Internet DRAFT - draft-boro-opsawg-ac-lxsm-lxnm-glue
draft-boro-opsawg-ac-lxsm-lxnm-glue
OPSAWG M. Boucadair
Internet-Draft Orange
Intended status: Standards Track R. Roberts
Expires: 24 January 2024 Juniper
S. B. Giraldo
Nokia
O. G. D. Dios
Telefonica
23 July 2023
A YANG Data Model for Augmenting VPN Service and Network Models with
Attachment Circuits
draft-boro-opsawg-ac-lxsm-lxnm-glue-00
Abstract
The document specifies a module that updates existing service and
network VPN modules with the required information to bind specific
services to ACs that are created using the Attachment Circuit (AC)
service model.
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 24 January 2024.
Copyright Notice
Copyright (c) 2023 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 Service
Provisioning . . . . . . . . . . . . . . . . . . . . . . 4
4. Module Tree Structure . . . . . . . . . . . . . . . . . . . . 5
5. The AC Glue ("ietf-ac-glue") YANG Module . . . . . . . . . . 6
6. Security Considerations . . . . . . . . . . . . . . . . . . . 9
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
8.1. Normative References . . . . . . . . . . . . . . . . . . 10
8.2. Informative References . . . . . . . . . . . . . . . . . 11
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 12
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction
The document specifies a YANG module that updates existing service
and 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.boro-opsawg-teas-attachment-circuit],
specifically the following modules are augmented:
* The Layer 2 Service Model (L2SM) [RFC8466]
* The Layer 3 Service Model (L3SM) [RFC8299]
* The Layer 2 Network Model (L2NM) [RFC9291]
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* The Layer 3 Network Model (L3NM) [RFC9182]
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.boro-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 SAP.
* 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.
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* 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 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
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 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.
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+---------------+
| 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
4. Module Tree Structure
ACs created using the "ietf-ac-svc" module
[I-D.boro-opsawg-teas-attachment-circuit] can be referenced in other
modules (e.g., L2SM, L3SM, L2NM, L3NM, and Slicing). Some
augmentations are required to that aim as 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
/l2vpn-svc:site-network-access:
+--rw ac-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-ref* ac-svc:attachment-circuit-reference
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-ref* ac-svc:attachment-circuit-reference
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-ref* ac-svc:attachment-circuit-reference
Figure 3: AC Glue Tree Structure
5. The AC Glue ("ietf-ac-glue") YANG Module
<CODE BEGINS>
file ietf-ac-glue@2023-07-13.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
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"RFC 9291: A YANG Network Data Model for Layer 2 VPNs";
}
import ietf-ac-svc {
prefix ac-svc;
reference
"RFC XXXX: YANG Service Data Models 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) 2023 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 2023-07-13 {
description
"Initial revision.";
reference
"RFC XXXX: A YANG Data Model for Augmenting VPN Service
and Network Models with Attachment Circuits";
}
grouping ac-glue {
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description
"A set of AC-related data.";
leaf-list ac-ref {
type ac-svc:attachment-circuit-reference;
description
"A reference to the AC as exposed at the service that
was provisionned using the AC module.";
}
}
augment "/l2vpn-svc:l2vpn-svc"
+ "/l2vpn-svc:sites/l2vpn-svc:site"
+ "/l2vpn-svc:site-network-accesses/l2vpn-svc:site-network-access" {
description
"Augments VPN network access with AC provisioning details.";
uses ac-glue;
}
augment "/l3vpn-svc:l3vpn-svc"
+ "/l3vpn-svc:sites/l3vpn-svc:site"
+ "/l3vpn-svc:site-network-accesses/l3vpn-svc:site-network-access" {
description
"Augments VPN network access with AC provisioning details.";
uses ac-glue;
}
augment "/l2nm:l2vpn-ntw/l2nm:vpn-services/l2nm:vpn-service"
+ "/l2nm:vpn-nodes/l2nm:vpn-node"
+ "/l2nm:vpn-network-accesses/l2nm:vpn-network-access" {
description
"Augments VPN network access with AC provisioning details.";
uses ac-glue;
}
augment "/l3nm:l3vpn-ntw/l3nm:vpn-services/l3nm:vpn-service"
+ "/l3nm:vpn-nodes/l3nm:vpn-node"
+ "/l3nm:vpn-network-accesses/l3nm:vpn-network-access" {
description
"Augments VPN network access with AC provisioning details.";
uses ac-glue;
}
}
<CODE ENDS>
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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-svc" module:
* TBC
* TBC
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-svc"
module:
* TBC
* TBC
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.
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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
Maintained by IANA? N
Namespace: urn:ietf:params:xml:ns:yang:ietf-ac-glue
Prefix: ac-glue
Reference: RFC xxxx
8. References
8.1. Normative References
[I-D.boro-opsawg-teas-attachment-circuit]
Boucadair, M., Roberts, R., de Dios, O. G., Barguil, S.,
and B. Wu, "YANG Data Models for 'Attachment Circuits'-as-
a-Service (ACaaS)", Work in Progress, Internet-Draft,
draft-boro-opsawg-teas-attachment-circuit-07, 10 July
2023, <https://datatracker.ietf.org/doc/html/draft-boro-
opsawg-teas-attachment-circuit-07>.
[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>.
[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>.
[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>.
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[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>.
[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
[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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Appendix A. Examples
Add some examples.
Acknowledgments
Thanks to TBC for the comments.
Authors' Addresses
Mohamed Boucadair
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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