Internet DRAFT - draft-ietf-opsawg-ac-lxsm-lxnm-glue
draft-ietf-opsawg-ac-lxsm-lxnm-glue
OPSAWG M. Boucadair, Ed.
Internet-Draft Orange
Intended status: Standards Track R. Roberts
Expires: 12 August 2024 Juniper
S. B. Giraldo
Nokia
O. G. D. Dios
Telefonica
9 February 2024
A YANG Data Model for Augmenting VPN Service and Network Models with
Attachment Circuits
draft-ietf-opsawg-ac-lxsm-lxnm-glue-06
Abstract
The document specifies a module that updates existing service and
network Virtual Private Network (VPN) modules with the required
information to bind specific services to ACs that are created using
the Attachment Circuit (AC) service and network models.
Discussion Venues
This note is to be removed before publishing as an RFC.
Discussion of this document takes place on the Operations and
Management Area Working Group Working Group mailing list
(opsawg@ietf.org), which is archived at
https://mailarchive.ietf.org/arch/browse/opsawg/.
Source for this draft and an issue tracker can be found at
https://github.com/boucadair/attachment-circuit-model.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
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This Internet-Draft will expire on 12 August 2024.
Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions and Definitions . . . . . . . . . . . . . . . . . 3
3. Sample Uses of the Data Models . . . . . . . . . . . . . . . 3
3.1. ACs Terminated by One or Multiple Customer Edges (CEs) . 3
3.2. Separate AC Provisioning vs. Actual VPN Service
Provisioning . . . . . . . . . . . . . . . . . . . . . . 4
4. Module Tree Structure . . . . . . . . . . . . . . . . . . . . 6
5. The AC Glue ("ietf-ac-glue") YANG Module . . . . . . . . . . 8
6. Security Considerations . . . . . . . . . . . . . . . . . . . 13
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
8.1. Normative References . . . . . . . . . . . . . . . . . . 14
8.2. Informative References . . . . . . . . . . . . . . . . . 16
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 17
A.1. A Service AC Reference within The VPN Network Access . . 17
A.2. Network and Service AC References . . . . . . . . . . . . 21
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 28
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 28
1. Introduction
The document specifies a YANG module ("ietf-ac-glue", Section 5) that
updates existing service and network Virtual Private Network (VPN)
modules with the required information to bind specific services to
Attachment Circuits (ACs) that are created using the AC service model
[I-D.ietf-opsawg-teas-attachment-circuit], specifically the following
modules are augmented:
* The Layer 2 Service Model (L2SM) [RFC8466]
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* The Layer 3 Service Model (L3SM) [RFC8299]
* The Layer 2 Network Model (L2NM) [RFC9291]
* The Layer 3 Network Model (L3NM) [RFC9182]
Likewise, the document augments the L2NM and L3NM with references to
the ACs that are managed using the AC network model
[I-D.ietf-opsawg-ntw-attachment-circuit].
The YANG data model in this document conforms to the Network
Management Datastore Architecture (NMDA) defined in [RFC8342].
An example to illustrate the use of the "ietf-ac-glue" model is
provided in Appendix A.
2. Conventions and Definitions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
The meanings of the symbols in the YANG tree diagrams are defined in
[RFC8340].
This document uses terms defined in
[I-D.ietf-opsawg-teas-attachment-circuit].
LxSM refers to both the L2SM and the L3SM.
LxNM refers to both the L2NM and the L3NM.
3. Sample Uses of the Data Models
3.1. ACs Terminated by One or Multiple Customer Edges (CEs)
Figure 1 depicts two target topology flavors that involve ACs. These
topologies have the following characteristics:
* A Customer Edges (CEs) can be either a physical device or a
logical entity. Such logical entity is typically a software
component (e.g., a virtual service function that is hosted within
the provider's network or a third-party infrastructure). A CE is
seen by the network as a peer Service Attachment Point (SAP)
[RFC9408].
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* An AC service request may include one or multiple ACs, which may
be associated to a single CE or multiple CEs.
* CEs may be either dedicated to one single connectivity service or
host multiple connectivity services (e.g., CEs with roles of
service functions [RFC7665]).
* A network provider may bind a single AC to one or multiple peer
SAPs (e.g., CE#1 and CE#2 are tagged as peer SAPs for the same
AC). For example, and as discussed in [RFC4364], multiple CEs can
be attached to a PE over the same attachment circuit. This
scenario is typically implemented when the Layer 2 infrastructure
between the CE and the network is a multipoint service.
* A single CE may terminate multiple ACs, which can be associated
with the same bearer or distinct bearers.
* Customers may request protection schemes in which the ACs
associated with their endpoints are terminated by the same PE
(e.g., CE#3), distinct PEs (e.g., CE#34), etc. The network
provider uses this request to decide where to terminate the AC in
the network provider network and also whether to enable specific
capabilities (e.g., Virtual Router Redundancy Protocol (VRRP)).
.-------. .--------------------. .-------.
│ +------. | +---AC----+ |
│ CE#1 │ | | +---AC----+ CE#3 |
'-------' | | | '-------'
+---AC----+ Network |
.-------. | | |
| | | | | .-------.
| CE#2 +------' | +---AC----+ CE#4 |
'-------' | | '----+--'
'-----------+--------' |
| |
'-----------AC----------'
Figure 1: Examples of ACs
3.2. Separate AC Provisioning vs. Actual VPN Service Provisioning
The procedure to provision a service in a service provider network
may depend on the practices adopted by a service provider. This
includes the flow put in place for the provisioning of advanced
network services and how they are bound to an attachment circuit.
For example, a single attachment circuit may be used to host multiple
connectivity services. In order to avoid service interference and
redundant information in various locations, a service provider may
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expose an interface to manage ACs network-wide. Customers can then
request a bearer or an attachment circuit to be put in place, and
then refer to that bearer or AC when requesting VPN services that are
bound to the bearer or AC.
Figure 2 shows the positioning of the AC service model is the overall
service delivery process.
.---------------.
| Customer |
'-------+-------'
Customer Service Model |
e.g., slice-svc, ac-svc,| and bearer-svc
.-------+-------.
| Service |
| Orchestration |
'-------+-------'
Network Model |
e.g., l3vpn-ntw, sap, and ac-ntw|
.-------+-------.
| Network |
| Orchestration |
'-------+-------'
Network Configuration Model |
.-----------+-----------.
| |
.--------+------. .--------+------.
| Domain | | Domain |
| Orchestration | | Orchestration |
'---+-----------' '--------+------'
Device | | |
Configuration | | |
Model | | |
.----+----. | |
| Config | | |
| Manager | | |
'----+----' | |
| | |
| NETCONF/CLI..................
| | |
.--------------------------------.
.----. Bearer | | Bearer .----.
|CE#1+--------+ Network +--------+CE#2|
'----' | | '----'
'--------------------------------'
Site A Site B
Figure 2: An Example of AC Model Usage
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4. Module Tree Structure
[RFC8299] specifies that a 'site-network-access' attachment is
achieved through a 'bearer' with an 'ip-connection' on top. From
that standpoint, a 'site-network-access' is mapped to an attachment
circuit with both Layers 2 and 3 properties as per
[I-D.ietf-opsawg-teas-attachment-circuit]. [RFC8466] specifies that
a 'site-network-access' represents a logical Layer 2 connection to a
site. A 'site-network-access' can thus be mapped to an attachment
circuit with Layer 2 properties
[I-D.ietf-opsawg-teas-attachment-circuit]. Similarly, 'vpn-network-
access' defined in both [RFC9182] and [RFC9291] is mapped to an
attachment circuit as per [I-D.ietf-opsawg-teas-attachment-circuit]
or [I-D.ietf-opsawg-ntw-attachment-circuit].
As such, ACs created using the "ietf-ac-svc" module
[I-D.ietf-opsawg-teas-attachment-circuit] can be referenced in other
VPN-related modules (e.g., L2SM, L3SM, L2NM, and L3NM). Also, ACs
managed using the "ietf-ac-ntw" module
[I-D.ietf-opsawg-ntw-attachment-circuit] can be referenced in VPN-
related network modules (mainly, L2NM and L3NM). The required
augmentations to that aim are shown in Figure 3.
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module: ietf-ac-glue
augment /l2vpn-svc:l2vpn-svc/l2vpn-svc:sites/l2vpn-svc:site
/l2vpn-svc:site-network-accesses:
+--rw ac-svc-ref* ac-svc:attachment-circuit-reference
augment /l2vpn-svc:l2vpn-svc/l2vpn-svc:sites/l2vpn-svc:site
/l2vpn-svc:site-network-accesses
/l2vpn-svc:site-network-access:
+--rw ac-svc-ref? ac-svc:attachment-circuit-reference {ac-glue}?
augment /l3vpn-svc:l3vpn-svc/l3vpn-svc:sites/l3vpn-svc:site
/l3vpn-svc:site-network-accesses:
+--rw ac-svc-ref* ac-svc:attachment-circuit-reference
augment /l3vpn-svc:l3vpn-svc/l3vpn-svc:sites/l3vpn-svc:site
/l3vpn-svc:site-network-accesses
/l3vpn-svc:site-network-access:
+--rw ac-svc-ref? ac-svc:attachment-circuit-reference {ac-glue}?
augment /l2nm:l2vpn-ntw/l2nm:vpn-services/l2nm:vpn-service
/l2nm:vpn-nodes/l2nm:vpn-node/l2nm:vpn-network-accesses:
+--rw ac-svc-ref* ac-svc:attachment-circuit-reference
+--rw ac-ntw-ref* [ac-ref]
+--rw ac-ref leafref
+--rw node-ref? leafref
+--rw network-ref? -> /nw:networks/network/network-id
augment /l2nm:l2vpn-ntw/l2nm:vpn-services/l2nm:vpn-service
/l2nm:vpn-nodes/l2nm:vpn-node/l2nm:vpn-network-accesses
/l2nm:vpn-network-access:
+--rw ac-svc-ref? ac-svc:attachment-circuit-reference {ac-glue}?
+--rw ac-ntw-ref {ac-glue}?
+--rw ac-ref? leafref
+--rw node-ref? leafref
+--rw network-ref? -> /nw:networks/network/network-id
augment /l3nm:l3vpn-ntw/l3nm:vpn-services/l3nm:vpn-service
/l3nm:vpn-nodes/l3nm:vpn-node/l3nm:vpn-network-accesses:
+--rw ac-svc-ref* ac-svc:attachment-circuit-reference
+--rw ac-ntw-ref* [ac-ref]
+--rw ac-ref leafref
+--rw node-ref? leafref
+--rw network-ref? -> /nw:networks/network/network-id
augment /l3nm:l3vpn-ntw/l3nm:vpn-services/l3nm:vpn-service
/l3nm:vpn-nodes/l3nm:vpn-node/l3nm:vpn-network-accesses
/l3nm:vpn-network-access:
+--rw ac-svc-ref? ac-svc:attachment-circuit-reference {ac-glue}?
+--rw ac-ntw-ref {ac-glue}?
+--rw ac-ref? leafref
+--rw node-ref? leafref
+--rw network-ref? -> /nw:networks/network/network-id
Figure 3: AC Glue Tree Structure
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When an AC is referenced within a specific network access, then that
AC information takes precedence over any overlapping information that
is also enclosed for this network access.
This approach is consistent with the design in
[I-D.ietf-teas-ietf-network-slice-nbi-yang] where an AC service
reference, called 'ac-svc-name', is used to indicate the names of
AC services. As per [I-D.ietf-teas-ietf-network-slice-nbi-yang],
when both 'ac-svc-name' and the attributes of 'attachment-
circuits' are defined, the 'ac-svc-name' takes precedence.
The module includes provisions to reference ACs within or outside a
VPN network access to accommodate deployment contexts where an AC
reference may be created before or after a VPN instance is created.
Appendix A.1 illustrates how an AC reference can be included as part
of a specific VPN network access, while Appendix A.2 shows how AC
references can be indicated outside individual VPN network access
entries.
5. The AC Glue ("ietf-ac-glue") YANG Module
<CODE BEGINS> file "ietf-ac-glue@2023-11-13.yang"
module ietf-ac-glue {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-ac-glue";
prefix ac-glue;
import ietf-l3vpn-svc {
prefix l3vpn-svc;
reference
"RFC 8299: YANG Data Model for L3VPN Service Delivery";
}
import ietf-l2vpn-svc {
prefix l2vpn-svc;
reference
"RFC 8466: A YANG Data Model for Layer 2 Virtual Private
Network (L2VPN) Service Delivery";
}
import ietf-l3vpn-ntw {
prefix l3nm;
reference
"RFC 9182: A YANG Network Data Model for Layer 3 VPNs";
}
import ietf-l2vpn-ntw {
prefix l2nm;
reference
"RFC 9291: A YANG Network Data Model for Layer 2 VPNs";
}
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import ietf-ac-svc {
prefix ac-svc;
reference
"RFC SSSS: YANG Service Data Models for Attachment Circuits";
}
import ietf-ac-ntw {
prefix ac-ntw;
reference
"RFC NNNN: A Network YANG Data Model for Attachment Circuits";
}
organization
"IETF OPSAWG (Operations and Management Area Working Group)";
contact
"WG Web: <https://datatracker.ietf.org/wg/opsawg/>
WG List: <mailto:opsawg@ietf.org>
Editor: Mohamed Boucadair
<mailto:mohamed.boucadair@orange.com>
Author: Richard Roberts
<mailto:rroberts@juniper.net>
Author: Samier Barguil
<mailto:ssamier.barguil_giraldo@nokia.com>
Author: Oscar Gonzalez de Dios
<mailto:oscar.gonzalezdedios@telefonica.com>";
description
"This YANG module defines a YANG model for augmenting the LxSM
and the LxNM with attachment circuit references.
Copyright (c) 2024 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Revised BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see the
RFC itself for full legal notices.";
revision 2023-11-13 {
description
"Initial revision.";
reference
"RFC XXXX: A YANG Data Model for Augmenting VPN Service
and Network Models with Attachment Circuits";
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}
feature ac-glue {
description
"The VPN implementation supports binding a specific VPN
network access or site access to an attachment circuit.";
}
grouping single-ac-svc-ref {
description
"A grouping with single reference to a service AC.";
leaf ac-svc-ref {
type ac-svc:attachment-circuit-reference;
description
"A reference to the AC as exposed at the service that
was provisioned using the ACaaS module.";
}
}
grouping single-ac-svc-ntw-ref {
description
"A grouping with single AC references.";
leaf ac-svc-ref {
type ac-svc:attachment-circuit-reference;
description
"A reference to the AC as exposed at the service that
was provisioned using the ACaaS module.";
}
container ac-ntw-ref {
uses ac-ntw:attachment-circuit-reference;
description
"A reference to the AC that was provisioned
using the AC network module.";
}
}
grouping ac-svc-ref {
description
"A set of service-specific AC-related data.";
leaf-list ac-svc-ref {
type ac-svc:attachment-circuit-reference;
description
"A reference to the AC as exposed at the service that
was provisioned using the ACaaS module.";
}
}
grouping ac-svc-ntw-ref {
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description
"A set of AC-related data.";
leaf-list ac-svc-ref {
type ac-svc:attachment-circuit-reference;
description
"A reference to the AC as exposed at the service that
was provisioned using the ACaaS module.";
}
list ac-ntw-ref {
key "ac-ref";
description
"A reference to the AC that was provisioned
using the AC network module.";
uses ac-ntw:attachment-circuit-reference;
}
}
augment "/l2vpn-svc:l2vpn-svc"
+ "/l2vpn-svc:sites/l2vpn-svc:site"
+ "/l2vpn-svc:site-network-accesses" {
description
"Augments VPN site network access with AC provisioning
details.";
uses ac-svc-ref;
}
augment "/l2vpn-svc:l2vpn-svc"
+ "/l2vpn-svc:sites/l2vpn-svc:site"
+ "/l2vpn-svc:site-network-accesses"
+ "/l2vpn-svc:site-network-access" {
if-feature "ac-glue";
description
"Augments VPN site network access with a reference to
a service AC.";
uses single-ac-svc-ref;
}
augment "/l3vpn-svc:l3vpn-svc"
+ "/l3vpn-svc:sites/l3vpn-svc:site"
+ "/l3vpn-svc:site-network-accesses" {
description
"Augments VPN network access with AC provisioning details.";
uses ac-svc-ref;
}
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augment "/l3vpn-svc:l3vpn-svc"
+ "/l3vpn-svc:sites/l3vpn-svc:site"
+ "/l3vpn-svc:site-network-accesses"
+ "/l3vpn-svc:site-network-access" {
if-feature "ac-glue";
description
"Augments VPN site network access with a reference to
a service AC.";
uses single-ac-svc-ref;
}
augment "/l2nm:l2vpn-ntw/l2nm:vpn-services/l2nm:vpn-service"
+ "/l2nm:vpn-nodes/l2nm:vpn-node"
+ "/l2nm:vpn-network-accesses" {
description
"Augments VPN network access with AC provisioning details.";
uses ac-svc-ntw-ref;
}
augment "/l2nm:l2vpn-ntw/l2nm:vpn-services/l2nm:vpn-service"
+ "/l2nm:vpn-nodes/l2nm:vpn-node"
+ "/l2nm:vpn-network-accesses"
+ "/l2nm:vpn-network-access" {
if-feature "ac-glue";
description
"Augments VPN network access with service and network
references to an AC.";
uses single-ac-svc-ntw-ref;
}
augment "/l3nm:l3vpn-ntw/l3nm:vpn-services/l3nm:vpn-service"
+ "/l3nm:vpn-nodes/l3nm:vpn-node"
+ "/l3nm:vpn-network-accesses" {
description
"Augments VPN network access with AC provisioning details.";
uses ac-svc-ntw-ref;
}
augment "/l3nm:l3vpn-ntw/l3nm:vpn-services/l3nm:vpn-service"
+ "/l3nm:vpn-nodes/l3nm:vpn-node"
+ "/l3nm:vpn-network-accesses"
+ "/l3nm:vpn-network-access" {
if-feature "ac-glue";
description
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"Augments VPN network access with service and network
references to an AC.";
uses single-ac-svc-ntw-ref;
}
}
<CODE ENDS>
6. Security Considerations
The YANG module specified in this document defines 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.
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)
and delete operations to these data nodes without proper protection
or authentication can have a negative effect on network operations.
These are the subtrees and data nodes and their sensitivity/
vulnerability in the "ietf-ac-glue" module:
'ac-svc-ref' and 'ac-ntw-ref': An attacker who is able to access
network nodes can undertake various attacks, such as deleting a
running VPN service, interrupting all the traffic of a client.
Specifically, an attacker may modify (including delete) the ACs
that are bound to a running service, leading to malfunctioning of
the service and therefore to Service Level Agreement (SLA)
violations. : Such activity can be detected by adequately
monitoring and tracking network configuration changes.
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 in the "ietf-ac-glue"
module:
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'ac-svc-ref' and 'ac-ntw-ref': These references do not expose per se
privacy-related information, however 'ac-svc-ref' may be used to
track the set of VPN instances in which a given customer is
involved.
Note that, unlike 'ac-svc-ref', 'ac-ntw-ref' is unique within the
scope of a node and may multiplex many peer CEs.
7. IANA Considerations
IANA is requested to register the following URI in the "ns"
subregistry within the "IETF XML Registry" [RFC3688]:
URI: urn:ietf:params:xml:ns:yang:ietf-ac-glue
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.
IANA is requested to register the following YANG module in the "YANG
Module Names" registry [RFC6020] within the "YANG Parameters"
registry group:
Name: ietf-ac-glue
Namespace: urn:ietf:params:xml:ns:yang:ietf-ac-glue
Prefix: ac-glue
Maintained by IANA? N
Reference: RFC xxxx
8. References
8.1. Normative References
[I-D.ietf-opsawg-ntw-attachment-circuit]
Boucadair, M., Roberts, R., de Dios, O. G., Barguil, S.,
and B. Wu, "A Network YANG Data Model for Attachment
Circuits", Work in Progress, Internet-Draft, draft-ietf-
opsawg-ntw-attachment-circuit-04, 14 December 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-opsawg-
ntw-attachment-circuit-04>.
[I-D.ietf-opsawg-teas-attachment-circuit]
Boucadair, M., Roberts, R., de Dios, O. G., Barguil, S.,
and B. Wu, "YANG Data Models for Bearers and 'Attachment
Circuits'-as-a-Service (ACaaS)", Work in Progress,
Internet-Draft, draft-ietf-opsawg-teas-attachment-circuit-
05, 22 January 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-opsawg-
teas-attachment-circuit-05>.
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[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/rfc/rfc3688>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/rfc/rfc6020>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/rfc/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/rfc/rfc6242>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/rfc/rfc8040>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8299] Wu, Q., Ed., Litkowski, S., Tomotaki, L., and K. Ogaki,
"YANG Data Model for L3VPN Service Delivery", RFC 8299,
DOI 10.17487/RFC8299, January 2018,
<https://www.rfc-editor.org/rfc/rfc8299>.
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/rfc/rfc8341>.
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "Network Management Datastore Architecture
(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
<https://www.rfc-editor.org/rfc/rfc8342>.
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[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/rfc/rfc8446>.
[RFC8466] Wen, B., Fioccola, G., Ed., Xie, C., and L. Jalil, "A YANG
Data Model for Layer 2 Virtual Private Network (L2VPN)
Service Delivery", RFC 8466, DOI 10.17487/RFC8466, October
2018, <https://www.rfc-editor.org/rfc/rfc8466>.
[RFC9182] Barguil, S., Gonzalez de Dios, O., Ed., Boucadair, M.,
Ed., Munoz, L., and A. Aguado, "A YANG Network Data Model
for Layer 3 VPNs", RFC 9182, DOI 10.17487/RFC9182,
February 2022, <https://www.rfc-editor.org/rfc/rfc9182>.
[RFC9291] Boucadair, M., Ed., Gonzalez de Dios, O., Ed., Barguil,
S., and L. Munoz, "A YANG Network Data Model for Layer 2
VPNs", RFC 9291, DOI 10.17487/RFC9291, September 2022,
<https://www.rfc-editor.org/rfc/rfc9291>.
8.2. Informative References
[I-D.ietf-teas-ietf-network-slice-nbi-yang]
Wu, B., Dhody, D., Rokui, R., Saad, T., and J. Mullooly,
"A YANG Data Model for the IETF Network Slice Service",
Work in Progress, Internet-Draft, draft-ietf-teas-ietf-
network-slice-nbi-yang-08, 23 October 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-teas-
ietf-network-slice-nbi-yang-08>.
[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
2006, <https://www.rfc-editor.org/rfc/rfc4364>.
[RFC4664] Andersson, L., Ed. and E. Rosen, Ed., "Framework for Layer
2 Virtual Private Networks (L2VPNs)", RFC 4664,
DOI 10.17487/RFC4664, September 2006,
<https://www.rfc-editor.org/rfc/rfc4664>.
[RFC7665] Halpern, J., Ed. and C. Pignataro, Ed., "Service Function
Chaining (SFC) Architecture", RFC 7665,
DOI 10.17487/RFC7665, October 2015,
<https://www.rfc-editor.org/rfc/rfc7665>.
[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/rfc/rfc8340>.
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[RFC9408] Boucadair, M., Ed., Gonzalez de Dios, O., Barguil, S., Wu,
Q., and V. Lopez, "A YANG Network Data Model for Service
Attachment Points (SAPs)", RFC 9408, DOI 10.17487/RFC9408,
June 2023, <https://www.rfc-editor.org/rfc/rfc9408>.
Appendix A. Examples
A.1. A Service AC Reference within The VPN Network Access
Let's consider the example depicted in Figure 4 which is inspired
from Section 2.1 of [RFC4664]. Each PE is servicing two CEs. Let's
also assume that the service references to identify attachment
circuits with these CEs are shown in the figure.
.-----. .-----.
| | AC1 AC2 | |
| CE1 |--+ +--| CE2 |
| | | .-----. .-----. .-----. | | |
'-----' +----|---- | | P | | ----+----+ '-----'
|VPWS\----|-----|-----|/VPWS|
| PE1 |===|=====|=====| PE2 |
| /|---|-----|-----|\\ |
.-----. +----|---- | | | | ----|----+ .-----.
| | | '-----' '-----' '-----' | | |
| CE3 |--+ +--| CE4 |
| | AC3 AC4 | |
'-----' '-----'
Figure 4: VPWS Topology Example
As shown in Figure 5, the service AC references can be explicitly
indicated in the L2NM query for the realization of the Virtual
Private Wire Service (VPWS) Section 3.1.1 of [RFC4664]).
=============== NOTE: '\' line wrapping per RFC 8792 ================
{
"ietf-l2vpn-ntw:l2vpn-ntw":{
"vpn-services":{
"vpn-service":[
{
"vpn-id":"vpws12345",
"vpn-description":"Sample VPWS with AC service \
references",
"customer-name":"customer-12345",
"vpn-type":"ietf-vpn-common:vpws",
"bgp-ad-enabled":true,
"signaling-type":"ietf-vpn-common:ldp-signaling",
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"global-parameters-profiles":{
"global-parameters-profile":[
{
"profile-id":"simple-profile",
"local-autonomous-system":65550,
"rd-auto":{
"auto":[
null
]
},
"vpn-target":[
{
"id":1,
"route-targets":[
{
"route-target":"0:65535:1"
}
],
"route-target-type":"both"
}
]
}
]
},
"vpn-nodes":{
"vpn-node":[
{
"vpn-node-id":"pe1",
"ne-id":"2001:db8:100::1",
"active-global-parameters-profiles":{
"global-parameters-profile":[
{
"profile-id":"simple-profile"
}
]
},
"bgp-auto-discovery":{
"vpn-id":"587"
},
"signaling-option":{
"advertise-mtu":true,
"ldp-or-l2tp":{
"saii":1,
"remote-targets":[
{
"taii":2
}
],
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"t-ldp-pw-type":"ethernet"
}
},
"vpn-network-accesses":{
"vpn-network-access":[
{
"id":"1/1/1.1",
"interface-id":"1/1/1",
"description":"Interface to CE1",
"active-vpn-node-profile":"simple-\
profile",
"status":{
"admin-status":{
"status":"ietf-vpn-common:\
admin-up"
},
"ietf-ac-glue:ac-svc-ref":"AC1"
}
},
{
"id":"1/1/3.1",
"interface-id":"1/1/3",
"description":"Interface to CE3",
"active-vpn-node-profile":"simple-\
profile",
"status":{
"admin-status":{
"status":"ietf-vpn-common:\
admin-up"
},
"ietf-ac-glue:ac-svc-ref":"AC3"
}
}
]
}
},
{
"vpn-node-id":"pe2",
"ne-id":"2001:db8:200::1",
"active-global-parameters-profiles":{
"global-parameters-profile":[
{
"profile-id":"simple-profile"
}
]
},
"bgp-auto-discovery":{
"vpn-id":"587"
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},
"signaling-option":{
"advertise-mtu":true,
"ldp-or-l2tp":{
"saii":2,
"remote-targets":[
{
"taii":1
}
],
"t-ldp-pw-type":"ethernet"
}
},
"vpn-network-accesses":{
"vpn-network-access":[
{
"id":"2/1/1.1",
"interface-id":"2/1/1",
"description":"Interface to CE2",
"active-vpn-node-profile":"simple-\
profile",
"status":{
"admin-status":{
"status":"ietf-vpn-common:\
admin-up"
},
"ietf-ac-glue:ac-svc-ref":"AC2"
}
},
{
"id":"2/1/2.1",
"interface-id":"2/1/1",
"description":"Interface to CE4",
"active-vpn-node-profile":"simple-\
profile",
"status":{
"admin-status":{
"status":"ietf-vpn-common:\
admin-up"
},
"ietf-ac-glue:ac-svc-ref":"AC4"
}
}
]
}
}
]
}
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}
]
}
}
}
Figure 5: Example of VPWS Creation with AC Service References
A.2. Network and Service AC References
Let's consider the example depicted in Figure 6 with two customer
terminating points (CE1 and CE2). Let's also assume that the bearers
to attach these CEs to the provider network are already in place.
References to the identify these bearers are shown in the figure.
.-----. .--------------. .-----.
.----. | PE1 +===+ +===+ PE2 | .----.
| CE1+------+"450"| | MPLS | |"451"+------+ CE2|
'----' ^ '-----' | | '-----' ^ '----'
| | Core | |
Bearer:1234 '--------------' Bearer:5678
Figure 6: Topology Example
The AC service model [I-D.ietf-opsawg-teas-attachment-circuit] can be
used by the provider to manage and expose the ACs over existing
bearers as shown in Figure 7.
{
"ietf-ac-svc:attachment-circuits":{
"ac-group-profile":[
{
"name":"an-ac-profile",
"l2-connection":{
"encapsulation":{
"encap-type":"ietf-vpn-common:dot1q",
"dot1q":{
"tag-type":"ietf-vpn-common:c-vlan",
"cvlan-id":550
}
}
},
"service":{
"mtu":1550,
"svc-pe-to-ce-bandwidth":{
"pe-to-ce-bandwidth":[
{
"bw-type":"ietf-vpn-common:bw-per-port",
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"cir":"20480000"
}
]
},
"svc-ce-to-pe-bandwidth":{
"ce-to-pe-bandwidth":[
{
"bw-type":"ietf-vpn-common:bw-per-port",
"cir":"20480000"
}
]
},
"qos":{
"qos-profile":{
"qos-profile":[
{
"profile":"QoS_Profile_A",
"direction":"ietf-vpn-common:both"
}
]
}
}
}
}
],
"ac":[
{
"name":"ac-1",
"description":"First attachment",
"ac-group-profile":["an-ac-profile"],
"l2-connection":{
"bearer-reference":"1234"
}
},
{
"name":"ac-2",
"description":"Second attachment",
"ac-group-profile": ["an-ac-profile"],
"l2-connection":{
"bearer-reference":"5678"
}
}
]
}
}
Figure 7: ACs Created Using ACaaS
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Let's now consider that the customer wants to request a VPLS instance
between the sites as shown in Figure 8.
|---------- VPLS "1543" ----------|
.-----. .--------------. .-----.
.----. AC1 | PE1 +===+ +===+ PE2 | AC2 .----.
| CE1+------+"450"| | MPLS | |"451"+------+ CE2|
'----' ^ '-----' | | '-----' ^ '----'
| | Core | |
Bearer:1234 '--------------' Bearer:5678
Figure 8: Example of VPLS
To that aim, existing ACs are referenced during the creation of the
VPLS instance using the L2NM and the "ietf-ac-glue" as shown in
Figure 9.
{
"ietf-l2vpn-ntw:l2vpn-ntw": {
"vpn-services": {
"vpn-service": [
{
"vpn-id": "1543",
"vpn-name": "CORPO-EXAMPLE",
"customer-name": "EXAMPLE",
"vpn-type": "ietf-vpn-common:vpls",
"vpn-service-topology": "ietf-vpn-common:hub-spoke",
"bgp-ad-enabled": false,
"signaling-type": "ietf-vpn-common:ldp-signaling",
"global-parameters-profiles": {
"global-parameters-profile": [
{
"profile-id": "simple-profile",
"ce-vlan-preservation": true,
"ce-vlan-cos-preservation": true
}
]
},
"vpn-nodes": {
"vpn-node": [
{
"vpn-node-id": "450",
"ne-id": "2001:db8:5::1",
"role": "ietf-vpn-common:hub-role",
"status": {
"admin-status": {
"status": "ietf-vpn-common:admin-up"
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}
},
"active-global-parameters-profiles": {
"global-parameters-profile": [
{
"profile-id": "simple-profile"
}
]
},
"signaling-option": {
"ldp-or-l2tp": {
"t-ldp-pw-type": "vpls-type",
"pw-peer-list": [
{
"peer-addr": "2001:db8:50::1",
"vc-id": "1543"
}
]
}
},
"vpn-network-accesses": {
"ietf-ac-glue:ac-svc-ref": ["ac-1"]
}
},
{
"vpn-node-id": "451",
"ne-id": "2001:db8:50::1",
"role": "ietf-vpn-common:spoke-role",
"status": {
"admin-status": {
"status": "ietf-vpn-common:admin-up"
}
},
"active-global-parameters-profiles": {
"global-parameters-profile": [
{
"profile-id": "simple-profile"
}
]
},
"signaling-option": {
"ldp-or-l2tp": {
"t-ldp-pw-type": "vpls-type",
"pw-peer-list": [
{
"peer-addr": "2001:db8:5::1",
"vc-id": "1543"
}
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]
}
},
"vpn-network-accesses": {
"ietf-ac-glue:ac-svc-ref": ["ac-2"]
}
}
]
}
}
]
}
}
}
Figure 9: Example of a VPLS Request Using L2NM and AC Glue
(Message Body)
Note that before implementing the VPLS instance creation request, the
provider service orchestrator may first check if the VPLS service can
be provided to the customer using the target delivery locations. The
orchestrator uses the SAP model [RFC9408] as exemplified in
Figure 10. This example assumes that the query concerns only PE1. A
similar query can be issued for PE2.
{
"ietf-sap-ntw:service":[
{
"service-type":"ietf-vpn-common:vpls",
"sap":[
{
"sap-id":"sap#1",
"peer-sap-id":[
"ce-1"
],
"description":"A parent SAP",
"attachment-interface":"GE0/6/1",
"interface-type":"ietf-sap-ntw:phy",
"role":"ietf-sap-ntw:uni",
"allows-child-saps":true,
"sap-status":{
"status":"ietf-vpn-common:op-up"
}
}
]
}
]
}
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Figure 10: Example of SAP Response (Message Body)
The response in Figure 10 indicates that the VPLS service can be
delivered to CE1. [I-D.ietf-opsawg-ntw-attachment-circuit] can be
also used to access AC-related details that are bound to the target
SAP (Figure 11).
{
"ietf-sap-ntw:service":[
{
"service-type":"ietf-vpn-common:vpls",
"sap":[
{
"sap-id":"sap#1",
"peer-sap-id":[
"ce-1"
],
"description":"A parent SAP",
"attachment-interface":"GE0/6/1",
"interface-type":"ietf-sap-ntw:phy",
"role":"ietf-sap-ntw:uni",
"allows-child-saps":true,
"sap-status":{
"status":"ietf-vpn-common:op-up"
}
},
{
"sap-id":"sap#11",
"description":"A child SAP",
"parent-termination-point":"GE0/6/4",
"attachment-interface":"GE0/6/4.2",
"interface-type":"ietf-sap-ntw:logical",
"encapsulation-type":"ietf-vpn-common:vlan-type",
"sap-status":{
"status":"ietf-vpn-common:op-up"
},
"ietf-ac-ntw:ac":[
{
"ac-ref":"ac-1",
"node-ref":"example:pe2",
"network-ref":"example:an-id"
}
]
}
]
}
]
}
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Figure 11: Example of AC Network Response with SAP (Message Body)
The provisioned AC at PE1 can be retrieved using the AC network model
as depicted in Figure 12.
{
"ietf-ac-ntw:ac":[
{
"name":"ac-11",
"ac-svc-ref":"ac-1",
"peer-sap-id":[
"ce-1"
],
"status":{
"admin-status":{
"status":"ietf-vpn-common:admin-up"
},
"oper-status":{
"status":"ietf-vpn-common:op-up"
}
},
"l2-connection":{
"encapsulation":{
"encap-type":"ietf-vpn-common:dot1q",
"dot1q":{
"tag-type":"ietf-vpn-common:c-vlan",
"cvlan-id":550
}
},
"bearer-reference":"1234"
},
"service":{
"mtu":1550,
"svc-pe-to-ce-bandwidth":{
"pe-to-ce-bandwidth":[
{
"cir":"20480000"
}
]
},
"svc-ce-to-pe-bandwidth":{
"ce-to-pe-bandwidth":[
{
"cir":"20480000"
}
]
},
"qos":{
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"qos-profile":{
"qos-profile":[
{
"qos-profile-ref":"QoS_Profile_A",
"network-ref":"example:an-id",
"direction":"ietf-vpn-common:both"
}
]
}
}
}
}
]
}
Figure 12: Example of AC Network Response (Message Body)
Acknowledgments
Thanks to Bo Wu for the review and comments.
Thanks to Martin Björklund for the yangdoctors review.
Authors' Addresses
Mohamed Boucadair (editor)
Orange
Email: mohamed.boucadair@orange.com
Richard Roberts
Juniper
Email: rroberts@juniper.net
Samier Barguil Giraldo
Nokia
Email: samier.barguil_giraldo@nokia.com
Oscar Gonzalez de Dios
Telefonica
Email: oscar.gonzalezdedios@telefonica.com
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