Network Working Group B. Wu Internet-Draft D. Dhody Intended status: Standards Track Huawei Technologies Expires: May 3, 2021 L. Han China Mobile R. Rokui Nokia Canada October 30, 2020 A Yang Data Model for IETF Network Slice NBI draft-wd-teas-ietf-network-slice-nbi-yang-00 Abstract This document provides a YANG data model for the IETF Network Slice NBI (Northbound Interface). The model can be used by a higher level system which is the IETF Network Slice consumer of an IETF Network Slice Controller (NSC) to request, configure, and manage the components of an IETF Network Slice. The YANG modules in this document conforms to the Network Management Datastore Architecture (NMDA) defined in RFC 8342. 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 May 3, 2021. Copyright Notice Copyright (c) 2020 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 Wu, et al. Expires May 3, 2021 [Page 1] Internet-Draft IETF Network Slice NBI YANG model October 2020 (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 Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions used in this document . . . . . . . . . . . . . . 3 2.1. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 4 3. IETF Network Slice NBI Model Usage . . . . . . . . . . . . . 4 4. IETF Network Slice NBI Model Overview . . . . . . . . . . . . 5 5. IETF Network Slice NBI Model Description . . . . . . . . . . 8 5.1. IETF Network Slice Connection Types . . . . . . . . . . . 8 5.2. IETF Network Slice Endpoint (NSE) . . . . . . . . . . . . 9 5.3. IETF Network Slice SLO . . . . . . . . . . . . . . . . . 9 6. IETF Network Slice Monitoring . . . . . . . . . . . . . . . . 11 7. IETF Network Slice NBI Model Usage Example . . . . . . . . . 11 8. IETF Network Slice NBI Module . . . . . . . . . . . . . . . . 11 9. Security Considerations . . . . . . . . . . . . . . . . . . . 28 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 28 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 29 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 29 12.1. Normative References . . . . . . . . . . . . . . . . . . 29 12.2. Informative References . . . . . . . . . . . . . . . . . 30 Appendix A. Comparison with Other Possible Design choices for IETF Network Slice NBI . . . . . . . . . . . . . . . 31 A.1. ACTN VN Model Augmentation . . . . . . . . . . . . . . . 31 A.2. RFC8345 Augmentation Model . . . . . . . . . . . . . . . 32 Appendix B. Appendix B IETF Network Slice Filter Criteria . . . 33 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 34 1. Introduction This document provides a YANG [RFC7950] data model for the IETF Network Slice NBI. The YANG model discussed in this document is defined based on the description of the IETF Network Slice in [I-D.nsdt-teas-ietf-network-slice-definition] and [I-D.nsdt-teas-ns-framework], which is used to operate IETF Network Slice during the IETF Network Slice instantiation, and the operations includes modification, deletion, and monitoring. Wu, et al. Expires May 3, 2021 [Page 2] Internet-Draft IETF Network Slice NBI YANG model October 2020 The YANG model discussed in this document describes the requirements of an IETF Network Slice that interconnects a set of IETF Network Slice Endpoints from the point of view of the consumer, which is classified as Customer Service Model in [RFC8309]. It will be up to the management system or NSC (IETF Network Slice controller) to take this model as an input and use other management system or specific configuration models to configure the different network elements to deliver an IETF Network Slice. The YANG models can be used with network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. How the configuration of network elements is done is out of scope for this document. The IETF Network Slice operational state is included in the same tree as the configuration consistent with Network Management Datastore Architecture [RFC8342]. 2. Conventions used in this document The keywords "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 BCP14, [RFC2119], [RFC8174] when, and only when, they appear in all capitals, as shown here. The following terms are defined in [RFC6241] and are used in this specification: o client o configuration data o state data This document also makes use of the following terminology introduced in the YANG 1.1 Data Modeling Language [RFC7950]: o augment o data model o data node This document also makes use of the following terminology introduced in the IETF Network Slice definition draft [I-D.nsdt-teas-ietf-network-slice-definition]: Wu, et al. Expires May 3, 2021 [Page 3] Internet-Draft IETF Network Slice NBI YANG model October 2020 o IETF Network Slice (NS): An IETF Network Slice is a logical network topology connecting a number of endpoints and a set of shared or dedicated network resources, which are used to satisfy specific Service Level Objectives (SLO). The definition is from Section 3 of [I-D.nsdt-teas-ietf-network-slice-definition]. o IETF Network Slice Endpoint (NSE): An IETF Network Slice Endpoint is a logical identifier at DAN (Device,Application,Network Function) of the customer network to identify the logical access to which, a particular subset of traffic traversing the external interface, is mapped to a specific IETF Network Slice and it follows the definition of NSE (IETF Network Slice Endpoint) in Section 4.2 of [I-D.nsdt-teas-ietf-network-slice-definition]. o SLO: An SLO is a service level objective o DAN: Device,Application,Network Function o NSC: IETF Network Slice Controller o NBI: Northbound Interface In addition, this document defines the following terminology: o IETF Network Slice Member (Network-Slice-Member): A IETF Network- Slice-Member is an abstract entity which represents the network resources mapped to a particular connection between a pair of NSEs belonging to an IETF Network Slice. Note that different SLO requirement per Network-Slice-Member could be applied. o Network-Slice-Slo-Group: Indicates a group of Network-Slice- Members with same SLOs in one IETF Network Slice. 2.1. Tree Diagrams Tree diagrams used in this document follow the notation defined in [RFC8340]. 3. IETF Network Slice NBI Model Usage The intention of the IETF Network Slice NBI model is to allow the consumer, e.g. A higher level management system, to request and monitor IETF Network Slices. In particular, the model allows consumers to operate in an abstract, technology-agnostic manner, with implementation details hidden. In the use case of 5G transport application, the E2E network slice orchestrator acts as the higher layer system to request the IETF Wu, et al. Expires May 3, 2021 [Page 4] Internet-Draft IETF Network Slice NBI YANG model October 2020 Network Slices. The interface is used to support dynamic IETF Network Slice creation and its lifecycle management to facilitate end-to-end network slice services. +----------------------------------------+ | IETF Network Slice Consumer | |(e.g 5G E2E network slice orchestrator) | +----------------+-----------------------+ | | |IETF Network Slice NBI YANG | +---------------------+--------------------------+ | IETF Network Slice Controller (NSC) | +------------------------------------------------+ Figure 1 IETF Network Slice NBI Model Context 4. IETF Network Slice NBI Model Overview From a consumer perspective, an example of an IETF Network Slice is shown in figure 2. IETF scoped Network DAN1 +---------------------------------+ DAN3 +--------+ +------+ | +--------+ | o +---o| A | +------+ | | | NSE1 | +------+ | C |o---+ | +--------+ | +------+ | | | | | o | +--------+ | +------+ | NSE3 | | | +------+ | D |o---+ | | o +---o| B | +------+ | | | NSE2 | +------+ | | | +--------+ | | +--------+ DAN2 +---------------------------------+ | | | | |<----------------IETF Network Slice 1----------------->| Legend:DAN (Device,Application,Network Function) Network-Slice-SLO-Group Red Network-Slice-SLO-Group Blue Network-Slice-Member 1 NSE1-NSE3 Network-Slice-Member 3 NSE1-NSE2 Network-Slice-Member 2 NSE2-NSE3 Figure 2: An example of an IETF Network Slice Wu, et al. Expires May 3, 2021 [Page 5] Internet-Draft IETF Network Slice NBI YANG model October 2020 As shown in figure 2, an IETF Network Slice (NS) links together NSEs at the DANs, which are customer endpoints that request an IETF Network Slice. At each customer DAN, one or multiple NSEs could be connected to the IETF Network Slice. A NS is a connectivity with specific SLO characteristics, including bandwidth, QoS metric, etc. The connectivity is a combination of logical connections, represented by Network-Slice-Members. When some parts of a slice have different SLO requirements, a group of Network- Slice-Members with the same SLO is described by Network-Slice-SLO- Group. Based on this design, the IETF Network Slice YANG module consists of the main containers: "network-slice", "network-slice-endpoint", "network-slice-member",and "network-slice-slo-group". The figure below describes the overall structure of the YANG module: module: ietf-network-slice +--rw network-slices +--rw slice-templates | +--rw slo-template* [id] | +--rw id string | +--rw template-description? string +--rw network-slice* [network-slice-id] +--rw network-slice-id uint32 +--rw network-slice-name? string +--rw network-slice-tag? string +--rw network-slice-topology* identityref +--rw network-slice-slo-group* [slo-group-name] | +--rw slo-group-name string | +--rw default-slo-group? boolean | +--rw (slo-template)? | | +--:(standard) | | | +--rw template? leafref | | +--:(custom) | | +--rw network-slice-slo-policy | | +--rw latency | | | +--rw one-way-latency? uint32 | | | +--rw two-way-latency? uint32 | | +--rw jitter | | | +--rw one-way-jitter? uint32 | | | +--rw two-way-jitter? uint32 | | +--rw loss | | | +--rw one-way-loss? decimal64 | | | +--rw two-way-loss? decimal64 | | +--rw availability-type? identityref | | +--rw isolation-type? identityref Wu, et al. Expires May 3, 2021 [Page 6] Internet-Draft IETF Network Slice NBI YANG model October 2020 | | +--rw network-slice-metric-bounds | | +--rw network-slice-metric-bound* | | [metric-type] | | +--rw metric-type identityref | | +--rw upper-bound? uint64 | +--rw network-slice-member-group* | | [network-slice-member-id] | | +--rw network-slice-member-id leafref | +--ro slo-group-monitoring | +--ro latency? uint32 | +--ro jitter? uint32 | +--ro loss? decimal64 +--rw status | +--rw admin-enabled? boolean | +--ro oper-status? operational-type +--rw network-slice-endpoint* [endpoint-id] | +--rw endpoint-id uint32 | +--rw endpoint-name? string | +--rw endpoint-role* identityref | +--rw geolocation | | +--rw altitude? int64 | | +--rw latitude? decimal64 | | +--rw longitude? decimal64 | +--rw node-id? string | +--rw port-id? string | +--rw network-slice-match-criteria | | +--rw network-slice-match-criteria* [match-type] | | +--rw match-type identityref | | +--rw value? string | +--rw endpoint-ip? inet:host | +--rw bandwidth | | +--rw incoming-bandwidth | | | +--rw guaranteed-bandwidth? te-types:te-bandwidth | | +--rw outgoing-bandwidth | | +--rw guaranteed-bandwidth? te-types:te-bandwidth | +--rw mtu uint16 | +--rw routing | | +--rw bgp | | | +--rw bgp-peer-ipv4* inet:ipv4-prefix | | | +--rw bgp-peer-ipv6* inet:ipv6-prefix | | +--rw static | | +--rw static-route-ipv4* inet:ipv4-prefix | | +--rw static-route-ipv6* inet:ipv6-prefix | +--rw status | | +--rw admin-enabled? boolean | | +--ro oper-status? operational-type | +--ro endpoint-monitoring | +--ro incoming-utilized-bandwidth? Wu, et al. Expires May 3, 2021 [Page 7] Internet-Draft IETF Network Slice NBI YANG model October 2020 | | te-types:te-bandwidth | +--ro incoming-bw-utilization decimal64 | +--ro outgoing-utilized-bandwidth? | | te-types:te-bandwidth | +--ro outgoing-bw-utilization decimal64 +--rw network-slice-member* [network-slice-member-id] +--rw network-slice-member-id uint32 +--rw src | +--rw src-network-slice-endpoint-id? leafref +--rw dest | +--rw dest-network-slice-endpoint-id? leafref +--rw monitoring-type? | network-slice-monitoring-type +--ro network-slice-member-monitoring +--ro latency? uint32 +--ro jitter? uint32 +--ro loss? decimal64 5. IETF Network Slice NBI Model Description An IETF Network Slice consists of a group of interconnected NSEs, and the connections between NSEs may have different SLO requirements, including symmetrical or asymmetrical traffic throughput, different traffic delay, etc. 5.1. IETF Network Slice Connection Types An IETF Network Slice can be point-to-point (P2P), point-to- multipoint (P2MP), multipoint-to-point (MP2P), or multipoint-to- multipoint (MP2MP) based on the consumer's traffic pattern requirements. Therefore, the "network-slice-topology" under the node "network- slice" is required for configuration. The model supports any-to-any, Hub and Spoke (where Hubs can exchange traffic), and the different combinations. New topologies could be added via augmentation. By default, the any-to-any topology is used. In addition, "endpoint-role" under the node "network-slice-endpoint" also needs to be defined, which specifies the role of the NSE in a particular Network Slice topology. In the any-to-any topology, all NSEs MUST have the same role, which will be "any-to-any-role". In the Hub-and-Spoke topology, NSEs MUST have a Hub role or a Spoke role. Wu, et al. Expires May 3, 2021 [Page 8] Internet-Draft IETF Network Slice NBI YANG model October 2020 5.2. IETF Network Slice Endpoint (NSE) An NSE belong to a single IETF Network Slice. An IETF Network Slice involves two or more NSEs. A NSE is used to define the limit on the user traffic that can be injected to a network slice. For example, in some scenarios, the access traffic of a DAN is allowed only when it matches the logical Layer 2 connection identifier. In some scenarios, the access traffic of a DAN is allowed only when the traffic matches a source IP address. Sometimes, the traffic from a distinct physical connection of a DAN is allowed. Therefore, to ensure that the NSE is uniquely identified, the model use the following parameters including "node-id", "port-id" and "network-slice-match-criteria". The "node-id" identifies a DAN node, the "port-id" identifies a port, and the "network-slice-filter- criteria" identifies a possible logical L2 ID or IP address or other possible traffic identifier in the user traffic. Additionally, a number of slice interconnection parameters need to be agreed with a customer DAN and the IETF network, such as IP address (v4 or v6) etc. 5.3. IETF Network Slice SLO As defined in [I-D.nsdt-teas-ietf-network-slice-definition], this model defines the minimum IETF Network Slice SLO attributes, and other SLO nodes can be augmented as needed. NS SLO assurance is implemented through the following mechanisms: o Network Slice SLO list: Which defines the performance objectives of the NS. Performance objectives can be specified for various performance metrics,and different objectives are as follows: Latency: Indicates the maximum latency between two NSE. The unit is micro seconds. The latency could be round trip times or one-way metrics. Jitter: Indicates the jitter constraint of the slice maximum permissible delay variation, and is measured by the difference in the one- way delay between sequential packets in a flow. Loss: Indicates maximum permissible packet loss rate, which is defined by the ratio of packets dropped to packets transmitted between two endpoints. Wu, et al. Expires May 3, 2021 [Page 9] Internet-Draft IETF Network Slice NBI YANG model October 2020 Availability: Is defined as the ratio of up-time to total_time(up-time+down-time), where up-time is the time the IETF Network Slice is available in accordance with the SLOs associated with it. Isolation: Whether the isolation needs to be explicitly requested is still in discussion. o Bandwidth: Indicates the guaranteed minimum bandwidth between any two NSE. The unit is data rate per second. And the bandwidth is unidirectional. The bandwidth is specified at each NSE and can be applied to incoming NS traffic or outgoing NS traffic. When applied in the incoming direction, the Bandwidth is applicable to the traffic from the NSE to the IETF scope Network that passes through the external interface. When Bandwidth is applied to the outgoing direction, it is applied to the traffic from the IETF Network to the NSE of that particular NS. Note: About the definition of SLO parameters, the author is discussing to reuse the TE-Types grouping definition as much as possible, to avoid duplication of definitions. Consumers' Network Slices can be very different, e.g. some slices has the same SLO requirements of connections, some slices has the different SLO requirements for different parts of the slice. In some slices, the bandwidth of one endpoint is different from that of other endpoints, for example, one is central endpoint, the other endpoints are access endpoints. The list "ns-slo-group" defines a group of different SLOs, which are used to describe that different parts of the slice have different SLOs. The specific SLO of the slice SLO group may use a standard SLO template, or may use different customized parameters. A group of "network-slice-member" is used to describe which connections of the slice use the SLO. For some simplest IETF Network Slices, only one category SLO of "network-slice-slo-group" needs to be defined. For some complicated network slices, in addition to the configurations above, multiple "network-slice-slo-group" needs to be defined, and "network-slice- member-group" describes details of the per-connection SLO. In addition to SLO performance objectives, there are also some other NS objectives, such as MTU and security which can be augmented when needed. MTU specifies the maximum packet length that the network slice guarantee to be able to carry across. Wu, et al. Expires May 3, 2021 [Page 10] Internet-Draft IETF Network Slice NBI YANG model October 2020 Note: In some use cases, the number of connections represented by "network-slice-member-group" may be huge, which may lead to configuration issues, for example, the scalability or error-prone. 6. IETF Network Slice Monitoring This model also describes performance status of an IETF Network Slice. The statistics are described in the following granularity: o Per NS SLO group: specified in 'network-slice-member-group- monitoring' under the "network-slice-slo-groupr" o Per NS connection: specified in 'network-slice-member-monitoring' under the "network-slice-member" o Per NS Endpoint: specified in 'ep-monitoring' under the "network- slice-endpoint" This model does not define monitoring enabling methods. The mechanism defined in [RFC8640] and [RFC8641] can be used for either periodic or on-demand subscription. By specifying subtree filters or xpath filters to 'network-slice- member' or 'network-slice-endpoint' ,so that only interested contents will be sent. These mechanisms can be used for monitoring the IETF Network Slice performance status so that the client management system could initiate modification based on the IETF Network Slice running status. 7. IETF Network Slice NBI Model Usage Example TBD 8. IETF Network Slice NBI Module file "ietf-transport-slice@2020-07-12.yang" module ietf-network-slice { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-network-slice"; prefix ietf-ns; import ietf-inet-types { prefix inet; } import ietf-te-types { prefix te-types; } Wu, et al. Expires May 3, 2021 [Page 11] Internet-Draft IETF Network Slice NBI YANG model October 2020 organization "IETF Traffic Engineering Architecture and Signaling (TEAS) Working Group"; contact "WG Web: WG List: Editor: Bo Wu : Dhruv Dhody "; description "This module contains a YANG module for the IETF Network Slice. Copyright (c) 2020 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 Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://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 2020-10-27 { description "initial version."; reference "RFC XXXX: A Yang Data Model for IETF Network Slice Operation"; } /* Features */ /* Identities */ identity network-slice-topology { description "Base identity for IETF Network Slice topology."; } identity any-to-any { base network-slice-topology; description "Identity for any-to-any IETF Network Slice topology."; } identity hub-spoke { base network-slice-topology; description Wu, et al. Expires May 3, 2021 [Page 12] Internet-Draft IETF Network Slice NBI YANG model October 2020 "Identity for Hub-and-Spoke IETF Network Slice topology."; } identity endpoint-role { description "Network Slice Endpoint Role in an IETF Network Slice topology "; } identity any-to-any-role { base endpoint-role; description "Network Slice Endpoint as the any-to-any role in an any-to-any IETF Network Slice."; } identity hub { base endpoint-role; description "Network Slice Endpoint as the hub role in a Hub-and-Spoke IETF Network Slice."; } identity spoke { base endpoint-role; description "Network Slice Endpoint as the spoke role in a Hub-and-Spoke IETF Network Slice."; } identity isolation-type { description "Base identity from which specific isolation types are derived."; } identity physical-isolation { base isolation-type; description "physical isolation."; } identity logical-isolation { base isolation-type; description "logical-isolation."; } identity network-slice-slo-metric-type { description Wu, et al. Expires May 3, 2021 [Page 13] Internet-Draft IETF Network Slice NBI YANG model October 2020 "Base identity for Network Slice SLO metric type"; } identity network-slice-match-type { description "Base identity for Network Slice traffic match type"; } identity network-slice-vlan-match { base network-slice-match-type; description "VLAN as Network Slice traffic match criteria."; } /* * Identity for availability-type */ identity availability-type { description "Base identity from which specific availability types are derived."; } identity level-1 { base availability-type; description "level 1: 99.9999%"; } identity level-2 { base availability-type; description "level 2: 99.999%"; } identity level-3 { base availability-type; description "level 3: 99.99%"; } identity level-4 { base availability-type; description "level 4: 99.9%"; } Wu, et al. Expires May 3, 2021 [Page 14] Internet-Draft IETF Network Slice NBI YANG model October 2020 identity level-5 { base availability-type; description "level 5: 99%"; } /* typedef */ typedef operational-type { type enumeration { enum up { value 0; description "Operational status UP."; } enum down { value 1; description "Operational status DOWN"; } enum unknown { value 2; description "Operational status UNKNOWN"; } } description "This is a read-only attribute used to determine the status of a particular element"; } typedef network-slice-monitoring-type { type enumeration { enum one-way { description "represents one-way monitoring type"; } enum two-way { description "represents two-way monitoring type"; } } description "enumerated type of monitoring on a network-slice-member "; } /* Groupings */ Wu, et al. Expires May 3, 2021 [Page 15] Internet-Draft IETF Network Slice NBI YANG model October 2020 grouping status-params { description "Grouping used to join operational and administrative status"; container status { description "Container for status of administration and operational"; leaf admin-enabled { type boolean; description "Administrative Status UP/DOWN"; } leaf oper-status { type operational-type; config false; description "Operations status"; } } } grouping network-slice-match-criteria { description "Grouping for Network Slice match definition."; container network-slice-match-criteria { description "Describes Network Slice match criteria."; list network-slice-match-criteria { key "match-type"; description "List of Network Slice traffic criteria"; leaf match-type { type identityref { base network-slice-match-type; } description "Identifies an entry in the list of match-type for the Network Slice."; } leaf value { type string; description "Describes Network Slice match criteria,e.g. IP address, VLAN, etc."; } } } } Wu, et al. Expires May 3, 2021 [Page 16] Internet-Draft IETF Network Slice NBI YANG model October 2020 grouping network-slice-metric-bounds { description "Network Slice metric bounds grouping"; container network-slice-metric-bounds { description "Network Slice metric bounds container"; list network-slice-metric-bound { key "metric-type"; description "List of Network Slice metric bounds"; leaf metric-type { type identityref { base network-slice-slo-metric-type; } description "Identifies an entry in the list of metric-types bound for the Network Slice."; } leaf upper-bound { type uint64; default "0"; description "Upper bound on network-slice-member metric. A zero indicate an unbounded upper limit for the specific metric-type"; } } } } grouping routing-protocols { description "Grouping for endpoint protocols definition."; container routing { description "Describes protocol between Network Slice Endpoint and IETF scoped network edge device."; container bgp { description "BGP-specific configuration."; leaf-list bgp-peer-ipv4 { type inet:ipv4-prefix; description "BGP peer ipv4 address."; } leaf-list bgp-peer-ipv6 { type inet:ipv6-prefix; description "BGP peer ipv6 address."; Wu, et al. Expires May 3, 2021 [Page 17] Internet-Draft IETF Network Slice NBI YANG model October 2020 } } container static { description "Only applies when protocol is static."; leaf-list static-route-ipv4 { type inet:ipv4-prefix; description "ipv4 static route"; } leaf-list static-route-ipv6 { type inet:ipv6-prefix; description "ipv6 static route"; } } } } grouping endpoint-monitoring-parameters { description "Grouping for endpoint-monitoring-parameters."; container endpoint-monitoring { config false; description "Container for endpoint-monitoring-parameters."; leaf incoming-utilized-bandwidth { type te-types:te-bandwidth; description "Bandwidth utilization that represents the actual utilization of the incoming endpoint."; } leaf incoming-bw-utilization { type decimal64 { fraction-digits 5; range "0..100"; } units "percent"; mandatory true; description "To be used to define the bandwidth utilization as a percentage of the available bandwidth."; } leaf outgoing-utilized-bandwidth { type te-types:te-bandwidth; description "Bandwidth utilization that represents the actual utilization of the incoming endpoint."; Wu, et al. Expires May 3, 2021 [Page 18] Internet-Draft IETF Network Slice NBI YANG model October 2020 } leaf outgoing-bw-utilization { type decimal64 { fraction-digits 5; range "0..100"; } units "percent"; mandatory true; description "To be used to define the bandwidth utilization as a percentage of the available bandwidth."; } } } grouping common-monitoring-parameters { description "Grouping for link-monitoring-parameters."; leaf latency { type uint32; units "usec"; description "The latency statistics per Network Slice member."; } leaf jitter { type uint32 { range "0..16777215"; } description "The jitter statistics per Network Slice member."; } leaf loss { type decimal64 { fraction-digits 6; range "0 .. 50.331642"; } description "Packet loss as a percentage of the total traffic sent over a configurable interval. The finest precision is 0.000003%. where the maximum 50.331642%."; reference "RFC 7810, section-4.4"; } } grouping geolocation-container { description "A grouping containing a GPS location."; Wu, et al. Expires May 3, 2021 [Page 19] Internet-Draft IETF Network Slice NBI YANG model October 2020 container geolocation { description "A container containing a GPS location."; leaf altitude { type int64; units "millimeter"; description "Distance above the sea level."; } leaf latitude { type decimal64 { fraction-digits 8; range "-90..90"; } description "Relative position north or south on the Earth's surface."; } leaf longitude { type decimal64 { fraction-digits 8; range "-180..180"; } description "Angular distance east or west on the Earth's surface."; } } // gps-location } // geolocation-container grouping endpoint { description "IETF Network Slice endpoint related information"; leaf endpoint-id { type uint32; description "unique identifier for the referred IETF Network Slice endpoint"; } leaf endpoint-name { type string; description "endpoint name"; } leaf-list endpoint-role { type identityref { base endpoint-role; Wu, et al. Expires May 3, 2021 [Page 20] Internet-Draft IETF Network Slice NBI YANG model October 2020 } default "any-to-any-role"; description "Role of the endpoint in the IETF Network Slice."; } uses geolocation-container; leaf node-id { type string; description "Uniquely identifies an edge node within the IETF slice network."; } leaf port-id { type string; description "Reference to the Port-id of the customer node."; } uses network-slice-match-criteria; leaf endpoint-ip { type inet:host; description "The address of the TACACS+ server."; } container bandwidth { container incoming-bandwidth { leaf guaranteed-bandwidth { type te-types:te-bandwidth; description "If guaranteed-bandwidth is 0, it means best effort, no minimum throughput is guaranteed."; } description "Container for the incoming bandwidth policy"; } container outgoing-bandwidth { leaf guaranteed-bandwidth { type te-types:te-bandwidth; description "If guaranteed-bandwidth is 0, it means best effort, no minimum throughput is guaranteed."; } description "Container for the bandwidth policy"; } description "Container for the bandwidth policy"; } leaf mtu { Wu, et al. Expires May 3, 2021 [Page 21] Internet-Draft IETF Network Slice NBI YANG model October 2020 type uint16; units "bytes"; mandatory true; description "MTU of Network Slice traffic. If the traffic type is IP, it refers to the IP MTU. If the traffic type is Ethertype, will refer to the Ethernet MTU. "; } uses routing-protocols; uses status-params; uses endpoint-monitoring-parameters; } //network-slice-endpoint grouping network-slice-member { description "network-slice-member is described by this container"; leaf network-slice-member-id { type uint32; description "network-slice-member identifier"; } container src { description "the source of Network Slice link"; leaf src-network-slice-endpoint-id { type leafref { path "/network-slices/network-slice/" + "network-slice-endpoint/endpoint-id"; } description "reference to source Network Slice endpoint"; } } container dest { description "the destination of Network Slice link "; leaf dest-network-slice-endpoint-id { type leafref { path "/network-slices/network-slice" + "/network-slice-endpoint/endpoint-id"; } description "reference to dest Network Slice endpoint"; } } leaf monitoring-type { Wu, et al. Expires May 3, 2021 [Page 22] Internet-Draft IETF Network Slice NBI YANG model October 2020 type network-slice-monitoring-type; description "One way or two way monitoring type."; } container network-slice-member-monitoring { config false; description "SLO status Per network-slice endpoint to endpoint "; uses common-monitoring-parameters; } } //network-slice-member grouping network-slice-slo-group { description "Grouping for SLO definition of Network Slice"; list network-slice-slo-group { key "slo-group-name"; description "List of Network Slice SLO groups, the SLO group is used to support different SLO objectives between different network-slice-members in the same slice."; leaf slo-group-name { type string; description "Identifies an entry in the list of SLO group for the Network Slice."; } leaf default-slo-group { type boolean; default "false"; description "Is the SLO group is selected as the default-slo-group"; } choice slo-template { description "Choice for SLO template. Can be standard template or customized template."; case standard { description "Standard SLO template."; leaf template { type leafref { path "/network-slices/slice-templates/slo-template/id"; } description "QoS template to be used."; Wu, et al. Expires May 3, 2021 [Page 23] Internet-Draft IETF Network Slice NBI YANG model October 2020 } } case custom { description "Customized SLO template."; container network-slice-slo-policy { container latency { leaf one-way-latency { type uint32 { range "0..16777215"; } units "usec"; description "Lowest latency in micro seconds."; } leaf two-way-latency { type uint32 { range "0..16777215"; } description "Lowest-way delay or latency in micro seconds."; } description "Latency constraint on the traffic class."; } container jitter { leaf one-way-jitter { type uint32 { range "0..16777215"; } description "lowest latency in micro seconds."; } leaf two-way-jitter { type uint32 { range "0..16777215"; } description "lowest-way delay or latency in micro seconds."; } description "Jitter constraint on the traffic class."; } container loss { leaf one-way-loss { type decimal64 { fraction-digits 6; range "0 .. 50.331642"; Wu, et al. Expires May 3, 2021 [Page 24] Internet-Draft IETF Network Slice NBI YANG model October 2020 } description "Packet loss as a percentage of the total traffic sent over a configurable interval. The finest precision is 0.000003%. where the maximum 50.331642%."; reference "RFC 7810, section-4.4"; } leaf two-way-loss { type decimal64 { fraction-digits 6; range "0 .. 50.331642"; } description "Packet loss as a percentage of the total traffic sent over a configurable interval. The finest precision is 0.000003%. where the maximum 50.331642%."; reference "RFC 7810, section-4.4"; } description "Loss constraint on the traffic class."; } leaf availability-type { type identityref { base availability-type; } description "Availability Requirement for the Network Slice"; } leaf isolation-type { type identityref { base isolation-type; } default "logical-isolation"; description "Network Slice isolation-level."; } uses network-slice-metric-bounds; description "container for customized policy constraint on the slice traffic."; } } } list network-slice-member-group { key "network-slice-member-id"; description Wu, et al. Expires May 3, 2021 [Page 25] Internet-Draft IETF Network Slice NBI YANG model October 2020 "List of included Network Slice Member groups for the SLO."; leaf network-slice-member-id { type leafref { path "/network-slices/network-slice/" + "network-slice-member/network-slice-member-id"; } description "Identifies the included list of Network Slice member."; } } container slo-group-monitoring { config false; description "SLO status Per slo group "; uses common-monitoring-parameters; } } } grouping slice-template { description "Grouping for slice-templates."; container slice-templates { description "Container for slice-templates."; list slo-template { key "id"; leaf id { type string; description "Identification of the SLO Template to be used. Local administration meaning."; } leaf template-description { type string; description "Description of the SLO template."; } description "List for SLO template identifiers."; } } } /* Configuration data nodes */ container network-slices { description Wu, et al. Expires May 3, 2021 [Page 26] Internet-Draft IETF Network Slice NBI YANG model October 2020 "network-slice configurations"; uses slice-template; list network-slice { key "network-slice-id"; description "a network-slice is identified by a network-slice-id"; leaf network-slice-id { type uint32; description "a unique network-slice identifier"; } leaf network-slice-name { type string; description "network-slice name"; } leaf network-slice-tag { type string; description "Network Slice tag for operational management"; } leaf-list network-slice-topology { type identityref { base network-slice-topology; } default "any-to-any"; description "Network Slice topology."; } uses network-slice-slo-group; uses status-params; list network-slice-endpoint { key "endpoint-id"; uses endpoint; description "list of endpoints in this slice"; } list network-slice-member { key "network-slice-member-id"; description "List of network-slice-member in a slice"; uses network-slice-member; } } //network-slice-list } } Wu, et al. Expires May 3, 2021 [Page 27] Internet-Draft IETF Network Slice NBI YANG model October 2020 9. Security Considerations The YANG module defined in this document 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 NETCONF access control model [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) to these data nodes without proper protection can have a negative effect on network operations. o /ietf-network-slice/network-slices/network-slice The entries in the list above include the whole network configurations corresponding with the slice which the higher management system requests, and indirectly create or modify the PE or P device configurations. Unexpected changes to these entries could lead to service disruption and/or network misbehavior. 10. IANA Considerations This document registers a URI in the IETF XML registry [RFC3688]. Following the format in [RFC3688], the following registration is requested to be made: URI: urn:ietf:params:xml:ns:yang:ietf-network-slice Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. This document requests to register a YANG module in the YANG Module Names registry [RFC7950]. Wu, et al. Expires May 3, 2021 [Page 28] Internet-Draft IETF Network Slice NBI YANG model October 2020 Name: ietf-network-slice Namespace: urn:ietf:params:xml:ns:yang:ietf-network-slice Prefix: ietf-ns Reference: RFC XXXX 11. Acknowledgments The authors wish to thank Sergio Belotti, Qin Wu, Susan Hares, Eric Grey, and many other NS DT members for their helpful comments and suggestions. 12. References 12.1. Normative References [I-D.nsdt-teas-ietf-network-slice-definition] Rokui, R., Homma, S., Makhijani, K., Contreras, L., and J. Tantsura, "Definition of IETF Network Slices", draft-nsdt- teas-ietf-network-slice-definition-00 (work in progress), October 2020. [I-D.nsdt-teas-ns-framework] Gray, E. and J. Drake, "Framework for Transport Network Slices", draft-nsdt-teas-ns-framework-04 (work in progress), July 2020. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [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, . [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . Wu, et al. Expires May 3, 2021 [Page 29] Internet-Draft IETF Network Slice NBI YANG model October 2020 [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . [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, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . [RFC8640] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard, E., and A. Tripathy, "Dynamic Subscription to YANG Events and Datastores over NETCONF", RFC 8640, DOI 10.17487/RFC8640, September 2019, . [RFC8641] Clemm, A. and E. Voit, "Subscription to YANG Notifications for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641, September 2019, . 12.2. Informative References [I-D.geng-teas-network-slice-mapping] Geng, X., Dong, J., Pang, R., Han, L., Niwa, T., Jin, J., Liu, C., and N. Nageshar, "5G End-to-end Network Slice Mapping from the view of Transport Network", draft-geng- teas-network-slice-mapping-02 (work in progress), July 2020. Wu, et al. Expires May 3, 2021 [Page 30] Internet-Draft IETF Network Slice NBI YANG model October 2020 [I-D.ietf-teas-actn-vn-yang] Lee, Y., Dhody, D., Ceccarelli, D., Bryskin, I., and B. Yoon, "A YANG Data Model for VN Operation", draft-ietf- teas-actn-vn-yang-09 (work in progress), July 2020. [I-D.liu-teas-transport-network-slice-yang] Liu, X., Tantsura, J., Bryskin, I., Contreras, L., WU, Q., Belotti, S., and R. Rokui, "Transport Network Slice YANG Data Model", draft-liu-teas-transport-network-slice- yang-01 (work in progress), July 2020. [RFC8309] Wu, Q., Liu, W., and A. Farrel, "Service Models Explained", RFC 8309, DOI 10.17487/RFC8309, January 2018, . Appendix A. Comparison with Other Possible Design choices for IETF Network Slice NBI According to the 3.3.1. Northbound Inteface (NBI) [I-D.nsdt-teas-ns-framework], the IETF Network Slice NBI is a technology-agnostic interface, which is used for a consumer to express requirements for a particular IETF Network Slice. Consumers operate on abstract IETF Network Slices, with details related to their realization hidden. As classified by [RFC8309], the IETF Network Slice NBI is classified as Customer Service Model. This draft analyzes the following existing IETF models to identify the gap between the IETF Network Slice NBI requirements. A.1. ACTN VN Model Augmentation The difference between the ACTN VN model and the IETF Network Slice NBI requirements is that the IETF Network Slice NBI is a technology- agnostic interface, whereas the VN model is bound to the IETF TE Topologies. The realization of the IETF Network Slice does not necessarily require the slice network to support the TE technology. The ACTN VN (Virtual Network) model introduced in [I-D.ietf-teas-actn-vn-yang] is the abstract consumer view of the TE network. Its YANG structure includes four components: o VN: A Virtual Network (VN) is a network provided by a service provider to a customer for use and two types of VN has defined. The Type 1 VN can be seen as a set of edge-to-edge abstract links. Each link is an abstraction of the underlying network which can encompass edge points of the customer's network, access links, intra-domain paths, and inter-domain links. Wu, et al. Expires May 3, 2021 [Page 31] Internet-Draft IETF Network Slice NBI YANG model October 2020 o AP: An AP is a logical identifier used to identify the access link which is shared between the customer and the IETF scoped Network. o VN-AP: A VN-AP is a logical binding between an AP and a given VN. o VN-member: A VN-member is an abstract edge-to-edge link between any two APs or VN-APs. Each link is formed as an E2E tunnel across the underlying networks. The Type 1 VN can be used to describe IETF Network Slice connection requirements. However, the Network Slice SLO and Network Slice Endpoint are not clearly defined and there's no direct equivalent. For example, the SLO requirement of the VN is defined through the IETF TE Topologies YANG model, but the TE Topologies model is related to a specific implementation technology. Also, VN-AP does not define "network-slice-match-criteria" to specify a specific NSE belonging to an IETF Network Slice. A.2. RFC8345 Augmentation Model The difference between the IETF Network Slice NBI requirements and the IETF basic network model is that the IETF Network Slice NBI requests abstract consumer IETF Network Slices, with details related to the slice Network hidden. But the IETF network model is used to describe the interconnection details of a Network. The customer service model does not need to provide details on the Network. For example, IETF Network Topologies YANG data model extension introduced in Transport Network Slice YANG Data Model [I-D.liu-teas-transport-network-slice-yang] includes three major parts: o Network: a transport network list and an list of nodes contained in the network o Link: "links" list and "termination points" list describe how nodes in a network are connected to each other o Support network: vertical layering relationships between IETF Network Slice networks and underlay networks Based on this structure, the IETF Network Slice-specific SLO attributes nodes are augmented on the Network Topologies model,, e.g. isolation etc. However, this modeling design requires the slice network to expose a lot of details of the network, such as the actual topology including nodes interconnection and different network layers interconnection. Wu, et al. Expires May 3, 2021 [Page 32] Internet-Draft IETF Network Slice NBI YANG model October 2020 Appendix B. Appendix B IETF Network Slice Filter Criteria 5G is a use case of the IETF Network Slice and 5G End-to-end Network Slice Mapping from the view of IETF Network [I-D.geng-teas-network-slice-mapping] defines two types of Network Slice interconnection and differentiation methods: by physical interface or by TNSII (Transport Network Slice Interworking Identifier). TNSII is a field in the packet header when different 5G wireless network slices are transported through a single physical interfaces of the IETF scoped Network. In the 5G scenario, "network-slice-match-criteria" refers to TNSII. +------------------------------------------------------------+ | 5G E2E network slice orchestrator | ++-----------------------------------------------------+-----+ | | | | IETF Network Slice NBI | +---+-------+ | +-----+-----+ | | +------------------+ | | |RAN Slice | |IETF Network Slice| |Core Slice | |controller | | controller | | controller| +----+------+ +-------+----------+ +-----+-----+ | | | | | | +---+--+ +------------+----------------+ ++-----+ | | | | | | | | | | | | |+----+| | | | | || ||NS1-NSE1 | Network Slice 1 | |+----+| ||gNB1|+---------+-----+-----------------------+--------+|UPF1|| || |+************ / |NS1-NSE3|+----+| |+----+|NS2-NSE1 | */ | | | | | /* | | | |+----+|NS1-NSE2 | / * | | | || |+---------- * Network Slice 2 |NS2-NSE3|+----+| ||gNB2|+************************************************+|UPF2|| || ||NS2-NSE2 | | |+----+| |+----+| | | | | | | | | | | | | | | | +------+ +----------- -----------------+ +------+ As shown in the figure, gNodeB 1 and gNodeB 2 use IP gNB1 and IP gNB2 to communicate with the IETF network, respectively. In addition, the traffic of NS1 and NS2 on gNodeB 1 and gNodeB 2 is transmitted Wu, et al. Expires May 3, 2021 [Page 33] Internet-Draft IETF Network Slice NBI YANG model October 2020 through the same access links to the IETF slice network. The IETF slice network need to to distinguish different IETF Network Slice traffic of same gNB. Therefore, in addition to using "node-id" and "port-id" to identify a Network Slice Endpont, other information is needed along with these parameters to uniquely distinguish a NSE. For example, VLAN IDs in the user traffic can be used to distinguish the NSEs of gNBs and UPFs. Authors' Addresses Bo Wu Huawei Technologies 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: lana.wubo@huawei.com Dhruv Dhody Huawei Technologies Divyashree Techno Park Bangalore, Karnataka 560066 India Email: dhruv.ietf@gmail.com Liuyan Han China Mobile Email: hanliuyan@chinamobile.com Reza Rokui Nokia Canada Email: reza.rokui@nokia.com Wu, et al. 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