draft-ietf-netmod-yang-model-classification-08.txt   rfc8199.txt 
NETMOD D. Bogdanovic Internet Engineering Task Force (IETF) D. Bogdanovic
Internet-Draft Volta Networks, Inc. Request for Comments: 8199 Volta Networks, Inc.
Intended status: Informational B. Claise Category: Informational B. Claise
Expires: December 15, 2017 C. Moberg ISSN: 2070-1721 C. Moberg
Cisco Systems, Inc. Cisco Systems, Inc.
June 13, 2017 July 2017
YANG Module Classification YANG Module Classification
draft-ietf-netmod-yang-model-classification-08
Abstract Abstract
The YANG data modeling language is currently being considered for a The YANG data modeling language is currently being considered for a
wide variety of applications throughout the networking industry at wide variety of applications throughout the networking industry at
large. Many standards development organizations (SDOs), open source large. Many standards development organizations (SDOs), open-source
software projects, vendors and users are using YANG to develop and software projects, vendors, and users are using YANG to develop and
publish YANG modules for a wide variety of applications. At the same publish YANG modules for a wide variety of applications. At the same
time, there is currently no well-known terminology to categorize time, there is currently no well-known terminology to categorize
various types of YANG modules. various types of YANG modules.
A consistent terminology would help with the categorization of YANG A consistent terminology would help with the categorization of YANG
modules, assist in the analysis of the YANG data modeling efforts in modules, assist in the analysis of the YANG data modeling efforts in
the IETF and other organizations, and bring clarity to the YANG- the IETF and other organizations, and bring clarity to the YANG-
related discussions between the different groups. related discussions between the different groups.
This document describes a set of concepts and associated terms to This document describes a set of concepts and associated terms to
support consistent classification of YANG modules. support consistent classification of YANG modules.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This document is not an Internet Standards Track specification; it is
provisions of BCP 78 and BCP 79. published for informational purposes.
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 http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 7841.
This Internet-Draft will expire on December 15, 2017. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc8199.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 27 skipping to change at page 2, line 27
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2. First Dimension: YANG Module Abstraction Layers . . . . . . . 4 2. First Dimension: YANG Module Abstraction Layers . . . . . . . 4
2.1. Network Service YANG Modules . . . . . . . . . . . . . . 6 2.1. Network Service YANG Modules . . . . . . . . . . . . . . 6
2.2. Network Element YANG Modules . . . . . . . . . . . . . . 7 2.2. Network Element YANG Modules . . . . . . . . . . . . . . 7
3. Second Dimension: Module Origin Types . . . . . . . . . . . . 7 3. Second Dimension: YANG Module Origin Types . . . . . . . . . 7
3.1. Standard YANG Modules . . . . . . . . . . . . . . . . . . 8 3.1. Standard YANG Modules . . . . . . . . . . . . . . . . . . 8
3.2. Vendor-specific YANG Modules and Extensions . . . . . . . 8 3.2. Vendor-Specific YANG Modules and Extensions . . . . . . . 8
3.3. User-specific YANG Modules and Extensions . . . . . . . . 9 3.3. User-Specific YANG Modules and Extensions . . . . . . . . 9
4. Security Considerations . . . . . . . . . . . . . . . . . . . 9 4. Security Considerations . . . . . . . . . . . . . . . . . . . 9
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
7. Change log [RFC Editor: Please remove] . . . . . . . . . . . 9 6.1. Normative References . . . . . . . . . . . . . . . . . . 10
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 6.2. Informative References . . . . . . . . . . . . . . . . . 10
8.1. Normative References . . . . . . . . . . . . . . . . . . 10 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 11
8.2. Informative References . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction 1. Introduction
The Internet Engineering Steering Group (IESG) has been actively The Internet Engineering Steering Group (IESG) has been actively
encouraging IETF working groups to use the YANG data modeling encouraging IETF working groups to use the YANG data modeling
language [RFC7950], [RFC7950] and NETCONF protocol [RFC6241] for language [RFC7950] and the Network Configuration Protocol (NETCONF)
configuration management purposes, especially in new working group [RFC6241] for configuration management purposes, especially in new
charters [Writable-MIB-Module-IESG-Statement]. working group charters [IESG-Statement].
YANG is also gaining wide acceptance as the de-facto standard data YANG is also gaining wide acceptance as the de facto standard data
modeling language in the broader industry. This extends beyond the modeling language in the broader industry. This extends beyond the
IETF, including many standards development organizations, industry IETF to include many SDOs, industry consortia, ad hoc groups, open-
consortia, ad hoc groups, open source projects, vendors, and end- source projects, vendors, and end users.
users.
There are currently no clear guidelines on how to classify the There are currently no clear guidelines on how to classify the
layering of YANG modules according to abstraction, or how to classify layering of YANG modules according to abstraction or how to classify
modules along the continuum spanning formal standards publications, modules along the continuum spanning formal standards publications,
vendor-specific modules and modules provided by end-users. vendor-specific modules, and modules provided by end users.
This document presents a set of concepts and terms to form a useful This document presents a set of concepts and terms to form a useful
taxonomy for consistent classification of YANG modules in two taxonomy for consistent classification of YANG modules in two
dimensions: dimensions:
o The layering of modules based on their abstraction levels o The layering of modules based on their abstraction levels
o The module origin type based on the nature and intent of the o The module origin type based on the nature and intent of the
content content
The intent of this document is to provide a taxonomy to simplify The intent of this document is to provide a taxonomy to simplify
human communication around YANG modules. While the classification human communication around YANG modules. While the classification
boundaries are at times blurry, this document should provide a robust boundaries are at times blurry, this document should provide a robust
starting point as the YANG community gains further experience with starting point as the YANG community gains further experience with
designing and deploying modules. To be more explicit, it is expected designing and deploying modules. To be more explicit, it is expected
that the classification criteria will change over time. that the classification criteria will change over time.
A number of modules have created substantial discussion during the A number of modules, for example, modules concerned with topologies,
development of this document: for examples, modules concerned with created substantial discussion during the development of this
topologies. Topology modules are useful both on the Network Element document. Topology modules are useful both on the network element
level (e.g. link-state database content) as well as on the Network level (e.g., link-state database content) and on the network service
Service level (e.g. network-wide, configured topologies). In the level (e.g., network-wide, configured topologies). In the end, it is
end, it is the module developer that classifies the module according the module developer that classifies the module according to the
to the initial intent of the module content. initial intent of the module content.
This document should provide benefits to multiple audiences: This document should provide benefits to multiple audiences:
o First, a common taxonomy helps with the different standards o First, a common taxonomy helps with discussions among SDOs and
development organizations and industry consortia discussions, industry consortia; the goals of such discussions are determined
whose goals are determined in their respective areas of work. by the respective areas of work.
o Second, operators might look at the YANG module abstraction layers o Second, operators might look at the YANG module abstraction layers
to understand which Network Service YANG modules and Network to understand which Network Service YANG Modules and Network
Element YANG modules are available for their service composition. Element YANG Modules are available for their service composition.
It is difficult to determine the module type without inspecting It is difficult to determine the module type without inspecting
the YANG module itself. The YANG module name might provide some the YANG module itself. The YANG module name might provide some
useful information but is not a definite answer. For example, an useful information but is not a definite answer. For example, a
L2VPN YANG module might be a Network Service YANG module, ready to Layer 2 Virtual Private Network (L2VPN) YANG module might be a
be used as a service model by a network operator. Alternatively, Network Service YANG Module, ready to be used as a service model
it might be a Network Element YANG module that contains the L2VPN by a network operator. Alternatively, it might be a Network
data definitions required to be configured on a single device. Element YANG Module that contains the L2VPN data definitions
required to be configured on a single device.
o And thirdly, this taxonomy would help equipment vendors (whether o Third, this taxonomy will help equipment vendors (whether physical
physical or virtual), controller vendors, orchestrator vendors to or virtual), controller vendors, and orchestrator vendors to
explain to their customers the relationship between the different explain to their customers the relationship between the different
YANG modules they support in their products. YANG modules they support in their products.
1.1. Terminology 1.1. Terminology
[RFC7950] specifies: [RFC7950] specifies:
o data model: A data model describes how data is represented and o data model: A data model describes how data is represented and
accessed. accessed.
o module: A YANG module defines hierarchies of schema nodes. With o module: A YANG module defines hierarchies of schema nodes. With
its definitions and the definitions it imports or includes from its definitions and the definitions it imports or includes from
elsewhere, a module is self-contained and "compilable". elsewhere, a module is self-contained and "compilable".
2. First Dimension: YANG Module Abstraction Layers 2. First Dimension: YANG Module Abstraction Layers
Module developers have taken two approaches to developing YANG Module developers have taken two approaches to developing YANG
modules: top-down and bottom-up. The top-down approach starts with modules: top-down and bottom-up. The top-down approach starts with
high level abstractions modeling business or customer requirements high-level abstractions modeling business or customer requirements
and maps them to specific networking technologies. The bottom-up and maps them to specific networking technologies. The bottom-up
approach starts with fundamental networking technologies and maps approach starts with fundamental networking technologies and maps
them into more abstract constructs. them into more abstract constructs.
There are currently no specific requirements on, or well-defined best There are currently no specific requirements or well-defined best
practices around the development of YANG modules. This document practices for the development of YANG modules. This document
considers both bottom-up and top-down approaches as they are both considers both bottom-up and top-down approaches as they are both
used and they each provide benefits that appeal to different groups. used and they each provide benefits that appeal to different groups.
For layering purposes, this document suggests the classification of For layering purposes, this document suggests the classification of
YANG modules into two distinct abstraction layers: YANG modules into two distinct abstraction layers:
o Network Element YANG Modules describe the configuration, state o Network Element YANG Modules describe the configuration, state
data, operations and notifications of specific device-centric data, operations, and notifications of specific device-centric
technologies or features technologies or features.
o Network Service YANG Modules describe the configuration, state o Network Service YANG Modules describe the configuration, state
data, operations and notifications of abstract representations of data, operations, and notifications of abstract representations of
services implemented on one or multiple network elements services implemented on one or multiple network elements.
+--------------------------+ +--------------------------+
| Operations and Business | | Operations and Business |
| Support Systems | | Support Systems |
| (OSS/BSS) | | (OSSs and BSSs) |
+--------------------------+ +--------------------------+
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Network Service YANG Modules Network Service YANG Modules
+------------+ +-------------+ +-------------+ +------------+ +-------------+ +-------------+
| | | | | | | | | | | |
| - L2VPN | | - L2VPN | | L3VPN | | - L2VPN | | - L2VPN | | L3VPN |
| - VPWS | | - VPLS | | | | - VPWS | | - VPLS | | |
| | | | | | | | | | | |
skipping to change at page 5, line 38 skipping to change at page 5, line 39
L2VPN: Layer 2 Virtual Private Network L2VPN: Layer 2 Virtual Private Network
L3VPN: Layer 3 Virtual Private Network L3VPN: Layer 3 Virtual Private Network
VPWS: Virtual Private Wire Service VPWS: Virtual Private Wire Service
VPLS: Virtual Private LAN Service VPLS: Virtual Private LAN Service
Figure 1: YANG Module Abstraction Layers Figure 1: YANG Module Abstraction Layers
Figure 1 illustrates the application of YANG modules at different Figure 1 illustrates the application of YANG modules at different
layers of abstraction. Layering of modules allows for reusability of layers of abstraction. Layering of modules allows for reusability of
existing lower layer modules by higher level modules while limiting existing lower-layer modules by higher-level modules while limiting
duplication of features across layers. duplication of features across layers.
For module developers, per-layer modeling allows for separation of For module developers, per-layer modeling allows for separation of
concern across editing teams focusing on specific areas. concern across editing teams focusing on specific areas.
As an example, experience from the IETF shows that creating useful As an example, experience from the IETF shows that creating useful
Network Element YANG modules for e.g. routing or switching protocols Network Element YANG Modules (e.g., for routing or switching
requires teams that include developers with experience of protocols) requires teams that include developers with experience
implementing those protocols. implementing those protocols.
On the other hand, Network Service YANG modules are best developed by On the other hand, Network Service YANG Modules are best developed by
network operators experienced in defining network services for network operators experienced in defining network services for
consumption by programmers developing e.g. flow-through provisioning consumption by programmers, e.g., those developing flow-through
systems or self-service portals. provisioning systems or self-service portals.
2.1. Network Service YANG Modules 2.1. Network Service YANG Modules
Network Service YANG Modules describe the characteristics of a Network Service YANG Modules describe the characteristics of a
service, as agreed upon with consumers of that service. That is, a service, as agreed upon with consumers of that service. That is, a
service module does not expose the detailed configuration parameters service module does not expose the detailed configuration parameters
of all participating network elements and features, but describes an of all participating network elements and features but describes an
abstract model that allows instances of the service to be decomposed abstract model that allows instances of the service to be decomposed
into instance data according to the Network Element YANG Modules of into instance data according to the Network Element YANG Modules of
the participating network elements. The service-to-element the participating network elements. The service-to-element
decomposition is a separate process with details depending on how the decomposition is a separate process; the details depend on how the
network operator chooses to realize the service. For the purpose of network operator chooses to realize the service. For the purpose of
this document, the term "orchestrator" is used to describe to this document, the term "orchestrator" is used to describe a system
describe a system implementing such a process. implementing such a process.
Network Service YANG Modules define service models to be consumed by External systems can be provisioning systems, service orchestrators,
external systems. External systems can be provisioning systems, Operations Support Systems, Business Support Systems, and
service orchestrators, Operations Support Systems, Business Support applications exposed to network service consumers (either internal
Systems and applications exposed to network service consumers, being network operations people or external customers). These modules are
either internal network operations people or external customers. commonly designed, developed, and deployed by network infrastructure
These modules are commonly designed, developed and deployed by teams.
network infrastructure teams.
YANG allows for different design patterns to describe network YANG allows for different design patterns to describe network
services, ranging from monolithic to component-based approaches. services, ranging from monolithic to component-based approaches.
The monolithic approach captures the entire service in a single The monolithic approach captures the entire service in a single
module and does not put focus on reusability of internal data module and does not put focus on reusability of internal data
definitions and groupings. The monolithic approach has the definitions and groupings. The monolithic approach has the
advantages of single-purpose development including development speed advantages of single-purpose development, including development speed
at the expense of reusability. at the expense of reusability.
The component-based approach captures device-centric features (e.g. The component-based approach captures device-centric features (e.g.,
the definition of a VPN Routing and Forwarding (VRF), routing VPN Routing and Forwarding (VRF), routing protocols, or packet
protocols, or packet filtering) in a vendor-independent manner. The filtering) in a vendor-independent manner. The components are
components are designed for reuse across many service modules. The designed for reuse across many service modules. The set of
set of components required for a specific service is then composed components required for a specific service is then composed into the
into the higher-level service. The component-based approach has the higher-level service. The component-based approach has the
advantages of modular development including a higher degree of advantages of modular development, including a higher degree of
reusability at the expense of initial development speed. reusability at the expense of initial development speed.
As an example, an L2VPN service can be built on many different types As an example, an L2VPN service can be built on many different types
of transport network technologies, including e.g. MPLS or carrier of transport network technologies, including, e.g., MPLS or Carrier
ethernet. A component-based approach would allow for reuse of e.g. Ethernet. A component-based approach would allow for reuse of User-
User-Network Interface (UNI) definitions independent of the Network Interface (UNI) definitions, such as the MEF UNI interface or
underlying transport network (e.g. MEF UNI interface or MPLS MPLS interface, independent of the underlying transport network. The
interface). The monolithic approach would assume a specific set of monolithic approach would assume a specific set of transport
transport technologies and interface definitions. technologies and interface definitions.
An example of a Network Service YANG module is in [RFC8049]. It An example of a Network Service YANG Module is in [RFC8049]. It
provides an abstract model for Layer 3 IP VPN service configuration. provides an abstract model for Layer 3 IP VPN service configuration.
This module includes e.g. the concept of a 'site-network-access' to This module includes the concept of a 'site-network-access' to
represent bearer and connection parameters. An orchestrator receives represent bearer and connection parameters. An orchestrator receives
operations on service instances according to the service module and operations on service instances according to the service module and
decomposes the data into configuration data according to specific decomposes the data into configuration data according to specific
Network Element YANG Modules to configure the participating network Network Element YANG Modules to configure the participating network
elements to the service. In the case of the L3VPN module, this would elements to the service. In the case of the L3VPN module, this would
include translating the 'site-network-access' parameters to the include translating the 'site-network-access' parameters to the
appropriate parameters in the Network Element YANG Module implemented appropriate parameters in the Network Element YANG Module implemented
on the constituent elements. on the constituent elements.
2.2. Network Element YANG Modules 2.2. Network Element YANG Modules
Network Element YANG Modules describe the characteristics of a Network Element YANG Modules describe the characteristics of a
network device as defined by the vendor of that device. The modules network device as defined by the vendor of that device. The modules
are commonly structured around features of the device, e.g. interface are commonly structured around features of the device, e.g.,
configuration [RFC7223], OSPF configuration [I-D.ietf-ospf-yang], and interface configuration [RFC7223], OSPF configuration [OSPF-YANG],
firewall rules definitions [I-D.ietf-netmod-acl-model]. and access control list (ACL) configuration [ACL-YANG].
The module provides a coherent data model representation of the The Network Element YANG Module provides a coherent data model
software environment consisting of the operating system and representation of the software environment consisting of the
applications running on the device. The decomposition, ordering, and operating system and applications running on the device. The
execution of changes to the operating system and application decomposition, ordering, and execution of changes to the operating
configuration is the task of the agent that implements the module. system and application configuration is the task of the agent that
implements the module.
3. Second Dimension: Module Origin Types 3. Second Dimension: YANG Module Origin Types
This document suggests classifying YANG module origin types as This document suggests classifying YANG module origin types as
standard YANG modules, vendor-specific YANG modules and extensions, Standard YANG Modules, Vendor-Specific YANG Modules and Extensions,
or user-specific YANG modules and extensions or User-Specific YANG Modules and Extensions.
The suggested classification applies to both Network Element YANG The suggested classification applies to both Network Element YANG
Modules and Network Service YANG Modules. Modules and Network Service YANG Modules.
It is to be expected that real-world implementations of both Network It is to be expected that real-world implementations of both Network
Service YANG Modules and Network Element YANG Modules will include a Service YANG Modules and Network Element YANG Modules will include a
mix of all three module origin types. mix of all three module origin types.
Figure 2 illustrates the relationship between the three types of Figure 2 illustrates the relationship between the three types of
modules. modules.
skipping to change at page 8, line 24 skipping to change at page 8, line 27
Augments Augments Augments Augments Augments Augments
+------+-----------------+-------+ +------+-------+ +--------------+ +------+-----------------+-------+ +------+-------+ +--------------+
| Standard | | Vendor | | User | | Standard | | Vendor | | User |
| Modules | | Modules | | Modules | | Modules | | Modules | | Modules |
+--------------------------------+ +--------------+ +--------------+ +--------------------------------+ +--------------+ +--------------+
Figure 2: YANG Module Origin Types Figure 2: YANG Module Origin Types
3.1. Standard YANG Modules 3.1. Standard YANG Modules
Standard YANG Modules are published by standards development Standard YANG Modules are published by SDOs. Most SDOs create
organizations (SDOs). Most SDOs create specifications according to a specifications according to a formal process in order to produce a
formal process in order to produce a standard that is useful for standard that is useful for their constituencies.
their constituencies.
The lifecycle of these modules is driven by the editing cycle of the The lifecycles of these modules are driven by the editing cycles of
specification and not tied to a specific implementation. the specifications and not tied to a specific implementation.
Examples of SDOs in the networking industry are the IETF and the Examples of SDOs in the networking industry are the IETF and the
IEEE. IEEE.
3.2. Vendor-specific YANG Modules and Extensions 3.2. Vendor-Specific YANG Modules and Extensions
Vendor-specific YANG Modules are developed by organizations with the Vendor-Specific YANG Modules are developed by organizations with the
intent to support a specific set of implementations under control of intent to support a specific set of implementations under control of
that organization. For example vendors of virtual or physical that organization, for example, vendors of virtual or physical
equipment, industry consortia, and opensource projects. The intent equipment, industry consortia, and open-source projects. The intent
of these modules range from providing openly published YANG modules of these modules ranges from providing openly published YANG modules
that may eventually be contributed back to, or adopted by, an SDO, to that may eventually be contributed back to or adopted by an SDO to
strictly internal YANG modules not intended for external consumption. strictly internal YANG modules not intended for external consumption.
The lifecycle of these modules are generally aligned with the release The lifecycles of these modules are generally aligned with the
cycle of the product or open source software project deliverables. release cycles of the product or open-source software project
deliverables.
It is worth noting that there is an increasing amount of interaction It is worth noting that there is an increasing amount of interaction
between open source projects and SDOs in the networking industry. between open-source projects and SDOs in the networking industry.
This includes open source projects implementing published standards This includes open-source projects implementing published standards
as well as open source projects contributing content to SDO as well as open-source projects contributing content to SDO
processes. processes.
Vendors also develop Vendor-specific Extensions to standard modules Vendors also develop vendor-specific extensions to standard modules
using YANG constructs for extending data definitions of previously using YANG constructs for extending data definitions of previously
published modules. This is done using the 'augment' statement that published modules. This is done using the 'augment' statement that
allows locally defined data trees to be added into locations in allows locally defined data trees to be added into locations in
externally defined data trees. externally defined data trees.
Vendors use this to extend standard modules to cover the full scope Vendors use this to extend standard modules to cover the full scope
of features in implementations, which commonly is broader than that of features in implementations, which commonly is broader than that
covered by the standard module. covered by the standard module.
3.3. User-specific YANG Modules and Extensions 3.3. User-Specific YANG Modules and Extensions
User-specific YANG Modules are developed by organizations that User-Specific YANG Modules are developed by organizations that
operate YANG-based infrastructure including devices and operate YANG-based infrastructure including devices and
orchestrators. For example, network administrators in enterprises, orchestrators, for example, network administrators in enterprises or
or at service providers. The intent of these modules is to express at service providers. The intent of these modules is to express the
the specific needs for a certain implementation, above and beyond specific needs for a certain implementation, above and beyond what is
what is provided by vendors. provided by vendors.
This module type obviously requires the infrastructure to support the This module type obviously requires the infrastructure to support the
introduction of user-provided modules and extensions. This would introduction of user-provided modules and extensions. This would
include the ability to describe the service-to-network decomposition include the ability to describe the service-to-network decomposition
in orchestrators and the module to configuration decomposition in in orchestrators and the module-to-configuration decomposition in
devices. devices.
The lifecycles of these modules are generally aligned with the change The lifecycles of these modules are generally aligned with the change
cadence of the infrastructure. cadence of the infrastructure.
4. Security Considerations 4. Security Considerations
This document doesn't have any Security Considerations. This document doesn't have any Security Considerations.
5. IANA Considerations 5. IANA Considerations
This document has no IANA actions. This document does not require any IANA actions.
6. Acknowledgements
Thanks to David Ball and Jonathen Hansford for feedback and
suggestions.
7. Change log [RFC Editor: Please remove]
version 00: Renamed and small fixes based on WG feedback.
version 01: Language fixes, collapsing of vendor data models and
extensions, and the introduction of user data models and extensions.
version 02: Updated the YANG Module Catalog section, terminology
alignment (YANG data model versus YANG module), explain better the
distinction between the Network Element and Service YANG data models
even if sometimes there are grey areas, editorial pass. Changed the
use of the term 'model' to 'module' to be better aligned with
RFC6020.
version 06: updates based on comments from Adrian Farrel about YANG
Data Model for L3VPN Service Delivery.
version 07: updates based on comments from Pete Resnick
8. References 6. References
8.1. Normative References 6.1. Normative References
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<http://www.rfc-editor.org/info/rfc6241>. <http://www.rfc-editor.org/info/rfc6241>.
[RFC7223] Bjorklund, M., "A YANG Data Model for Interface [RFC7223] Bjorklund, M., "A YANG Data Model for Interface
Management", RFC 7223, DOI 10.17487/RFC7223, May 2014, Management", RFC 7223, DOI 10.17487/RFC7223, May 2014,
<http://www.rfc-editor.org/info/rfc7223>. <http://www.rfc-editor.org/info/rfc7223>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016, RFC 7950, DOI 10.17487/RFC7950, August 2016,
<http://www.rfc-editor.org/info/rfc7950>. <http://www.rfc-editor.org/info/rfc7950>.
[RFC8049] Litkowski, S., Tomotaki, L., and K. Ogaki, "YANG Data [RFC8049] Litkowski, S., Tomotaki, L., and K. Ogaki, "YANG Data
Model for L3VPN Service Delivery", RFC 8049, Model for L3VPN Service Delivery", RFC 8049,
DOI 10.17487/RFC8049, February 2017, DOI 10.17487/RFC8049, February 2017,
<http://www.rfc-editor.org/info/rfc8049>. <http://www.rfc-editor.org/info/rfc8049>.
8.2. Informative References 6.2. Informative References
[I-D.ietf-netmod-acl-model] [ACL-YANG]
Bogdanovic, D., Koushik, K., Huang, L., and D. Blair, Bogdanovic, D., Jethanandani, M., Huang, L., Agarwal, S.,
"Network Access Control List (ACL) YANG Data Model", and D. Blair, "Network Access Control List (ACL) YANG Data
draft-ietf-netmod-acl-model-10 (work in progress), March Model", Work in Progress, draft-ietf-netmod-acl-model-11,
2017. June 2017.
[I-D.ietf-ospf-yang] [IESG-Statement]
"Writable MIB Module IESG Statement",
<https://www.ietf.org/iesg/statement/
writable-mib-module.html>.
[OSPF-YANG]
Yeung, D., Qu, Y., Zhang, Z., Chen, I., and A. Lindem, Yeung, D., Qu, Y., Zhang, Z., Chen, I., and A. Lindem,
"Yang Data Model for OSPF Protocol", draft-ietf-ospf- "Yang Data Model for OSPF Protocol", Work in Progress,
yang-07 (work in progress), March 2017. draft-ietf-ospf-yang-08, July 2017.
[Writable-MIB-Module-IESG-Statement] Acknowledgements
"Writable MIB Module IESG Statement",
<https://www.ietf.org/iesg/statement/writable-mib- Thanks to David Ball and Jonathan Hansford for feedback and
module.html>. suggestions.
Authors' Addresses Authors' Addresses
Dean Bogdanovic Dean Bogdanovic
Volta Networks, Inc. Volta Networks, Inc.
Email: dean@voltanet.io Email: dean@voltanet.io
Benoit Claise Benoit Claise
Cisco Systems, Inc. Cisco Systems, Inc.
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