Internet Engineering Task Force (IETF) Y. Lee, Ed.
Request for Comments: 9731 Samsung Electronics
Category: Standards Track D. Dhody, Ed.
ISSN: 2070-1721 Huawei
D. Ceccarelli
Cisco
I. Bryskin
Individual
B. Yoon
ETRI
January
February 2025
A YANG Data Model for Virtual Network (VN) Operations
Abstract
A Virtual Network (VN) is a network provided by a service provider to
a customer for the customer to use in any way it wants as though it
were a physical network. This document provides a YANG data model
generally applicable to any mode of VN operations. This includes VN
operations as per the Abstraction and Control of TE Networks (ACTN)
framework.
framework (see RFC 8453).
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9731.
Copyright Notice
Copyright (c) 2025 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Table of Contents
1. Introduction
1.1. Terminology and Conventions
1.2. Tree Diagram
1.3. Prefixes in Data Node Names
2. Use Case of VN YANG Data Model in the ACTN Context
2.1. Type 1 VN
2.2. Type 2 VN
3. High-Level Control Flows with Examples
3.1. Type 1 VN Illustration
3.2. Type 2 VN Illustration
3.2.1. VN and AP Usage
4. VN YANG Data Model Usage
4.1. Customer View of VN
4.2. Auto-creation of VN by MDSC
4.3. Innovative Services
4.3.1. VN Compute
4.3.2. Multiple Sources and Multiple Destinations
4.4. Others
4.5. Summary
5. VN YANG Data Model (Tree Structure)
6. VN YANG Data Model
7. Security Considerations
8. IANA Considerations
9. References
9.1. Normative References
9.2. Informative References
Appendix A. Performance Constraints
Appendix B. JSON Example
B.1. VN JSON
B.2. TE-Topology TE Topology JSON
Acknowledgments
Contributors' Addresses
Authors' Addresses
1. Introduction
Abstraction and Control of TE Networks (ACTN) describes a set of
management and control functions used to operate one or more Traffic
Engineered (TE) networks to construct a Virtual Network (VN). A VN
is represented to customers and is built from the abstractions of the
underlying TE networks [RFC8453]. This document provides a YANG data
model [RFC7950] generally applicable to any mode of VN operation.
ACTN is the primary example of the usage of the VN YANG data model,
but VN is not limited to it.
The VN model defined in this document is applicable in a generic
sense as an independent model in and of itself. It can also work
together with other customer service models such as the L3VPN Service
Model (L3SM) [RFC8299], the L2VPN Service Model (L2SM) [RFC8466], and
the L1 Connectivity Service Model (L1CSM) [L1CSM-YANG] to provide
complete life-cycle service management and operations.
The YANG data model discussed in this document basically provides the
following:
* Characteristics of Access Points (APs) that describe customer's
endpoint characteristics;
* Characteristics of Virtual Network Access Points (VNAPs) that
describe how an AP is partitioned for multiple VNs sharing the AP
and its reference to a Link Termination Point (LTP) of the
Provider Edge (PE) node;
* Characteristics of Virtual Networks (VNs) VNs that describe the customer's VN in terms of
multiple VN Members members comprising a VN, multi-source and/or multi-destination multi-
destination characteristics of the VN
Member, member, the VN's reference
to TE-topology's Abstract Node; abstract node.
An abstract TE topology is a topology that contains abstract
topological elements (nodes, links) created and customized based on
customer preference [RFC8795]. The actual VN instantiation and
computation is performed with Connectivity Matrices connectivity matrices of the TE- TE
Topology Model model [RFC8795], which provides a TE network topology
abstraction and management operation. As per [RFC8795], a TE node
connectivity matrix is the TE node's switching limitations in the
form of valid switching combinations of the TE node's LTPs and
potential TE paths. The VN representation relies on a single
abstract TE node with a connectivity matrix. The VN can be
abstracted as a set of edge-to-edge links (a Type 1 VN). Each link
is the VN member that is mapped to the connectivity matrix entry
(Section 2.1). The VN can also be abstracted as a topology of
virtual nodes and virtual links (a Type 2 VN). Alongside the mapping
of VN members to a connectivity matrix entry, an underlay path can
also be specified (Section 2.2).
Once the TE-topology Model TE Topology model is used in triggering VN instantiation
over the networks, the TE-tunnel Model TE model [YANG-TE] will inevitably interact
with the TE-Topology TE Topology model when setting up actual tunnels and Label
Switched Paths (LSPs) under the tunnels.
Sections 2 and 3 provide a discussion of how the VN YANG data model
is applicable to the ACTN context where a Virtual Network Service
(VNS) operation is implemented for the interface of the Customer
Network Controller (CNC) and the Multi-Domain Service Coordinator
(MDSC).
The YANG data model for the CNC-MDSC Interface (CMI) is also known as
the "customer service model" in [RFC8309]. The YANG data model
discussed in this document is used to operate customer-driven VNs
during the VN instantiation and computation as well as its life-cycle
service management and operations.
The VN operational state is included in the same tree as the
configuration consistent with Network Management Datastore
Architecture (NMDA) [RFC8342].
1.1. Terminology and Conventions
This document borrows the following terms abbreviations from [RFC8453]: [RFC8453] and/
or [RFC8795]:
VN: Virtual Network
AP: Access Point
VNAP: VN Access Point
ACTN: Abstraction and Control of TE Networks
CNC: Customer Network Controller
MDSC: Multi-Domain Service Coordinator
CMI: CNC-MDSC Interface
This document borrows the following terms from [RFC8795]:
LTP: Link Termination Point
Connectivity Matrix
This document borrows the terminology in Section 1.1 of [RFC7926].
This document uses [RFC7926],
the term "Service Model" from [RFC8309], and the term 'Service Model' "Connectivity
Matrix" from [RFC8795].
Various examples in this document contain long lines that may be
folded, as described in
[RFC8309]. [RFC8792].
1.2. Tree Diagram
A simplified graphical representation of the data model is used in
Section 5 of this document. The meaning of the symbols in these
diagrams is defined in [RFC8340].
1.3. Prefixes in Data Node Names
In this document, the names of data nodes and other data model
objects are prefixed using the standard prefix associated with the
corresponding YANG imported modules as shown in Table 1.
+==========+=======================+===========+
| Prefix | YANG Module | Reference |
+==========+=======================+===========+
| vn | ietf-vn | RFC 9731 |
+----------+-----------------------+-----------+
| yang | ietf-yang-types | [RFC6991] |
+----------+-----------------------+-----------+
| nw | ietf-network | [RFC8345] |
+----------+-----------------------+-----------+
| nt | ietf-network-topology | [RFC8345] |
+----------+-----------------------+-----------+
| te-types | ietf-te-types | [RFC8776] |
+----------+-----------------------+-----------+
| tet | ietf-te-topology | [RFC8795] |
+----------+-----------------------+-----------+
Table 1: Prefixes and Corresponding YANG Modules
2. Use Case of VN YANG Data Model in the ACTN Context
In this section, ACTN is being used to illustrate the general usage
of the VN YANG data model. The model presented in this section has
the following ACTN context.
+-------+
| CNC |
+-------+
|
| VN YANG + TE-topology YANG TE Topology
|
+-----------------------+
| MDSC |
+-----------------------+
Figure 1: ACTN CMI
Both ACTN VN YANG and TE-topology TE Topology YANG data models are used over the CMI
to establish a VN over TE networks, as shown in Figure 1.
2.1. Type 1 VN
As defined in [RFC8453], a Virtual Network VN is a customer view of the TE network.
To recapitulate VN types from [RFC8453], a Type 1 VN is defined as
follows:
|
The VN can be seen as a set of edge-to-edge abstract links (a Type
| 1
VN). Each abstract link is referred to as a VN member and is
| formed
as an end-to-end tunnel across the underlying networks.
| Such tunnels
may be constructed by recursive slicing or
| abstraction of paths in
the underlying networks and can encompass
| edge points of the
customer's network, access links, intra-domain
| paths, and inter-domain inter-
domain links.
If we were to create a VN where we have four VN-members VN members as follows:
VN-member
VN member 1 L1-L4
VN-member
VN member 2 L1-L7
VN-member
VN member 3 L2-L4
VN-member
VN member 4 L3-L8
Figure 2 2: VN Members (Type 1 VN)
Where L1, L2, L3, L4, L7, and L8 correspond to a Customer Endpoint
(or AP).
This VN can be modeled as one abstract node representation as follows
in Figure 3:
+----------------------------------------------+
| |
L1----|..............................................|------L4
| . . |
| . AN1 . |
| . . |
| ..................................*.....|------L7
| . |
L2-----|....................................... |
| |
L3-----|..............................................|------L8
| |
+----------------------------------------------+
Figure 3: Abstract Node (One Node (Type 1 Topology)
Modeling a VN as one abstract node is the easiest way for customers
to express their end-to-end connectivity as shown in Figure 3.
2.2. Type 2 VN
For some VN members, the customers are allowed to configure the
intended path. To achieve this, alongside the single node abstract
topology, an underlay topology is also needed. The underlay topology
could be native TE topology or an abstract TE topology. The intended
path is set based on the nodes and links of the underlay topology. A
Type 1 VN can be seen viewed as a higher higher-level abstraction of a Type 2 VN (which
along with VN,
which represents a single node abstract topology, an topology over the underlay
topology and
the includes a mechanism to specify intended path are specified). paths. These
topologies could be mutually agreed upon between the CNC and the MDSC
prior to VN creation or they could be created as part of VN
instantiation.
If a Type 2 VN is desired for some or all of the VN members of a Type
1 VN (see the example in Section 2.1), the TE-topology TE Topology model can
provide the following abstract topologies (a single node topology AN1
and an underlay topology (with nodes S1 to S11 and corresponding
links)).
+----------------------------------------------+
| S1 S2 |
| O...............O |
| ......... ....... . |
| . . . |
|S3 . . S4 . S5 |
L1----|.O......................O.........O...........|------L4
| . . . |
| . . . |
| . S6 . S7 . S8 |
| O ................O.........O.......|------L7
| . . . . ..... |
|S9 . . .S10 . . |
L2-----|...O.....O.....................O..............|------L8
| . S11 |
L3-----|.. |
| AN1 |
+----------------------------------------------+
Figure 4: Type 2 Topology
As shown in Figure 4, the abstract node is AN1 and an underlay
topology is depicted with nodes and links (S1 to S11).
As an example, if VN-member VN member 1 (L1-L4) is chosen to configure its own
path over Type 2 topology, it can select, say, a path that consists
of the explicit abstract path {S3,S4,S5} based on the underlay topology and
its service requirement. This capability is enacted via TE-topology
configuration by the customer.
3. High-Level Control Flows with Examples
3.1. Type 1 VN Illustration
If this VN is Type 1, the following diagram shows the message flow
between CNC and MDSC to instantiate this VN using VN and TE-Topology
Models. TE Topology
YANG data models.
+--------+ +--------+
| CNC | | MDSC |
+--------+ +--------+
| |
| |
CNC POST TE-topo TE Topo | POST /nw:networks/nw:network/ |
model (with Conn.| (w/ Conn. | nw:node/te-node-id/ |
Matrix on one | tet:connectivity-matrices/ |
Abstract
abstract node) | tet:connectivity-matrix |
|-------------------------------->|
| HTTP 200 |
|<--------------------------------|
| |
CNC POST the | POST /virtual-network |
VN identifying |-------------------------------->| If there is
AP, VNAP, and VN-| VN | | multi-src/dest,
Members
members and maps | | then MDSC
to the TE-topo TE Topo | HTTP 200 | selects an
model |<--------------------------------| src or dest
| | and updates
| | VN YANG
CNC GET the | GET /virtual-network |
VN YANG status |-------------------------------->|
| |
| HTTP 200 (VN with status: |
| selected VN-members VN members |
| in case of multi-s-d) multi-s/d) |
|<--------------------------------|
| |
Figure 5: Type 1 VN Illustration
3.2. Type 2 VN Illustration
For some VN members, the customer may want to "configure" an explicit
path that connects its two endpoints. Let us consider the following
example:
VN-member
VN member 1 L1-L4 (via S3, S4, and S5)
VN-member
VN member 2 L1-L7 (via S3, S4, S7, and S8)
VN-member
VN member 3 L2-L7 (via S9, S10, and S11)
VN-member
VN member 4 L3-L8 (via S9, S10, and S11)
Figure 6 6: VN Members (Type 2 VN)
There are two options depending on whether CNC or MDSC creates the
single abstract node topology.
Case 1:
If the CNC creates the single-abstract-node single abstract node topology, the message
flow between the CNC and MDSC to instantiate this VN using a VN and
TE-Topology Model
TE Topology YANG data model would be as shown in the following
diagram:
+--------+ +--------+
| CNC | | MDSC |
+--------+ +--------+
| |
| |
CNC POST TE-topo TE Topo | POST /nw:networks/nw:network/ |
model (with Conn.| (w/ Conn. | nw:node/te-node-id/tet:connectivity- |
Matrix on one | matrices/tet:connectivity-matrix |
Abstract
abstract node and|---------------------------------------->|
explicit paths in| |
the Conn. Matrix)| HTTP 200 |
|<----------------------------------------|
| |
CNC POST the | POST /virtual-network |
VN identifying |---------------------------------------->|
AP, VNAP, and VN-| VN |
Members |
members and maps | |
to the TE-topo TE Topo | HTTP 200 |
model |<----------------------------------------|
| |
| |
CNC GET the | GET /virtual-network |
VN YANG status |---------------------------------------->|
| |
| HTTP 200 (VN with status) |
|<----------------------------------------|
| |
Figure 7: Type 2 VN Illustration: Case 1
Case 2:
On the other hand, if MDSC create the single-abstract-node single abstract node topology
based on VN YANG posted by the CNC, the following diagram shows the
message flow between CNC and MDSC to instantiate this VN using VN and
TE-Topology Models.
TE Topology YANG data models.
+--------+ +--------+
| CNC | | MDSC |
+--------+ +--------+
| |
| |
CNC POST VN | |
identifying AP, | |
VNAP and VN- VN | POST /virtual-network | MDSC populates
Members
members |-------------------------------->| a single Abst. abst.
| HTTP 200 | node topology
|<--------------------------------| by itself
| |
CNC GET VN & | GET /virtual-network & |
POST TE-topo TE Topo | POST /nw:networks/nw:network/ |
models (with (w/ | nw:node/te-node-id/tet: |
Conn. Matrix | connectivity-matrices/ |
on the | tet:connectivity-matrix |
Abstract
abstract node |-------------------------------->|
and explicit | |
paths in the | |
Conn. Matrix) | |
| HTTP 200 |
|<--------------------------------|
| |
| |
CNC GET the | GET /virtual-network |
VN YANG status |-------------------------------->|
| |
| HTTP 200 (VN with status) |
|<--------------------------------|
| |
Figure 8: Type 2 VN Illustration: Case 2
Note that the underlay topology (which is referred to by the single-
abstract-node single
abstract node topology) could be a Native/White topology or a Grey
topology ([RFC8453]) that is further customized based on the
requirements of the customer and configured at the MDSC.
Appendix B provides JSON examples for both the VN model and the TE-
topology TE
Topology Connectivity Matrix sub-model to illustrate how a VN can be
created by the CNC making use of the VN module model as well as the TE-
topology TE
Topology Connectivity Matrix module.
3.2.1. VN and AP Usage
The customer access information may be known at the time of VN
creation. A shared logical AP identifier is used between the
customer and the operator to identify the access link between
Customer Edge (CE) and Provider Edge (PE). This is described in
Section 6 of [RFC8453].
In some VN operations, the customer access may not be known at the
initial VN creation. The VN operation allows the creation of a VN
with only a PE identifier as well. identifier. The customer access information could be
added later.
To achieve this, the 'ap' container has a leaf for the 'pe' node that
allows the AP to be created with PE information. The vn-member VN member (and
vn)
VN) could use APs that initially only have PE information.
4. VN YANG Data Model Usage
4.1. Customer View of VN
The VN-YANG VN YANG data model allows the definition of a customer view and
allows the customer to communicate using the VN constructs as
described in [RFC8454]. It allows the grouping of edge-to-edge links
(i.e., VN members) under a common umbrella of VN. This allows the
customer to instantiate and view the VN as one entity, making it
easier for some customers to work on VN without worrying about the
details of the provider-based YANG data models.
This is similar to the benefits offered by a separate YANG data model
for customer services described in [RFC8309], which states that
service models do not make any assumptions about how a service is
actually engineered and delivered for a customer.
4.2. Auto-creation of VN by MDSC
The VN could be configured at the MDSC explicitly by the CNC using
the VN YANG data model. In some other cases, the VN is not
explicitly configured but is instead created automatically by the
MDSC based on the customer service model and local policy; even in
these cases, the VN YANG data model can be used by the CNC to learn
details of the underlying VN, created to meet the requirements of the
customer service model.
4.3. Innovative Services
4.3.1. VN Compute
The VN Model model supports VN compute (pre-instantiation mode) to view the
full VN as a single entity before instantiation; achieving this via
path computation or "compute only" "compute-only" tunnel setup ([YANG-TE]) does not
provide the same functionality.
+--------+ +--------+
| CNC | | MDSC |
+--------+ +--------+
| |
| |
CNC POST TE-topo TE Topo | POST /nw:networks/nw:network/ |
model(with
model (w/ Conn. | nw:node/te-node-id/tet:connectivity- |
Matrix on one | matrices/tet:connectivity-matrix |
Abstract
abstract node and|---------------------------------------->|
constraints in | |
the conn. matrix)| HTTP 200 |
|<----------------------------------------|
| |
| |
CNC calls RPC to | RPC /vn-compute /vn compute |
compute the VN |---------------------------------------->|
as per the | |
refered TE-Topo | |
| |
| HTTP 200 (Computed VN) |
|<----------------------------------------|
| |
Figure 9: VN Compute with Reference to TE Toplogy YANG Data Model
The VN compute RPC allows the optional inclusion of the constraints
and the optimization criteria at the VN as well as at the individual
VN-member level. Thus, the RPC can be used independently to get the
computed VN result without creating an abstract topology first.
+--------+ +--------+
| CNC | | MDSC |
+--------+ +--------+
| |
| |
CNC calls RPC to | RPC /vn-compute /vn compute |
compute the VN |---------------------------------------->|
as per the | |
constraints and | |
VN-members
VN members | |
| HTTP 200 (Computed VN) |
|<----------------------------------------|
| |
Figure 10: VN Compute
In either case,
Regardless of whether the TE Topology model is referenced, the RPC
output includes a reference to the single node abstract topology with
each VN-member VN member including a reference to the connectivity-matrix-id
where the path properties could be found.
To achieve this, the VN-compute VN compute RPC reuses the following common
groupings:
* te-types:generic-path-constraints: This is used optionally in the RPC
input at the VN VN-level and/or VN-member level. The VN-member level
overrides the VN-level data. This also overrides data including any constraints in the
referenced abstract node in the TE topology.
* te-types:generic-path-optimization: This is used optionally in the RPC
input at the VN VN-level and/or VN-member level. The VN-member level
overrides the VN-level data. This also overrides data including any optimization in the
referenced abstract node in the TE topology.
* vn-member: This vn member: identifies the VN member in both RPC input and output.
* vn-policy: This is used optionally in the RPC input to apply any
VN-level VN-
level policies.
When MDSC receives this RPC, it computes the VN based on the input
provided in the RPC. This computation does not create a VN or
reserve any resources in the system, it simply computes the resulting
VN based on information at the MDSC or in coordination with the CNC.
A single-node-abstract single node abstract topology is used to convey the result of each
VN member as a reference to the connectivity-matrix-id. In case of
an error, the error information is included.
rpcs:
+---x vn-compute
+---w input
| +---w te-topology-identifier
| | +---w provider-id? te-global-id
| | +---w client-id? te-global-id
| | +---w topology-id? te-topology-id
| +---w abstract-node?
| | -> /nw:networks/network/node/tet:te-node-id
| +---w path-constraints
| | +---w te-bandwidth
| | | +---w (technology)?
| | | ...
| | +---w link-protection? identityref
| | +---w setup-priority? uint8
| | +---w hold-priority? uint8
| | +---w signaling-type? identityref
| | +---w path-metric-bounds
| | | +---w path-metric-bound* [metric-type]
| | | ...
| | +---w path-affinities-values
| | | +---w path-affinities-value* [usage]
| | | ...
| | +---w path-affinity-names
| | | +---w path-affinity-name* [usage]
| | | ...
| | +---w path-srlgs-lists
| | | +---w path-srlgs-list* [usage]
| | | ...
| | +---w path-srlgs-names
| | | +---w path-srlgs-name* [usage]
| | | ...
| | +---w disjointness? te-path-disjointness
| +---w cos? te-types:te-ds-class
| +---w optimizations
| | +---w (algorithm)?
| | +--:(metric) {path-optimization-metric}?
| | | ...
| | +--:(objective-function)
| | {path-optimization-objective-function}?
| | ...
| +---w vn-member-list* [id]
| | +---w id vnm-id
| | +---w src
| | | +---w ap? -> /access-point/ap/id
| | | +---w vn-ap-id?
| | | | -> /access-point/ap[id=current()/../ap]/vn-ap/id /access-point/ap[id=current()/../ap]/vn-ap/\
id
| | | +---w multi-src? boolean {multi-src-dest}?
| | +---w dest
| | | +---w ap? -> /access-point/ap/id
| | | +---w vn-ap-id?
| | | | -> /access-point/ap[id=current()/../ap]/vn-ap/id /access-point/ap[id=current()/../ap]/vn-ap/\
id
| | | +---w multi-dest? boolean {multi-src-dest}?
| | +---w connectivity-matrix-id? leafref
| | +---w underlay
| | +---w path-constraints
| | | +---w te-bandwidth
| | | | ...
| | | +---w link-protection? identityref
| | | +---w setup-priority? uint8
| | | +---w hold-priority? uint8
| | | +---w signaling-type? identityref
| | | +---w path-metric-bounds
| | | | ...
| | | +---w path-affinities-values
| | | | ...
| | | +---w path-affinity-names
| | | | ...
| | | +---w path-srlgs-lists
| | | | ...
| | | +---w path-srlgs-names
| | | | ...
| | | +---w disjointness? te-path-disjointness
| | +---w cos? te-types:te-ds-class
| | +---w optimizations
| | +---w (algorithm)?
| | ...
| +---w vn-level-diversity? te-types:te-path-disjointness te-types:te-path-\
disjointness
+--ro output
+--ro te-topology-identifier
| +--ro provider-id? te-global-id
| +--ro client-id? te-global-id
| +--ro topology-id? te-topology-id
+--ro abstract-node?
| -> /nw:networks/network/node/tet:te-node-id
+--ro vn-member-list* [id]
+--ro id vnm-id
+--ro src
| +--ro ap? -> /access-point/ap/id
| +--ro vn-ap-id?
| | -> /access-point/ap[id=current()/../ap]/vn-ap/id /access-point/ap[id=current()/../ap]/vn-ap/\
id
| +--ro multi-src? boolean {multi-src-dest}?
+--ro dest
| +--ro ap? -> /access-point/ap/id
| +--ro vn-ap-id?
| | -> /access-point/ap[id=current()/../ap]/vn-ap/id /access-point/ap[id=current()/../ap]/vn-ap/\
id
| +--ro multi-dest? boolean {multi-src-dest}?
+--ro connectivity-matrix-id? leafref
+--ro underlay
+--ro if-selected? boolean {multi-src-dest}?
+--ro compute-status? vn-compute-status
+--ro error-info
+--ro error-description? string
+--ro error-timestamp? yang:date-and-time
+--ro error-reason? identityref
4.3.2. Multiple Sources and Multiple Destinations
In creating a virtual network, VN, the list of sources or destinations or both may not
be predetermined by the customer. For instance, for a given source,
there may be a list of multiple destinations to which the optimal
destination may be chosen depending on the network resource
situations. Likewise, for a given destination, there may also be
multiple sources from which the optimal source may be chosen. In
some cases, there may be a pool of multiple sources and destinations
from which the optimal source-destination may be chosen. The
following YANG tree shows how to model multiple sources and multiple
destinations.
module: ietf-vn
+--rw virtual-network
+--rw vn* [id]
+--rw id vn-id
+--rw te-topology-identifier
| +--rw provider-id? te-global-id
| +--rw client-id? te-global-id
| +--rw topology-id? te-topology-id
+--rw abstract-node?
| -> /nw:networks/network/node/tet:te-node-id
+--rw vn-member* [id]
| +--rw id vnm-id
| +--rw src
| | +--rw ap? -> /access-point/ap/id
| | +--rw vn-ap-id?
| | | -> /access-point/ap[id=current()/../ap]/vn-ap/id /access-point/ap[id=current()/../ap]/vn-ap/\
id
| | +--rw multi-src? boolean {multi-src-dest}?
| +--rw dest
| | +--rw ap? -> /access-point/ap/id
| | +--rw vn-ap-id?
| | | -> /access-point/ap[id=current()/../ap]/vn-ap/id /access-point/ap[id=current()/../ap]/vn-ap/\
id
| | +--rw multi-dest? boolean {multi-src-dest}?
| +--rw connectivity-matrix-id? leafref
| +--rw underlay
| +--ro oper-status? te-types:te-oper-status
| +--ro if-selected? boolean {multi-src-dest}?
+--rw admin-status? te-types:te-admin-status
+--ro oper-status? te-types:te-oper-status
+--rw vn-level-diversity? te-types:te-path-disjointness
4.4. Others
The VN YANG data model can easily be augmented to support the mapping
of VN to the services such as L3SM and L2SM as described in
[TE-SERVICE-MAPPING].
The VN YANG data model can be extended to support telemetry,
performance monitoring, and network autonomics as described in
[TEAS-ACTN-PM].
Note that the VN YANG data model is tightly coupled with the TE
Topology model [RFC8795]. Any underlay technology not supported by
the TE Topology model in [RFC8795] is also not supported by this the VN
model. The However, the VN model does include an empty container called
"underlay" that can be augmented. For example example, the Segment Routing
(SR) Policy [RFC9256] information can be augmented for the SR
underlay by a future model.
Apart from the te-types:generic-path-constraints and te-
types:generic-path-optimization, an additional leaf called "cos" for
the class of service [RFC4124] is added to represent the Class-Type of traffic
[RFC4124] to be used as one of the path constraints.
4.5. Summary
This section summarizes the features of the VN YANG data model.
* Maintenance of APs and VNAPs along with the VN
* VN construct to group of edge-to-edge links
* Ability to support various VN and VNS Types types
- VN Type 1: Customer configures the VN as a set of VN Members. members.
No other details need to be set by the customer, making for a
simplified operation for the customer.
- VN Type 2: Along with VN Members, members, the customer could also
provide an abstract topology, this topology is provided by the
Abstract TE Topology YANG Model. data model.
o Note that the VN Type type is not explicitly identified in the VN
Yang
YANG data model, as the VN Model YANG data model is exactly the
same for both VN Type 1 and VN Type 2. The VN type can be
implicitly known based on the referenced TE topology and
whether the connectivity matrix includes the underlay path
(Type 2) or not (Type 1).
* VN Compute (pre-instantiate)
* Multi-Source / Multi-Destination
5. VN YANG Data Model (Tree Structure)
module: ietf-vn
+--rw access-point
| +--rw ap* [id]
| +--rw id ap-id
| +--rw pe?
| | -> /nw:networks/network/node/tet:te-node-id
| +--rw max-bandwidth? te-types:te-bandwidth
| +--rw avl-bandwidth? te-types:te-bandwidth
| +--rw vn-ap* [id]
| +--rw id ap-id
| +--rw vn? -> /virtual-network/vn/id
| +--rw abstract-node? -> /nw:networks/network/node/node-id /nw:networks/network/node/\
node-id
| +--rw ltp? leafref
| +--ro max-bandwidth? te-types:te-bandwidth
+--rw virtual-network
+--rw vn* [id]
+--rw id vn-id
+--rw te-topology-identifier
| +--rw provider-id? te-global-id
| +--rw client-id? te-global-id
| +--rw topology-id? te-topology-id
+--rw abstract-node?
| -> /nw:networks/network/node/tet:te-node-id
+--rw vn-member* [id]
| +--rw id vnm-id
| +--rw src
| | +--rw ap? -> /access-point/ap/id
| | +--rw vn-ap-id?
| | | -> /access-point/ap[id=current()/../ap]/vn-ap/id /access-point/ap[id=current()/../ap]/\
vn-ap/id
| | +--rw multi-src? boolean {multi-src-dest}?
| +--rw dest
| | +--rw ap? -> /access-point/ap/id
| | +--rw vn-ap-id?
| | | -> /access-point/ap[id=current()/../ap]/vn-ap/id /access-point/ap[id=current()/../ap]/\
vn-ap/id
| | +--rw multi-dest? boolean {multi-src-dest}?
| +--rw connectivity-matrix-id? leafref
| +--rw underlay
| +--ro oper-status? te-types:te-oper-status
| +--ro if-selected? boolean {multi-src-dest}?
+--rw admin-status? te-types:te-admin-status
+--ro oper-status? te-types:te-oper-status
+--rw vn-level-diversity? te-types:te-path-disjointness
rpcs:
+---x vn-compute
+---w input
| +---w te-topology-identifier
| | +---w provider-id? te-global-id
| | +---w client-id? te-global-id
| | +---w topology-id? te-topology-id
| +---w abstract-node?
| | -> /nw:networks/network/node/tet:te-node-id
| +---w path-constraints
| | +---w te-bandwidth
| | | +---w (technology)?
| | | ...
| | +---w link-protection? identityref
| | +---w setup-priority? uint8
| | +---w hold-priority? uint8
| | +---w signaling-type? identityref
| | +---w path-metric-bounds
| | | +---w path-metric-bound* [metric-type]
| | | ...
| | +---w path-affinities-values
| | | +---w path-affinities-value* [usage]
| | | ...
| | +---w path-affinity-names
| | | +---w path-affinity-name* [usage]
| | | ...
| | +---w path-srlgs-lists
| | | +---w path-srlgs-list* [usage]
| | | ...
| | +---w path-srlgs-names
| | | +---w path-srlgs-name* [usage]
| | | ...
| | +---w disjointness? te-path-disjointness
| +---w cos? te-types:te-ds-class
| +---w optimizations
| | +---w (algorithm)?
| | +--:(metric) {path-optimization-metric}?
| | | ...
| | +--:(objective-function)
| | {path-optimization-objective-function}?
| | ...
| +---w vn-member-list* [id]
| | +---w id vnm-id
| | +---w src
| | | +---w ap? -> /access-point/ap/id
| | | +---w vn-ap-id?
| | | | -> /access-point/ap[id=current()/../ap]/vn-ap/id /access-point/ap[id=current()/../ap]/\
vn-ap/id
| | | +---w multi-src? boolean {multi-src-dest}?
| | +---w dest
| | | +---w ap? -> /access-point/ap/id
| | | +---w vn-ap-id?
| | | | -> /access-point/ap[id=current()/../ap]/vn-ap/id /access-point/ap[id=current()/../ap]/\
vn-ap/id
| | | +---w multi-dest? boolean {multi-src-dest}?
| | +---w connectivity-matrix-id? leafref
| | +---w underlay
| | +---w path-constraints
| | | +---w te-bandwidth
| | | | ...
| | | +---w link-protection? identityref
| | | +---w setup-priority? uint8
| | | +---w hold-priority? uint8
| | | +---w signaling-type? identityref
| | | +---w path-metric-bounds
| | | | ...
| | | +---w path-affinities-values
| | | | ...
| | | +---w path-affinity-names
| | | | ...
| | | +---w path-srlgs-lists
| | | | ...
| | | +---w path-srlgs-names
| | | | ...
| | | +---w disjointness? te-path-disjointness
| | +---w cos? te-types:te-ds-class
| | +---w optimizations
| | +---w (algorithm)?
| | ...
| +---w vn-level-diversity? te-types:te-path-disjointness te-types:te-path-\
disjointness
+--ro output
+--ro te-topology-identifier
| +--ro provider-id? te-global-id
| +--ro client-id? te-global-id
| +--ro topology-id? te-topology-id
+--ro abstract-node?
| -> /nw:networks/network/node/tet:te-node-id
+--ro vn-member-list* [id]
+--ro id vnm-id
+--ro src
| +--ro ap? -> /access-point/ap/id
| +--ro vn-ap-id?
| | -> /access-point/ap[id=current()/../ap]/vn-ap/id /access-point/ap[id=current()/../ap]/\
vn-ap/id
| +--ro multi-src? boolean {multi-src-dest}?
+--ro dest
| +--ro ap? -> /access-point/ap/id
| +--ro vn-ap-id?
| | -> /access-point/ap[id=current()/../ap]/vn-ap/id /access-point/ap[id=current()/../ap]/\
vn-ap/id
| +--ro multi-dest? boolean {multi-src-dest}?
+--ro connectivity-matrix-id? leafref
+--ro underlay
+--ro if-selected? boolean {multi-src-dest}? {multi-src-\
dest}?
+--ro compute-status? vn-compute-status
+--ro error-info
+--ro error-description? string
+--ro error-timestamp? yang:date-and-time
+--ro error-reason? identityref
6. VN YANG Data Model
The VN YANG data model is as follows:
<CODE BEGINS> file "ietf-vn@2025-01-27.yang"
module ietf-vn {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-vn";
prefix vn;
/* Import common YANG types */
import ietf-yang-types {
prefix yang;
reference
"RFC 6991: Common YANG Data Types";
}
/* Import network */
import ietf-network {
prefix nw;
reference
"RFC 8345: A YANG Data Model for Network Topologies";
}
/* Import network topology */
import ietf-network-topology {
prefix nt;
reference
"RFC 8345: A YANG Data Model for Network Topologies";
}
/* Import TE Common types */
import ietf-te-types {
prefix te-types;
reference
"RFC 8776: Common YANG Data Types for Traffic Engineering";
}
/* Import TE Topology */
import ietf-te-topology {
prefix tet;
reference
"RFC 8795: YANG Data Model for Traffic Engineering (TE)
Topologies";
}
organization
"IETF Traffic Engineering Architecture and Signaling (TEAS)
Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/teas/>
WG List: <mailto:teas@ietf.org>
Editor: Young Lee <younglee.tx@gmail.com>
Editor: Dhruv Dhody <dhruv.ietf@gmail.com>";
description
"This module contains a YANG module for the Virtual Network (VN).
It describes a VN operation module that can take place
in the context of the Customer Network Controller (CNC) -
Multi-Domain Service Coordinator (MDSC) interface (CMI) of
the Abstraction and Control of TE Networks (ACTN)
architecture where the CNC is the actor of a VN
instantiation/modification/deletion as per RFC 8453.
This module uses the following abbreviations:
- VN: Virtual Network
- AP: Access Point
- VNAP: Virtual Network Access Point
- LTP: Link Termination Point
- PE: Provider Edge
- COS: Class of Service
Further, src and dest are used for source and
destination, respectively.
Copyright (c) 2025 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject to
the license terms contained in, the Revised BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 9731; see the
RFC itself for full legal notices.";
revision 2025-01-27 {
description
"The initial version.";
reference
"RFC 9731: A YANG Data Model for Virtual Network (VN)
Operations";
}
/* Features */
feature multi-src-dest {
description
"Support for selection of one src source or dest destination
among multiple.";
reference
"RFC 8453: Framework for Abstraction and Control of TE
Networks (ACTN)";
}
/* Typedef */
typedef vn-id {
type string {
length "1..max";
}
description
"A type definition for a Virtual Network (VN) VN identifier.";
}
typedef ap-id {
type string {
length "1..max";
}
description
"A type definition for an Access Point (AP) identifier.";
}
typedef vnm-id {
type string {
length "1..max";
}
description
"A type definition for a VN member VN-member identifier.";
}
typedef vn-compute-status {
type te-types:te-common-status;
description
"A type definition for representing the VN compute status.
Note that all statuses apart from up and down are considered
to be unknown.";
}
/* identities */
identity vn-computation-error-reason {
description
"Base identity for VN computation error reasons.";
}
identity vn-computation-error-not-ready {
base vn-computation-error-reason;
description
"VN computation has failed because the MDSC is not
ready.";
}
identity vn-computation-error-no-cnc {
base vn-computation-error-reason;
description
"VN computation has failed because one or more dependent
CNCs are unavailable.";
}
identity vn-computation-error-no-resource {
base vn-computation-error-reason;
description
"VN computation has failed because there is no
available resource in one or more domains.";
}
identity vn-computation-error-path-not-found {
base vn-computation-error-reason;
description
"VN computation failed as no path found.";
}
identity vn-computation-ap-unknown {
base vn-computation-error-reason;
description
"VN computation failed as the source or destination Access
Point (AP) not known.";
}
/* Groupings */
grouping vn-member {
description
"The vn-member is described by this grouping.";
leaf id {
type vnm-id;
description
"A vn-member identifier.";
}
container src {
description
"The source of VN Member."; member.";
leaf ap {
type leafref {
path "/access-point/ap/id";
}
description
"A reference to the source AP.";
}
leaf vn-ap-id {
type leafref {
path "/access-point/ap[id=current()/../ap]/vn-ap"
+ "/id";
}
description
"A reference to the source VNAP.";
}
leaf multi-src {
if-feature "multi-src-dest";
type boolean;
default "false";
description
"Is the source part of a multi-source, where
only one of the sources is enabled?";
}
}
container dest {
description
"The destination of the VN Member."; member.";
leaf ap {
type leafref {
path "/access-point/ap/id";
}
description
"A reference to the destination AP.";
}
leaf vn-ap-id {
type leafref {
path "/access-point/ap[id=current()/../ap]/"
+ "vn-ap/id";
}
description
"A reference to the dest destination VNAP.";
}
leaf multi-dest {
if-feature "multi-src-dest";
type boolean;
default "false";
description
"Is the destination part of a multi-destination,
where only one of the destinations is enabled.";
}
}
leaf connectivity-matrix-id {
type leafref {
path "/nw:networks/nw:network/nw:node/tet:te/"
+ "tet:te-node-attributes/"
+ "tet:connectivity-matrices/"
+ "tet:connectivity-matrix/tet:id";
}
description
"A reference to the connectivity-matrix.";
reference
"RFC 8795: YANG Data Model for Traffic Engineering (TE)
Topologies";
}
container underlay {
description
"An empty container that can be augmented with underlay
technology information not supported by RFC 8795 (for
example -
example, Segment Routing (SR).";
}
reference
"RFC 8454: Information Model for Abstraction and Control of TE
Networks (ACTN)";
"RFC 8795: YANG Data Model for Traffic Engineering (TE)
Topologies";
}
grouping vn-policy {
description
"policy for VN-level diversity";
leaf vn-level-diversity {
type te-types:te-path-disjointness;
description
"The type of disjointness on the VN level (i.e., across all
VN members).";
}
}
/* Configuration data nodes */
container access-point {
description
"AP configurations.";
list ap {
key "id";
description
"The access-point identifier.";
leaf id {
type ap-id;
description
"An AP identifier unique within the scope of the entity
that controls the VN.";
}
leaf pe {
type leafref {
path "/nw:networks/nw:network/nw:node/tet:te-node-id";
}
description
"A reference to the PE node in the native TE Topology.";
}
leaf max-bandwidth {
type te-types:te-bandwidth;
description
"The max bandwidth of the AP.";
}
leaf avl-bandwidth {
type te-types:te-bandwidth;
description
"The available bandwidth of the AP.";
}
list vn-ap {
key "id";
leaf id {
type ap-id;
description
"A unique identifier for the VNAP.";
}
leaf vn {
type leafref {
path "/virtual-network/vn/id";
}
description
"A reference to the VN.";
}
leaf abstract-node {
type leafref {
path "/nw:networks/nw:network/nw:node/nw:node-id";
}
must '/nw:networks/nw:network/nw:node[nw:node-id='
+ 'current()/../abstract-node]/tet:te-node-id' {
description
"The associated network for the abstract-node
must be TE enabled.";
}
description
"A reference to the abstract node that represents
the VN.";
}
leaf ltp {
type leafref {
path "/nw:networks/nw:network/nw:node[nw:node-id="
+ "current()/../abstract-node]/nt:termination-point/"
+ "tet:te-tp-id";
}
description
"A reference to the Link Termination Point (LTP)
in the abstract-node, i.e., the LTP should be in
the abstract layer and not the underlying layer.";
reference
"RFC 8795: YANG Data Model for Traffic Engineering (TE)
Topologies";
}
leaf max-bandwidth {
type te-types:te-bandwidth;
config false;
description
"The max bandwidth of the VNAP.";
}
description
"List of VNAPs in this AP.";
}
}
reference
"RFC 8453: Framework for Abstraction and Control of TE
Networks (ACTN), Section 6";
}
container virtual-network {
description
"VN configurations.";
list vn {
key "id";
description
"A virtual network VN is identified by a vn-id.";
leaf id {
type vn-id;
description
"An identifier unique within the scope of the entity
that controls the VN.";
}
uses te-types:te-topology-identifier;
leaf abstract-node {
type leafref {
path "/nw:networks/nw:network/nw:node/tet:te-node-id";
}
description
"A reference to the abstract node in TE Topology.";
}
list vn-member {
key "id";
description
"List of vn-members in a VN.";
uses vn-member;
leaf oper-status {
type te-types:te-oper-status;
config false;
description
"The vn-member operational state.";
}
leaf if-selected {
if-feature "multi-src-dest";
type boolean;
default "false";
config false;
description
"Is the vn-member selected among the multi-src multi-source
or multi-dest multi-destination options?";
}
}
leaf admin-status {
type te-types:te-admin-status;
default "up";
description
"VN administrative state.";
}
leaf oper-status {
type te-types:te-oper-status;
config false;
description
"VN operational state.";
}
uses vn-policy;
}
reference
"RFC 8453: Framework for Abstraction and Control of TE
Networks (ACTN)";
}
/* RPC */
rpc vn-compute {
description
"The VN computation without actual instantiation. This is
used by the CNC to get the VN results without actually
creating it in the network.
The input could include a reference to the single-node
-abstract single node
abstract topology. It could optionally also include
constraints and optimization criteria. The computation
is done based on the list of VN-members. VN members.
The output includes a reference to the single-node
-abstract single node
abstract topology with each VN-member VN member including a
reference to the connectivity-matrix-id where the
path properties could be found. Error information is
also included.";
input {
uses te-types:te-topology-identifier;
leaf abstract-node {
type leafref {
path "/nw:networks/nw:network/nw:node/tet:te-node-id";
}
description
"A reference to the abstract node in TE Topology.";
}
uses te-types:generic-path-constraints;
leaf cos {
type te-types:te-ds-class;
description
"The class of service (COS).";
}
uses te-types:generic-path-optimization;
list vn-member-list {
key "id";
description
"List of VN-members VN members in a VN.";
uses vn-member;
uses te-types:generic-path-constraints;
leaf cos {
type te-types:te-ds-class;
description
"The class of service.";
reference
"RFC 4124: Protocol Extensions for Support of
Diffserv-aware MPLS Traffic Engineering,
Section 4.3.1";
}
uses te-types:generic-path-optimization;
}
uses vn-policy;
}
output {
uses te-types:te-topology-identifier;
leaf abstract-node {
type leafref {
path "/nw:networks/nw:network/nw:node/tet:te-node-id";
}
description
"A reference to the abstract node in TE Topology.";
}
list vn-member-list {
key "id";
description
"List of VN-members VN members in a VN.";
uses vn-member;
leaf if-selected {
if-feature "multi-src-dest";
type boolean;
default "false";
description
"Is the vn-member selected among the multi-src multi-source or
multi-dest
multi-destination options?";
reference
"RFC 8453: Framework for Abstraction and Control of TE
Networks (ACTN), Section 7";
}
leaf compute-status {
type vn-compute-status;
description
"The VN-member compute state.";
}
container error-info {
description
"Error information related to the VN member.";
leaf error-description {
type string {
length "1..max";
}
description
"Textual representation of the error that occurred
during VN compute.";
}
leaf error-timestamp {
type yang:date-and-time;
description
"Timestamp of the attempt.";
}
leaf error-reason {
type identityref {
base vn-computation-error-reason;
}
description
"Reason for the VN computation error.";
}
}
}
}
}
}
<CODE ENDS>
7. Security Considerations
The YANG module specified in this document defines a schema for data
that is designed to be accessed via network management protocols such
as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer
is the secure transport layer, and the mandatory-to-implement secure
transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer
is HTTPS, and the mandatory-to-implement secure transport is TLS
[RFC8446].
The Network Configuration Access Control Model (NACM) [RFC8341]
provides the means to restrict access for particular NETCONF or
RESTCONF users to a preconfigured subset of all available NETCONF or
RESTCONF protocol operations and content.
The model presented in this document is used in the interface between
the CNC and MDSC, which is referred to as CNC-MDSC Interface (CMI).
Security risks, such as malicious attack and rogue elements
attempting to connect to the various ACTN components, are possible.
Furthermore, some ACTN components (e.g., MDSC) represent a single
point of failure and threat vector. Also, there is a need to manage
policy conflicts and eavesdropping on communication between different
ACTN components.
There are a number of data nodes defined in this YANG module that are
writable/creatable/deletable (i.e., "config true", which is the
default). These data nodes may be considered sensitive or vulnerable
in some network environments. Write operations (e.g., edit-config)
to these data nodes without proper protection can have a negative
effect on network operations. These are the subtrees and data nodes
and their sensitivity/vulnerability:
* ap: This list includes a set of sensitive data that influences how
the APs in the VN service are attached. By accessing the
following data nodes, an attacker may be able to manipulate the
VN.
- id
- pe
- max-bandwidth
- avl-bandwidth
* vn-ap: This list includes a set of sensitive data that influences
how the VN service is delivered. By accessing the following data
nodes, an attacker may be able to manipulate the VN.
- id
- vn
- abstract-node
- ltp
- max-bandwidth
* vn: This list includes a set of sensitive data that influences how
the VN service is delivered. By accessing the following data
nodes, an attacker may be able to manipulate the VN.
- id
- te-topology-identifier
- abstract-node
* vn-member: This list includes a set of sensitive data that
influences how the VN member in the VN service is delivered. By
accessing the following data nodes, an attacker may be able to
manipulate the VN member.
- id
- src/ap
- src/vn-ap-id
- dest/ap
- dest/vn-ap-id
- connectivity-matrix-id
Some of the readable data nodes in this YANG module may be considered
sensitive or vulnerable in some network environments. It is thus
important to control read access (e.g., via get, get-config, or
notification) to these data nodes. These are the subtrees and data
nodes and their sensitivity/vulnerability:
* oper-status: This leaf can reveal the current operational state of
the VN.
* if-selected: This leaf can reveal which vn-member is selected
among the various multi-src/dest multi-source / multi-destination options.
Some of the RPC operations in this YANG module may be considered
sensitive or vulnerable in some network environments. It is thus
important to control access to these operations. These are the
operations and their sensitivity/vulnerability:
* vn-compute: This RPC triggers the VN computation at the MDSC,
which can reveal the VN information.
8. IANA Considerations
IANA has made the following allocation for a URI in the "ns" registry
within the "IETF XML Registry" registry group [RFC3688]:
URI: urn:ietf:params:xml:ns:yang:ietf-vn
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace.
IANA has made the following allocation for the VN YANG module data model
(see Section 5in 5 in the "YANG Module Names" registry [RFC6020]:
name: ietf-vn
namespace: urn:ietf:params:xml:ns:yang:ietf-vn
prefix: vn
reference: RFC 9731
9. References
9.1. Normative References
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC4124] Le Faucheur, F., Ed., "Protocol Extensions for Support of
Diffserv-aware MPLS Traffic Engineering", RFC 4124,
DOI 10.17487/RFC4124, June 2005,
<https://www.rfc-editor.org/info/rfc4124>.
[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/info/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/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/info/rfc6242>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/info/rfc6991>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
[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/info/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/info/rfc8342>.
[RFC8345] Clemm, A., Medved, J., Varga, R., Bahadur, N.,
Ananthakrishnan, H., and X. Liu, "A YANG Data Model for
Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March
2018, <https://www.rfc-editor.org/info/rfc8345>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[RFC8776] Saad, T., Gandhi, R., Liu, X., Beeram, V., and I. Bryskin,
"Common YANG Data Types for Traffic Engineering",
RFC 8776, DOI 10.17487/RFC8776, June 2020,
<https://www.rfc-editor.org/info/rfc8776>.
[RFC8795] Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and
O. Gonzalez de Dios, "YANG Data Model for Traffic
Engineering (TE) Topologies", RFC 8795,
DOI 10.17487/RFC8795, August 2020,
<https://www.rfc-editor.org/info/rfc8795>.
9.2. Informative References
[L1CSM-YANG]
Lee, Y., Lee, K., Zheng, H., Gonzalez de Dios, O., and D.
Ceccarelli, "A YANG Data Model for L1 Connectivity Service
Model (L1CSM)", Work in Progress, Internet-Draft, draft-
ietf-ccamp-l1csm-yang-26, 11 April 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-ccamp-
l1csm-yang-26>.
[RFC7926] Farrel, A., Ed., Drake, J., Bitar, N., Swallow, G.,
Ceccarelli, D., and X. Zhang, "Problem Statement and
Architecture for Information Exchange between
Interconnected Traffic-Engineered Networks", BCP 206,
RFC 7926, DOI 10.17487/RFC7926, July 2016,
<https://www.rfc-editor.org/info/rfc7926>.
[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/info/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/info/rfc8309>.
[RFC8453] Ceccarelli, D., Ed. and Y. Lee, Ed., "Framework for
Abstraction and Control of TE Networks (ACTN)", RFC 8453,
DOI 10.17487/RFC8453, August 2018,
<https://www.rfc-editor.org/info/rfc8453>.
[RFC8454] Lee, Y., Belotti, S., Dhody, D., Ceccarelli, D., and B.
Yoon, "Information Model for Abstraction and Control of TE
Networks (ACTN)", RFC 8454, DOI 10.17487/RFC8454,
September 2018, <https://www.rfc-editor.org/info/rfc8454>.
[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/info/rfc8466>.
[RFC8792] Watsen, K., Auerswald, E., Farrel, A., and Q. Wu,
"Handling Long Lines in Content of Internet-Drafts and
RFCs", RFC 8792, DOI 10.17487/RFC8792, June 2020,
<https://www.rfc-editor.org/info/rfc8792>.
[RFC9256] Filsfils, C., Talaulikar, K., Ed., Voyer, D., Bogdanov,
A., and P. Mattes, "Segment Routing Policy Architecture",
RFC 9256, DOI 10.17487/RFC9256, July 2022,
<https://www.rfc-editor.org/info/rfc9256>.
[TE-SERVICE-MAPPING]
Lee, Y., Dhody, D., Fioccola, G., Wu, Q., Ceccarelli, D.,
and J. Tantsura, "Traffic Engineering (TE) and Service
Mapping YANG Data Model", Work in Progress, Internet-
Draft, draft-ietf-teas-te-service-mapping-yang-16, 20
October 2024, draft-ietf-teas-te-service-mapping-yang-17, 29
January 2025, <https://datatracker.ietf.org/doc/html/
draft-ietf-teas-te-service-mapping-yang-16>.
draft-ietf-teas-te-service-mapping-yang-17>.
[TEAS-ACTN-PM]
Lee, Y., Dhody, D., Vilalta, R., King, D., and D.
Ceccarelli, "YANG models for Virtual Network (VN)/TE
Performance Monitoring Telemetry and Scaling Intent
Autonomics", Work in Progress, Internet-Draft, draft-ietf-
teas-actn-pm-telemetry-autonomics-14, 19 October 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-teas-
actn-pm-telemetry-autonomics-14>.
[YANG-TE] Saad, T., Gandhi, R., Liu, X., Beeram, V. P., and I.
Bryskin, "A YANG Data Model for Traffic Engineering
Tunnels, Label Switched Paths and Interfaces", Work in
Progress, Internet-Draft, draft-ietf-teas-yang-te-37, 9
October 2024, <https://datatracker.ietf.org/doc/html/
draft-ietf-teas-yang-te-37>.
Appendix A. Performance Constraints
At the creation of a VN, it is natural to provide VN-level
constraints and optimization criteria. It should be noted that the
VN YANG module data model described in this document relies on the TE-Topology
Model TE
Topology model in [RFC8795] by using a reference to an abstract node
to
achieve this. provide VN-level constraints and optimization criteria. Further,
the connectivity-matrix structure is used to assign the constraints
and optimization criteria including delay, jitter, etc. [RFC8776]
defines some of the metric-types; future documents are meant to
augment it.
Note that the VN compute allows the inclusion of the constraints and
the optimization criteria directly in the RPC to allow it to be used
independently.
Appendix B. JSON Example
B.1. VN JSON
This section provides JSON examples of how the VN YANG data model and
TE
topology Topology YANG data model are used together to instantiate a VN.
The example in this section includes the following VNs:
* VN1 (Type 1): This VN maps to the single node topology abstract1
and consists of VN Members members 104 (L1 to L4), 107 (L1 to L7), 204 (L2
to L4), 308 (L3 to L8), and 108 (L1 to L8).
* VN2 (Type 2): This VN maps to the single node topology abstract2;
this topology has an underlay topology (called underlay). This VN
has a single VN member 105 (L1 to L5) and an underlay path (S4 and
S7) has been set in the connectivity matrix of the abstract2
topology;
* VN3 (Type 1): This VN has a multi-source and multi-destination
feature enabled. VN Member member 106 (L1 to L6) and 107 (L1 to L7)
showcase multi-dest and VN Member member 108 (L1 to L8) and 308 (L3 to
L8) showcase the multi-src feature. The selected VN-member VN member is
known via the field "if-selected" and the corresponding
connectivity-matrix-id.
L1---104---L4 L1---105---L5 L1---106---L6(md)
L1---107---L7 Underlay Path: L1---107---L7(md)
L2---204---L4 (S4 and S7) L1---108---L8(ms)
L3---308---L8 L3---308---L8(ms)
L1---108---L8
--- --- ---
VN1 VN2 VN3
--- --- ---
Figure 11 11: Example
Note that the VN YANG data model also includes the AP and VNAP, which
shows various VNs using the same AP.
{
"ietf-vn:access-point": {
"ap": [
{
"id": "101",
"vn-ap": [
{
"id": "10101",
"vn": "1",
"abstract-node": "192.0.2.1",
"ltp": "203.0.113.11"
},
{
"id": "10102",
"vn": "2",
"abstract-node": "192.0.2.2",
"ltp": "203.0.113.12"
},
{
"id": "10103",
"vn": "3",
"abstract-node": "192.0.2.3",
"ltp": "203.0.113.13"
}
]
},
{
"id": "202",
"vn-ap": [
{
"id": "20201",
"vn": "1",
"abstract-node": "192.0.2.1",
"ltp": "203.0.113.21"
}
]
},
{
"id": "303",
"vn-ap": [
{
"id": "30301",
"vn": "1",
"abstract-node": "192.0.2.1",
"ltp": "203.0.113.31"
},
{
"id": "30303",
"vn": "3",
"abstract-node": "192.0.2.3",
"ltp": "203.0.113.33"
}
]
},
{
"id": "404",
"vn-ap": [
{
"id": "40401",
"vn": "1",
"abstract-node": "192.0.2.1",
"ltp": "203.0.113.41"
}
]
},
{
"id": "505",
"vn-ap": [
{
"id": "50502",
"vn": "2",
"abstract-node": "192.0.2.2",
"ltp": "203.0.113.52"
}
]
},
{
"id": "606",
"vn-ap": [
{
"id": "60603",
"vn": "3",
"abstract-node": "192.0.2.3",
"ltp": "203.0.113.63"
}
]
},
{
"id": "707",
"vn-ap": [
{
"id": "70701",
"vn": "1",
"abstract-node": "192.0.2.1",
"ltp": "203.0.113.71"
},
{
"id": "70703",
"vn": "3",
"abstract-node": "192.0.2.3",
"ltp": "203.0.113.73"
}
]
},
{
"id": "808",
"vn-ap": [
{
"id": "80801",
"vn": "1",
"abstract-node": "192.0.2.1",
"ltp": "203.0.113.81"
},
{
"id": "80803",
"vn": "3",
"abstract-node": "192.0.2.3",
"ltp": "203.0.113.83"
}
]
}
]
},
"ietf-vn:virtual-network": {
"vn": [
{
"id": "1",
"te-topology-identifier": {
"topology-id": "abstract1"
},
"abstract-node": "192.0.2.1",
"vn-member": [
{
"id": "104",
"src": {
"ap": "101",
"vn-ap-id": "10101"
},
"dest": {
"ap": "404",
"vn-ap-id": "40401"
},
"connectivity-matrix-id": 10104
},
{
"id": "107",
"src": {
"ap": "101",
"vn-ap-id": "10101"
},
"dest": {
"ap": "707",
"vn-ap-id": "70701"
},
"connectivity-matrix-id": 10107
},
{
"id": "204",
"src": {
"ap": "202",
"vn-ap-id": "20201"
},
"dest": {
"ap": "404",
"vn-ap-id": "40401"
},
"connectivity-matrix-id": 10204
},
{
"id": "308",
"src": {
"ap": "303",
"vn-ap-id": "30301"
},
"dest": {
"ap": "808",
"vn-ap-id": "80801"
},
"connectivity-matrix-id": 10308
},
{
"id": "108",
"src": {
"ap": "101",
"vn-ap-id": "10101"
},
"dest": {
"ap": "808",
"vn-ap-id": "80801"
},
"connectivity-matrix-id": 10108
}
]
},
{
"id": "2",
"te-topology-identifier": {
"topology-id": "abstract2"
},
"abstract-node": "192.0.2.2",
"vn-member": [
{
"id": "105",
"src": {
"ap": "101",
"vn-ap-id": "10102"
},
"dest": {
"ap": "505",
"vn-ap-id": "50502"
},
"connectivity-matrix-id": 20105
}
]
},
{
"id": "3",
"te-topology-identifier": {
"topology-id": "abstract3"
},
"abstract-node": "192.0.2.3",
"vn-member": [
{
"id": "106",
"src": {
"ap": "101",
"vn-ap-id": "10103"
},
"dest": {
"ap": "606",
"vn-ap-id": "60603",
"multi-dest": true
},
"connectivity-matrix-id": 30106,
"if-selected": false
},
{
"id": "107",
"src": {
"ap": "101",
"vn-ap-id": "10103"
},
"dest": {
"ap": "707",
"vn-ap-id": "70703",
"multi-dest": true
},
"connectivity-matrix-id": 30107,
"if-selected": true
},
{
"id": "108",
"src": {
"ap": "101",
"vn-ap-id": "10103",
"multi-src": true
},
"dest": {
"ap": "808",
"vn-ap-id": "80803",
},
"connectivity-matrix-id": 30108,
"if-selected": false
},
{
"id": "308",
"src": {
"ap": "303",
"vn-ap-id": "30303",
"multi-src": true
},
"dest": {
"ap": "808",
"vn-ap-id": "80803"
},
"connectivity-matrix-id": 30308,
"if-selected": true
}
]
}
]
}
}
B.2. TE-Topology TE Topology JSON
This section provides JSON examples of the various TE topology
instances.
The example in this section includes the following TE Topologies:
* abstract1: a single node TE topology referenced by VN1. We also
show how disjointness (node, link, Shared Risk Link Group (SRLG))
is supported in the example on the connectivity matrices.
* abstract2: a single node TE topology referenced by VN2 with an
underlay path.
* underlay: the topology with multiple nodes (in the underlay path
of abstract2). For brevity, the example includes only the node:
other parameters are not included.
* abstract3: a single node TE topology referenced by VN3.
{
"ietf-network:networks": {
"network": [
{
"network-types": {
"ietf-te-topology:te-topology": {}
},
"network-id": "example:abstract1",
"ietf-te-topology:te-topology-identifier": {
"provider-id": 0,
"client-id": 0,
"topology-id": "example:abstract1"
},
"node": [
{
"node-id": "example:192.0.2.1",
"ietf-network-topology:termination-point": [
{
"tp-id": "example:1-0-1",
"ietf-te-topology:te-tp-id": "203.0.113.11"
},
{
"tp-id": "example:1-0-2",
"ietf-te-topology:te-tp-id": "203.0.113.21"
},
{
"tp-id": "example:1-0-3",
"ietf-te-topology:te-tp-id": "203.0.113.31"
},
{
"tp-id": "example:1-0-4",
"ietf-te-topology:te-tp-id": "203.0.113.41"
},
{
"tp-id": "example:1-0-7",
"ietf-te-topology:te-tp-id": "203.0.113.71"
},
{
"tp-id": "example:1-0-8",
"ietf-te-topology:te-tp-id": "203.0.113.81"
}
],
"ietf-te-topology:te-node-id": "192.0.2.1",
"ietf-te-topology:te": {
"te-node-attributes": {
"domain-id": 1,
"is-abstract": [
null
],
"connectivity-matrices": {
"is-allowed": true,
"path-constraints": {
"te-bandwidth": {
"generic": "0x1p10"
},
"disjointness": "node link srlg"
},
"connectivity-matrix": [
{
"id": 10104,
"from": {
"tp-ref": "example:1-0-1"
},
"to": {
"tp-ref": "example:1-0-4"
}
},
{
"id": 10107,
"from": {
"tp-ref": "example:1-0-1"
},
"to": {
"tp-ref": "example:1-0-7"
}
},
{
"id": 10204,
"from": {
"tp-ref": "example:1-0-2"
},
"to": {
"tp-ref": "example:1-0-4"
}
},
{
"id": 10308,
"from": {
"tp-ref": "example:1-0-3"
},
"to": {
"tp-ref": "example:1-0-8"
}
},
{
"id": 10108,
"from": {
"tp-ref": "example:1-0-1"
},
"to": {
"tp-ref": "example:1-0-8"
}
}
]
}
}
}
}
]
},
{
"network-types": {
"ietf-te-topology:te-topology": {}
},
"network-id": "example:abstract2",
"ietf-te-topology:te-topology-identifier": {
"provider-id": 0,
"client-id": 0,
"topology-id": "example:abstract2"
},
"node": [
{
"node-id": "example:192.0.2.2",
"ietf-network-topology:termination-point": [
{
"tp-id": "example:2-0-1",
"ietf-te-topology:te-tp-id": "203.0.113.12"
},
{
"tp-id": "example:2-0-5",
"ietf-te-topology:te-tp-id": "203.0.113.52"
}
],
"ietf-te-topology:te-node-id": "192.0.2.2",
"ietf-te-topology:te": {
"te-node-attributes": {
"domain-id": 1,
"is-abstract": [
null
],
"connectivity-matrices": {
"is-allowed": true,
"underlay": {
"enabled": true
},
"path-constraints": {
"te-bandwidth": {
"generic": "0x1p10"
}
},
"optimizations": {
"objective-function": {
"objective-function-type":
"ietf-te-types:of-maximize-residual-bandwidth"
}
},
"ietf-te-topology:connectivity-matrix": [
{
"id": 20105,
"from": {
"tp-ref": "example:2-0-1"
},
"to": {
"tp-ref": "example:2-0-5"
},
"underlay": {
"enabled": true,
"primary-path": {
"network-ref": "example:underlay",
"path-element": [
{
"path-element-id": 1,
"numbered-node-hop": {
"node-id": "198.51.100.44",
"hop-type": "strict"
}
},
{
"path-element-id": 2,
"numbered-node-hop": {
"node-id": "198.51.100.77",
"hop-type": "strict"
}
}
]
}
}
}
]
}
}
}
}
]
},
{
"network-types": {
"ietf-te-topology:te-topology": {}
},
"network-id": "example:underlay",
"ietf-te-topology:te-topology-identifier": {
"provider-id": 0,
"client-id": 0,
"topology-id": "example:underlay"
},
"node": [
{
"node-id": "example:198.51.100.11",
"ietf-te-topology:te-node-id": "198.51.100.11"
},
{
"node-id": "example:198.51.100.22",
"ietf-te-topology:te-node-id": "198.51.100.22"
},
{
"node-id": "example:198.51.100.33",
"ietf-te-topology:te-node-id": "198.51.100.33"
},
{
"node-id": "example:198.51.100.44",
"ietf-te-topology:te-node-id": "198.51.100.44"
},
{
"node-id": "example:198.51.100.55",
"ietf-te-topology:te-node-id": "198.51.100.55"
},
{
"node-id": "example:198.51.100.66",
"ietf-te-topology:te-node-id": "198.51.100.66"
},
{
"node-id": "example:198.51.100.77",
"ietf-te-topology:te-node-id": "198.51.100.77"
},
{
"node-id": "example:198.51.100.88",
"ietf-te-topology:te-node-id": "198.51.100.88"
},
{
"node-id": "example:198.51.100.99",
"ietf-te-topology:te-node-id": "198.51.100.99"
}
]
},
{
"network-types": {
"ietf-te-topology:te-topology": {}
},
"network-id": "example:abstract3",
"ietf-te-topology:te-topology-identifier": {
"provider-id": 0,
"client-id": 0,
"topology-id": "example:abstract3"
},
"node": [
{
"node-id": "example:192.0.2.3",
"ietf-network-topology:termination-point": [
{
"tp-id": "example:3-0-1",
"ietf-te-topology:te-tp-id": "203.0.113.13"
},
{
"tp-id": "example:3-0-3",
"ietf-te-topology:te-tp-id": "203.0.113.33"
},
{
"tp-id": "example:3-0-6",
"ietf-te-topology:te-tp-id": "203.0.113.63"
},
{
"tp-id": "example:3-0-7",
"ietf-te-topology:te-tp-id": "203.0.113.73"
},
{
"tp-id": "example:3-0-8",
"ietf-te-topology:te-tp-id": "203.0.113.83"
}
],
"ietf-te-topology:te-node-id": "192.0.2.3",
"ietf-te-topology:te": {
"te-node-attributes": {
"domain-id": 3,
"is-abstract": [
null
],
"connectivity-matrices": {
"is-allowed": true,
"path-constraints": {
"te-bandwidth": {
"generic": "0x1p10"
}
},
"connectivity-matrix": [
{
"id": 30107,
"from": {
"tp-ref": "example:3-0-1"
},
"to": {
"tp-ref": "example:3-0-7"
}
},
{
"id": 30106,
"from": {
"tp-ref": "example:3-0-1"
},
"to": {
"tp-ref": "example:3-0-6"
}
},
{
"id": 30108,
"from": {
"tp-ref": "example:3-0-1"
},
"to": {
"tp-ref": "example:3-0-8"
}
},
{
"id": 30308,
"from": {
"tp-ref": "example:3-0-3"
},
"to": {
"tp-ref": "example:3-0-8"
}
}
]
}
}
}
}
]
}
]
}
}
Acknowledgments
The authors would like to thank Xufeng Liu, Adrian Farrel, Tom Petch,
Mohamed Boucadair, Italo Busi, Bo Wu, and Daniel King for their
helpful comments and valuable suggestions.
Thanks to:
* Andy Bierman for the YANGDIR review.
* Darren Dukes and Susan Hares for the RTGDIR review.
* Behcet Sarikaya for the GENART review.
* Bo Wu for the OPSDIR review.
* Shivan Sahib for the SECDIR review.
* Deb Cooley, Francesca Palombini, Gunter Van de Velde, and Mahesh
Jethanandani for the IESG review.
Contributors' Addresses
Qin Wu
Huawei Technologies
Email: bill.wu@huawei.com
Peter Park
KT
Email: peter.park@kt.com
Haomian Zheng
Huawei Technologies
Email: zhenghaomian@huawei.com
Xian Zhang
Huawei Technologies
Email: zhang.xian@huawei.com
Sergio Belotti
Nokia
Email: sergio.belotti@nokia.com
Takuya Miyasaka
KDDI
Email: ta-miyasaka@kddi.com
Kenichi Ogaki
KDDI
Email: ke-oogaki@kddi.com
Authors' Addresses
Young Lee (editor)
Samsung Electronics
Email: younglee.tx@gmail.com
Dhruv Dhody (editor)
Huawei
India
Email: dhruv.ietf@gmail.com
Daniele Ceccarelli
Cisco
Email: daniele.ietf@gmail.com
Igor Bryskin
Individual
Email: i_bryskin@yahoo.com
Bin Yeong Yoon
ETRI
Email: byyun@etri.re.kr