| Internet-Draft | AC Glue for VPN Models | July 2023 |
| Boucadair, et al. | Expires 24 January 2024 | [Page] |
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.¶
This note is to be removed before publishing as an RFC.¶
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Source for this draft and an issue tracker can be found at https://github.com/boucadair/attachment-circuit-model.¶
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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 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.¶
Figure 1 depicts two target topology flavors that involve ACs. These topologies have the following characteristics:¶
┌───────┐ ┌────────────────────┐ ┌───────┐
│ ├──────┐ │ ├────AC─────┤ │
│ CE#1 │ │ │ ├────AC─────┤ CE#3 |
└───────┘ │ │ │ └───────┘
├───AC────┤ Network │
┌───────┐ │ │ │
│ │ │ │ │ ┌───────┐
│ CE#2 ├──────┘ │ │─────AC────┤ CE#4 │
└───────┘ │ │ └────+──┘
└───────────+────────┘ |
| |
└────────────AC───────────┘
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.¶
+---------------+
| 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
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.¶
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
<CODE BEGINS> file [email protected] 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"; } 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:[email protected]> Editor: Mohamed Boucadair <mailto:[email protected]> Author: Richard Roberts <mailto:[email protected]> Author: Samier Barguil <mailto:[email protected]> Author: Oscar Gonzalez de Dios <mailto:[email protected]>"; 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 { 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>¶
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:¶
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:¶
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 Maintained by IANA? N Namespace: urn:ietf:params:xml:ns:yang:ietf-ac-glue Prefix: ac-glue Reference: RFC xxxx¶
Add some examples.¶
Thanks to TBC for the comments.¶