Internet-Draft | ACaaS | March 2023 |
Boucadair, et al. | Expires 3 September 2023 | [Page] |
- Workgroup:
- OPSAWG
- Internet-Draft:
- draft-boro-opsawg-teas-attachment-circuit-04
- Published:
- Intended Status:
- Standards Track
- Expires:
YANG Data Models for 'Attachment Circuits'-as-a-Service (ACaaS)
Abstract
This document specifies a YANG service data model for Attachment Circuits (ACs). This model can be used for the provisioning of ACs prior or during service provisioning (e.g., Network Slice Service). The document specifies also a module that updates other service and network modules with the required information to bind specific services to ACs that are created using the AC service model.¶
Also, the document specifies a set of reusable groupings. Whether a service model reuses structures defined in the AC models or simply include an AC reference is a design choice of these service models. Relying upon the AC service model to manage ACs over which a service is delivered has the merit to decorrelate the management of a service vs. upgrade the AC components to reflect recent AC technologies or features.¶
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."¶
This Internet-Draft will expire on 3 September 2023.¶
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.¶
1. Introduction
1.1. Scope and Intended Use
Connectivity services are provided by networks to customers via dedicated terminating points (e.g., service functions, customer edges (CEs), peer ASBRs, data centers gateways, Internet Exchange Points). A connectivity service is basically about ensuring data transfer received from (or destined to) a given terminating point to (or from) other terminating points that belong to the same customer/service, an interconnection node, or an ancillary node. A set of objectives for the connectivity service may eventually be negotiated and agreed upon between a customer a network provider. For that data transfer to take place within the provider network, it is assumed that adequate setup is provisioned over the links that connect customer terminating points and a provider network so that data can be successfully exchanged over these links. The required setup is referred to in this document as Attachment Circuits (ACs), while the underlying link is referred to as "bearers".¶
This document adheres to the definition of an Attachment Circuit as provided in Section 1.2 of [RFC4364], especially:¶
-
Routers can be attached to each other, or to end systems, in a variety of different ways: PPP connections, ATM Virtual Circuits (VCs), Frame Relay VCs, ethernet interfaces, Virtual Local Area Networks (VLANs) on ethernet interfaces, GRE tunnels, Layer 2 Tunneling Protocol (L2TP) tunnels, IPsec tunnels, etc. We will use the term "attachment circuit" to refer generally to some such means of attaching to a router. An attachment circuit may be the sort of connection that is usually thought of as a "data link", or it may be a tunnel of some sort; what matters is that it be possible for two devices to be network layer peers over the attachment circuit.¶
When a customer requests a new value-added service, the service can be bound to existing attachment circuits or trigger the instantiation of new attachment circuits. The provisioning of an value-added service should, thus, accommodate both deployments.¶
Also, because the instantiation of an attachment circuit requires coordinating the provisioning of endpoints that might not belong to the same administrative entity (customer vs. provider or distinct operational teams within the same provider, etc.), programmatic means to expose 'attachment circuits'-as-a-service will greatly simplify the provisioning of value added services that will be delivered over an attachment circuits.¶
This document specifies a YANG service data model ("ietf-ac-svc") for managing attachment circuits that are exposed by a network to its customers (e.g., an enterprise site, a network function, a hosting infrastructure, a peer network provider). The model can be used for the provisioning of ACs prior or during advanced service provisioning (e.g., Network Slice Service).¶
The "ietf-ac-svc" includes a set of reusable groupings. Whether a service model reuses structures defined in the "ietf-ac-svc" or simply includes an AC reference (that was communicated during AC service instantiation) is a design choice of these service models. Relying upon the AC service model to manage ACes over which services are delivered has the merit to decorrelate the management of the (core) service vs. upgrade the AC components to reflect recent AC technologies or new features (e.g., new encryption scheme, additional routing protocol). This document favors the approach of completely relying upon the AC service model instead of duplicating into specific modules of advanced services that are delivered over an Attachment Circuit.¶
Because the provisioning of an AC requires a bearer to be in place, this document allows customers to manage their bearer requests by means of a new module, called "ietf-bearer-svc". The customers can then retrieve a provider-assigned bearer reference that they will include in their AC service requests.¶
A AC service request can provide a reference to a bearer or a set of peer SAPs. Both schemes are supported in the AC service model.¶
Each AC is identified with a unique identifier within a (provider) domain. From a network provider standpoint, an AC can be bound to a single or multiple Service Attachment Points (SAPs) [I-D.ietf-opsawg-sap]. Likewise, a SAP can be bound to one or multiple ACs. However, the mapping between an AC and a PE in the provider network that terminates that AC is hidden to the application that makes use of the AC service model. Such mapping information is internal to the network controllers. As such, the details about the (node-specific) attachment interfaces are not exposed in the AC service model.¶
The AC service model does not make any assumption about the internal structure or even the nature or the services that will be delivered over an attachment circuit. Customers do not have access to that network view other than the ACes that the ordered. For example, the AC service model can be used to provision a set of ACes to connect multiple sites (Site1, Site2, ..., SiteX) for customer that also requested VPN services. If these provisioning of these services require specific configured on ASBR nodes, such configuration is handled at the network level and is not exposed at the service level to the customer. However, the network controller will have access to such a view as the service points in these ASBRs will be exposed as SAPs with "role" set to "ietf-sap-ntw:nni" [I-D.ietf-opsawg-sap].¶
The AC service model can be used in a variety of contexts, such as (but not limited to) those provided in Appendix A:¶
- Request an attachment circuit for a known peer SAP (Appendix A.3).¶
- Instantiate multiple attachment circuits over the same bearer (Appendix A.4).¶
- Control the precedence over multiple attachment circuits (Appendix A.5).¶
- Bind a slice service to a set of pre-provisioned attachment circuits (Appendix A.9).¶
- Connect a Cloud Infrastructure to a service provider network (Appendix A.10).¶
These examples use the IPv4 address blocks reserved for documentation [RFC5737], the IPv6 prefix reserved for documentation [RFC3849], and the Autonomous System (AS) numbers reserved for documentation [RFC5398].¶
The YANG data models in this document conform to the Network Management Datastore Architecture (NMDA) defined in [RFC8342].¶
1.2. Position ACaaS vs. Other Data Models
The model specified in this document is not a network model [RFC8969]. As such, the model does not expose details related to specific nodes in the provider's network that terminate a requested AC. The mapping between an AC as seen by a customer and the network implementation of an AC is maintained by the network controllers and not exposed to the customer. Such a mapping can be maintained using a variety of network models (e.g., SAPs) AC Network Model [I-D.boro-opsawg-ntw-attachment-circuit], etc.¶
The AC service model is not a device model. A network provider may use a variety of device models (e.g., Routing management [RFC8349] or BGP [I-D.ietf-idr-bgp-model]) to provision an AC service.¶
1.2.1. Why Not Using L2SM as Reference Data Model for ACaaS?
The L2SM [RFC8466] covers some AC-related considerations. Nevertheless, the L2SM structure is too layer 2 centric. For example, the L2SM part does not cover Layer 3 provisioning, which is required for the instantiation of typical ACs.¶
1.2.2. Why Not Using L3SM as Reference Data Model for ACaaS?
Similar to the L2NM, the L3SM [RFC8299] covers some AC-related considerations. Nevertheless, the L3SM structure does not adequately cover layer 2 provisioning matters. Moreover, the L3SM is drawn with conventional L3VPN deployments in mind and, as such, has some limitations for instantiating ACs in other deployment contexts (e.g., cloud environments). For example, the L3SM does not allow to provision multiple BGP sessions over the same AC.¶
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 the following terms:¶
- Bearer:
-
A physical or logical link that connects a customer node (or site) to a provider network. A bearer can be a wireless or wired link. One or multiple technologies can be used to build a bearer. The bearer type can be specified by a customer.¶
-
The operator allocates a unique bearer reference to identify a bearer within its network (e.g., customer line identifier). Such a reference can be retrieved by a customer and used in subsequent service placement requests to unambiguously identify where a service is to be bound.¶
-
The concept of bearer can be generalized to refer to the required underlying connection for the provisioning of an attachment circuit. One or multiple attachment circuits may be hosted over the same bearer (e.g., multiple VLANs on the same bearer that is provided by a physical link).¶
- Network controller:
-
Denotes a functional entity responsible for the management of the service provider network.¶
- Service orchestrator:
-
Refers to a functional entity that interacts with the customer of a network service. The service orchestrator is typically responsible for the attachment circuits, the Provider Edge (PE) selection, and requesting the activation of the requested service to a network controller.¶
- Service provider network:
-
A network that is able to provide network services (e.g., Layer 2 VPN, Layer 3, and Network Slice Services).¶
- Service provider:
-
A service provider that offers network services (e.g., Layer 2 VPN, Layer 3, and Network Slice Services).¶
3. Sample Uses of the Data Models
3.1. ACs Terminated by One or Multiple Customer Devices
Figure 1 depicts two target topology flavors that involve ACs. These topologies are characterized as follows:¶
- A Customer Terminating Point (CTP) may be a physical node or a logical entity. A CTP is seen by the network as a peer SAP.¶
- The same AC request may include one or multiple ACs that may belong to one or both of these flavors. For the sake of simplfying the illustration, only a subset of these ACs is shown in Figure 1.¶
- CTPs may be dedicated to one single service or host multiple services (e.g., service functions [RFC7665]).¶
- A single AC (as seen by a network provider) may be bound to one or multiple peer SAPs (e.g., CTP#1 and CTP#2). For example, and as discussed in [RFC4364], multiple CTPs (CEs) can be attached to a PE over the same attachment circuit. This is typically implemented if the layer 2 infrastructure between the CTP and the network provides a multipoint service.¶
- The same CTP may terminate multiple ACs. These ACes may be over the same or distinct bearers.¶
- The customer may request protection schemes where the ACs bound to a customer endpoints are terminated by the same PE (e.g., CTP#3), distinct PEs (e.g., CTP#34), etc.¶
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, including the flow put in place for the provisioning of advanced network services and how they are bound to an attachment circuit. For example, the same attachment circuit may be used to host multiple 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 the request a base attachment circuit to be put in place, and then refer to that base AC when requesting services that are bound to that AC.¶
Figure 2 shows the positioning of the AC service model is the overall service delivery process.¶
4. Description of the Data Models
4.1. The Bearer Service ("ietf-bearer-svc") YANG Module
Figure 3 shows the tree for managing the bearers (that is, the properties of the attachment that are below Layer 3). A bearer can be a wireless or wired link. A reference to a bearer is generated by the operator. Such a reference can be used, e.g., in a subsequent service request to create an AC. The anchroing of the AC can also be achieved by indicating (with or without a bearer reference), a peer SAP identifier (e.g., An identifier of a Service Function).¶
The same customer site (CE, NF, etc.) can terminate one or multiple bearers; each of them uniquely identified by a refrence that is assigned by the network provider. These bearers can terminate on the same or distinct network nodes. CEs that terminate multiple bearers are called multi-homed CEs.¶
4.2. The Attachment Circuit Service ("ietf-ac-svc") YANG Module
4.2.1. Overall Structure
The overall tree structure of the AC service module is shown in Figure 4.¶
> Note: The full ACaaS tree is available at {{AC-SVC-Tree}}. The full reusable groupings defined in the ACaaS module are shown in {{AC-SVC-GRP}}.¶
Each AC is identified with a unique identifier within a domain. The mapping between this AC and a local PE that terminates the AC is hidden to the application that makes use of the AC service model. This information is internal to the Network controller. As such, the details about the (node-specific) attachment interfaces are not exposed in this service model.¶
The AC service model uses groupings and types defined in the AC common model [I-D.boro-opsawg-teas-common-ac]. Therefore, the description of these nodes are not reiterated in the following subsections.¶
4.2.2. Service Profiles
4.2.2.1. Description
The 'specific-provisioning-profiles' container (Figure 5) can be used by a service provider to maintain a set of specific profiles that are similar to those defined in [RFC9181]. The exact definition of the profiles is local to each service provider. The model only includes an identifier for these profiles in order to facilitate identifying and binding local policies when building an AC.¶
As shown in Figure 5, two profile types can be defined: 'specific-provisioning-profiles' and 'service-provisioning-profiles'. Whether only specific profiles, service profiles, or a combination thereff are used is local to each service provider.¶
The following specific rovisioning profiles can be defined:¶
- 'external-connectivity-identifier':
-
Refers to a profile that defines the external connectivity provided to a site that is connected via an AC. External connectivity may be access to the Internet or restricted connectivity, such as access to a public/private cloud.¶
- 'encryption-profile-identifier':
-
Refers to a set of policies related to the encryption setup that can be applied when provisioning an AC.¶
- 'qos-profile-identifier':
-
Refers to a set of policies, such as classification, marking, and actions (e.g., [RFC3644]).¶
- 'bfd-profile-identifier':
-
Refers to a set of Bidirectional Forwarding Detection (BFD) policies [RFC5880] that can be invoked when building an AC.¶
- 'forwarding-profile-identifier':
-
Refers to the policies that apply to the forwarding of packets conveyed within an AC. Such policies may consist, for example, of applying Access Control Lists (ACLs).¶
- 'routing-profile-identifier':
-
Refers to a set of routing policies that will be invoked (e.g., BGP policies) when building an AC.¶
4.2.2.2. Referencing Service/Specific Profiles
All these profiles are uniquely identified by the NETCONF/RESTCONF server by an identifier. To ease referencing these profiles by other data models, specific typedefs are defined for each of these profiles. Likewise, an attachment circuit referenc typedef is defiened when referencing a (global) attachment circuit by its name is required. These typedefs SHOULD be used when other modules need a reference to one of these profiles or attahment circuits.¶
4.2.4. Attachment Circuits
The structure of 'attachment-circuits' is shown in Figure 6.¶
4.2.4.1. AC Placement Constraints
The structure of 'placement-constraints' is shown in Figure 7.¶
4.2.4.2. Layer 2 Connection Structure
As shown in the tree depicted in Figure 8, the 'l2-connection' container defines service parameters to enable such connectivity at Layer 2.¶
4.2.4.3. Layer 3 Connection Structure
The 'l3-connection' container defines a set of service parameters to enable Layer 3 connectivity for an AC. Both IPv4 and IPv6 parameters are supported.¶
Figure 9 shows the structure of the IPv4 connection.¶
Figure 10 shows the structure of the IPv6 connection.¶
4.2.4.4. Routing
As shown in the tree depicted in Figure 11, the 'routing-protocols' container defines th erequired parameters to enable the required routing features for an AC. One or more routing protocols can be associated with an AC. Such routing protocols are then enabled between a PE and the CE. Each routing instance is uniquely identified to accommodate scenarios where multiple instances of the same routing protocol have to be configured on the same link.¶
In addition to static routing, the module supports BGP, OSPF, IS-IS, and RIP.¶
The model also supports the Virtual Router Redundancy Protocol (VRRP) [RFC5798] on an AC.¶
For all supported routing protocols, 'address-family' indicates whether IPv4, IPv6, or both address families are to be activated. For example, this parameter is used to determine whether RIPv2 [RFC2453], RIP Next Generation (RIPng), or both are to be enabled [RFC2080].¶
Similar to [RFC9182], this version of the ACaaS assumes that parameters specific to the TCP-AO are preconfigured as part of the key chain that is referenced in the ACaaS. No assumption is made about how such a key chain is preconfigured. However, the structure of the key chain should cover data nodes beyond those in [RFC8177], mainly SendID and RecvID (Section 3.1 of [RFC5925]).¶
5. YANG Modules
5.1. The Bearer Service ("ietf-bearer-svc") YANG Module
This module uses types defined in [RFC6991] and [RFC9181].¶
<CODE BEGINS> file "ietf-bearer-svc@2022-11-30.yang" module ietf-bearer-svc { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-bearer-svc"; prefix bearer-svc; import ietf-vpn-common { prefix vpn-common; reference "RFC 9181: A Common YANG Data Model for Layer 2 and Layer 3 VPNs"; } import ietf-ac-common { prefix ac-common; reference "RFC xxxx: A YANG Service 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: Oscar Gonzalez de Dios <mailto:oscar.gonzalezdedios@telefonica.com> Author: Samier Barguil <mailto:ssamier.barguil_giraldo@nokia.com> Author: Bo Wu <mailto:lana.wubo@huawei.com>"; description "This YANG module defines a generic YANG model for exposing network bearers as a service. 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 xxx; see the RFC itself for full legal notices."; revision 2022-11-30 { description "Initial revision."; reference "RFC xxxx: A YANG Service Data Model for Attachment Circuits"; } // Identities identity bearer-type { description "Base identity for bearers type."; } identity ethernet { base bearer-type; description "Ethernet."; } identity wireless { base bearer-type; description "Wireless."; } container bearers { description "Main container for the bearers."; list bearer { key "id"; description "Maintains a list of bearers."; leaf id { type string; description "An identifier of the bearer."; } leaf description { type string; description "A description of this bearer."; } container customer-device { description "Identification of the customer device that terminates the bearer."; leaf device-id { type string; description "Identifier for the device."; } container location { description "Location of the node."; leaf address { type string; description "Address (number and street) of the site."; } leaf postal-code { type string; description "Postal code of the site."; } leaf state { type string; description "State of the site. This leaf can also be used to describe a region for a country that does not have states."; } leaf city { type string; description "City of the site."; } leaf country-code { type string { pattern '[A-Z]{2}'; } description "Country of the site. Expressed as ISO ALPHA-2 code."; } } } leaf requested-type { type identityref { base bearer-type; } description "Type of the requested bearer (e.g., Ethernet, or wireless)"; } leaf bearer-reference { if-feature "vpn-common:bearer-reference"; type string; config false; description "This is an internal reference for the service provider to identify the bearers."; } uses ac-common:op-instructions; } } } <CODE ENDS>¶
5.2. The AC Service ("ietf-ac-svc") YANG Module
This module uses types defined in [RFC6991], [RFC9181], [RFC8177], and [I-D.boro-opsawg-teas-common-ac].¶
<CODE BEGINS> file "ietf-ac-svc@2022-11-30.yang" module ietf-ac-svc { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-ac-svc"; prefix ac-svc; import ietf-ac-common { prefix ac-common; reference "RFC CCCC: A Common YANG Data Model for Attachment Circuits"; } import ietf-vpn-common { prefix vpn-common; reference "RFC 9181: A Common YANG Data Model for Layer 2 and Layer 3 VPNs"; } import ietf-inet-types { prefix inet; reference "RFC 6991: Common YANG Data Types, Section 4"; } import ietf-key-chain { prefix key-chain; reference "RFC 8177: YANG Data Model for Key Chains"; } 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: Oscar Gonzalez de Dios <mailto:oscar.gonzalezdedios@telefonica.com> Author: Samier Barguil <mailto:ssamier.barguil_giraldo@nokia.com> Author: Bo Wu <mailto:lana.wubo@huawei.com>"; description "This YANG module defines a YANG model for exposing attachment circuits (ACs) as a service. 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 2022-11-30 { description "Initial revision."; reference "RFC XXXX: A YANG Service Data Model for Attachment Circuits"; } /* A set of typedefs to ease referencing cross-modules */ typedef attachment-circuit-reference { type leafref { path "/ac-svc:attachment-circuits/ac-svc:ac/ac-svc:name"; } description "Defines a reference to an attachment circuit that can be used by other modules."; } /*typedef ac-global-profile-reference { type leafref { path "/ac-svc:attachment-circuits/ac-global-profile/id"; } description "Defines a reference to a gloabl attachment circuit that can be used by other modules."; }*/ typedef ac-group-reference { type leafref { path "/ac-svc:attachment-circuits/ac-group-profile/name"; } description "Defines a reference to an attachment circuit profile."; } typedef encryption-profile-reference { type leafref { path "/ac-svc:specific-provisioning-profiles/valid-provider-identifiers" + "/encryption-profile-identifier/id"; } description "Defines a type to an encryption profile for referencing purposes."; } typedef qos-profile-reference { type leafref { path "/ac-svc:specific-provisioning-profiles/valid-provider-identifiers" + "/qos-profile-identifier/ac-svc:id"; } description "Defines a type to a QoS profile for referencing purposes."; } typedef bfd-profile-reference { type leafref { path "/ac-svc:specific-provisioning-profiles/valid-provider-identifiers" + "/bfd-profile-identifier/ac-svc:id"; } description "Defines a type to a BFD profile for referencing purposes."; } typedef forwarding-profile-reference { type leafref { path "/ac-svc:specific-provisioning-profiles/valid-provider-identifiers" + "/forwarding-profile-identifier/ac-svc:id"; } description "Defines a type to a forwarding profile for referencing purposes."; } typedef routing-profile-reference { type leafref { path "/ac-svc:specific-provisioning-profiles/valid-provider-identifiers" + "/routing-profile-identifier/id"; } description "Defines a type to a routing profile for referencing purposes."; } /******************** Reusable groupings ********************/ // Basic Layer 2 connection grouping l2-connection-basic { description "Defines Layer 2 protocols and parameters that can be factorized when provisioning Layer 2 connectivity among multiple ACs."; container encapsulation { description "Container for Layer 2 encapsulation."; leaf type { type identityref { base vpn-common:encapsulation-type; } description "Encapsulation type."; } container dot1q { when "derived-from-or-self(../type, 'vpn-common:dot1q')" { description "Only applies when the type of the tagged interface is 'dot1q'."; } description "Tagged interface."; uses ac-common:dot1q; } container qinq { when "derived-from-or-self(../type, 'vpn-common:qinq')" { description "Only applies when the type of the tagged interface is 'qinq'."; } description "Includes QinQ parameters."; uses ac-common:qinq; } } } // Full Layer 2 connection grouping l2-connection { description "Defines Layer 2 protocols and parameters that are used to enable AC connectivity."; container encapsulation { description "Container for Layer 2 encapsulation."; leaf type { type identityref { base vpn-common:encapsulation-type; } description "Encapsulation type."; } container dot1q { when "derived-from-or-self(../type, 'vpn-common:dot1q')" { description "Only applies when the type of the tagged interface is 'dot1q'."; } description "Tagged interface."; uses ac-common:dot1q; } container priority-tagged { when "derived-from-or-self(../type, " + "'vpn-common:priority-tagged')" { description "Only applies when the type of the tagged interface is 'priority-tagged'."; } description "Priority-tagged interface."; uses ac-common:priority-tagged; } container qinq { when "derived-from-or-self(../type, 'vpn-common:qinq')" { description "Only applies when the type of the tagged interface is 'qinq'."; } description "Includes QinQ parameters."; uses ac-common:qinq; } } choice l2-service { description "The Layer 2 connectivity service can be provided by indicating a pointer to an L2VPN or by specifying a Layer 2 tunnel service."; container l2-tunnel-service { description "Defines a Layer 2 tunnel termination. It is only applicable when a tunnel is required."; uses ac-common:l2-tunnel-service; } case l2vpn { leaf l2vpn-id { type vpn-common:vpn-id; description "Indicates the L2VPN service associated with an Integrated Routing and Bridging (IRB) interface."; } } } leaf bearer-reference { if-feature "vpn-common:bearer-reference"; type string; description "This is an internal reference for the service provider to identify the bearer associated with this AC."; } } // Basic IP connection grouping ip-connection-basic { description "Defines basic IP connection parameters."; container ipv4 { if-feature "vpn-common:ipv4"; description "IPv4-specific parameters."; uses ac-common:ipv4-connection-basic; } container ipv6 { if-feature "vpn-common:ipv6"; description "IPv6-specific parameters."; uses ac-common:ipv6-connection-basic; } } // Full IP connection grouping ip-connection { description "Defines IP connection parameters."; container ipv4 { if-feature "vpn-common:ipv4"; description "IPv4-specific parameters."; uses ac-common:ipv4-connection; } container ipv6 { if-feature "vpn-common:ipv6"; description "IPv6-specific parameters."; uses ac-common:ipv6-connection; } } // Routing protocol list grouping routing-protocol-list { description "List of routing protocols used on the AC."; leaf type { type identityref { base vpn-common:routing-protocol-type; } description "Type of routing protocol."; } list routing-profiles { key "id"; description "Routing profiles."; leaf id { type routing-profile-reference; description "Reference to the routing profile to be used."; } leaf type { type identityref { base vpn-common:ie-type; } description "Import, export, or both."; } } } // Basic routing parameters grouping routing-basic { description "Defines basic parameters for routing protocols."; list routing-protocol { key "id"; description "List of routing protocols used on the AC."; leaf id { type string; description "Unique identifier for the routing protocol."; } uses routing-protocol-list; container bgp { when "derived-from-or-self(../type, 'vpn-common:bgp-routing')" { description "Only applies when the protocol is BGP."; } description "Configuration specific to BGP."; container peer-groups { description "Configuration for BGP peer-groups"; list peer-group { key "name"; description "List of BGP peer-groups configured on the local system - uniquely identified by peer-group name"; uses ac-common:bgp-peer-group-with-name; } } } container ospf { when "derived-from-or-self(../type, " + "'vpn-common:ospf-routing')" { description "Only applies when the protocol is OSPF."; } description "Configuration specific to OSPF."; uses ac-common:ospf-basic; } container isis { when "derived-from-or-self(../type, " + "'vpn-common:isis-routing')" { description "Only applies when the protocol is IS-IS."; } description "Configuration specific to IS-IS."; uses ac-common:isis-basic; } container rip { when "derived-from-or-self(../type, " + "'vpn-common:rip-routing')" { description "Only applies when the protocol is RIP. For IPv4, the model assumes that RIP version 2 is used."; } description "Configuration specific to RIP routing."; leaf address-family { type identityref { base vpn-common:address-family; } description "Indicates whether IPv4, IPv6, or both address families are to be activated."; } } container vrrp { when "derived-from-or-self(../type, " + "'vpn-common:vrrp-routing')" { description "Only applies when the protocol is the Virtual Router Redundancy Protocol (VRRP)."; } description "Configuration specific to VRRP."; reference "RFC 5798: Virtual Router Redundancy Protocol (VRRP) Version 3 for IPv4 and IPv6"; leaf address-family { type identityref { base vpn-common:address-family; } description "Indicates whether IPv4, IPv6, or both address families are to be enabled."; } } } } // Full routing parameters grouping routing { description "Defines routing protocols."; list routing-protocol { key "id"; description "List of routing protocols used on the AC."; leaf id { type string; description "Unique identifier for the routing protocol."; } uses routing-protocol-list; container static { when "derived-from-or-self(../type, " + "'vpn-common:static-routing')" { description "Only applies when the protocol is static routing protocol."; } description "Configuration specific to static routing."; container cascaded-lan-prefixes { description "LAN prefixes from the customer."; uses ac-common:ipv4-static-rtg; uses ac-common:ipv6-static-rtg; } } container bgp { when "derived-from-or-self(../type, " + "'vpn-common:bgp-routing')" { description "Only applies when the protocol is BGP."; } description "Configuration specific to BGP."; container peer-groups { description "Configuration for BGP peer-groups"; list peer-group { key "name"; description "List of BGP peer-groups configured on the local system - uniquely identified by peer-group name"; uses ac-common:bgp-peer-group-with-name; leaf local-address { type inet:ip-address; config false; description "The local IP address that will be used to establish the BGP session."; } uses ac-common:bgp-authentication; } } list neighbor { key "id"; description "List of BGP neighbors."; leaf id { type string; description "A neighbor identifier."; } leaf remote-address { type inet:ip-address; description "The remote IP address of this entry's BGP peer. If this leaf is not present, this means that the primary customer IP address is used as remote IP address."; } leaf local-address { type inet:ip-address; config false; description "The local IP address that will be used to establish the BGP session."; } leaf peer-group { type leafref { path "../../peer-groups/peer-group/name"; } description "The peer-group with which this neighbor is associated."; } uses ac-common:bgp-peer-group-without-name; uses ac-common:bgp-authentication; uses vpn-common:service-status; } } container ospf { when "derived-from-or-self(../type, " + "'vpn-common:ospf-routing')" { description "Only applies when the protocol is OSPF."; } description "Configuration specific to OSPF."; uses ac-common:ospf-basic; uses ac-common:ospf-authentication; uses vpn-common:service-status; } container isis { when "derived-from-or-self(../type, " + "'vpn-common:isis-routing')" { description "Only applies when the protocol is IS-IS."; } description "Configuration specific to IS-IS."; uses ac-common:isis-basic; uses ac-common:isis-authentication; uses vpn-common:service-status; } container rip { when "derived-from-or-self(../type, " + "'vpn-common:rip-routing')" { description "Only applies when the protocol is RIP. For IPv4, the model assumes that RIP version 2 is used."; } description "Configuration specific to RIP routing."; leaf address-family { type identityref { base vpn-common:address-family; } description "Indicates whether IPv4, IPv6, or both address families are to be activated."; } uses ac-common:rip-authentication; uses vpn-common:service-status; } container vrrp { when "derived-from-or-self(../type, " + "'vpn-common:vrrp-routing')" { description "Only applies when the protocol is the Virtual Router Redundancy Protocol (VRRP)."; } description "Configuration specific to VRRP."; reference "RFC 5798: Virtual Router Redundancy Protocol (VRRP) Version 3 for IPv4 and IPv6"; leaf address-family { type identityref { base vpn-common:address-family; } description "Indicates whether IPv4, IPv6, or both address families are to be enabled."; } uses vpn-common:service-status; } } } // Encryption choice grouping encryption-choice { description "Container for the encryption profile."; choice profile { description "Choice for the encryption profile."; case provider-profile { leaf provider-profile { type encryption-profile-reference; description "Reference to a provider encryption profile."; } } case customer-profile { leaf customer-key-chain { type key-chain:key-chain-ref; description "Customer-supplied key chain."; } } } } // Basic security parameters grouping ac-security-basic { description "AC-specific security parameters."; container encryption { if-feature "vpn-common:encryption"; description "Container for AC security encryption."; leaf enabled { type boolean; description "If set to 'true', traffic encryption on the connection is required. Otherwise, it is disabled."; } leaf layer { when "../enabled = 'true'" { description "Included only when encryption is enabled."; } type enumeration { enum layer2 { description "Encryption occurs at Layer 2."; } enum layer3 { description "Encryption occurs at Layer 3. For example, IPsec may be used when a customer requests Layer 3 encryption."; } } description "Indicates the layer on which encryption is applied."; } } container encryption-profile { when "../encryption/enabled = 'true'" { description "Indicates the layer on which encryption is enabled."; } description "Container for the encryption profile."; uses encryption-choice; } } // Basic AC parameter grouping ac-basic { description "Grouping for basic parameters for an attachment circuit."; leaf id { type string; description "An identifier of the AC."; } container l2-connection { description "Defines Layer 2 protocols and parameters that are required to enable AC connectivity."; uses l2-connection-basic; } container ip-connection { description "Defines IP connection parameters."; uses ip-connection-basic; } container routing-protocols { description "Defines routing protocols."; uses routing-basic; } container oam { description "Defines the Operations, Administration, and Maintenance (OAM) mechanisms used."; container bfd { if-feature "vpn-common:bfd"; description "Container for BFD."; uses ac-common:bfd; } } container security { description "AC-specific security parameters."; uses ac-security-basic; } } // Full AC parameters grouping ac { description "Grouping for an attachment circuit."; leaf name { type string; description "A name of the AC. Data models that need to reference an attachment circuits should use attachment-circuit-reference."; } container l2-connection { description "Defines Layer 2 protocols and parameters that are required to enable AC connectivity."; uses l2-connection; } container ip-connection { description "Defines IP connection parameters."; uses ip-connection; } container routing-protocols { description "Defines routing protocols."; uses routing; } container oam { description "Defines the OAM mechanisms used."; container bfd { if-feature "vpn-common:bfd"; description "Container for BFD."; uses ac-common:bfd; uses vpn-common:service-status; } } container security { description "AC-specific security parameters."; uses ac-security-basic; } } /******************** Main AC containers ********************/ container specific-provisioning-profiles { description "Contains a set of valid profiles to reference for an AC."; uses vpn-common:vpn-profile-cfg; } container service-provisioning-profiles { description "Contains a set of valid profiles to reference for an AC."; list service-profile-identifier { key "id"; description "List of generic service profile identifiers."; leaf id { type string; description "Identification of the service profile to be used. The profile only has significance within the service provider's administrative domain."; } } } container attachment-circuits { description "Main container for the attachment circuits."; /*list ac-global-profile { key "id"; description "Maintains a list of AC profiles."; uses ac-basic; }*/ list ac-group-profile { key "name"; description "Maintains a list of per-node AC profiles."; uses ac; } container placement-constraints { description "Diversity constraint type."; uses vpn-common:placement-constraints; } list ac { key "name"; description "Global provisioning of attachment circuits."; leaf customer-name { type string; description "Indicates the name of the customer that requested this AC."; } leaf description { type string; description "Associates a description with an AC."; } uses ac-common:op-instructions; leaf-list peer-sap-id { type string; description "One or more peer SAPs can be indicated."; } /*leaf-list ac-global-profile { type ac-global-profile-reference; description "A reference to an AC profile."; }*/ leaf-list ac-group-profile { type ac-group-reference; description "A reference to a per-node AC profile."; } list group { key "group-id"; description "List of group-ids."; leaf group-id { type string; description "Indicates the group-id to which the network access belongs."; } leaf precedence { type identityref { base ac-common:precedence-type; } description "Defines redundancy of an AC."; } } uses ac; } } } <CODE ENDS>¶
6. Security Considerations
The YANG modules specified in this document define 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 these YANG modules 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 these 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:¶
Several data nodes ('bgp', 'ospf', 'isis', and 'rip') rely upon [RFC8177] for authentication purposes. As such, the AC service module inherits the security considerations discussed in Section 5 of [RFC8177]. Also, these data nodes support supplying explicit keys as strings in ASCII format. The use of keys in hexadecimal string format would afford greater key entropy with the same number of key- string octets. However, such a format is not included in this version of the AC service model, because it is not supported by the underlying device modules (e.g., [RFC8695]).¶
7. IANA Considerations
IANA is requested to register the following URIs in the "ns" subregistry within the "IETF XML Registry" [RFC3688]:¶
URI: urn:ietf:params:xml:ns:yang:ietf-bearer-svc Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-ac-svc Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace.¶
IANA is requested to register the following YANG modules in the "YANG Module Names" subregistry [RFC6020] within the "YANG Parameters" registry.¶
Name: ietf-bearer-svc Maintained by IANA? N Namespace: urn:ietf:params:xml:ns:yang:ietf-bearer-svc Prefix: bearer-svc Reference: RFC xxxx Name: ietf-ac-svc Maintained by IANA? N Namespace: urn:ietf:params:xml:ns:yang:ietf-ac-svc Prefix: ac-svc Reference: RFC xxxx¶
8. References
8.1. Normative References
- [I-D.boro-opsawg-teas-common-ac]
- Boucadair, M., Roberts, R., de Dios, O. G., Barguil, S., and B. Wu, "A Common YANG Data Model for Attachment Circuits", Work in Progress, Internet-Draft, draft-boro-opsawg-teas-common-ac-00, , <https://datatracker.ietf.org/doc/html/draft-boro-opsawg-teas-common-ac-00>.
- [RFC2119]
- Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/rfc/rfc2119>.
- [RFC3688]
- Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, , <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, , <https://www.rfc-editor.org/rfc/rfc4364>.
- [RFC5880]
- Katz, D. and D. Ward, "Bidirectional Forwarding Detection (BFD)", RFC 5880, DOI 10.17487/RFC5880, , <https://www.rfc-editor.org/rfc/rfc5880>.
- [RFC6020]
- Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, , <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, , <https://www.rfc-editor.org/rfc/rfc6241>.
- [RFC6242]
- Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, , <https://www.rfc-editor.org/rfc/rfc6242>.
- [RFC6991]
- Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, , <https://www.rfc-editor.org/rfc/rfc6991>.
- [RFC8040]
- Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, , <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, , <https://www.rfc-editor.org/rfc/rfc8174>.
- [RFC8177]
- Lindem, A., Ed., Qu, Y., Yeung, D., Chen, I., and J. Zhang, "YANG Data Model for Key Chains", RFC 8177, DOI 10.17487/RFC8177, , <https://www.rfc-editor.org/rfc/rfc8177>.
- [RFC8341]
- Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, , <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, , <https://www.rfc-editor.org/rfc/rfc8342>.
- [RFC8446]
- Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, , <https://www.rfc-editor.org/rfc/rfc8446>.
- [RFC9181]
- Barguil, S., Gonzalez de Dios, O., Ed., Boucadair, M., Ed., and Q. Wu, "A Common YANG Data Model for Layer 2 and Layer 3 VPNs", RFC 9181, DOI 10.17487/RFC9181, , <https://www.rfc-editor.org/rfc/rfc9181>.
8.2. Informative References
- [AC-SVC-GRP]
- "Reusable Groupings in Service Attachment Circuits", , <https://raw.githubusercontent.com/boucadair/attachment-circuit-model/main/yang/full-trees/ac-svc-groupings.txt>.
- [AC-SVC-Tree]
- "Full Service Attachment Circuit Tree Structure", , <https://raw.githubusercontent.com/boucadair/attachment-circuit-model/main/yang/full-trees/ac-svc-without-groupings.txt>.
- [I-D.boro-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-boro-opsawg-ntw-attachment-circuit-01, , <https://datatracker.ietf.org/doc/html/draft-boro-opsawg-ntw-attachment-circuit-01>.
- [I-D.ietf-idr-bgp-model]
- Jethanandani, M., Patel, K., Hares, S., and J. Haas, "YANG Model for Border Gateway Protocol (BGP-4)", Work in Progress, Internet-Draft, draft-ietf-idr-bgp-model-16, , <https://datatracker.ietf.org/doc/html/draft-ietf-idr-bgp-model-16>.
- [I-D.ietf-opsawg-sap]
- Boucadair, M., de Dios, O. G., Barguil, S., Wu, Q., and V. Lopez, "A YANG Network Model for Service Attachment Points (SAPs)", Work in Progress, Internet-Draft, draft-ietf-opsawg-sap-15, , <https://datatracker.ietf.org/doc/html/draft-ietf-opsawg-sap-15>.
- [I-D.ietf-teas-ietf-network-slice-nbi-yang]
- Wu, B., Dhody, D., Rokui, R., Saad, T., Han, L., and J. Mullooly, "IETF Network Slice Service YANG Model", Work in Progress, Internet-Draft, draft-ietf-teas-ietf-network-slice-nbi-yang-03, , <https://datatracker.ietf.org/doc/html/draft-ietf-teas-ietf-network-slice-nbi-yang-03>.
- [RFC2080]
- Malkin, G. and R. Minnear, "RIPng for IPv6", RFC 2080, DOI 10.17487/RFC2080, , <https://www.rfc-editor.org/rfc/rfc2080>.
- [RFC2453]
- Malkin, G., "RIP Version 2", STD 56, RFC 2453, DOI 10.17487/RFC2453, , <https://www.rfc-editor.org/rfc/rfc2453>.
- [RFC3644]
- Snir, Y., Ramberg, Y., Strassner, J., Cohen, R., and B. Moore, "Policy Quality of Service (QoS) Information Model", RFC 3644, DOI 10.17487/RFC3644, , <https://www.rfc-editor.org/rfc/rfc3644>.
- [RFC3849]
- Huston, G., Lord, A., and P. Smith, "IPv6 Address Prefix Reserved for Documentation", RFC 3849, DOI 10.17487/RFC3849, , <https://www.rfc-editor.org/rfc/rfc3849>.
- [RFC5398]
- Huston, G., "Autonomous System (AS) Number Reservation for Documentation Use", RFC 5398, DOI 10.17487/RFC5398, , <https://www.rfc-editor.org/rfc/rfc5398>.
- [RFC5737]
- Arkko, J., Cotton, M., and L. Vegoda, "IPv4 Address Blocks Reserved for Documentation", RFC 5737, DOI 10.17487/RFC5737, , <https://www.rfc-editor.org/rfc/rfc5737>.
- [RFC5798]
- Nadas, S., Ed., "Virtual Router Redundancy Protocol (VRRP) Version 3 for IPv4 and IPv6", RFC 5798, DOI 10.17487/RFC5798, , <https://www.rfc-editor.org/rfc/rfc5798>.
- [RFC5925]
- Touch, J., Mankin, A., and R. Bonica, "The TCP Authentication Option", RFC 5925, DOI 10.17487/RFC5925, , <https://www.rfc-editor.org/rfc/rfc5925>.
- [RFC6151]
- Turner, S. and L. Chen, "Updated Security Considerations for the MD5 Message-Digest and the HMAC-MD5 Algorithms", RFC 6151, DOI 10.17487/RFC6151, , <https://www.rfc-editor.org/rfc/rfc6151>.
- [RFC6952]
- Jethanandani, M., Patel, K., and L. Zheng, "Analysis of BGP, LDP, PCEP, and MSDP Issues According to the Keying and Authentication for Routing Protocols (KARP) Design Guide", RFC 6952, DOI 10.17487/RFC6952, , <https://www.rfc-editor.org/rfc/rfc6952>.
- [RFC7665]
- Halpern, J., Ed. and C. Pignataro, Ed., "Service Function Chaining (SFC) Architecture", RFC 7665, DOI 10.17487/RFC7665, , <https://www.rfc-editor.org/rfc/rfc7665>.
- [RFC8299]
- Wu, Q., Ed., Litkowski, S., Tomotaki, L., and K. Ogaki, "YANG Data Model for L3VPN Service Delivery", RFC 8299, DOI 10.17487/RFC8299, , <https://www.rfc-editor.org/rfc/rfc8299>.
- [RFC8340]
- Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, , <https://www.rfc-editor.org/rfc/rfc8340>.
- [RFC8349]
- Lhotka, L., Lindem, A., and Y. Qu, "A YANG Data Model for Routing Management (NMDA Version)", RFC 8349, DOI 10.17487/RFC8349, , <https://www.rfc-editor.org/rfc/rfc8349>.
- [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, , <https://www.rfc-editor.org/rfc/rfc8466>.
- [RFC8695]
- Liu, X., Sarda, P., and V. Choudhary, "A YANG Data Model for the Routing Information Protocol (RIP)", RFC 8695, DOI 10.17487/RFC8695, , <https://www.rfc-editor.org/rfc/rfc8695>.
- [RFC8969]
- Wu, Q., Ed., Boucadair, M., Ed., Lopez, D., Xie, C., and L. Geng, "A Framework for Automating Service and Network Management with YANG", RFC 8969, DOI 10.17487/RFC8969, , <https://www.rfc-editor.org/rfc/rfc8969>.
- [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, , <https://www.rfc-editor.org/rfc/rfc9182>.
Appendix A. Examples
This section includes a non-exhaustive list of examples to illustrate the use of the service models defined in this document.¶
A.1. Request A New Bearer
An example of a request message body to create a bearer is shown in Figure 14.¶
A bearer-reference is then generated by the controller for this bearer. Figure 15 shows the example of a response message body that is sent by the controller to reply to a GET request:¶
A.2. Request An AC over An Existing Bearer
An example of a request message body to create a simple AC over an existing bearer is shown in Figure 16. The bearer reference is assumed to be known to both the customer and the network provider. Such a reference can be retrieved, e.g., following the example described in Appendix A.1 or using other means (including, exchanged out-of-band or via proprietary APIs).¶
A.3. Request An AC for a Knwon Peer SAP
An example of a request to create a simple AC, when the peer SAP is known, is shown in Figure 17. In this example, the peer SAP identifier points to an identifier of a service function. The (topological) location of that service function is assumed to be known to the network controller. For example, this can be determined as part of an on-demand procedure to instantiate a service function in a cloud. That instantiated service function can be granted a connectivity service via the provider network.¶
A.4. One CE, Two ACs
Lets consider the example of an eNodeB (CTP) that is directly connected to the access routers of the mobile backhaul (see Figure 18). In this example, two ACs are needed to service the eNodeB.¶
An example of a request to create the ACs to service the eNodeB is shown in Figure 19. This example assumes that static addressing is used for both ACs.¶
A.5. Control Precedence over Multiple ACs
When multiple ACs are requested by the same customer (for the same site), the request can tag one of these ACes as "primary" and the other ones as "secondary". An example of such a request is shown in Figure 20. In this example, both ACes are bound to the same "group-id", and the "precedence" data node is set as a function of the intended role of each AC (primary or secondary).¶
A.6. Illustrate the Use of Global Profiles
An example of a request to create two ACs to service the same CE on the same link is shown in Figure 21. Unlike Figure 19, this example factorizes some of the redundant data.¶
A.7. Illustrate the Use of Per-Node Profiles
An example of a request to create two ACs to service the same CE on the same link is shown in Figure 22. Unlike Figure 19, this example factorizes all redundant data.¶
A customer may request adding a new AC by simply referring to an existing per-node AC profile as shown in Figure 23. This AC inherites all the data that was enclosed in the indicated per-node AC profile (IP addressing, routing, etc.).¶
A.8. Multiple CEs
Figure 24 shows an example of CEs that are interconnected by a service provider network.¶
Figure 25 depicts an example of the message body of a request to instantiate the various ACs that are shown in Figure 24.¶
A.9. Binding Attachment Circuits to an IETF Network Slice
This example shows how the AC service model complements [I-D.ietf-teas-ietf-network-slice-nbi-yang] to connect a site to a slice service.¶
First, Figure 26 describes the end-to-end network topology as well the orchestration scopes:¶
- The topology is made up of two sites (site1 and site2), interconnected via a Transport Network (e.g. IP/MPLS Network). A Network Function is deployed within each site in a dedicated IP Subnet.¶
- A 5G SMO is responsible for the deployment Network Functions and the indirect management of a local Gateway (i.e., CE device).¶
- An IETF Network Slice Controller is responsible for the deployment of IETF Network Slices accross the TN.¶
Network Functions are deployed within each site.¶
Figure 27 describes the logical connectivity enforced thanks to both IETF Network Slice and Attachment Circuit models.¶
Figure 28 shows the message body of the request to create the required ACs using the Attachment Circuit module.¶
Figure 29 shows the message body of the request to create the a slice service bound to the ACs created using Figure 28. Only references to these ACs are included in the Slice Service request. This example assumes that the module that "glues" the service/AC is also supported by the NSC.¶
A.10. Connecting a Virtualized Environment Running in a Cloud Provider
This example (Figure 30) shows how the AC service model can be used to connect a Cloud Infrastructure to a service provider network. This example makes the following assumptions:¶
- A customer (e.g., Mobile Network Team or partner) has a virtualized infrastructure running in a Cloud Provider. A simplistic deployment is represented here with a set of Virtual Machines running in a Virtual Private Environment. The deployment and management of this infrastructure is achieved via private APIs that are supported by the Cloud Provider: this realization is out of the scope of this document.¶
- The connectivity to the Data Center is achieved thanks to a service based on direct attachment (physical connection), which is delivered upon ordering via an API exposed by the Cloud Provider. When ordering that connection, a unique "Connection Identifier" is generated and returned via the API.¶
- The customer provisions the networking logic within the Cloud Provider based on that unique connection Identifier (i.e., logical interfaces, IP addressing, and routing).¶
Figure 31 illustrates the pre-provisioning logic for the physical connection to the Cloud Provider. After this connection is delivered to the service provider, the network inventory is updated with "bearer-reference" set to the value of the "Connection Identifier".¶
Next, API workflows can be initiated:¶
- Cloud Provider for the configuration as per (3) above.¶
- Service provider network via the Attachment Circuit model. This request can be used in conjunction with additional requests based on L3SM (VPN provisioning) or Network Slice Service model (5G hybrid Cloud deployment).¶
Figure 32 shows the message body of the request to create the required ACs to connect the Cloud Provider Virtualized (VM) using the Attachment Circuit module. Note that this Cloud Provider mandates the use of MD5 authentication for establishing BGP connections.¶
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The module supports MD5 to basically accommodate the installed BGP base (including by some Cloud Providers). Note that MD5 suffers from the security weaknesses discussed in Section 2 of [RFC6151] and Section 2.1 of [RFC6952].¶
Acknowledgments
TBC.¶