+----------------+
| NEW-OPS-REQ-GUIDANCE | Section 5.18 |
+-------------------------------+----------------+
Table 1
The document also provide an assessment of the RFC3535
recommendations (Section 3) and to what extend that roadmap was
driving network management efforts within the IETF (Section 4).
2. Technology Advances Since RFC 3535
Since the publication of [RFC3535] major advances were achieved in
the Network Managment area, such as (but not limited to):
* NETCONF [RFC6241]
* YANG [RFC7950]
* RESTCONF [RFC8040]
* SDN & Programmable Networks [RFC7149][RFC7426]
Boucadair, et al. Expires 29 May 2025 [Page 4]
Internet-Draft RFC 3535, 20 Years Later November 2024
* Automation [RFC8969]
* Virtualization [RFC8568]
* Containerization [I-D.ietf-bmwg-containerized-infra]
* Intent-based [RFC9315]
* Network APIs
* Models for management of services, networks, and devices
[RFC8199][RFC8309]
* Telemetry [RFC9232]
* JSON Encoding of Data Modeled with YANG [RFC7951]
* CoAP Management Interface (CORECONF) [I-D.ietf-core-comi]
* YANG to CBOR mapping [RFC9254]
* YANG Schema Item iDentifier (YANG SID) [I-D.ietf-core-sid]
See also "An Overview of the IETF Network Management Standards"
[RFC6632].
3. Assessment of RFC 3535 Operator Requirements
Section 3 of [RFC3535] includes the following recommendations:
| Ease of use is a key requirement for any network management
| technology from the operators point of view.
*Status Update*: This is still a valid requirement. It is even
exacerbated with the amount of techniques and extensions that were
specified since then.
| It is necessary to make a clear distinction between configuration
| data, data that describes operational state and statistics. Some
| devices make it very hard to determine which parameters were
| administratively configured and which were obtained via other
| mechanisms such as routing protocols.
*Status Update*: This requirement was taken into account when
designing IETF solutions. Specifically, datastores are a
fundamental concept in NETCONF/YANG (e.g., [RFC8342].
Boucadair, et al. Expires 29 May 2025 [Page 5]
Internet-Draft RFC 3535, 20 Years Later November 2024
| It is required to be able to fetch separately configuration data,
| operational state data, and statistics from devices, and to be
| able to compare these between devices.
*Status Update*: This is supported by NETCONF and RESTCONF.
| It is necessary to enable operators to concentrate on the
| configuration of the network as a whole rather than individual
| devices.
*Status Update*: Protocols such as NETCONF supports means to handle
transactions at the level of a network. For example, a controller
can establish parallel sessions with a set of devices and make use
of confirmed commit.
Also, [RFC8969] describes how YANG/RESTONF/YANG can be used to
manage a network and map it to involves underlying functions/
nodes. Several service and network data models are required for
this aim.
The IETF defined in the past models to manage few servcies such as
VPN at both service and network levels (e.g., the Layer 2 Service
Model (L2SM) [RFC8466], the Layer 3 Service Model (L3SM)
[RFC8299], the Layer 2 Network Model (L2NM) [RFC9291], and the
Layer 3 Network Model (L3NM) [RFC9182]).
A similar effort is currently ongoing for handling attachement
circuits at both service and network layers (e.g.,
[I-D.ietf-opsawg-teas-attachment-circuit],
[I-D.ietf-opsawg-ntw-attachment-circuit]).
More effort is still needed in this area.
| Support for configuration transactions across a number of devices
| would significantly simplify network configuration management.
*Status Update*: This feature is supported by NETCONF.
| Given configuration A and configuration B, it should be possible
| to generate the operations necessary to get from A to B with
| minimal state changes and effects on network and systems. It is
| important to minimize the impact caused by configuration changes.
*Status Update*: This feature is supported by NETCONF.
| A mechanism to dump and restore configurations is a primitive
| operation needed by operators. Standards for pulling and pushing
| configurations from/to devices are desirable.
Boucadair, et al. Expires 29 May 2025 [Page 6]
Internet-Draft RFC 3535, 20 Years Later November 2024
*Status Update*: This feature is supported by NETCONF.
| It must be easy to do consistency checks of configurations over
| time and between the ends of a link in order to determine the
| changes between two configurations and whether those
| configurations are consistent.
*Status Update*: A mechanism is specified in [RFC9144].
| Network wide configurations are typically stored in central
| master databases and transformed into formats that can be pushed
| to devices, either by generating sequences of CLI commands or
| complete configuration files that are pushed to devices. There
| is no common database schema for network configuration, although
| the models used by various operators are probably very similar.
| It is desirable to extract, document, and standardize the common
| parts of these network wide configuration database schemas.
*Status Update*: Covered by current implementations.
| It is highly desirable that text processing tools such as diff,
| and version management tools such as RCS or CVS, can be used to
| process configurations, which implies that devices should not
| arbitrarily reorder data such as access control lists.
*Status Update*: This is deployment-specific.
| The granularity of access control needed on management interfaces
| needs to match operational needs. Typical requirements are a
| role-based access control model and the principle of least
| privilege, where a user can be given only the minimum access
| necessary to perform a required task.
*Status Update*: RBAC is supported by existing implementation.
Also, the IETF defined [RFC8341] for this purpose.
| It must be possible to do consistency checks of access control
| lists across devices.
*Status Update*: This is implementation-specific.
| It is important to distinguish between the distribution of
| configurations and the activation of a certain configuration.
| Devices should be able to hold multiple configurations.
*Status Update*: This is supported by existing NETCONF methods.
Boucadair, et al. Expires 29 May 2025 [Page 7]
Internet-Draft RFC 3535, 20 Years Later November 2024
| SNMP access control is data-oriented, while CLI access control is
| usually command (task) oriented. Depending on the management
| function, sometimes data-oriented or task-oriented access control
| makes more sense. As such, it is a requirement to support both
| data-oriented and task-oriented access control.
*Status Update*: This is supported by [RFC8341].
4. Assessment of RFC 3535 Recommendations
Section 6 of [RFC3535] includes the following recommendations:
| The workshop recommended that the IETF stop forcing working groups
| to provide writable MIB modules. It should be the decision of
| the working group whether they want to provide writable objects
| or not.
*Status Update*: In 2014, the IESG published a statement Writable
MIB Module, which states that:
SNMP MIB modules creating and modifying configuration state
should only be produced by working groups in cases of clear
utility and consensus to use SNMP write operations for
configuration, and in consultation with the OPS ADs/MIB
doctors.
| The workshop recommended that a group be formed to investigate why
| current MIB modules do not contain all the objects needed by
| operators to monitor their networks.
*Status Update*: No such group was formed to our knowledge.
| The workshop recommended that a group be formed to investigate why
| the current SNMP protocol does not satisfy all the monitoring
| requirements of operators.
*Status Update*: No such group was formed to our knowledge.
This SNMP shortcoming was also reiterated in Section 3.5.2 of
[RFC5345].
| The workshop recommended, with strong consensus from both protocol
| developers and operators, that the IETF focus resources on the
| standardization of configuration management mechanisms.
*Status Update*: NETCONF [RFC6241], RESTCONF [RFC8040], CORECONF
[I-D.ietf-core-comi], YANG.
Boucadair, et al. Expires 29 May 2025 [Page 8]
Internet-Draft RFC 3535, 20 Years Later November 2024
YANG is a transport-independent data modeling language. It can be
used independently of NETCONF/RESTCONF. For example, YANG can be
used to define abstract data structures [RFC8791] that can be
manipulated by other protocols (e.g., [RFC9132]).
| The workshop recommended, with strong consensus from the operators
| and rough consensus from the protocol developers, that the
| IETF/IRTF should spend resources on the development and
| standardization of XML-based device configuration and management
| technologies (such as common XML configuration schemas, exchange
| protocols and so on).
*Status Update*: OK. This recommendation was also mirrored in other
documents such as [RFC5706].
| The workshop recommended, with strong consensus from the operators
| and rough consensus from the protocol developers, that the
| IETF/IRTF should not spend resources on developing HTML-based or
| HTTP-based methods for configuration management.
*Status Update*: The IETF deviated from this recommendation, e.g.,
RESTCONF [RFC8040] or CoAP Management Interface (CORECONF)
[I-D.ietf-core-comi].
| The workshop recommended, with rough consensus from the operators
| and strong consensus from the protocol developers, that the IETF
| should continue to spend resources on the evolution of the
| SMI/SPPI data definition languages as being done in the SMIng
| working group.
*Status Update*: SMIng WG was concluded in 2003-04-04.
| The workshop recommended, with split consensus from the operators
| and rough consensus from the protocol developers, that the IETF
| should spend resources on fixing the MIB development and
| standardization processs.
*Status Update*: The IETF dedicated some resources to fix some SNMP
shortcomings with a focus on security (e.g., Transport Layer
Security (TLS) Transport Model for the SNMP [RFC6353] or
[RFC9456], HMAC-SHA-2 Authentication Protocols in User-Based
Security Model (USM) for SNMPv3 [RFC7860]).
Section 6 of [RFC3535] also includes the following but without
tagging them as recommendations:
Boucadair, et al. Expires 29 May 2025 [Page 9]
Internet-Draft RFC 3535, 20 Years Later November 2024
| The workshop had split consensus from the operators and rough
| consensus from the protocol developers, that the IETF should not
| focus resources on CIM extensions.
*Status Update*: The IETF didn't dedicate any resources on CIM
extensions.
| The workshop had rough consensus from the protocol developers
| that the IETF should not spend resources on COPS-PR development.
| So far, the operators have only very limited experience with
| COPS-PR. In general, however, they felt that further development
| of COPS-PR might be a waste of resources as they assume that
| COPS-PR does not really address their requirements.
*Status Update*: The IETF has reclassified COPS Usage for Policy
Provisioning [RFC3084] to Historic status.
| The workshop had rough consensus from the protocol developers
| that the IETF should not spend resources on SPPI PIB definitions.
| The operators had rough consensus that they do not care about
| SPPI PIBs.
*Status Update*: The IETF has reclassified Structure of Policy
Provisioning Information [RFC3159], as well as three Policy
Information Bases ([RFC3317], [RFC3318], and [RFC3571]) to
Historic status.
5. Observations and New Requirements
5.1. On the Importance of Data Models
An appealing aspect about network automation techniques is that they
almost apply to any kind of network. From that perspective, the
functional component of a network automation framework that probably
matters the most, and independent of the underlying interfaces and
protocols, are the data models. Concretely, data models are
instrumental in the automation of networks, especially that they can
provide closed-loop control for adaptive and deterministic service
creation, delivery, and maintenance.
Data models can be used to derive required configuration information
for both network and service components, and state information that
will be monitored and tracked. Likewise, they can be used during the
service/network management life cycle (e.g., service instantiation,
provisioning, optimization, monitoring, diagnostic, and assurance).
Boucadair, et al. Expires 29 May 2025 [Page 10]
Internet-Draft RFC 3535, 20 Years Later November 2024
More than three decades of "Internet standardization" have shown that
the specification of data models is not that straightforward. This
is because of at least two major reasons:
* For more than 30 years, legacy network equipment manufacturers
have considered their technology as a competitive advantage,
thereby leading to proprietary, vendor-specific, data models and
the burden of vendor lock-ins. For example, there are more YANG
proprietary modules than standarized ones.
* Over the same period, operators have also developed their savoir-
faire as a key competitive advantage. Such savoir-faire had to
rely upon these proprietary data models. Operators were reluctant
in the past to share their design and management practices.
The situation has changed since network "softwarization" strategies
have been disclosed by vendors and operators. From a business
standpoint, network "softwarization" is seen as a major
transformation effort by operators, because of the flexibility and
the "a la carte" approach that is promoted by "X-as-a-service" (XaaS)
designs, "X" being network, platform, Network Slice, etc.
XaaS designs assume the availability of data models that are
dynamically instantiated (along with a set of relevant policies) as a
function of the "X" (and its design, for that matter). *XaaS services
cannot be designed, delivered, and operated without data models.*
Standard data models are thus key as they allow to:
* Ease mapping among many (network/service) layers.
* Ease data correlation from distinct sources.
* Nullify (soften) CLI specifics to vendors.
* Support both top-down and bottom-up approaches:
* Accurate control loops for adaptive and deterministic service
creation, delivery, and maintenance.
* Feed an intelligence that will drive appropriate actions to adjust
the current status to align with the intended status.
NEW-OPS-REQ-STRENGTHEN-DM: Network softwarization can only happen
with a strong, committed standardization effort, complemented by
active involvement in open-source projects that facilitate access
to code.
Particularly, *without data models, a Network API is essentially
Boucadair, et al. Expires 29 May 2025 [Page 11]
Internet-Draft RFC 3535, 20 Years Later November 2024
useless* (see also Section 5.4).
5.2. Fragmented Ecosystem
The current YANG device models ecosystem is *fragmented*: some
standards models are defined through the IETF, while similar ones are
defined in other forums such as Openconfig or ONF. Unlike service
and network models, IETF-defined device models are not widely
implemented.
NEW-OPS-REQ-DM-RATIONALIZE: There is a need to rationalize this
space and avoid redundant efforts.
5.3. The Network Becomes Consumable
Network connectivity can support tailored services in terms of
Service Level Obejctives (SLOs), for instance, by means of Network
Slice Services [RFC9543]. This approach of "consuming" the network
flexibly and dynamically is made possible by enabling means of
exposing network capabilities to either internal or external
applications. Then, network management is no longer limited to
collect network status information, but it should be now extended to
permit the exposure of resources, capabilities, functionality, and
associated information (e.g., inventory based data).
NEW-OPS-REQ-EASE-EXPOSURE: Focus on protocols and data models to
expose network/service capabilities, network-wide services, and
related operations.
NEW-OPS-REQ-NW-API-DISCOVERY: Define a reference approach/process
for service exposure discovery (APIs discovery).
5.4. Network APIfication
APIs are getting momentum as means of interworking between parties,
also at the time of providing network services. As an example,
[I-D.ramseyer-grow-peering-api] defines an API for dynamically
establishing BGP peering sessions between Autonomous Systems of
different administrative domains. That same objective is also
covered by the YANG data model defined in
[I-D.ietf-opsawg-teas-attachment-circuit] as exemplified in
Appendix A.10. Tools such as YANG/OpenAPI transforms are key to
leverage existing data models and allow for better integration and
mapping to actual realization models.
NEW-OPS-REQ-DM-API: Readily available API specifications could be
generalized from YANG modules for fast development, prototyping,
and validation.
Boucadair, et al. Expires 29 May 2025 [Page 12]
Internet-Draft RFC 3535, 20 Years Later November 2024
5.5. Lack of Profiling
Many NETCONF-related features are (being) specified by the IETF, but
these features are not widely supported (e.g., YANG-Push [RFC8639]).
NEW-OPS-REQ-PROFILING: Editing a profile document that outlines a
set of recommendations for core/key features, along with
appropriate justifications, will help foster more implementations
that meet operators’ needs.
Examples of such profile documents are the various RFCs that were
published by the Behavior Engineering for Hindrance Avoidance
(behave) WG [BCP127]. Another approach could be to consider a
model similar to the "Roadmap for Transmission Control Protocol
(TCP) Specification Documents" [RFC7414]. Such a document would
serve as a guide and reference for implementers and others seeking
information on 'NETCONF/RESTCONF/YANG'-related RFCs.
NEW-OPS-REQ-REASSESS: Additionally, reassessing the value of some
IETF proposals compared to competing or emerging solutions (e.g.,
gRPC vs. YANG-Push) would be beneficial.
5.6. Lack of Agile Process for (The Maintenance of) YANG Modules
RFCs might not be suited for documenting YANG modules (it takes much
too long, especiallly for updates). In the meantime, there is a need
for "reference models" and "sufficiently stable models".
An hybrid approach might be investigated for documenting IETF-
endorsed YANG modules, such as considering an RFC to describe the
initial module sketch and objectives and an official IETF repository
for maintaining intermediate YANG versions.
By drawing a parallel between YANG data models and the concept of
ontology used in the field of Semantic Web, the topic of YANG module
maintenance could greatly benefit from proven methodologies in
knowledge engineering such as [LOT2019] and automatic documentation
tools like [Widoco2017].
NEW-OPS-REQ-AGILE: Develop a more agile process for the development
and maintenance of YANG modules in the IETF.
Boucadair, et al. Expires 29 May 2025 [Page 13]
Internet-Draft RFC 3535, 20 Years Later November 2024
5.7. Integration Complexity
Section 3 of [RFC3535] describes a set of network operator
requirements. One of the requirements is the ease of use which,
according to Section 3.2 of [RFC6244], is addressed by NETCONF and
YANG. For configuration this holds true, for network observability
it is unfortunately not yet. This has been confirmed with a set of
network operators asking how long it takes from subscribing YANG data
to make it accessible to the operator. Minutes, Hours, Days, or
Weeks. None of them answered Minutes or Hours. All of them
responded Days or Weeks. Hinting manual post processing of YANG
data.
Collecting YANG metrics from networks is already a struggle due to
late arrival of [RFC8639], [RFC8640], [RFC8641],
[I-D.ietf-netconf-https-notif], and [I-D.ietf-netconf-udp-notif] for
configured subscription transport protocols which defined YANG-Push
in the industry. This caused network vendors to implement
alternative solutions to collect real-time streaming data in the
meanwhile, such as gNMI which was proposed in 2018 in
[I-D.openconfig-rtgwg-gnmi-spec] to the IETF but not followed up on.
Unfortunately, these implementations differ between network Operating
Systems due to the lack of standardization, specifically for the
metadata which would ensure machine readability.
When a set of network operators where asked to where operational YANG
data needs to be integrated to, the answer homogeneously was Apache
Kafka Message Broker and Time Series Databases. There is a need to
specify how YANG-Push can be integrated into Apache Kafka and
references needed YANG-Push extensions and YANG schema registry
development. The YANG-Push extensions addressing needs to make YANG-
Push messages machine readable and against semantic validate able to
ensure a consistent data processing.
Another challenge is that the subscribed YANG data referenced with
datastore-subtree-filter or datastore-xpath-filter breaks semantic
integrity which needs to be addressed by either updating Section 4 of
[RFC8641] or proposing a new YANG module being used at the YANG-Push
receiver.
NEW-OPS-REQ-INTEGRATION: Consider approaches to ease integration by-
design (e.g., protocols and data models).
Boucadair, et al. Expires 29 May 2025 [Page 14]
Internet-Draft RFC 3535, 20 Years Later November 2024
5.8. YANG-formatted Data Manipulation
The use of a flat tree hierarchy in YANG models may induce some
performance issues compared to other graph models. This can be the
case, for example, during a path calculation on a network topology.
Different approaches using graph theory and compatible with YANG are
currently available, but require further experimentation to
generalize their adoption. For instance, [ODL] implements an in-
memory connected graph version of YANG-based data to enable fast
breadth-first search (BFS).
NEW-OPS-REQ-Y2KG: Need for a reference specification to translate
YANG-based data into the knowledge graph (KG).
For example, [I-D.marcas-nmop-knowledge-graph-yang] and
[I-D.tailhardat-nmop-incident-management-noria] discuss YANG-2-KG
proposals to leverage automated reasoning and graph traversal
techniques.
NEW-OPS-REQ-SCALE: Consider approaches for YANG models to scale.
5.9. Translation and Mapping Between Service/Network and Device Models
Navigating among multiple levels of the hierarchy (service, network,
device) relies currently on proprietary solutions to graft and
translate between two layers. There is no programmatic approach to
ensure lossless mappings.
NEW-OPS-REQ-LOSSLESS: Consider programmatic approaches to ensure
lossless mappings between service/network/device data models.
5.10. (In)Consistent Data Structures in Network Protocols for Data
Export
Network Telemetry, as described in [RFC9232], involve a set of
protocols. Due to the different requirements, one Network Telemetry
protocol doesn't address all needs. This is mainly due to the nature
of the subscribed data. BGP Monitoring Protocol (BMP) [RFC7854] adds
monitoring and tracing capabilities natively to the BGP process to
minimize the processing overhead. While IPFIX [RFC7011][RFC7012] can
be applied according to [RFC5472] to gain visibility into the data
and forwarding planes, due to the amount of data, sampling as defined
in [RFC5476] and applied to IPFIX in [RFC5477] and aggregation as
defined in [RFC7015] for IPFIX is needed to reduce the amount of
exposed data. While YANG-Push focuses on exposing already YANG
modelled data, which eases the correlation among network
configuration and operational data.
Boucadair, et al. Expires 29 May 2025 [Page 15]
Internet-Draft RFC 3535, 20 Years Later November 2024
[RFC9232] is an informational document and does not specify what
these Network Telemetry protocols should have in common to ensure
consistent data structures for data export. While data types are
fairly good aligned, a lack of metadata standardization among the
Network Telemetry protocols is observed. In particular describing
from where the metrics has been exported from and timestamping. In
Section 4.2 of [RFC7854] timestamps are optional and sysName
[RFC1213] is only carried in the BMP initiation message (Section 4.3
of [RFC7854]), while the message header of IPFIX defined in
Section 4.3 of [RFC7011] lacks the sysName definition.
The lack of information from where the data is being pushed from is
only known to the Network Telemetry data collection due to the
transport session being established from the network node exporting
the information. When Network Telemetry messages are being
transformed and forwarded, this information is being lost.
Therefore, it is common among network operators to augment sysName
and other metadata at the data collection.
The same common principle applies to when observation timestamping is
missing in the Network Telemetry message. Since the data collection
is the closest element to the network, a time stamp is added to give
the network operator at least the information when the Network
Telemetry message was collected. However, since Network Telemetry
addresses real-time streaming needs, this is often not accurate
enough for data correlation.
NEW-OPS-REQ-REUSABILITY: Consider approach to ensure reuse/
consistent data structure.
5.11. Proprietary YANG Modules, CLI, and Limited Abstraction
Leveraging on pluggins, propietary YANG models or even CLI is still
the rule in many operations, sometimes forced by the need of
operating legacy infrastructures.
The complexity of developing and maintaining these means of operation
is huge, as it is required to to cover many OS and vendors along the
lifetime of the network device.
Network models for the realization of services provide some "level"
of abstraction and then automation.
Boucadair, et al. Expires 29 May 2025 [Page 16]
Internet-Draft RFC 3535, 20 Years Later November 2024
5.12. Distinct Networks, Distinct Management Requirements
From the time [RFC3535] was released up to now, new kind of services
and applications have been developed and deployed over the time, with
very diverse, and some times contradicting, requirements. Those
services have been engineered on top of multi-service networks for
the sake of efficiency and simplicity, accommodating such a variety
of needs. As a result, services requiring mobility, data
replication, large capacity, adaptability, multi-path support,
determinism, etc., coexist on the same shared network, needing from
it mechanisms for graceful operation.
Likewise, such diversity of services also require different
management capabilities. For example, session continuity,
distribution trees, traffic engineering, congestion status
notification, reordering, or on-time delivery impose very different
management needs to be satisfied.
This reality is different from the one existing at the time of
[RFC3535], and as such, the new identified needs can require from
novel approaches to guarantee the aforementioned co-existence of
services.
NEW-OPS-REQ-NEW-NEED: Some networks have specific network management
requirements such as the need for asynchronous operations or
constraints on data compactness. An example of such networks is
Delay-Tolerant Networking (DTN) [RFC838] or DetNet [RFC8557].
5.13. Implications of External Dependency
Networks are being updated to abandon the silo approach from the past
towards an increasing convergence. Specifically, there are trends
towards a tighter interaction and integration of different
technologies previously considered as totally separated from an
operational perspective. Examples of that trends are the IP and
Optical integration (e.g., the introduction of colored interfaces on
routers), or the extension of deterministic-behavior features to
Layer 3 networks. This kind of convergence in most cases creates
dependencies on the conventional network management features, which
require to incorporate or integrate functionality from other
technological domains.
Boucadair, et al. Expires 29 May 2025 [Page 17]
Internet-Draft RFC 3535, 20 Years Later November 2024
Such convergence is also reflected on the need of interacting and
interworking with distinct network parts participating in the end-to-
end service delivery. Mobile access, fixed access, data center,
enterprise, radio functional split (i.e., fronthaul and midhaul),
neutral exchanges, intensive data networks (e.g., scientific academic
networks), content distribution, etc., represent network parts
constituent of end-to-end services that can impose dependencies of
the management of an intermediate network.
NEW-OPS-REQ-UNSILO: The convergence observed in recent years also
implies the need for an up-to-date refresh of management
capabilities and tools for conventional networks.
It highlights the necessity to handle the heterogeneity of data,
configuration, and network management/requirements.
From a YANG perspective, this involves easily mapping and relating
the data models used to manage each specific segment.
Resolving such issue could draw on insights from parallel
technical fields such as knowledge engineering practices and
concepts associated with Linked Data in the Semantic Web, areas
where it is common to manage problems of heterogeneity and data
reconciliation across various application domains.
5.14. Too Much Time Between Publication of New Networking Functionality
and the Associated YANG
For example, [RFC8667] (IS-IS extensions for SR) was published in
December 2019, while [I-D.ietf-isis-sr-yang] will be published ~5
years after.
NEW-OPS-REQ-TIMELY-DM: Consider having YANG as part of the protocol
specification/change where possible, or have the YANG document
progress in parallel. That may slow down the protocol
specification, though.
5.15. Lack of Implementation of Proposed Solutions
New solutions proposed by WGs such as NETMOD and NETCONF very often
lack an implementation or only have a partial implementation. The
situation has improved with the last hackathons (e.g., for YANG-
Push), but these solutions became RFCs without a known
implementation:
* YANG-Push [RFC8641]
* Schema-mount [RFC8528]
Boucadair, et al. Expires 29 May 2025 [Page 18]
Internet-Draft RFC 3535, 20 Years Later November 2024
* NMDA [RFC8342]
Schema-mount allegedly has only one known implementation because of
the complexity of the solution. That means the IETF most likely
spent lots of cycles for something which won't be deployed ever.
While hackathons have improved the situation, the availablability of
implementation is concerning. For open-source, 'sysrepo'/'libyang'
are decent choices.
NEW-OPS-REQ-READILTY-IMPLEM: It is tempting to consider mandating at
least one implementation. However, there were areas which imposed
in the past rules for implementations for I-Ds to be published as
PS (e.g., [RFC1264]), but these rules were relaxed for reasons
described, e.g., [RFC4794] and left it to the WGs to decide about
the actual measures to put in place. To date, only IDR WG has
clear guidance on two implementations.
5.16. Tooling & Skills
5.16.1. Integration with "native" IT Tooling
NEW-OPS-REQ-IT-INTEGRATION: There is a need to ease the integration
of low-level/network-oriented solution with native "IT tooling"
(e.g., "https://opentelemetry.io/").
5.16.2. IETF Support for Better YANG Integration
NEW-OPS-REQ-IETF-TOOLS Ease exposure of libraries and host tools
(e.g., yangkit) to ease integration.
5.16.3. Open-source Tools
While there are open-source implementations for NETCONF (e.g.,
NETOPEER), the gRPC/gNMI suite seems to have more support for tools
on the client side. For example, "ygot" generates structures from
YANG models and these can easily be used by a client to configure a
device with gNMI. NETCONF is not supported though (we need the XML
tags).
NEW-OPS-REQ-CLIENT-TOOLS: Focus on tooling is needed, especially on
the client side.
5.16.4. Skills
The IETF is not the expert community in data engineering. The
experts are in the data industry. Without them, integration in data
processing chains like Data Mesh is going to be a challenge.
Boucadair, et al. Expires 29 May 2025 [Page 19]
Internet-Draft RFC 3535, 20 Years Later November 2024
NEW-OPS-REQ-BRIDGE: Create an eco-system where data and networking
engineers can collaborate.
5.17. New Service Approaches
The virtualization trend have made posible to dynamically instantiate
Service Functions (SFs) in distributed compute facilities in the form
of virtual machines or containers, as micro-services. The
instantiation of the SFs is governed by cloud management systems, as
it is the connectivity among the different instances or micro-
services. That connectivity is typically realized by using overlay
mechanisms, without any further interaction with the network.
However, this appraoch seems to be insuficient for future services
demanding stringent requirements in terms of SLOs.
NEW-OPS-REQ-GLUE: The distinct approaches followed in both the
compute and the network environments makes necessary to define
suitable mechanisms for enabling an efficient interplay, while
highly automating the overall service delivery procedure.
5.18. Many Solutions for the Same Problem, but Lack of Clear Applicably
Guidance
There are several solutions that were standardized for network
management purposes. For example, management of ACLs by means to BGP
FlowSpec [RFC8955][RFC8956] or by means of NETCONF/YANG [RFC8519].
There is no cross referencing between the two standards or delimits
its applicability scope vs the other approach.
NEW-OPS-REQ-GUIDANCE: The target application/applicability of a
network management approach should be integrated in the
specification itself.
6. Security Considerations
This document does not define any protocol or architecture.
7. IANA Considerations
This document has no IANA actions.
8. Informative References
[BCP127] Best Current Practice 127,
<https://www.rfc-editor.org/info/bcp127>.
At the time of writing, this BCP comprises the following:
Boucadair, et al. Expires 29 May 2025 [Page 20]
Internet-Draft RFC 3535, 20 Years Later November 2024
Audet, F., Ed. and C. Jennings, "Network Address
Translation (NAT) Behavioral Requirements for Unicast
UDP", BCP 127, RFC 4787, DOI 10.17487/RFC4787, January
2007, <https://www.rfc-editor.org/info/rfc4787>.
Perreault, S., Ed., Yamagata, I., Miyakawa, S., Nakagawa,
A., and H. Ashida, "Common Requirements for Carrier-Grade
NATs (CGNs)", BCP 127, RFC 6888, DOI 10.17487/RFC6888,
April 2013, <https://www.rfc-editor.org/info/rfc6888>.
Penno, R., Perreault, S., Boucadair, M., Ed., Sivakumar,
S., and K. Naito, "Updates to Network Address Translation
(NAT) Behavioral Requirements", BCP 127, RFC 7857,
DOI 10.17487/RFC7857, April 2016,
<https://www.rfc-editor.org/info/rfc7857>.
[I-D.ietf-bmwg-containerized-infra]
Ngọc, T. M., Rao, S., Lee, J., and Y. Kim, "Considerations
for Benchmarking Network Performance in Containerized
Infrastructures", Work in Progress, Internet-Draft, draft-
ietf-bmwg-containerized-infra-03, 4 November 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-bmwg-
containerized-infra-03>.
[I-D.ietf-core-comi]
Veillette, M., Van der Stok, P., Pelov, A., Bierman, A.,
and C. Bormann, "CoAP Management Interface (CORECONF)",
Work in Progress, Internet-Draft, draft-ietf-core-comi-19,
3 November 2024, <https://datatracker.ietf.org/doc/html/
draft-ietf-core-comi-19>.
[I-D.ietf-core-sid]
Veillette, M., Pelov, A., Petrov, I., Bormann, C., and M.
Richardson, "YANG Schema Item iDentifier (YANG SID)", Work
in Progress, Internet-Draft, draft-ietf-core-sid-24, 22
December 2023, <https://datatracker.ietf.org/doc/html/
draft-ietf-core-sid-24>.
[I-D.ietf-isis-sr-yang]
Litkowski, S., Qu, Y., Sarkar, P., Chen, H., and J.
Tantsura, "A YANG Data Model for IS-IS Segment Routing for
the MPLS Data Plane", Work in Progress, Internet-Draft,
draft-ietf-isis-sr-yang-22, 1 July 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-isis-sr-
yang-22>.
Boucadair, et al. Expires 29 May 2025 [Page 21]
Internet-Draft RFC 3535, 20 Years Later November 2024
[I-D.ietf-netconf-https-notif]
Jethanandani, M. and K. Watsen, "An HTTPS-based Transport
for YANG Notifications", Work in Progress, Internet-Draft,
draft-ietf-netconf-https-notif-15, 1 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
https-notif-15>.
[I-D.ietf-netconf-udp-notif]
Zheng, G., Zhou, T., Graf, T., Francois, P., Feng, A. H.,
and P. Lucente, "UDP-based Transport for Configured
Subscriptions", Work in Progress, Internet-Draft, draft-
ietf-netconf-udp-notif-16, 21 October 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-netconf-
udp-notif-16>.
[I-D.ietf-opsawg-ntw-attachment-circuit]
Boucadair, M., Roberts, R., de Dios, O. G., Barguil, S.,
and B. Wu, "A Network YANG Data Model for Attachment
Circuits", Work in Progress, Internet-Draft, draft-ietf-
opsawg-ntw-attachment-circuit-14, 7 November 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-opsawg-
ntw-attachment-circuit-14>.
[I-D.ietf-opsawg-teas-attachment-circuit]
Boucadair, M., Roberts, R., de Dios, O. G., Barguil, S.,
and B. Wu, "YANG Data Models for Bearers and 'Attachment
Circuits'-as-a-Service (ACaaS)", Work in Progress,
Internet-Draft, draft-ietf-opsawg-teas-attachment-circuit-
18, 7 November 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-opsawg-
teas-attachment-circuit-18>.
[I-D.marcas-nmop-knowledge-graph-yang]
Martinez-Casanueva, I. D., Rodríguez, L. C., and P.
Martinez-Julia, "Knowledge Graphs for YANG-based Network
Management", Work in Progress, Internet-Draft, draft-
marcas-nmop-knowledge-graph-yang-05, 21 October 2024,
<https://datatracker.ietf.org/doc/html/draft-marcas-nmop-
knowledge-graph-yang-05>.
[I-D.openconfig-rtgwg-gnmi-spec]
Shakir, R., Shaikh, A., Borman, P., Hines, M., Lebsack,
C., and C. Morrow, "gRPC Network Management Interface
(gNMI)", Work in Progress, Internet-Draft, draft-
openconfig-rtgwg-gnmi-spec-01, 5 March 2018,
<https://datatracker.ietf.org/doc/html/draft-openconfig-
rtgwg-gnmi-spec-01>.
Boucadair, et al. Expires 29 May 2025 [Page 22]
Internet-Draft RFC 3535, 20 Years Later November 2024
[I-D.ramseyer-grow-peering-api]
Aguado, C., Griswold, M., Ramseyer, J., Servin, A., and T.
Strickx, "Peering API", Work in Progress, Internet-Draft,
draft-ramseyer-grow-peering-api-06, 4 November 2024,
<https://datatracker.ietf.org/doc/html/draft-ramseyer-
grow-peering-api-06>.
[I-D.tailhardat-nmop-incident-management-noria]
Tailhardat, L., Troncy, R., and Y. Chabot, "Knowledge
Graphs for Enhanced Cross-Operator Incident Management and
Network Design", Work in Progress, Internet-Draft, draft-
tailhardat-nmop-incident-management-noria-01, 29 August
2024, <https://datatracker.ietf.org/doc/html/draft-
tailhardat-nmop-incident-management-noria-01>.
[LOT2019] Poveda-Villalon, M., Fernandez-Izquierdo, A., Fernandez-
Lopez, M., and R. Garcia-Castro, "LOT: An industrial
oriented ontology engineering framework", 2022,
<https://doi.org/10.1016/j.engappai.2022.104755>.
[ODL] "Graph Model Overview", 2023,
<https://docs.opendaylight.org/projects/bgpcep/en/latest/
graph/graph-user-guide-graph-model.html#>.
[RFC1213] McCloghrie, K. and M. Rose, "Management Information Base
for Network Management of TCP/IP-based internets: MIB-II",
STD 17, RFC 1213, DOI 10.17487/RFC1213, March 1991,
<https://www.rfc-editor.org/rfc/rfc1213>.
[RFC1264] Hinden, R., "Internet Engineering Task Force Internet
Routing Protocol Standardization Criteria", RFC 1264,
DOI 10.17487/RFC1264, October 1991,
<https://www.rfc-editor.org/rfc/rfc1264>.
[RFC3084] Chan, K., Seligson, J., Durham, D., Gai, S., McCloghrie,
K., Herzog, S., Reichmeyer, F., Yavatkar, R., and A.
Smith, "COPS Usage for Policy Provisioning (COPS-PR)",
RFC 3084, DOI 10.17487/RFC3084, March 2001,
<https://www.rfc-editor.org/rfc/rfc3084>.
[RFC3159] McCloghrie, K., Fine, M., Seligson, J., Chan, K., Hahn,
S., Sahita, R., Smith, A., and F. Reichmeyer, "Structure
of Policy Provisioning Information (SPPI)", RFC 3159,
DOI 10.17487/RFC3159, August 2001,
<https://www.rfc-editor.org/rfc/rfc3159>.
Boucadair, et al. Expires 29 May 2025 [Page 23]
Internet-Draft RFC 3535, 20 Years Later November 2024
[RFC3317] Chan, K., Sahita, R., Hahn, S., and K. McCloghrie,
"Differentiated Services Quality of Service Policy
Information Base", RFC 3317, DOI 10.17487/RFC3317, March
2003, <https://www.rfc-editor.org/rfc/rfc3317>.
[RFC3318] Sahita, R., Ed., Hahn, S., Chan, K., and K. McCloghrie,
"Framework Policy Information Base", RFC 3318,
DOI 10.17487/RFC3318, March 2003,
<https://www.rfc-editor.org/rfc/rfc3318>.
[RFC3535] Schoenwaelder, J., "Overview of the 2002 IAB Network
Management Workshop", RFC 3535, DOI 10.17487/RFC3535, May
2003, <https://www.rfc-editor.org/rfc/rfc3535>.
[RFC3571] Rawlins, D., Kulkarni, A., Ho Chan, K., Bokaemper, M., and
D. Dutt, "Framework Policy Information Base for Usage
Feedback", RFC 3571, DOI 10.17487/RFC3571, August 2003,
<https://www.rfc-editor.org/rfc/rfc3571>.
[RFC4794] Fenner, B., "RFC 1264 Is Obsolete", RFC 4794,
DOI 10.17487/RFC4794, December 2006,
<https://www.rfc-editor.org/rfc/rfc4794>.
[RFC5345] Schoenwaelder, J., "Simple Network Management Protocol
(SNMP) Traffic Measurements and Trace Exchange Formats",
RFC 5345, DOI 10.17487/RFC5345, October 2008,
<https://www.rfc-editor.org/rfc/rfc5345>.
[RFC5472] Zseby, T., Boschi, E., Brownlee, N., and B. Claise, "IP
Flow Information Export (IPFIX) Applicability", RFC 5472,
DOI 10.17487/RFC5472, March 2009,
<https://www.rfc-editor.org/rfc/rfc5472>.
[RFC5476] Claise, B., Ed., Johnson, A., and J. Quittek, "Packet
Sampling (PSAMP) Protocol Specifications", RFC 5476,
DOI 10.17487/RFC5476, March 2009,
<https://www.rfc-editor.org/rfc/rfc5476>.
[RFC5477] Dietz, T., Claise, B., Aitken, P., Dressler, F., and G.
Carle, "Information Model for Packet Sampling Exports",
RFC 5477, DOI 10.17487/RFC5477, March 2009,
<https://www.rfc-editor.org/rfc/rfc5477>.
[RFC5706] Harrington, D., "Guidelines for Considering Operations and
Management of New Protocols and Protocol Extensions",
RFC 5706, DOI 10.17487/RFC5706, November 2009,
<https://www.rfc-editor.org/rfc/rfc5706>.
Boucadair, et al. Expires 29 May 2025 [Page 24]
Internet-Draft RFC 3535, 20 Years Later November 2024
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/rfc/rfc6020>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/rfc/rfc6241>.
[RFC6244] Shafer, P., "An Architecture for Network Management Using
NETCONF and YANG", RFC 6244, DOI 10.17487/RFC6244, June
2011, <https://www.rfc-editor.org/rfc/rfc6244>.
[RFC6353] Hardaker, W., "Transport Layer Security (TLS) Transport
Model for the Simple Network Management Protocol (SNMP)",
STD 78, RFC 6353, DOI 10.17487/RFC6353, July 2011,
<https://www.rfc-editor.org/rfc/rfc6353>.
[RFC6632] Ersue, M., Ed. and B. Claise, "An Overview of the IETF
Network Management Standards", RFC 6632,
DOI 10.17487/RFC6632, June 2012,
<https://www.rfc-editor.org/rfc/rfc6632>.
[RFC7011] Claise, B., Ed., Trammell, B., Ed., and P. Aitken,
"Specification of the IP Flow Information Export (IPFIX)
Protocol for the Exchange of Flow Information", STD 77,
RFC 7011, DOI 10.17487/RFC7011, September 2013,
<https://www.rfc-editor.org/rfc/rfc7011>.
[RFC7012] Claise, B., Ed. and B. Trammell, Ed., "Information Model
for IP Flow Information Export (IPFIX)", RFC 7012,
DOI 10.17487/RFC7012, September 2013,
<https://www.rfc-editor.org/rfc/rfc7012>.
[RFC7015] Trammell, B., Wagner, A., and B. Claise, "Flow Aggregation
for the IP Flow Information Export (IPFIX) Protocol",
RFC 7015, DOI 10.17487/RFC7015, September 2013,
<https://www.rfc-editor.org/rfc/rfc7015>.
[RFC7149] Boucadair, M. and C. Jacquenet, "Software-Defined
Networking: A Perspective from within a Service Provider
Environment", RFC 7149, DOI 10.17487/RFC7149, March 2014,
<https://www.rfc-editor.org/rfc/rfc7149>.
Boucadair, et al. Expires 29 May 2025 [Page 25]
Internet-Draft RFC 3535, 20 Years Later November 2024
[RFC7414] Duke, M., Braden, R., Eddy, W., Blanton, E., and A.
Zimmermann, "A Roadmap for Transmission Control Protocol
(TCP) Specification Documents", RFC 7414,
DOI 10.17487/RFC7414, February 2015,
<https://www.rfc-editor.org/rfc/rfc7414>.
[RFC7426] Haleplidis, E., Ed., Pentikousis, K., Ed., Denazis, S.,
Hadi Salim, J., Meyer, D., and O. Koufopavlou, "Software-
Defined Networking (SDN): Layers and Architecture
Terminology", RFC 7426, DOI 10.17487/RFC7426, January
2015, <https://www.rfc-editor.org/rfc/rfc7426>.
[RFC7854] Scudder, J., Ed., Fernando, R., and S. Stuart, "BGP
Monitoring Protocol (BMP)", RFC 7854,
DOI 10.17487/RFC7854, June 2016,
<https://www.rfc-editor.org/rfc/rfc7854>.
[RFC7860] Merkle, J., Ed. and M. Lochter, "HMAC-SHA-2 Authentication
Protocols in User-Based Security Model (USM) for SNMPv3",
RFC 7860, DOI 10.17487/RFC7860, April 2016,
<https://www.rfc-editor.org/rfc/rfc7860>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/rfc/rfc7950>.
[RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG",
RFC 7951, DOI 10.17487/RFC7951, August 2016,
<https://www.rfc-editor.org/rfc/rfc7951>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/rfc/rfc8040>.
[RFC8199] Bogdanovic, D., Claise, B., and C. Moberg, "YANG Module
Classification", RFC 8199, DOI 10.17487/RFC8199, July
2017, <https://www.rfc-editor.org/rfc/rfc8199>.
[RFC8299] Wu, Q., Ed., Litkowski, S., Tomotaki, L., and K. Ogaki,
"YANG Data Model for L3VPN Service Delivery", RFC 8299,
DOI 10.17487/RFC8299, January 2018,
<https://www.rfc-editor.org/rfc/rfc8299>.
[RFC8309] Wu, Q., Liu, W., and A. Farrel, "Service Models
Explained", RFC 8309, DOI 10.17487/RFC8309, January 2018,
<https://www.rfc-editor.org/rfc/rfc8309>.
Boucadair, et al. Expires 29 May 2025 [Page 26]
Internet-Draft RFC 3535, 20 Years Later November 2024
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/rfc/rfc8341>.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "Network Management Datastore Architecture
(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
<https://www.rfc-editor.org/rfc/rfc8342>.
[RFC838] Smallberg, D., "Who talks TCP?", RFC 838,
DOI 10.17487/RFC0838, January 1983,
<https://www.rfc-editor.org/rfc/rfc838>.
[RFC8466] Wen, B., Fioccola, G., Ed., Xie, C., and L. Jalil, "A YANG
Data Model for Layer 2 Virtual Private Network (L2VPN)
Service Delivery", RFC 8466, DOI 10.17487/RFC8466, October
2018, <https://www.rfc-editor.org/rfc/rfc8466>.
[RFC8519] Jethanandani, M., Agarwal, S., Huang, L., and D. Blair,
"YANG Data Model for Network Access Control Lists (ACLs)",
RFC 8519, DOI 10.17487/RFC8519, March 2019,
<https://www.rfc-editor.org/rfc/rfc8519>.
[RFC8528] Bjorklund, M. and L. Lhotka, "YANG Schema Mount",
RFC 8528, DOI 10.17487/RFC8528, March 2019,
<https://www.rfc-editor.org/rfc/rfc8528>.
[RFC8557] Finn, N. and P. Thubert, "Deterministic Networking Problem
Statement", RFC 8557, DOI 10.17487/RFC8557, May 2019,
<https://www.rfc-editor.org/rfc/rfc8557>.
[RFC8568] Bernardos, CJ., Rahman, A., Zuniga, JC., Contreras, LM.,
Aranda, P., and P. Lynch, "Network Virtualization Research
Challenges", RFC 8568, DOI 10.17487/RFC8568, April 2019,
<https://www.rfc-editor.org/rfc/rfc8568>.
[RFC8639] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard,
E., and A. Tripathy, "Subscription to YANG Notifications",
RFC 8639, DOI 10.17487/RFC8639, September 2019,
<https://www.rfc-editor.org/rfc/rfc8639>.
[RFC8640] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard,
E., and A. Tripathy, "Dynamic Subscription to YANG Events
and Datastores over NETCONF", RFC 8640,
DOI 10.17487/RFC8640, September 2019,
<https://www.rfc-editor.org/rfc/rfc8640>.
Boucadair, et al. Expires 29 May 2025 [Page 27]
Internet-Draft RFC 3535, 20 Years Later November 2024
[RFC8641] Clemm, A. and E. Voit, "Subscription to YANG Notifications
for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641,
September 2019, <https://www.rfc-editor.org/rfc/rfc8641>.
[RFC8667] Previdi, S., Ed., Ginsberg, L., Ed., Filsfils, C.,
Bashandy, A., Gredler, H., and B. Decraene, "IS-IS
Extensions for Segment Routing", RFC 8667,
DOI 10.17487/RFC8667, December 2019,
<https://www.rfc-editor.org/rfc/rfc8667>.
[RFC8791] Bierman, A., Björklund, M., and K. Watsen, "YANG Data
Structure Extensions", RFC 8791, DOI 10.17487/RFC8791,
June 2020, <https://www.rfc-editor.org/rfc/rfc8791>.
[RFC8955] Loibl, C., Hares, S., Raszuk, R., McPherson, D., and M.
Bacher, "Dissemination of Flow Specification Rules",
RFC 8955, DOI 10.17487/RFC8955, December 2020,
<https://www.rfc-editor.org/rfc/rfc8955>.
[RFC8956] Loibl, C., Ed., Raszuk, R., Ed., and S. Hares, Ed.,
"Dissemination of Flow Specification Rules for IPv6",
RFC 8956, DOI 10.17487/RFC8956, December 2020,
<https://www.rfc-editor.org/rfc/rfc8956>.
[RFC8969] Wu, Q., Ed., Boucadair, M., Ed., Lopez, D., Xie, C., and
L. Geng, "A Framework for Automating Service and Network
Management with YANG", RFC 8969, DOI 10.17487/RFC8969,
January 2021, <https://www.rfc-editor.org/rfc/rfc8969>.
[RFC9132] Boucadair, M., Ed., Shallow, J., and T. Reddy.K,
"Distributed Denial-of-Service Open Threat Signaling
(DOTS) Signal Channel Specification", RFC 9132,
DOI 10.17487/RFC9132, September 2021,
<https://www.rfc-editor.org/rfc/rfc9132>.
[RFC9144] Clemm, A., Qu, Y., Tantsura, J., and A. Bierman,
"Comparison of Network Management Datastore Architecture
(NMDA) Datastores", RFC 9144, DOI 10.17487/RFC9144,
December 2021, <https://www.rfc-editor.org/rfc/rfc9144>.
[RFC9182] Barguil, S., Gonzalez de Dios, O., Ed., Boucadair, M.,
Ed., Munoz, L., and A. Aguado, "A YANG Network Data Model
for Layer 3 VPNs", RFC 9182, DOI 10.17487/RFC9182,
February 2022, <https://www.rfc-editor.org/rfc/rfc9182>.
Boucadair, et al. Expires 29 May 2025 [Page 28]
Internet-Draft RFC 3535, 20 Years Later November 2024
[RFC9232] Song, H., Qin, F., Martinez-Julia, P., Ciavaglia, L., and
A. Wang, "Network Telemetry Framework", RFC 9232,
DOI 10.17487/RFC9232, May 2022,
<https://www.rfc-editor.org/rfc/rfc9232>.
[RFC9254] Veillette, M., Ed., Petrov, I., Ed., Pelov, A., Bormann,
C., and M. Richardson, "Encoding of Data Modeled with YANG
in the Concise Binary Object Representation (CBOR)",
RFC 9254, DOI 10.17487/RFC9254, July 2022,
<https://www.rfc-editor.org/rfc/rfc9254>.
[RFC9291] Boucadair, M., Ed., Gonzalez de Dios, O., Ed., Barguil,
S., and L. Munoz, "A YANG Network Data Model for Layer 2
VPNs", RFC 9291, DOI 10.17487/RFC9291, September 2022,
<https://www.rfc-editor.org/rfc/rfc9291>.
[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/rfc/rfc9315>.
[RFC9456] Vaughn, K., Ed., "Updates to the TLS Transport Model for
SNMP", RFC 9456, DOI 10.17487/RFC9456, November 2023,
<https://www.rfc-editor.org/rfc/rfc9456>.
[RFC9543] Farrel, A., Ed., Drake, J., Ed., Rokui, R., Homma, S.,
Makhijani, K., Contreras, L., and J. Tantsura, "A
Framework for Network Slices in Networks Built from IETF
Technologies", RFC 9543, DOI 10.17487/RFC9543, March 2024,
<https://www.rfc-editor.org/rfc/rfc9543>.
[Widoco2017]
Garijo, D., "WIDOCO: a wizard for documenting ontologies",
2017, <http://dgarijo.com/papers/widoco-iswc2017.pdf>.
Acknowledgments
Thanks to Christian Jacquenet and Jean-Michel Combes for their
inputs.
Authors' Addresses
Mohamed Boucadair
Orange
Email: mohamed.boucadair@orange.com
Boucadair, et al. Expires 29 May 2025 [Page 29]
Internet-Draft RFC 3535, 20 Years Later November 2024
Luis M. Contreras
Telefonica
Email: luismiguel.contrerasmurillo@telefonica.com
Oscar Gonzalez de Dios
Telefonica
Email: oscar.gonzalezdedios@telefonica.com
Thomas Graf
Swisscom
Email: thomas.graf@swisscom.com
Reshad Rahman
Equinix
Email: rrahman@equinix.com
Lionel Tailhardat
Orange
Email: lionel.tailhardat@orange.com
Boucadair, et al. Expires 29 May 2025 [Page 30]