IETF Network Slice Service YANG Model
Bo Wu
Huawei Technologies
101 Software Avenue, Yuhua District
Nanjing
Jiangsu
210012
China
lana.wubo@huawei.com
Dhruv Dhody
Huawei Technologies
Divyashree Techno Park
Bangalore
Karnataka
560066
India
dhruv.ietf@gmail.com
Reza Rokui
Ciena
rrokui@ciena.com
Tarek Saad
Juniper Networks
tsaad@juniper.net
Liuyan Han
China Mobile
hanliuyan@chinamobile.com
2022
Routing Area
TEAS
This document defines a YANG model for the IETF Network Slice service. The model can be used by an IETF Network Slice customer to manage IETF Network Slices.

Introduction
This document defines a YANG [RFC7950] data model for the IETF Network Slice service.
The YANG model discussed in this document is defined based on the description of the IETF Network Slice service in [I-D.ietf-teas-ietf-network-slices], which is used to operate IETF Network Slices during the IETF Network Slice instantiation. This YANG model supports various operations on IETF Network Slices such as creation, modification, deletion, and monitoring.
The YANG model discussed in this document describes the requirements of an IETF Network Slice service from the point of view of the customer. It is thus classified as customer service model in [RFC8309].
The IETF Network Slice operational state is included in the same tree as the configuration consistent with Network Management Datastore Architecture [RFC8342].
Editorial Note: (To be removed by RFC Editor)
This draft contains several placeholder values that need to be replaced with finalized values at the time of publication. Please apply the following replacements:
- "XXXX" --> the assigned RFC value for this draft both in this draft and in the YANG models under the revision statement.
- The "revision" date in model, in the format XXXX-XX-XX, needs to be updated with the date the draft gets approved.

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:
- client
- configuration data
- state data
This document makes use of the terms defined in [RFC7950].
The tree diagram used in this document follow the notation defined in [RFC8340].
This document also makes use of the terms introduced in the Framework for IETF Network Slices [I-D.ietf-teas-ietf-network-slices]:
- Attachment Circuit (AC): as defined in section 3.1 [I-D.ietf-teas-ietf-network-slices].
- Service Demarcation Point (SDP): The point at which an IETF Network Slice service is delivered by a service provider to a customer, as defined in section 4.2 [I-D.ietf-teas-ietf-network-slices]
- Connectivity Construct: A set of SDPs together with a communication type that defines how traffic flows between the SDPs, as defined in section 3.2 [I-D.ietf-teas-ietf-network-slices].
This document defines the following terms:
- Connection Group: Connection group is an arbitrary collection of one or more connection constructs, which can be used for the following possible purposes:
  Assign the same SLO/SLE policies to multiple connectivity constructs unless SLO/SLE policy is explicitly overriden at the individual connectivity construct level.
  Combine multiple connectivity constructs to support some well-known connectivity types, such as bidirectional unicast service, multipoint-to-point (MP2P) service, hub-and-spoke service etc.
  Share specific SLO limits within multiple connectivity constructs.

Acronyms
The following acronyms are used in the document:
AC: Attachment Circuit
CE: Customer Edge
NSC: Network Slice Controller
MTU: Maximum Transmission Unit
PE: Provider Edge
SDP: Service Demarcation Point
SLE: Service Level Expectation
SLO: Service Level Objective

IETF Network Slice Service Overview
As defined in [I-D.ietf-teas-ietf-network-slices], an IETF Network Slice service is specified in terms of a set of SDPs, a set of one or more connectivity constructs between subsets of these SDPs, and a set of SLOs and SLEs (see Section 4) for each SDP sending to each connectivity construct. A communication type (point- to-point (P2P), point-to-multipoint (P2MP), or any-to-any (A2A)) is specified for each connectivity construct.
A slice service may include only one connectivity construct or multiple connectivity constructs that associate sets of SDPs. The SDPs serve as the IETF Network Slice ingress/egress points. An SDP is identified by a unique identifier in the context of an IETF Network Slice service.
An example of IETF network slice services containing only one connectivity construct is shown in Figure 1.

An Example of IETF Network Slice Services
       +----------------------------------------------+
       |                                              |
       |                                              |
       |       Slice Service 1 with 1 P2P CC          |
 SDP1  O------------------->--------------------------O SDP2
       |                                              |
       |                                              |
       |       Slice Service 2 with 1 P2MP CC
       |                  +---------------------------O SDP4
 SDP3  O----------->------+                           |
       |                  +---------------------------O SDP5
       |                                              |
       |                                              |
       |       Slice Service 3 with 1 A2A  CC
 SDP6  O-----------<>-----+---------<>----------------O SDP8
       |                  |                           |
 SDP7  O-----------<>-----+---------<>----------------O SDP9
       |                                              |
       |                                              |
       +----------------------------------------------+
       |<----------IETF Network Slice Services------->|
       |        between endpoints SDP1 to SDP9       |

 SDP:  Service Demarcation Point
 P2P:  Point-to-point
 P2MP: Point-to-multipoint
 A2A:  Any-to-any
 CC:   Connectivity Construct
 O  : Represents Service Demarcation Point
----: Represents Connectivity Construct
< > : Direction

An example of IETF network slice services containing multiple connectivity constructs is shown in Figure 2.

An Example of IETF Network Slice Services
       +----------------------------------------------+
       |                                              |
       |       Slice Service 4 with 2 P2P CCs         |
 SDP10 O------------------->--------------------------O SDP12
 SDP11 O------------------->--------------------------O SDP13
       |                                              |
       |                                              |
       |      Slice Service 5 with 2 P2P CCs          |
       | +----------------->-----------------------+  |
 SDP14 o/                                           \ o SDP15
       |\                                           / |
       | +-----------------<-----------------------+  |
       |                                              |
 Application of                                       |
 match criteria                                       |
       |                                              |
       |      Slice Service 6 with 2 P2P CCs          |
       v +--x-x-x-x-x-x---->---x-x-x-x-x-x-x-x-x---+  |
 SDP16 o/                                           \ o SDP17
       |\                                           / |
       | +--%-%-%-%-%-%---->---%-%-%-%-%-%-%-%-%---+  |
       |                                              |
       +----------------------------------------------+
       |<----------IETF Network Slice Services------->|
       |        between endpoints SDP10 to SDP17      |

 Slice Service: IETF Network Slice Service
 SDP:  Service Demarcation Point
 P2P:  Point-to-point
 CC:   Connectivity Construct
 o  : Represents Service Demarcation Point
----: Represents Connectivity Construct
-x-x-x-: Represents connectivity construct applying match-criteria 1
-%-%-%-: Represents connectivity construct applying match-criteria 2
< > : Direction

As shown in the example, The IETF network slice service 4 contains two P2P connectivity constructs between various SDPs. The IETF network slice service 5 is a bidirectional P2P service on SDP14 and SDP15. The service consists of two unidirectional P2P connectivity constructs. For the traffic from each SDPs, there is only one connectivity construct. For the IETF network slice service 6, an P2P service on SDP 16 and SDP 17, this service includes two unidirectional P2P connectivity constructs with different set of SLOs between the two SDPs. Since SDP16 is the source of two connectivity constructs, this requires matching criteria be applied to traffic of SDP16 to distinguish between flows constructed by two connections. One example could be that the SDP16 uses DSCPs in the packets to differentiate traffic and steers to different connectivity constructs to ensure different SLOs.

IETF Network Slice Service Model Usage
The intention of the IETF Network Slice service model is to allow the customer to manage IETF Network Slices. In particular, the model allows customers to operate in an abstract and technology-agnostic manner, with details of the IETF Network Slices realization hidden.
According to the [I-D.ietf-teas-ietf-network-slices] description, IETF Network Slices are applicable to use cases such as (but not limited to) network wholesale services, network infrastructure sharing among operators, NFV (Network Function Virtualization) connectivity, Data Center Interconnect, and 5G E2E network slice.
As shown in Figure 3, in all these use-cases, the model is used by the customer higher level operation system to communicate with NSC for life cycle management of IETF Network Slices including both enablement and monitoring. For example, in 5G E2E (End-to-end) network slicing use-case the E2E network slice orchestrator acts as the higher layer system to request the IETF 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.
The IETF Network Slice Controller (NSC) is a logical entity that allows customers to manage IETF network slices. The NSC receives request from its customer-facing interface (e.g., from a management system). This interface carries data objects the IETF Network Slice service customer provides, describing the needed IETF network slices service in terms of a set of SDPs, the associated connectivity constructs and the service objectives that the customer wishes to be fulfilled. These requirements are then translated into technology-specific actions that are implemented in the underlying network using a network-facing interface. The details of how the IETF Network Slices are put into effect are out of scope for this document.

IETF Network Slice Service Reference Architecture
          +----------------------------------------+
          |   IETF Network Slice Customer          |
          |                                        |
          +----------------+-----------------------+
                           |
                           |
                           |IETF Network Slice service model
                           |
     +---------------------+--------------------------+
     |      IETF Network Slice Controller (NSC)       |
     +------------------------------------------------+

IETF Network Slice Service Modeling Description
The 'ietf-network-slice-service' module uses two main data nodes: list 'slice-service' and container 'slo-sle-templates' (see Figure 4).
The 'slice-service' list includes the set of IETF Network Slice services managed within a provider network. 'slice-service' is the data structure that abstracts an IETF Network Slice service. Under the "slice-service", list "sdp" is used to abstract the SDPs. And list "connection-group" is used to abstract connectivity constructs between SDPs.
The 'slo-sle-templates' container is used by the NSC to maintain a set of common network slice SLO and SLE templates that apply to one or several IETF Network Slice services.
The figure below describes the overall structure of the YANG module:
module: ietf-network-slice-service
  +--rw network-slice-services
     +--rw slo-sle-templates
     |  +--rw slo-sle-template* [id]
     |     +--rw id                      string
     |     +--rw template-description?   string
     +--rw slice-service* [service-id]
        +--rw service-id                      string
        +--rw service-description?            string
        +--rw service-tags
        |  +--rw tag-type* [tag-type]
        |  |  +--rw tag-type    identityref
        |  |  +--rw value*      string
        |  +--rw tag-opaque* [tag-name]
        |     +--rw tag-name    string
        |     +--rw value*      string
        +--rw (slo-sle-policy)?
        |  +--:(standard)
        |  |  +--rw slo-sle-template?         leafref
        |  +--:(custom)
        |     +--rw service-slo-sle-policy
        |        +--rw policy-description?     string
        |        +--rw metric-bounds
        |        |  +--rw metric-bound* [metric-type]
        |        |     +--rw metric-type          identityref
        |        |     +--rw metric-unit          string
        |        |     +--rw value-description?   string
        |        |     +--rw bound?               uint64
        |        +--rw security*               identityref
        |        +--rw isolation?              identityref
        |        +--rw max-occupancy-level?    uint8
        |        +--rw mtu?                    uint16
        |        +--rw steering-constraints
        |           +--rw path-constraints
        |           +--rw service-function
        +--rw status
        |  +--rw admin-status
        |  |  +--rw status?         identityref
        |  |  +--rw last-updated?   yang:date-and-time
        |  +--ro oper-status
        |     +--ro status?         identityref
        |     +--ro last-updated?   yang:date-and-time
        +--rw sdps
        |  +--rw sdp* [sdp-id]
        |     +--rw sdp-id                    string
        |     +--rw sdp-description?          string
        |     +--rw location
        |     |  +--rw altitude?    int64
        |     |  +--rw latitude?    decimal64
        |     |  +--rw longitude?   decimal64
        |     +--rw node-id?                  string
        |     +--rw sdp-ip?                   inet:ip-address
        |     +--rw service-match-criteria
        |     |  +--rw match-criterion* [index]
        |     |     +--rw index                               uint32
        |     |     +--rw match-type
        |     |     |       identityref
        |     |     +--rw value*                              string
        |     |     +--rw target-connection-group-id          leafref
        |     |     +--rw connection-group-sdp-role?
        |     |     |       identityref
        |     |     +--rw target-connectivity-construct-id?   leafref
        |     +--rw sdp-peering
        |     |  +--rw protocol* [protocol-type]
        |     |  |  +--rw protocol-type    identityref
        |     |  |  +--rw attribute* [attribute-type]
        |     |  |     +--rw attribute-type    identityref
        |     |  |     +--rw value*            string
        |     |  +--rw opaque* [attribute-name]
        |     |     +--rw attribute-name    string
        |     |     +--rw value*            string
        |     +--rw attachment-circuits
        |     |  +--rw attachment-circuit* [ac-id]
        |     |     +--rw ac-id                     string
        |     |     +--rw ac-description?           string
        |     |     +--rw ac-node-id?               string
        |     |     +--rw ac-tp-id?                 string
        |     |     +--rw ac-ip-address?            inet:ip-address
        |     |     +--rw ac-ip-prefix-length?      uint8
        |     |     +--rw ac-qos-policy-name?       string
        |     |     +--rw mtu?                      uint16
        |     |     +--rw ac-tags
        |     |     |  +--rw ac-tags* [ac-tag-type]
        |     |     |  |  +--rw ac-tag-type    identityref
        |     |     |  |  +--rw value*         string
        |     |     |  +--rw ac-tag-opaque* [tag-name]
        |     |     |     +--rw tag-name    string
        |     |     |     +--rw value*      string
        |     |     +--rw service-match-criteria
        |     |     |  +--rw match-criterion* [index]
        |     |     |     +--rw index
        |     |     |     |       uint32
        |     |     |     +--rw match-type
        |     |     |     |       identityref
        |     |     |     +--rw value*
        |     |     |     |       string
        |     |     |     +--rw target-connection-group-id          leafref
        |     |     |     +--rw connection-group-sdp-role?
        |     |     |     |       identityref
        |     |     |     +--rw target-connectivity-construct-id?   leafref
        |     |     +--rw sdp-peering
        |     |     |  +--rw protocol* [protocol-type]
        |     |     |  |  +--rw protocol-type    identityref
        |     |     |  |  +--rw attribute* [attribute-type]
        |     |     |  |     +--rw attribute-type    identityref
        |     |     |  |     +--rw value*            string
        |     |     |  +--rw opaque* [attribute-name]
        |     |     |     +--rw attribute-name    string
        |     |     |     +--rw value*            string
        |     |     +--rw incoming-rate-limits
        |     |     |  +--rw cir?   uint64
        |     |     |  +--rw cbs?   uint64
        |     |     |  +--rw eir?   uint64
        |     |     |  +--rw ebs?   uint64
        |     |     |  +--rw pir?   uint64
        |     |     |  +--rw pbs?   uint64
        |     |     +--rw outgoing-rate-limits
        |     |        +--rw cir?   uint64
        |     |        +--rw cbs?   uint64
        |     |        +--rw eir?   uint64
        |     |        +--rw ebs?   uint64
        |     |        +--rw pir?   uint64
        |     |        +--rw pbs?   uint64
        |     +--rw incoming-rate-limits
        |     |  +--rw cir?   uint64
        |     |  +--rw cbs?   uint64
        |     |  +--rw eir?   uint64
        |     |  +--rw ebs?   uint64
        |     |  +--rw pir?   uint64
        |     |  +--rw pbs?   uint64
        |     +--rw outgoing-rate-limits
        |     |  +--rw cir?   uint64
        |     |  +--rw cbs?   uint64
        |     |  +--rw eir?   uint64
        |     |  +--rw ebs?   uint64
        |     |  +--rw pir?   uint64
        |     |  +--rw pbs?   uint64
        |     +--rw status
        |     |  +--rw admin-status
        |     |  |  +--rw status?         identityref
        |     |  |  +--rw last-updated?   yang:date-and-time
        |     |  +--ro oper-status
        |     |     +--ro status?         identityref
        |     |     +--ro last-updated?   yang:date-and-time
        |     +--ro sdp-monitoring
        |        +--ro incoming-utilized-bandwidth?
        |        |       te-types:te-bandwidth
        |        +--ro incoming-bw-utilization        decimal64
        |        +--ro outgoing-utilized-bandwidth?
        |        |       te-types:te-bandwidth
        |        +--ro outgoing-bw-utilization        decimal64
        +--rw connection-groups
           +--rw connection-group* [connection-group-id]
              +--rw connection-group-id             string
              +--rw connectivity-type?              identityref
              +--rw (slo-sle-policy)?
              |  +--:(standard)
              |  |  +--rw slo-sle-template?         leafref
              |  +--:(custom)
              |     +--rw service-slo-sle-policy
              |        +--rw policy-description?     string
              |        +--rw metric-bounds
              |        |  +--rw metric-bound* [metric-type]
              |        |     +--rw metric-type          identityref
              |        |     +--rw metric-unit          string
              |        |     +--rw value-description?   string
              |        |     +--rw bound?               uint64
              |        +--rw security*               identityref
              |        +--rw isolation?              identityref
              |        +--rw max-occupancy-level?    uint8
              |        +--rw mtu?                    uint16
              |        +--rw steering-constraints
              |           +--rw path-constraints
              |           +--rw service-function
              +--rw connectivity-construct* [cc-id]
              |  +--rw cc-id                                uint32
              |  +--rw (connectivity-construct-type)?
              |  |  +--:(p2p)
              |  |  |  +--rw p2p-sender-sdp?
              |  |  |  |       -> ../../../../sdps/sdp/sdp-id
              |  |  |  +--rw p2p-receiver-sdp?
              |  |  |          -> ../../../../sdps/sdp/sdp-id
              |  |  +--:(p2mp)
              |  |  |  +--rw p2mp-sender-sdp?
              |  |  |  |       -> ../../../../sdps/sdp/sdp-id
              |  |  |  +--rw p2mp-receiver-sdp*
              |  |  |          -> ../../../../sdps/sdp/sdp-id
              |  |  +--:(a2a)
              |  |     +--rw a2a-sdp* [sdp-id]
              |  |        +--rw sdp-id
              |  |        |       -> ../../../../../sdps/sdp/sdp-id
              |  |        +--rw (slo-sle-policy)?
              |  |           +--:(standard)
              |  |           |  +--rw slo-sle-template?         leafref
              |  |           +--:(custom)
              |  |              +--rw service-slo-sle-policy
              |  |                 +--rw policy-description?
              |  |                 |       string
              |  |                 +--rw metric-bounds
              |  |                 |  +--rw metric-bound*
              |  |                 |          [metric-type]
              |  |                 |     +--rw metric-type
              |  |                 |     |       identityref
              |  |                 |     +--rw metric-unit
              |  |                 |     |       string
              |  |                 |     +--rw value-description?
              |  |                 |     |       string
              |  |                 |     +--rw bound?
              |  |                 |             uint64
              |  |                 +--rw security*
              |  |                 |       identityref
              |  |                 +--rw isolation?
              |  |                 |       identityref
              |  |                 +--rw max-occupancy-level?
              |  |                 |       uint8
              |  |                 +--rw mtu?
              |  |                 |       uint16
              |  |                 +--rw steering-constraints
              |  |                    +--rw path-constraints
              |  |                    +--rw service-function
              |  +--rw (slo-sle-policy)?
              |  |  +--:(standard)
              |  |  |  +--rw slo-sle-template?              leafref
              |  |  +--:(custom)
              |  |     +--rw service-slo-sle-policy
              |  |        +--rw policy-description?     string
              |  |        +--rw metric-bounds
              |  |        |  +--rw metric-bound* [metric-type]
              |  |        |     +--rw metric-type
              |  |        |     |       identityref
              |  |        |     +--rw metric-unit          string
              |  |        |     +--rw value-description?   string
              |  |        |     +--rw bound?               uint64
              |  |        +--rw security*               identityref
              |  |        +--rw isolation?              identityref
              |  |        +--rw max-occupancy-level?    uint8
              |  |        +--rw mtu?                    uint16
              |  |        +--rw steering-constraints
              |  |           +--rw path-constraints
              |  |           +--rw service-function
              |  +--ro connectivity-construct-monitoring
              |     +--ro one-way-min-delay?         uint32
              |     +--ro one-way-max-delay?         uint32
              |     +--ro one-way-delay-variation?   uint32
              |     +--ro one-way-packet-loss?       decimal64
              |     +--ro two-way-min-delay?         uint32
              |     +--ro two-way-max-delay?         uint32
              |     +--ro two-way-delay-variation?   uint32
              |     +--ro two-way-packet-loss?       decimal64
              +--ro connection-group-monitoring
                 +--ro one-way-min-delay?         uint32
                 +--ro one-way-max-delay?         uint32
                 +--ro one-way-delay-variation?   uint32
                 +--ro one-way-packet-loss?       decimal64
                 +--ro two-way-min-delay?         uint32
                 +--ro two-way-max-delay?         uint32
                 +--ro two-way-delay-variation?   uint32
                 +--ro two-way-packet-loss?       decimal64

IETF Network Slice Service SLO and SLE Templates
The 'ns-templates' container (Figure 4) is used by the service provider of the NSC to define and maintain a set of common IETF Network Slice templates that apply to one or several IETF Network Slice services. The exact definition of the templates is deployment specific to each network provider.
The model includes only the identifiers of SLO and SLE templates. When creation of IETF Network slice, the SLO and SLE policies can be easily identified.
The following shows an example where two network slice templates can be retrieved by the customer higher level operation system:
{
  "network-slice-services": {
    "slo-sle-templates": {
      "slo-sle-template": [
       {
         "id":"GOLD-template",
         "template-description": "Two-way bandwidth: 1 Gbps,
          one-way latency 100ms "
         "sle-isolation":"service-isolation-shared",
        },
       {
         "id":"PLATINUM-template",
         "template-description": "Two-way bandwidth: 1 Gbps,
           one-way latency 50ms "
         "sle-isolation":"service-isolation-dedicated",
        },
       ],
      }
   }
}

IETF Network Slice Service
The 'slice-service' is the data structure that abstracts an IETF Network Slice service. Each 'slice-service' is uniquely identified by an identifier: 'service-id'.
An IETF Network Slice service has the following main parameters:
- "service-id": Is an identifier that is used to uniquely identify the IETF Network Slice service within NSC.
- "service-description": Gives some description of an IETF Network Slice service.
- "status": Is used to show the operative and administrative status of the IETF Network Slice service, and can be used as indicator to detect network slice anomalies.
- "service-tags": It is a means to correlate the higher level “Customer higher level operation system” and IETF network slices. It might be used by IETF network Slice service operator to provide additional information to the IETF Network Slice Controller (NSC) during the automation of the IETF network slices. E.g. adding tag with “customer-name” when multiple actual customers use a same network slice service. Another use-case for “service-tag” might be for an operator to provide additional attributes to NSC which might be used during the realization of IETF Network Slice services such as type of services (e.g., L2 or L3). These additional attributes can also be used by the NSC for various use-cases such as monitoring and assurance of the IETF Network Slice services where NSC can notify the customer system by issuing the notifications. Note that all these attributes are OPTIONAL but might be useful for some use-cases.
- "slo-sle-policy": Defines SLO and SLE policies for the "slice-service". More description are provided in Section 5.2.3
- "sdp“: Represents a set of endpoints (SDPs) involved in the IETF Network Slice service with each 'sdp' belonging to a single 'slice-service'. More description are provided in Section 5.2.1.
- "connection-groups“: Abstracts the connections to the set of SDPs of the IETF Network Slice service.

IETF Network Slice Service Demarcation Point
An SDP belong to a single IETF Network Slice service. An IETF Network Slice service involves two or more SDPs. An IETF Network Slice service can be modified by adding new "sdp" or removing existing "sdp".
Section 4.2 [I-D.ietf-teas-ietf-network-slices] describes four possible ways in which the SDP may be placed:
- Within CE
- Provider-facing ports on the CE
- Customer-facing ports on the PE
- Within PE
In the four options, the Attachment Circuit (AC) may be part of the IETF Network Slice service or may be external to it. Based on the definition of AC in section 2.1 [I-D.ietf-teas-ietf-network-slices], the customer and provider may agree on a per {IETF Network Slice service, connectivity construct, and SLOs/SLEs} basis to police or shape traffic on the AC in both the ingress (CE to PE) direction and egress (PE to CE) direction, This ensures that the traffic is within the capacity profile that is agreed in an IETF Network Slice service. Excess traffic is dropped by default, unless specific out-of-profile policies are agreed between the customer and the provider.
An IETF Network Slice SDP has several characteristics:
- "sdp-id": Uniquely identifies the SDP within the Network Slice Controller (NSC). The identifier is a string that allows any encoding for the local administration of the IETF Network Slice service.
- "location": Indicates SDP location information, which helps the NSC to identify an SDP.
- "node-id": The SDP node information, which helps the NSC to identify an SDP.
- "sdp-ip": The SDP IP information, which helps the NSC to identify an SDP.
- "service-match-criteria": Defines matching policies for network slice service traffic to apply on a given SDP.
- "attachment-circuit": Specifies the list of ACs by which the service traffic is received. This is an optional SDP attribute. When a SDP has multiple ACs and the AC specific attributes is needed, each "attachment-circuit“ can specify attributes such as interface specific IP address, service MTU, "service-match-criteria", etc.
- "incoming-rate-limits" and "outgoing-rate-limits": Set the rate-limiting policies to apply on a given SDP, including ingress and egress traffic to ensure access security. When applied in the incoming direction, the rate-limit is applicable to the traffic from the SDP to the IETF scope Network that passes through the AC. When Bandwidth is applied to the outgoing direction, it is applied to the traffic from the IETF Network to the SDP of that particular slice service. If an SDP has multiple AC, the “incoming-rate-limits” and "outgoing-rate-limits" of “attachment-circuit” can be set to an AC specific value, but the rate cannot exceed the “incoming-rate-limits” and "outgoing-rate-limits" of the SDP. If a SDP only contains a single AC, then the “incoming-rate-limits” and "outgoing-rate-limits" of "attachment-circuit" is the same with the SDP “incoming-rate-limits” and "outgoing-rate-limits". The definition refers to [I-D.ietf-teas-ietf-network-slices].
- "sdp-peering": Specifies the protocol for a SDP for exchanging control-plane information, e.g. L1 signaling protocol or L3 routing protocols,etc.
- "status": Enables the control of the operative and administrative status of the SDP, can be used as indicator to detect SDP anomalies.
The customer may choose to use an explicit "service-match-criteria" to map all the SDP's traffic or a subset of the SDP's traffic to a specific connection-group or connectivity-construct.
If an SDP is placed at the port or AC of a CE or PE, and there is only one single connectivity construct with a source at the SDP, traffic can be implicitly mapped to this connectivity construct since the port or AC can be used to identify the traffic and the SDP is the only source of the connectivity-construct.
If an SDP is placed within CE or PE, or there are many single connectivity constructs with a source at the SDP. Traffic needs to be explicitly mapped into the IETF Network Slice's specific connectivity construct. The policies, "service-match-criteria", are based on the values in which combination of layer 2 and layer 3 header and payload fields within a packet to identify to which {IETF Network Slice service, connectivity construct, and SLOs/SLEs} that packet is assigned.
The customer may choose to use an explicit match-type of “match-any” to map all the SDP's traffic to the appropriate connection-group or connectivity-construct.
Similarly, if a subset of traffic is matched (ie. dscp-match) and mapped to a connectivity-construct, the customer may choose to add a subsequent “match-any” to explicitly map the remaining SDP traffic to a separate connectivity-construct. If the customer chooses to implicitly map remaining traffic and if there is no additional connectivity constructs where the “sdp-id” source is specified, then that traffic will be dropped.
While explicit matching is optional in some use cases, explicit matching provides a more clear and readable implementation, but the choice is left to the customer.
To illustrate the use of SDP options, the below are two examples. How the NSC realize the mapping is out of scope for this document.
- SDPs at customer-facing ports on the PEs: As shown in Figure 5 , customer of the IETF network slice service would like to connect two SDPs to satisfy specific service, e.g., Network wholesale services. In this case, the IETF network slice SDPs are mapped to customer-facing ports of PE nodes. The IETF network slice controller (NSC) uses 'node-id' (PE device ID), 'attachment-circuit' ( ACs ) to map SDPs to the customer-facing ports on the PEs.

              SDP1                                     SDP2
       (With PE1 parameters)                       (with PE2 parameters)
               o<--------- IETF Network Slice 1 ------->o
               +     |                            |     +
               +     |<----------- S1 ----------->|     +
               +     |                            |     +
               +     |    |<------ T1 ------>|    |     +
                 +   v    v                  v    v   +
                   + +----+                  +----+ +
    +-----+    |     | PE1|==================| PE2|          +-----+
    |     |----------X    |                  |    |     |    |     |
    |     |    |     |    |                  |    X----------|     |
    |     |----------X    |                  |    |     |    |     |
    +-----+    |     |    |==================|    |     |    +-----+
               AC    +----+                  +----+     AC
    Customer         Provider                Provider        Customer
    Edge 1           Edge 1                  Edge 2           Edge 2

  Legend:
   O: Representation of the IETF network slice endpoints (SDP)
   +: Mapping of SDP to customer-facing ports on the PE
   X: Physical interfaces used for realization of IETF network slice service
   S1: L0/L1/L2/L3 services used for realization of IETF network slice service
   T1: Tunnels used for realization of IETF network slice service

- SDPs within CEs: As shown in Figure 6 , customer of the IETF network slice service would like to connect two SDPs to provide connectivity between transport portion of 5G RAN to 5G Core network functions. In this scenario, the IETF network slice controller (NSC) uses 'node-id' (CE device ID) , 'sdp-ip' (CE tunnel endpoint IP), 'service-match-criteria' (VLAN tag), 'attachment-circuit' (ACs ) to map SDPs to the CE tunnel endpoints. And the NSC can also retrieve the corresponding ACs, or PEs, and further map the slice service to services/tunnels/paths.
           SDP3                                     SDP4
    (With CE1 parameters)                       (with CE2 parameters)
    +<----------------- IETF Network Slice 2 -------------->o
    +                                                       +
    +|<------------------------- S2 ---------------------->|+
    +|                                                     |+
    +|                 |<------ T2 ------>|                |+
    +|                 v                  v                |+
    +v            +----+                  +----+           v+
 +--+--+    |     | PE1|==================| PE2|     |    +-+---+
 |  +  X----------X    |                  |    |     |    | +   |
 |  o  |    |     |    |                  |    X----------X o   |
 |     X----------X    |                  |    |     |    |     |
 +-----+    |     |    |==================|    |     |    +-----+
            AC    +----+                  +----+     AC
 Customer         Provider                Provider         Customer
 Edge 1           Edge 1                  Edge 2           Edge 2

Legend:
O: Representation of the IETF network slice endpoints (SDP)
+: Mapping of SDP to CE
X: Physical interfaces used for realization of IETF network slice
S2: L0/L1/L2/L3 services used for realization of IETF network slice
T2: Tunnels used for realization of IETF network slice

IETF Network Slice Service Connectivity Construct
Based on the customer's service traffic requirements, an IETF Network Slice service connectivity type could be point-to-point (P2P), point-to-multipoint (P2MP), any-to-any (A2A) or a combination of these types.
[I-D.ietf-teas-ietf-network-slices] defines the basic connectivity construct for a network slice, and the connectivity construct may have different SLO and SLE requirements. "connectivity-construct" represents this connectivity construct, and "slo-sle-policy" under it represents the per-connectivity construct SLO and SLE requirements.
Apart from the per-connectivity construct SLO and SLE, slice service traffic is usually managed by combining similar types of traffic. For example, some connections for video services require high bandwidth, and some connections for voice over IP request low latency and reliability. "connection-group" is thus defined to treat each type as a class with per-connection-group SLO and SLE such that the connectivity construct can inherit the SLO/SLE from the group if not explicitly defined.

IETF Network Slice Service SLO and SLE Policy
As defined in section 4 [I-D.ietf-teas-ietf-network-slices], the SLO and SLE policy of an IETF Network Slice service defines some common attributes.
"slo-sle-policy" is used to represent specific SLO and SLE policies. During the creation of an IETF Network Slice service, the policy can be specified either by a standard SLO and SLO template or a customized SLO and SLE policy.
The policy can apply to per-network slice service, per-connection group "connection group", or per-connectivity construct "connectivity-construct". Since there are multiple mechanisms for assigning a policy to a single connectivity construct, an overridden precedence order among them is as follows:
- Connectivity-construct at a individual sending SDP
- Connectivity-construct
- Connection-group
- Slice-level
That is, the policy assigned through the sending SDP has highest precedence, and the policy assigned by the slice level has lowest precedence. Therefore, the policy assigned through the sending SDP takes precedence over the policy assigned through the connection-construct entry.
The container "metric-bounds" supports all the variations and combinations of SLOs, which includes a list of "metric-bound" and each "metric-bound" could specify a particular "metric-type". "metric-type" is defined with YANG identity and supports the following options:
"service-slo-one-way-bandwidth": Indicates the guaranteed minimum bandwidth between any two SDP. And the bandwidth is unidirectional.
"service-slo-two-way-bandwidth": Indicates the guaranteed minimum bandwidth between any two SDP. And the bandwidth is bidirectional.
"service-slo-one-way-delay": Indicates the maximum one-way latency between two SDP.
"service-slo-two-way-delay": Indicates the maximum round-trip latency between two SDP.
"service-slo-one-way-delay-variation": Indicates the jitter constraint of the slice maximum permissible delay variation, and is measured by the difference in the one-way latency between sequential packets in a flow.
"service-slo-two-way-delay-variation": Indicates the jitter constraint of the slice maximum permissible delay variation, and is measured by the difference in the two-way latency between sequential packets in a flow.
"service-slo-one-way-packet-loss": Indicates maximum permissible packet loss rate, which is defined by the ratio of packets dropped to packets transmitted between two endpoints.
"service-slo-two-way-packet-loss": Indicates maximum permissible packet loss rate, which is defined by the ratio of packets dropped to packets transmitted between two endpoints.
"service-slo-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.
The following common SLEs are defined:
"mtu": Refers to the service MTU, which is the maximum PDU size that the customer may use.
"security": Includes the request for encryption or other security techniques to traffic flowing between the two NS endpoints.
"isolation": Specifies the isolation level that a customer expects, including dedicated, shared, or other level.
max-occupancy-level: Specifies the number of flows to be admitted and optionally a maximum number of countable resource units (e.g., IP or MAC addresses) an IETF Network Slice service can consume.
"steering-constraints": Specifies the constraints how the provider routes traffic for the IETF Network Slice service.
The following shows an example where a network slice policy can be configured:
{
  "slice-services": {
    "slice-service": {
      "service-id": "exp-slice",
      "service-slo-sle-policy": {
        "policy-description":"video-service-policy",
        "metric-bounds": {
            "metric-bound": [
             {
                "metric-type": "service-slo-one-way-bandwidth",
                "metric-unit": "mbps"
                "bound": "1000"
             },
             {
                "metric-type": "service-slo-availability",
                "bound": "99.9%"
             },
            ],
         }
      }
    }
  }
}

IETF Network Slice Service Monitoring
An IETF Network Slice service defines connectivity with specific SLO characteristics, including bandwidth, latency, etc. The connectivity is a combination of logical unidirectional connections, represented by 'connectivity-construct'.
This model also describes performance status of an IETF Network Slice. The statistics are described in the following granularity:
- Per SDP: specified in 'sdp-monitoring' under the "sdp".
- Per connectivity construct: specified in 'connectivity-construct-monitoring' under the "connectivity-construct".
- Per connection group: specified in 'connection-group-monitoring' under the "connection-group".
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 "sdp", "connectivity-construct", or "connection-group", so that only interested contents will be sent. These mechanisms can be used for monitoring the IETF Network Slice performance status so that the customer management system could initiate modification based on the IETF Network Slice running status.

IETF Network Slice Service Module
The "ietf-network-slice" module uses types defined in [RFC6991] , [RFC9181], and [RFC8776], and [RFC7640].
<CODE BEGINS> file "ietf-network-slice-service@2022-07-11.yang"
module ietf-network-slice-service {
  yang-version 1.1;
  namespace
    "urn:ietf:params:xml:ns:yang:ietf-network-slice-service";
  prefix ietf-nss;

  import ietf-inet-types {
    prefix inet;
    reference
      "RFC 6991: Common YANG Types.";
  }
  import ietf-vpn-common {
    prefix vpn-common;
    reference
      "RFC 9181: A Common YANG Data Model for Layer 2 and Layer 3
                    VPNs.";
  }
  import ietf-te-types {
    prefix te-types;
    reference
      "RFC 8776: Common YANG Data Types for Traffic Engineering.";
  }
  import ietf-te-packet-types {
    prefix te-packet-types;
    reference
      "RFC 8776: Common YANG Data Types for Traffic Engineering.";
  }

  organization
    "IETF Traffic Engineering Architecture and Signaling (TEAS)
     Working Group";
  contact
    "WG Web:  <https://tools.ietf.org/wg/teas/>
     WG List:  <mailto:teas@ietf.org>

     Editor: Bo Wu
          <lana.wubo@huawei.com>
     Editor: Dhruv Dhody
          <dhruv.ietf@gmail.com>
     Editor: Reza Rokui
          <reza.rokui@nokia.com>
     Editor: Tarek Saad
          <tsaad@juniper.net>
     Author: Liuyan Han
          <hanliuyan@chinamobile.com>";
  description
    "This module defines a model for the IETF Network Slice service.

        Copyright (c) 2022 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 2022-07-11 {
    description
      "initial version.";
    reference
      "RFC XXXX: A Yang Data Model for IETF Network Slice service
       operation";
  }

  /* Features */
  /* Identities */

  identity service-tag-type {
    description
      "Base identity for IETF Network Slice service tag type.";
  }

  identity service-tag-customer {
    base service-tag-type;
    description
      "The IETF Network Slice service customer ID tag type.";
  }

  identity service-tag-service {
    base service-tag-type;
    description
      "The IETF Network Slice service tag type.";
  }

  identity service-tag-opaque {
    base service-tag-type;
    description
      "The IETF Network Slice service opaque tag type.";
  }

  identity attachment-circuit-tag-type {
    description
      "Base identity for the attachment circuit tag type.";
  }

  identity attachment-circuit-tag-vlan-id {
    base attachment-circuit-tag-type;
    description
      "The attachment circuit VLAN ID tag type.";
  }

  identity attachment-circuit-tag-ip-mask {
    base attachment-circuit-tag-type;
    description
      "The attachment circuit tag IP mask.";
  }

  identity service-isolation-type {
    description
      "Base identity for IETF Network slice service isolation level.";
  }

  identity service-isolation-shared {
    base service-isolation-type;
    description
      "Shared resources (e.g. queues) are associated with the
       slice service traffic. Hence, the traffic can be impacted
       by effects of other services traffic
       sharing the same resources.";
  }

  identity service-isolation-dedicated {
    base service-isolation-type;
    description
      "Dedicated resources (e.g. queues) are associated with the
       Network Slice service traffic. Hence, the service traffic
       is isolated from other servceis traffic
       sharing the same resources.";
  }

  identity service-security-type {
    description
      "Base identity for for slice service security level.";
  }

  identity service-security-authenticate {
    base service-security-type;
    description
      "Indicates the slice service requires authentication.";
  }

  identity service-security-integrity {
    base service-security-type;
    description
      "Indicates the slice service requires data integrity.";
  }

  identity service-security-encryption {
    base service-security-type;
    description
      "Indicates the slice service requires data encryption.";
  }

  identity point-to-point {
    base vpn-common:vpn-topology;
    description
      "Identity for point-to-point IETF Network Slice
       service connectivity.";
  }

  identity point-to-multipoint {
    base vpn-common:vpn-topology;
    description
      "Identity for point-to-point IETF Network Slice
       service connectivity.";
  }

  identity multipoint-to-multipoint {
    base vpn-common:vpn-topology;
    description
      "Identity for point-to-point IETF Network Slice
       service connectivity.";
  }

  identity multipoint-to-point {
    base vpn-common:vpn-topology;
    description
      "Identity for point-to-point IETF Network Slice
       service connectivity.";
  }

  identity sender-role {
    base vpn-common:role;
    description
      "A SDP is acting as a sender.";
  }

  identity receiver-role {
    base vpn-common:role;
    description
      "A SDP is acting as a receiver.";
  }

  identity service-slo-metric-type {
    description
      "Base identity for IETF Network Slice service SLO metric type.";
  }

  identity service-slo-one-way-bandwidth {
    base service-slo-metric-type;
    description
      "SLO bandwidth metric. Minimum guaranteed bandwidth between
       two SDPs at any time and is measured unidirectionally.";
  }

  identity service-slo-two-way-bandwidth {
    base service-slo-metric-type;
    description
      "SLO bandwidth metric. Minimum guaranteed bandwidth between
       two SDPs at any time.";
  }

  identity service-slo-shared-bandwidth {
    base service-slo-metric-type;
    description
      "The shared SLO bandwidth bound. It is the limit on the
       bandwidth that can be shared amongst a group of
       connectivity constructs of a slice service.";
  }

  identity service-slo-one-way-delay {
    base service-slo-metric-type;
    description
      "SLO one-way-delay is the upper bound of network delay when
       transmitting between two SDPs. The metric is defined in
       RFC7679.";
  }

  identity service-slo-two-way-delay {
    base service-slo-metric-type;
    description
      "SLO two-way delay is the upper bound of network delay when
       transmitting between two SDPs. The metric is defined in
       RFC2681.";
  }

  identity service-slo-one-way-delay-variation {
    base service-slo-metric-type;
    description
      "SLO one-way delay variation is defined by RFC3393, is the
       difference in the one-way delay between sequential packets
       between two SDPs.";
  }

  identity service-slo-two-way-delay-variation {
    base service-slo-metric-type;
    description
      "SLO two-way delay variation is defined by RFC5481, is the
       difference in the round-trip delay between sequential packets
       between two SDPs.";
  }

  identity service-slo-one-way-packet-loss {
    base service-slo-metric-type;
    description
      "SLO loss metric. The ratio of packets dropped to packets
       transmitted between two SDPs in one-way
       over a period of time as specified in RFC7680.";
  }

  identity service-slo-two-way-packet-loss {
    base service-slo-metric-type;
    description
      "SLO loss metric. The ratio of packets dropped to packets
       transmitted between two SDPs in two-way
       over a period of time as specified in RFC7680.";
  }

  identity service-slo-availability {
    base service-slo-metric-type;
    description
      "SLO availability level.";
  }

  identity service-match-type {
    description
      "Base identity for IETF Network Slice service traffic
       match type.";
  }

  identity service-phy-interface-match {
    base service-match-type;
    description
      "Use the physical interface as match criteria for
       slice service traffic.";
  }

  identity service-vlan-match {
    base service-match-type;
    description
      "Use the VLAN ID as match criteria for the slice service
       traffic.";
  }

  identity service-label-match {
    base service-match-type;
    description
      "Use the MPLS label as match criteria for the slice service
       traffic.";
  }

  identity service-source-ip-match {
    base service-match-type;
    description
      "Use source ip-address in the packet header as match criteria
       for the slice service traffic.";
  }

  identity service-destination-ip-match {
    base service-match-type;
    description
      "Use destination ip-address in the packet header as
       match criteria for the slice service traffic.";
  }

  identity service-dscp-match {
    base service-match-type;
    description
      "Use DSCP in the IP packet header as match criteria
       for the slice service traffic.";
  }

  identity service-any-match {
    base service-match-type;
    description
      "Match all slice service traffic.";
  }

  identity peering-protocol-type {
    description
      "Base identity for SDP peering protocol type.";
  }

  identity peering-protocol-bgp {
    base peering-protocol-type;
    description
      "Use BGP as protocol for SDP peering with customer device.";
  }

  identity peering-static-routing {
    base peering-protocol-type;
    description
      "Use static routing for SDP peering with customer device.";
  }

  identity peering-attribute-type {
    description
      "Base identity for BGP peering";
  }

  identity remote-as {
    base peering-attribute-type;
    description
      "Identity for remote-as attribute of BGP peering.";
  }

  identity neighbor {
    base peering-attribute-type;
    description
      "Identity for neighbor attribute of BGP peering.";
  }

  identity local-as {
    base peering-attribute-type;
    description
      "Identity for local-as attribute of BGP peering.";
  }

  /*
   * 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%";
  }

  identity level-5 {
    base availability-type;
    description
      "level 5: 99%";
  }

  /* grouping */

  grouping service-match-criteria {
    description
      "A grouping for the slice service match definition.";
    container service-match-criteria {
      description
        "Describes the slice service match criteria.";
      list match-criterion {
        key "index";
        description
          "List of the slice service traffic match criteria.";
        leaf index {
          type uint32;
          description
            "The entry index.";
        }
        leaf match-type {
          type identityref {
            base service-match-type;
          }
          mandatory true;
          description
            "Identifies an entry in the list of the slice service
             match criteria.";
        }
        leaf-list value {
          type string;
          description
            "Describes the slice service match criteria, e.g.
             IP address, VLAN, etc.";
        }
        leaf target-connection-group-id {
          type leafref {
            path
              "/ietf-nss:network-slice-services"
            + "/ietf-nss:slice-service"
            + "/ietf-nss:connection-groups/ietf-nss:connection-group"
            + "/ietf-nss:connection-group-id";
          }
          mandatory true;
          description
            "Reference to the slice service connection group.";
        }
        leaf connection-group-sdp-role {
          type identityref {
            base vpn-common:role;
          }
          default "vpn-common:any-to-any-role";
          description
            "Indicates the role in the connection group when
             a slice service has multiple multipoint-to-multipoint
             connection groups, e.g., hub-spoke.";
        }
        leaf target-connectivity-construct-id {
          type leafref {
            path
              "/ietf-nss:network-slice-services/slice-service"
            + "/ietf-nss:connection-groups"
            + "/ietf-nss:connection-group[connection-group-id"
            + "=current()/../target-connection-group-id]"
            + "/ietf-nss:connectivity-construct/ietf-nss:cc-id";
          }
          description
            "Reference to a Network Slice connection construct.";
        }
      }
    }
  }

  grouping service-sles {
    description
      "Indirectly Measurable Objectives of a slice service.";
    leaf-list security {
      type identityref {
        base service-security-type;
      }
      description
        "The slice service security SLE(s)";
    }
    leaf isolation {
      type identityref {
        base service-isolation-type;
      }
      default "service-isolation-shared";
      description
        "The slice service isolation SLE requirement.";
    }
    leaf max-occupancy-level {
      type uint8 {
        range "1..100";
      }
      description
        "The maximal occupancy level specifies the number of flows to
         be admitted.";
    }
    leaf mtu {
      type uint16;
      units "bytes";
      description
        "The MTU specifies the maximum length in octets of data
         packets that can be transmitted by the slice service.
         The value needs to be less than or equal to the
         minimum MTU value of all 'attachment-circuits' in the SDPs.";
    }
    container steering-constraints {
      description
        "Container for the policy of steering constraints
         applicable to the slice service.";
      container path-constraints {
        description
          "Container for the policy of path constraints
           applicable to the slice service.";
      }
      container service-function {
        description
          "Container for the policy of service function
           applicable to the slice service.";
      }
    }
  }

  grouping service-metric-bounds {
    description
      "Slice service metric bounds grouping.";
    container metric-bounds {
      description
        "Slice service metric bounds container.";
      list metric-bound {
        key "metric-type";
        description
          "List of slice service metric bounds.";
        leaf metric-type {
          type identityref {
            base service-slo-metric-type;
          }
          description
            "Identifies an entry in the list of metric type
             bounds for the slice service.";
        }
        leaf metric-unit {
          type string;
          mandatory true;
          description
            "The metric unit of the parameter. For example,
             s, ms, ns, and so on.";
        }
        leaf value-description {
          type string;
          description
            "The description of previous value.";
        }
        leaf bound {
          type uint64;
          default "0";
          description
            "The Bound on the slice service connection metric.
             A zero indicate an unbounded upper limit for the
             specific metric-type.";
        }
      }
    }
  }

  grouping sdp-peering {
    description
      "A grouping for the slice service SDP peering.";
    container sdp-peering {
      description
        "Describes SDP peering attributes.";
      list protocol {
        key "protocol-type";
        description
          "List of the SDP peering protocol.";
        leaf protocol-type {
          type identityref {
            base peering-protocol-type;
          }
          description
            "Identifies an entry in the list of SDP peering
             protocol type.";
        }
        list attribute {
          key "attribute-type";
          description
            "list of protocol attributes";
          leaf attribute-type {
            type identityref {
              base peering-attribute-type;
            }
            description
              "identifies the attribute type";
          }
          leaf-list value {
            type string;
            description
              "Describes the value of protocol attribute, e.g.
               nexthop address, peer address, etc.";
          }
        }
      }
      list opaque {
        key "attribute-name";
        description
          "List of protocol attributes.";
        leaf attribute-name {
          type string;
          description
            "The name of the attribute.";
        }
        leaf-list value {
          type string;
          description
            "The value(s) of the attribute";
        }
      }
    }
  }

  grouping sdp-attachment-circuits {
    description
      "Grouping for the SDP attachment circuit definition.";
    container attachment-circuits {
      description
        "List of attachment circuit.";
      list attachment-circuit {
        key "ac-id";
        description
          "The IETF Network Slice service SDP attachment circuit
           related parameters.";
        leaf ac-id {
          type string;
          description
            "Uniquely identifier a attachment circuit.";
        }
        leaf ac-description {
          type string;
          description
            "The attachment circuit description.";
        }
        leaf ac-node-id {
          type string;
          description
            "The attachment circuit node ID in the case of
             multi-homing.";
        }
        leaf ac-tp-id {
          type string;
          description
            "The termination port ID of the attachment circuit.";
        }
        leaf ac-ip-address {
          type inet:ip-address;
          description
            "The IP address of the attachment circuit.";
        }
        leaf ac-ip-prefix-length {
          type uint8;
          description
            "The subnet prefix length expressed in bits.";
        }
        leaf ac-qos-policy-name {
          type string;
          description
            "The name of the QoS policy that is applied to the
             attachment circuit. The name can reference a QoS
             profile that is pre-provisioned on the device.";
        }
        leaf mtu {
          type uint16;
          units "bytes";
          description
            "Maximum size in octets of the slice service data packet
             that can traverse a SDP.";
        }
        container ac-tags {
          description
            "Container for the attachment circuit tags.";
          list ac-tags {
            key "ac-tag-type";
            description
              "The attachment circuit tags list.";
            leaf ac-tag-type {
              type identityref {
                base attachment-circuit-tag-type;
              }
              description
                "The attachment circuit tag type.";
            }
            leaf-list value {
              type string;
              description
                "The attachment circuit tag value.";
            }
          }
          list ac-tag-opaque {
            key "tag-name";
            description
              "The attachment circuit tag opaque list.";
            leaf tag-name {
              type string;
              description
                "The opaque tags name";
            }
            leaf-list value {
              type string;
              description
                "The opaque tags value";
            }
          }
        }
        /* Per ac rate limits */
        uses service-match-criteria;
        uses sdp-peering;
        uses service-rate-limit;
      }
    }
  }

  grouping sdp-monitoring-metrics {
    description
      "Grouping for the SDP monitoring metrics.";
    container sdp-monitoring {
      config false;
      description
        "Container for SDP monitoring metrics.";
      leaf incoming-utilized-bandwidth {
        type te-types:te-bandwidth;
        description
          "Incoming bandwidth utilization at a SDP.";
      }
      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
          "Outoing service bandwidth utilization at a SDP.";
      }
      leaf outgoing-bw-utilization {
        type decimal64 {
          fraction-digits 5;
          range "0..100";
        }
        units "percent";
        mandatory true;
        description
          "To be used to define the service bandwidth utilization
           as a percentage of the available bandwidth.";
      }
    }
  }

  grouping connectivity-construct-monitoring-metrics {
    description
      "Grouping for connectivity construct monitoring metrics.";
    uses te-packet-types:one-way-performance-metrics-packet;
    uses te-packet-types:two-way-performance-metrics-packet;
  }

  grouping geolocation-container {
    description
      "A grouping containing a GPS location.";
    container location {
      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 bw-rate-limits {
    description
      "Bandwidth rate limits grouping.";
    reference
      "RFC 7640: Traffic Management Benchmarking";
    leaf cir {
      type uint64;
      units "bps";
      description
        "Committed Information Rate. The maximum number of bits
         that a port can receive or send during one-second over an
         interface.";
    }
    leaf cbs {
      type uint64;
      units "bytes";
      description
        "Committed Burst Size. CBS controls the bursty nature
         of the traffic. Traffic that does not use the configured
         CIR accumulates credits until the credits reach the
         configured CBS.";
    }
    leaf eir {
      type uint64;
      units "bps";
      description
        "Excess Information Rate, i.e., excess frame delivery
         allowed not subject to SLA. The traffic rate can be
         limited by EIR.";
    }
    leaf ebs {
      type uint64;
      units "bytes";
      description
        "Excess Burst Size. The bandwidth available for burst
         traffic from the EBS is subject to the amount of
         bandwidth that is accumulated during periods when
         traffic allocated by the EIR policy is not used.";
    }
    leaf pir {
      type uint64;
      units "bps";
      description
        "Peak Information Rate, i.e., maximum frame delivery
         allowed. It is equal to or less than sum of CIR and EIR.";
    }
    leaf pbs {
      type uint64;
      units "bytes";
      description
        "Peak Burst Size.";
    }
  }

  grouping service-rate-limit {
    description
      "The rate limits grouping.";
    container incoming-rate-limits {
      description
        "Container for the asymmetric traffic control.";
      uses bw-rate-limits;
    }
    container outgoing-rate-limits {
      description
        "The rate-limit imposed on outgoing traffic.";
      uses bw-rate-limits;
    }
  }

  grouping sdp {
    description
      "Slice service SDP related information";
    leaf sdp-id {
      type string;
      description
        "Unique identifier for the referred slice service SDP.";
    }
    leaf sdp-description {
      type string;
      description
        "Give more description of the SDP.";
    }
    uses geolocation-container;
    leaf node-id {
      type string;
      description
        "Uniquely identifies an edge node of the SDP.";
    }
    leaf sdp-ip {
      type inet:ip-address;
      description
        "The IP address of the SDP.";
    }
    uses service-match-criteria;
    uses sdp-peering;
    uses sdp-attachment-circuits;
    uses service-rate-limit;
    /* Per SDP rate limits */
    uses vpn-common:service-status;
    uses sdp-monitoring-metrics;
  }

  //service-sdp

  grouping connectivity-construct {
    description
      "Grouping for slice service connectivity construct.";
    list connectivity-construct {
      key "cc-id";
      description
        "List of connectivity constructs.";
      leaf cc-id {
        type uint32;
        description
          "The connectivity construct identifier.";
      }
      choice connectivity-construct-type {
        default "p2p";
        description
          "Choice for connectivity construct type.";
        case p2p {
          description
            "P2P connectivity construct.";
          leaf p2p-sender-sdp {
            type leafref {
              path "../../../../sdps/sdp/sdp-id";
            }
            description
              "Reference to a sender SDP.";
          }
          leaf p2p-receiver-sdp {
            type leafref {
              path "../../../../sdps/sdp/sdp-id";
            }
            description
              "Reference to a receiver SDP.";
          }
        }
        case p2mp {
          description
            "P2MP connectivity construct.";
          leaf p2mp-sender-sdp {
            type leafref {
              path "../../../../sdps/sdp/sdp-id";
            }
            description
              "Reference to a sender SDP.";
          }
          leaf-list p2mp-receiver-sdp {
            type leafref {
              path "../../../../sdps/sdp/sdp-id";
            }
            description
              "Reference to a receiver SDP.";
          }
        }
        case a2a {
          description
            "A2A connectivity construct.";
          list a2a-sdp {
            key "sdp-id";
            description
              "List of included A2A SDPs.";
            leaf sdp-id {
              type leafref {
                path "../../../../../sdps/sdp/sdp-id";
              }
              description
                "Reference to a SDP.";
            }
            uses service-slo-sle-policy;
          }
        }
      }
      uses service-slo-sle-policy;
      /* Per connectivity construct service-slo-sle-policy
       * overrides the per slice service-slo-sle-policy.
       */
      container connectivity-construct-monitoring {
        config false;
        description
          "SLO status per connectivity construct.";
        uses connectivity-construct-monitoring-metrics;
      }
    }
  }

  //connectivity-construct

  grouping connection-group {
    description
      "Grouping for slice service connection group.";
    leaf connection-group-id {
      type string;
      description
        "The connection group identifier.";
    }
    leaf connectivity-type {
      type identityref {
        base vpn-common:vpn-topology;
      }
      default "vpn-common:any-to-any";
      description
        "Connection group connectivity type.";
    }
    uses service-slo-sle-policy;
    uses connectivity-construct;
    /* Per connection group service-slo-sle-policy overrides
     * the per slice service-slo-sle-policy.
     */
    container connection-group-monitoring {
      config false;
      description
        "SLO status per connection group.";
      uses connectivity-construct-monitoring-metrics;
    }
  }

  //connection-group

  grouping slice-service-template {
    description
      "Grouping for slice service templates.";
    container slo-sle-templates {
      description
        "Contains a set of slice service templates.";
      list slo-sle-template {
        key "id";
        leaf id {
          type string;
          description
            "Identification of the Service Level Objective (SLO)
             and Service Level Expectation (SLE) template to be used.
             Local administration meaning.";
        }
        leaf template-description {
          type string;
          description
            "Description of the SLO and SLE policy template.";
        }
        description
          "List for SLO and SLE template identifiers.";
      }
    }
  }

  /* Configuration data nodes */

  grouping service-slo-sle-policy {
    description
      "Slice service policy grouping.";
    choice slo-sle-policy {
      description
        "Choice for SLO and SLE policy template.
         Can be standard template or customized template.";
      case standard {
        description
          "Standard SLO template.";
        leaf slo-sle-template {
          type leafref {
            path "/ietf-nss:network-slice-services"
               + "/ietf-nss:slo-sle-templates"
               + "/ietf-nss:slo-sle-template/id";
          }
          description
            "Standard SLO and SLE template to be used.";
        }
      }
      case custom {
        description
          "Customized SLO and SLE template.";
        container service-slo-sle-policy {
          description
            "Contains the SLO and SLE policy.";
          leaf policy-description {
            type string;
            description
              "Description of the SLO and SLE policy.";
          }
          uses service-metric-bounds;
          uses service-sles;
        }
      }
    }
  }

  container network-slice-services {
    description
      "Containes a list of IETF network slice services";
    uses slice-service-template;
    list slice-service {
      key "service-id";
      description
        "A slice service is identified by a service-id.";
      leaf service-id {
        type string;
        description
          "A unique slice service identifier.";
      }
      leaf service-description {
        type string;
        description
          "Textual description of the slice service.";
      }
      container service-tags {
        description
          "Container for the list of service tags.";
        list tag-type {
          key "tag-type";
          description
            "The service tag list.";
          leaf tag-type {
            type identityref {
              base service-tag-type;
            }
            description
              "Slice service tag type.";
          }
          leaf-list value {
            type string;
            description
              "The tag value";
          }
        }
        list tag-opaque {
          key "tag-name";
          description
            "The service tag opaquelist.";
          leaf tag-name {
            type string;
            description
              "The opaque tag name";
          }
          leaf-list value {
            type string;
            description
              "The opaque tag value";
          }
        }
      }
      uses service-slo-sle-policy;
      uses vpn-common:service-status;
      container sdps {
        description
          "Slice service SDPs.";
        list sdp {
          key "sdp-id";
          uses sdp;
          description
            "List of SDPs in this slice service.";
        }
      }
      container connection-groups {
        description
          "Contains connections group.";
        list connection-group {
          key "connection-group-id";
          description
            "List of connection groups.";
          uses connection-group;
        }
      }
    }
    //ietf-network-slice-service list
  }
}
<CODE ENDS>

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-service/network-slice-services/slice-service
The entries in the list above include the whole network configurations corresponding with the slice service 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.

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-service
   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].

           Name: ietf-network-slice-service
           Namespace: urn:ietf:params:xml:ns:yang:ietf-network-slice-service
           Prefix: ietf-nss
           Reference: RFC XXXX

Acknowledgments
The authors wish to thank Mohamed Boucadair, Kenichi Ogaki, Sergio Belotti, Qin Wu, Susan Hares, Eric Grey, Daniele Ceccarelli, and many others for their helpful comments and suggestions.

Contributors
The following authors contributed significantly to this document:
   Luis M. Contreras
   Telefonica
   Spain

   Email: luismiguel.contrerasmurillo@telefonica.com

   John Mullooly
   Cisco
   Email:jmullool@cisco.com

Normative References

Informative References
[RFC7950]
[I-D.ietf-teas-ietf-network-slices]
[RFC8309]
[RFC8342]
[RFC2119]
[RFC8174]
[RFC6241]
[RFC8340]
[RFC8640]
[RFC8641]
[RFC6991]
[RFC9181]
[RFC8776]
[RFC7640]
[RFC8040]
[RFC6242]
[RFC8446]
[RFC8341]
[RFC3688]
[I-D.ietf-teas-actn-vn-yang]

Examples of Slice Services with Different Connection Types

Example-1: Two Any-to-any Slice Services with different match approach
The following example describes a simplified service configuration of two IETF Network slice instances where the SDPs are the customer-facing ports on the PE:
- IETF Network Slice 1 on SDP1, SDP11a, and SDP4, with any-to-any connectivity type. This is a L3 slice service and using the uniform low-latency slo-sle-template policy between all SDPs. These SDPs will also have AC eBGP peering sessions with unmanaged CE elements.
- IETF Network Slice 2 on SDP2, SDP11b, with any-to-any connectivity type. This is a L3 slice service and using the uniform high-BW slo-sle-template policy between all SDPs. These SDPs will also have AC eBGP peering sessions with unmanaged CE elements.
Slice 1 uses the explicit match approach for mapping SDP traffic to a connectivity-construct, while slice 2 uses the implicit approach. Both approaches are supported.
Note: These two slices both use service-tags of "L3". This service-tag is operator defined and has no specific meaning in the YANG model other to give a "hint" to the NSC on the Service Expectation being L3 forwarding. Other examples we may choose to eliminate it. The usage of this tag is arbitrary and up to the operator and the NSC on it's need and usage.
+--------+         192.0.2.1
|CE1     o------/  VLAN100
+--------+      |  SDP1 +------+
+--------+      +------o|  PE A+---------------+
|CE2     o-------/-----o|      |               |
+--------+         SDP2 +---+--+               |
               198.51.100.1 |                  |    192.0.4.1
                  VLAN200   |              +---+--+ VLAN100
                            |              |      | SDP4      +--------+
                            |              |PE C  o-----/-----o CE21   |
+--------+        192.0.3.1 |              +---+--+           +--------+
|        o------/ VLAN101   |                  |
|        |      | SDP11a+---+---+              |
|CE11    |      +------o|PE B   +--------------+
|        o-------/-----o|       |
+--------+        SDP11b+------ +
                  198.51.101.1
                  VLAN201
{
  "data": {
    "ietf-network-slice-service:network-slice-services": {
      "slo-sle-templates": {
        "slo-sle-template": [
          {
            "id": "high-BW-template",
            "template-description": "take the highest BW forwarding path"
          },
          {
            "id": "low-latency-template",
            "template-description": "lowest possible latencey forwarding behavior"
          }
        ]
      },
      "slice-service": [
        {
          "service-id": "slice1",
          "service-description": "example slice1",
          "service-tags": {
            "tag-type": [
              {
                "tag-type": "ietf-nss:service-tag-service",
                "value": ["L3"]
              }
            ]
          },
          "slo-sle-template": "low-latency-template",
          "status": {
          },
          "sdps": {
            "sdp": [
              {
                "sdp-id": "1",
                "node-id": "PE-A",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac1",
                      "ac-description": "AC1 connected to device 1",
                      "ac-node-id": "PE-A",
                      "ac-tp-id": "GigabitEthernet5/0/0/0.100",
                      "ac-ip-address": "192.0.2.1",
                      "ac-ip-prefix-length": 24,
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ]
                      },
                      "service-match-criteria": {
                        "match-criterion": [
                          {
                            "index": 1,
                            "match-type": "ietf-network-slice-service:service-any-match",
                            "target-connection-group-id": "matrix1",
                            "target-connectivity-construct-id": 1
                          }
                        ]
                      },
                      "sdp-peering": {
                        "protocol": [
                          {
                            "protocol-type": "ietf-nss:peering-protocol-bgp",
                            "attribute": [
                              {
                                "attribute-type": "ietf-nss:neighbor",
                                "value": ["192.0.2.2"]
                              },
                              {
                                "attribute-type": "ietf-nss:remote-as",
                                "value": ["64001"]
                              },
                              {
                                "attribute-type": "ietf-nss:local-as",
                                "value": ["64000"]
                              }
                            ]
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "3a",
                "node-id": "PE-B",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac3a",
                      "ac-description": "AC3a connected to device 3",
                      "ac-node-id": "PE-B",
                      "ac-tp-id": "GigabitEthernet8/0/0/4.101",
                      "ac-ip-address": "192.0.3.1",
                      "ac-ip-prefix-length": 24,
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["101"]
                          }
                        ]
                      },
                      "service-match-criteria": {
                        "match-criterion": [
                          {
                            "index": 1,
                            "match-type": "ietf-network-slice-service:service-any-match",
                            "target-connection-group-id": "matrix1",
                            "target-connectivity-construct-id": 1
                          }
                        ]
                      },
                      "sdp-peering": {
                        "protocol": [
                          {
                            "protocol-type": "ietf-nss:peering-protocol-bgp",
                            "attribute": [
                              {
                                "attribute-type": "ietf-nss:neighbor",
                                "value": ["192.0.3.2"]
                              },
                              {
                                "attribute-type": "ietf-nss:remote-as",
                                "value": ["64002"]
                              },
                              {
                                "attribute-type": "ietf-nss:local-as",
                                "value": ["64000"]
                              }
                            ]
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "4",
                "node-id": "PE-C",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac4",
                      "ac-description": "AC4 connected to device 4",
                      "ac-node-id": "PE-C",
                      "ac-tp-id": "GigabitEthernet4/0/0/3.100",
                      "ac-ip-address": "192.0.4.1",
                      "ac-ip-prefix-length": 24,
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ]
                      },
                      "service-match-criteria": {
                        "match-criterion": [
                          {
                            "index": 1,
                            "match-type": "ietf-network-slice-service:service-any-match",
                            "target-connection-group-id": "matrix1",
                            "target-connectivity-construct-id": 1
                          }
                        ]
                      },
                      "sdp-peering": {
                        "protocol": [
                          {
                            "protocol-type": "ietf-nss:peering-protocol-bgp",
                            "attribute": [
                              {
                                "attribute-type": "ietf-nss:neighbor",
                                "value": ["192.0.4.2"]
                              },
                              {
                                "attribute-type": "ietf-nss:remote-as",
                                "value": ["64004"]
                              },
                              {
                                "attribute-type": "ietf-nss:local-as",
                                "value": ["64000"]
                              }
                            ]
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              }
            ]
          },
          "connection-groups": {
            "connection-group": [
              {
                "connection-group-id": "matrix1",
                "connectivity-type": "ietf-vpn-common:any-to-any",
                "connectivity-construct": [
                  {
                    "cc-id": 1,
                    "a2a-sdp": [
                      {
                        "sdp-id": "1"
                      },
                      {
                        "sdp-id": "3a"
                      },
                      {
                        "sdp-id": "4"
                      }
                    ]
                  }
                ]
              }
            ]
          }
        },
        {
          "service-id": "slice2",
          "service-description": "example slice2",
          "service-tags": {
            "tag-type": [
              {
                "tag-type": "ietf-nss:service-tag-service",
                "value": ["L3"]
              }
            ]
          },
          "slo-sle-template": "high-BW-template",
          "status": {
          },
          "sdps": {
            "sdp": [
              {
                "sdp-id": "2",
                "node-id": "PE-A",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac2",
                      "ac-description": "AC2 connected to device 2",
                      "ac-node-id": "PE-A",
                      "ac-tp-id": "GigabitEthernet7/0/0/3.200",
                      "ac-ip-address": "198.51.100.1",
                      "ac-ip-prefix-length": 24,
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ]
                      },
                      "sdp-peering": {
                        "protocol": [
                          {
                            "protocol-type": "ietf-nss:peering-protocol-bgp",
                            "attribute": [
                              {
                                "attribute-type": "ietf-nss:neighbor",
                                "value": ["192.51.100.2"]
                              },
                              {
                                "attribute-type": "ietf-nss:remote-as",
                                "value": ["64031"]
                              },
                              {
                                "attribute-type": "ietf-nss:local-as",
                                "value": ["64000"]
                              }
                            ]
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "3b",
                "node-id": "PE-B",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac3b",
                      "ac-description": "AC3b connected to device 3",
                      "ac-node-id": "PE-B",
                      "ac-tp-id": "GigabitEthernet8/0/0/4.201",
                      "ac-ip-address": "198.51.101.1",
                      "ac-ip-prefix-length": 24,
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["201"]
                          }
                        ]
                      },
                      "sdp-peering": {
                        "protocol": [
                          {
                            "protocol-type": "ietf-nss:peering-protocol-bgp",
                            "attribute": [
                              {
                                "attribute-type": "ietf-nss:neighbor",
                                "value": ["192.51.101.2"]
                              },
                              {
                                "attribute-type": "ietf-nss:remote-as",
                                "value": ["64032"]
                              },
                              {
                                "attribute-type": "ietf-nss:local-as",
                                "value": ["64000"]
                              }
                            ]
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              }
            ]
          },
          "connection-groups": {
            "connection-group": [
              {
                "connection-group-id": "matrix2",
                "connectivity-type": "ietf-vpn-common:any-to-any",
                "connectivity-construct": [
                  {
                    "cc-id": 1,
                    "a2a-sdp": [
                      {
                        "sdp-id": "2"
                      },
                      {
                        "sdp-id": "3b"
                      }
                    ]
                  }
                ]
              }
            ]
          }
        }
      ]
    }
  }
}

Example-2: Two P2P slice services with different match approachs
The following example describes a simplified service configuration of two IETF Network slice instances where the SDPs are the customer-facing ports on the PE:
- IETF Network Slice 3 on SDP5 and SDP7a with pt-to-pt connectivity type. This is a L2 slice service and using the uniform low-latency slo-sle-template policies between the SDPs.
- IETF Network Slice 4 on SDP6 and SDP7b, with pt-to-pt connectivity type. This is a L2 slice service and using the a high-BW slo-sle-template policies between the SDPs. Traffic from SDP6 and SDP7b is requesting a BW of 1000Mbps, while in the reverse direction from SDO7b to SDP6, 5000Mbps is being requested.
Slice 3 uses the explicit match approach for mapping SDP traffic to a Connectivity-group, while slice 2 uses the implicit approach. Both approaches are supported.
Note: These two slices both use service-tags of "L2". This service-tag is operator defined and has no specific meaning in the YANG model other to give a "hint" to the NSC on the Service Expectation being L2 forwarding. Other examples we may choose to eliminate it. The usage of this tag is arbitrary and up to the operator and the NSC on it's need and usage.
+--------+
|  CE5   o------/  VLAN100
+--------+      |  SDP5 +------+
+--------+      +------o| PE A +---------------+
|  CE6   o-------/-----o|      |               |
+--------+         SDP6 +---+--+               |
                 VLAN200    |                  |
                            |              +---+--+
                            |              |      |
                            |              | PE C o
+--------+                  |              +---+--+
|        o------/ VLAN101   |                  |
|        |      | SDP7a +---+--+               |
| CE7    |      +------o| PE B +---------------+
|        o-------/-----o|      |
+--------+        SDP7b +------+
                  VLAN201

{
  "data": {
    "ietf-network-slice-service:network-slice-services": {
      "slo-sle-templates": {
        "slo-sle-template": [
          {
            "id": "high-BW-template",
            "template-description": "take the highest BW forwarding path"
          },
          {
            "id": "low-latency-template",
            "template-description": "lowest possible latencey forwarding behavior"
          }
        ]
      },
      "slice-service": [
        {
          "service-id": "slice3",
          "service-description": "example slice3",
          "slo-sle-template": "low-latency-template",
          "status": {
          },
          "sdps": {
            "sdp": [
              {
                "sdp-id": "5",
                "node-id": "PE-A",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac5",
                      "ac-description": "AC5 connected to device 5",
                      "ac-node-id": "PE-A",
                      "ac-tp-id": "GigabitEthernet5/0/0/1",
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ]
                      },
                      "service-match-criteria": {
                        "match-criterion": [
                          {
                            "index": 1,
                            "match-type": "ietf-network-slice-service:service-any-match",
                            "target-connection-group-id": "matrix3"
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "7a",
                "node-id": "PE-B",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac7a",
                      "ac-description": "AC7a connected to device 7",
                      "ac-node-id": "PE-B",
                      "ac-tp-id": "GigabitEthernet8/0/0/5",
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["200"]
                          }
                        ]
                      },
                      "service-match-criteria": {
                        "match-criterion": [
                          {
                            "index": 1,
                            "match-type": "ietf-network-slice-service:service-any-match",
                            "target-connection-group-id": "matrix3"
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              }
            ]
          },
          "connection-groups": {
            "connection-group": [
              {
                "connection-group-id": "matrix3",
                "connectivity-type": "ietf-network-slice-service:point-to-point",
                "connectivity-construct": [
                  {
                    "cc-id": 1,
                    "p2p-sender-sdp": "5",
                    "p2p-receiver-sdp": "7a"
                  },
                  {
                    "cc-id": 2,
                    "p2p-sender-sdp": "7a",
                    "p2p-receiver-sdp": "5"
                  }
                ]
              }
            ]
          }
        },
        {
          "service-id": "slice4",
          "service-description": "example slice4",
          "slo-sle-template": "high-BW-template",
          "status": {
          },
          "sdps": {
            "sdp": [
              {
                "sdp-id": "6",
                "node-id": "PE-A",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac6",
                      "ac-description": "AC6 connected to device 6",
                      "ac-node-id": "PE-A",
                      "ac-tp-id": "GigabitEthernet7/0/0/4",
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["101"]
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "7b",
                "node-id": "PE-B",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac7b",
                      "ac-description": "AC7b connected to device 7",
                      "ac-node-id": "PE-B",
                      "ac-tp-id": "GigabitEthernet8/0/0/5",
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["201"]
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              }
            ]
          },
          "connection-groups": {
            "connection-group": [
              {
                "connection-group-id": "matrix4",
                "connectivity-type": "ietf-network-slice-service:point-to-point",
                "connectivity-construct": [
                  {
                    "cc-id": 1,
                    "p2p-sender-sdp": "6",
                    "p2p-receiver-sdp": "7b",
                    "service-slo-sle-policy": {
                      "metric-bounds": {
                        "metric-bound": [
                          {
                            "metric-type": "ietf-nss:service-slo-one-way-bandwidth",
                            "metric-unit": "Mbps",
                            "value-description": "1000"
                          }
                        ]
                      }
                    }
                  },
                  {
                    "cc-id": 2,
                    "p2p-sender-sdp": "7b",
                    "p2p-receiver-sdp": "6",
                    "service-slo-sle-policy": {
                      "metric-bounds": {
                        "metric-bound": [
                          {
                            "metric-type": "ietf-nss:service-slo-one-way-bandwidth",
                            "metric-unit": "Mbps",
                            "value-description": "5000"
                          }
                        ]
                      }
                    }
                  }
                ]
              }
            ]
          }
        }
      ]
    }
  }
}

Example-3: A Hub-and-spoke Slice Service with a P2MP connectivity construct
The following example describes a simplified service configuration of one IETF Network slice instance where the SDPs are the customer-facing ports on the PE:
IETF Network Slice 5 is a hub-spoke slice with SDP14 as the hub and SDP11, SDP12, SDP13a, SDP13b as spokes. This is a L3 slice service and using the uniform low-latency slo-sle-template policies between all spokes and the hub SDP, but using an explicit set of slo policies with a latency metric of 10ms for hub to spoke traffic. There is no peering protocol's configured in this example.

+--------+         196.0.2.1
|Device11o------/  VLAN100
+--------+      |  SDP11+------+
+--------+      +------o|  A   +---------------+
|Device12o-------/-----o|      |               |
+--------+         SDP12+---+--+               |
               196.51.100.1 |                  |    196.0.4.1
                  VLAN200   |              +---+--+ VLAN100
                            |              |      | SDP14     +--------+
                            |              |   C  o-----/-----oDevice14|
+--------+        196.0.3.1 |              +---+--+           +--------+
|        o------/ VLAN101   |                  |
|        |      | SDP13a+---+--+               |
|Device13|      +------o|  B   +---------------+
|        o-------/-----o|      |
+--------+        SDP13b+------+
                  196.51.101.1
                  VLAN201

{
  "data": {
    "ietf-network-slice-service:network-slice-services": {
      "slo-sle-templates": {
        "slo-sle-template": [
          {
            "id": "high-BW-template",
            "template-description": "take the highest BW forwarding path"
          },
          {
            "id": "low-latency-template",
            "template-description": "lowest possible latencey forwarding behavior"
          }
        ]
      },
      "slice-service": [
        {
          "service-id": "slice5",
          "service-description": "example slice5",
          "service-tags": {
            "tag-type": [
              {
                "tag-type": "ietf-nss:service-tag-service",
                "value": ["L3"]
              }
            ]
          },
          "slo-sle-template": "low-latency-template",
          "status": {
          },
          "sdps": {
            "sdp": [
              {
                "sdp-id": "11",
                "node-id": "PE-A",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac11",
                      "ac-description": "AC11 connected to device 11",
                      "ac-node-id": "PE-A",
                      "ac-tp-id": "GigabitEthernet5/0/0/2",
                      "ac-ip-address": "196.0.2.1",
                      "ac-ip-prefix-length": 24,
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ]
                      },
                      "service-match-criteria": {
                        "match-criterion": [
                          {
                            "index": 1,
                            "match-type": "ietf-network-slice-service:service-any-match",
                            "target-connection-group-id": "matrix5",
                            "connection-group-sdp-role": "ietf-vpn-common:spoke-role"
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "12",
                "node-id": "PE-A",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac12",
                      "ac-description": "AC12 connected to device 12",
                      "ac-node-id": "PE-A",
                      "ac-tp-id": "GigabitEthernet7/0/0/5",
                      "ac-ip-address": "196.51.100.1",
                      "ac-ip-prefix-length": 24,
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["200"]
                          }
                        ]
                      },
                      "service-match-criteria": {
                        "match-criterion": [
                          {
                            "index": 1,
                            "match-type": "ietf-network-slice-service:service-any-match",
                            "target-connection-group-id": "matrix5",
                            "connection-group-sdp-role": "ietf-vpn-common:spoke-role"
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "13a",
                "node-id": "PE-B",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac13a",
                      "ac-description": "AC13a connected to device 13",
                      "ac-node-id": "PE-B",
                      "ac-tp-id": "GigabitEthernet8/0/0/6",
                      "ac-ip-address": "196.0.3.1",
                      "ac-ip-prefix-length": 24,
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["101"]
                          }
                        ]
                      },
                      "service-match-criteria": {
                        "match-criterion": [
                          {
                            "index": 1,
                            "match-type": "ietf-network-slice-service:service-any-match",
                            "target-connection-group-id": "matrix5",
                            "connection-group-sdp-role": "ietf-vpn-common:spoke-role"
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "13b",
                "node-id": "PE-B",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac13b",
                      "ac-description": "AC3b connected to device 13",
                      "ac-node-id": "PE-B",
                      "ac-tp-id": "GigabitEthernet8/0/0/4",
                      "ac-ip-address": "196.51.101.1",
                      "ac-ip-prefix-length": 24,
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["201"]
                          }
                        ]
                      },
                      "service-match-criteria": {
                        "match-criterion": [
                          {
                            "index": 1,
                            "match-type": "ietf-network-slice-service:service-any-match",
                            "target-connection-group-id": "matrix5",
                            "connection-group-sdp-role": "ietf-vpn-common:spoke-role"
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "14",
                "node-id": "PE-C",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac14",
                      "ac-description": "AC14 connected to device 14",
                      "ac-node-id": "PE-C",
                      "ac-tp-id": "GigabitEthernet4/0/0/3",
                      "ac-ip-address": "196.0.4.1",
                      "ac-ip-prefix-length": 24,
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ]
                      },
                      "service-match-criteria": {
                        "match-criterion": [
                          {
                            "index": 1,
                            "match-type": "ietf-network-slice-service:service-any-match",
                            "target-connection-group-id": "matrix5",
                            "connection-group-sdp-role": "ietf-vpn-common:hub-role"
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              }
            ]
          },
          "connection-groups": {
            "connection-group": [
              {
                "connection-group-id": "matrix5",
                "connectivity-type": "ietf-vpn-common:hub-spoke",
                "connectivity-construct": [
                  {
                    "cc-id": 1,
                    "p2mp-sender-sdp": "14",
                    "p2mp-receiver-sdp": ["11", "12", "13a", "13b"],
                    "service-slo-sle-policy": {
                      "metric-bounds": {
                        "metric-bound": [
                          {
                            "metric-type": "ietf-nss:service-slo-one-way-delay",
                            "metric-unit": "miliseconds",
                            "value-description": "10"
                          }
                        ]
                      }
                    }
                  },
                  {
                    "cc-id": 2,
                    "p2p-sender-sdp": "11",
                    "p2p-receiver-sdp": "14"
                  },
                  {
                    "cc-id": 3,
                    "p2p-sender-sdp": "12",
                    "p2p-receiver-sdp": "14"
                  },
                  {
                    "cc-id": 4,
                    "p2p-sender-sdp": "13a",
                    "p2p-receiver-sdp": "14"
                  },
                  {
                    "cc-id": 5,
                    "p2p-sender-sdp": "13b",
                    "p2p-receiver-sdp": "14"
                  }
                ]
              }
            ]
          }
        }
      ]
    }
  }
}

Example4: An Any-to-any Slice service with multiple SLOs and DSCP Matching
The following example describes a simplified service configuration of an IETF Network slice instance where the SDPs are the customer-facing ports on the PE:
IETF Network Slice 6 on SDP21, SDP23a, and SDP24, with any-to-any connectivity type. This is a L3 slice service and using the uniform standard slo-sle-template policies between all SDPs. For traffic matching the dscp of EF, a slo-sle-template policy of low-latency will be used. The slice uses the explicit match approach for mapping SDP traffic to a connectivity-construct.
+--------+         194.0.2.1
| CE21   o------/  VLAN100
+--------+      |  SDP21+------+
                +------o| PE A +---------------+
                        |      |               |
                        +---+--+               |
                            |                  |    194.0.4.1
                            |              +---+--+ VLAN100
                            |              |      | SDP24     +--------+
                            |              | PE C o-----/-----o CE24   |
+--------+        194.0.3.1 |              +---+--+           +--------+
|        o------/ VLAN101   |                  |
|        |      | SDP23a+---+--+               |
|CE23    |      +------o| PE B +---------------+
|        o              |      |
+--------+              +------+

{
  "data": {
    "ietf-network-slice-service:network-slice-services": {
      "slo-sle-templates": {
        "slo-sle-template": [
          {
            "id": "high-BW-template",
            "template-description": "take the highest BW forwarding path"
          },
          {
            "id": "low-latency-template",
            "template-description": "lowest possible latencey forwarding behavior"
          },
          {
            "id": "standard-template",
            "template-description": "take the standard forwarding path"
          }
        ]
      },
      "slice-service": [
        {
          "service-id": "slice6",
          "service-description": "example slice6",
          "service-tags": {
            "tag-type": [
              {
                "tag-type": "ietf-nss:service-tag-service",
                "value": ["L3"]
              }
            ]
          },
          "slo-sle-template": "standard-template",
          "status": {
          },
          "sdps": {
            "sdp": [
              {
                "sdp-id": "21",
                "node-id": "PE-A",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac21",
                      "ac-description": "AC21 connected to device 21",
                      "ac-node-id": "PE-A",
                      "ac-tp-id": "GigabitEthernet5/0/0/0",
                      "ac-ip-address": "194.0.2.1",
                      "ac-ip-prefix-length": 24,
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ]
                      },
                      "service-match-criteria": {
                        "match-criterion": [
                          {
                            "index": 1,
                            "match-type": "ietf-network-slice-service:service-dscp-match",
                            "value": ["EF"],
                            "target-connection-group-id": "matrix6",
                            "target-connectivity-construct-id": 2
                          },
                          {
                            "index": 2,
                            "match-type": "ietf-network-slice-service:service-any-match",
                            "target-connection-group-id": "matrix6",
                            "target-connectivity-construct-id": 1
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "23a",
                "node-id": "PE-B",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac23a",
                      "ac-description": "AC23a connected to device 23",
                      "ac-node-id": "PE-B",
                      "ac-tp-id": "GigabitEthernet8/0/0/4",
                      "ac-ip-address": "194.0.3.1",
                      "ac-ip-prefix-length": 24,
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["101"]
                          }
                        ]
                      },
                      "service-match-criteria": {
                        "match-criterion": [
                          {
                            "index": 1,
                            "match-type": "ietf-network-slice-service:service-dscp-match",
                            "value": ["EF"],
                            "target-connection-group-id": "matrix6",
                            "target-connectivity-construct-id": 2
                          },
                          {
                            "index": 2,
                            "match-type": "ietf-network-slice-service:service-any-match",
                            "target-connection-group-id": "matrix6",
                            "target-connectivity-construct-id": 1
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "24",
                "node-id": "PE-C",
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "ac24",
                      "ac-description": "AC24 connected to device 24",
                      "ac-node-id": "PE-C",
                      "ac-tp-id": "GigabitEthernet4/0/0/3",
                      "ac-ip-address": "194.0.4.1",
                      "ac-ip-prefix-length": 24,
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ]
                      },
                      "service-match-criteria": {
                        "match-criterion": [
                          {
                            "index": 1,
                            "match-type": "ietf-network-slice-service:service-dscp-match",
                            "value": ["EF"],
                            "target-connection-group-id": "matrix6",
                            "target-connectivity-construct-id": 2
                          },
                          {
                            "index": 2,
                            "match-type": "ietf-network-slice-service:service-any-match",
                            "target-connection-group-id": "matrix6",
                            "target-connectivity-construct-id": 1
                          }
                        ]
                      }
                    }
                  ]
                },
                "status": {
                }
              }
            ]
          },
          "connection-groups": {
            "connection-group": [
              {
                "connection-group-id": "matrix6",
                "connectivity-type": "ietf-vpn-common:any-to-any",
                "connectivity-construct": [
                  {
                    "cc-id": 1,
                    "a2a-sdp": [
                      {
                        "sdp-id": "21"
                      },
                      {
                        "sdp-id": "23a"
                      },
                      {
                        "sdp-id": "24"
                      }
                    ]
                  },
                  {
                    "cc-id": 2,
                    "a2a-sdp": [
                      {
                        "sdp-id": "21"
                      },
                      {
                        "sdp-id": "23a"
                      },
                      {
                        "sdp-id": "24"
                      }
                    ],
                    "slo-sle-template": "low-latency-template"
                  }
                ]
              }
            ]
          }
        }
      ]
    }
  }
}

Example-5: Two methods for an any-to-any Network Slice Service with multiple SLOs
The following examples describes a simplified service configuration of an IETF Network slice instance 'NS1' with four SDPs: SDP1, SDP2, SDP3 and SDP4 with any-to-any connectivity type. All SDPs are designated as customer-facing ports on the PE.

+--------+         192.0.1.1                        192.0.3.1
|CE1     o------/  VLAN100                          VLAN100
+--------+      |  SDP1 +------+           +------+ SDP3
                +------o| PE A +-----------| PE C |           +--------+
                        |      |           |      |-----/-----o CE3    |
                        +---+--+           +------+           +--------+
                            |                  |
                            |                  |
                            |                  |
                            |                  |
+--------+        192.0.2.1 |                  |
|CE2     o------/ VLAN100   |                  |    192.0.4.1
+--------+      | SDP2  +---+--+           +---+--+ VLAN100
                +------o| PE B +-----------|PE D  | SDP4      +--------+
                        |      |           |      o-----/-----o    CE4 |
                        +------+           +---+--+           +--------+

The method of a Single A2A connectivity construct
The service is realized using a single any-to-any connectivity construct, and a uniform low-bandwidth slo-sle-template policy applied to SDP2, SDP3, while a high-bandwidth slo-sle-template policy applied to SDP1 and SDP2.
{
  "data": {
    "ietf-network-slice-service:network-slice-services": {
      "slo-sle-templates": {
        "slo-sle-template": [
          {
            "id": "high-BW-template",
            "template-description": "take the highest BW forwarding path"
          },
          {
            "id": "low-BW-template",
            "template-description": "lowest BW forwarding behavior"
          }
        ]
      },
      "slice-service": [
        {
          "service-id": "NS1",
          "service-description": "URLLC",
          "service-tags": {
            "tag-type": [
              {
                "tag-type": "ietf-nss:service-tag-customer",
                "value": ["Customer-FOO"]
              },
              {
                "tag-type": "ietf-nss:service-tag-service",
                "value": ["L3"]
              }
            ]
          },
          "status": {
          },
          "sdps": {
            "sdp": [
              {
                "sdp-id": "SDP1",
                "sdp-description": "Central Office 1 at location PE-A",
                "node-id": "PE-A",
                "sdp-ip": "192.0.1.1",
                "service-match-criteria": {
                  "match-criterion": [
                    {
                      "index": 1,
                      "match-type": "ietf-network-slice-service:service-vlan-match",
                      "value": ["100"],
                      "target-connection-group-id": "matrix1"
                    }
                  ]
                },
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "AC-SDP1",
                      "ac-description": "Device 1 to PE-A",
                      "ac-node-id": "PE-A",
                      "ac-tp-id": "GigabitEthernet1/0/0/0",
                      "ac-ip-address": "192.0.1.1",
                      "ac-ip-prefix-length": 24,
                      "ac-qos-policy-name": "QoS-Gold",
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ],
                        "ac-tag-opaque": [
                          {
                            "tag-name": "VRF",
                            "value": ["FOO"]
                          }
                        ]
                      },
                      "sdp-peering": {
                        "protocol": [
                          {
                            "protocol-type": "ietf-nss:peering-protocol-bgp",
                            "attribute": [
                              {
                                "attribute-type": "ietf-nss:neighbor",
                                "value": ["192.0.1.2"]
                              }
                            ]
                          }
                        ],
                        "opaque": [
                          {
                            "attribute-name": "color",
                            "value": ["10"]
                          }
                        ]
                      },
                      "incoming-rate-limits": {
                        "cir": "1000000",
                        "cbs": "1000",
                        "pir": "5000000",
                        "pbs": "1000"
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "SDP2",
                "sdp-description": "Central Office 2 at location PE-B",
                "node-id": "PE-B",
                "sdp-ip": "192.0.2.1",
                "service-match-criteria": {
                  "match-criterion": [
                    {
                      "index": 1,
                      "match-type": "ietf-network-slice-service:service-vlan-match",
                      "value": ["100"],
                      "target-connection-group-id": "matrix1"
                    }
                  ]
                },
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "AC-SDP2",
                      "ac-description": "Device 2 to PE-B",
                      "ac-node-id": "PE-B",
                      "ac-tp-id": "GigabitEthernet2/0/0/0",
                      "ac-ip-address": "192.0.2.1",
                      "ac-ip-prefix-length": 24,
                      "ac-qos-policy-name": "QoS-Gold",
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ],
                        "ac-tag-opaque": [
                          {
                            "tag-name": "VRF",
                            "value": ["FOO"]
                          }
                        ]
                      },
                      "sdp-peering": {
                        "protocol": [
                          {
                            "protocol-type": "ietf-nss:peering-protocol-bgp",
                            "attribute": [
                              {
                                "attribute-type": "ietf-nss:neighbor",
                                "value": ["192.0.2.2"]
                              }
                            ]
                          }
                        ],
                        "opaque": [
                          {
                            "attribute-name": "color",
                            "value": ["10"]
                          }
                        ]
                      },
                      "incoming-rate-limits": {
                        "cir": "1000000",
                        "cbs": "1000",
                        "pir": "5000000",
                        "pbs": "1000"
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "SDP3",
                "sdp-description": "Remote Office 1 at location PE-C",
                "node-id": "PE-C",
                "sdp-ip": "192.0.3.1",
                "service-match-criteria": {
                  "match-criterion": [
                    {
                      "index": 1,
                      "match-type": "ietf-network-slice-service:service-vlan-match",
                      "value": ["100"],
                      "target-connection-group-id": "matrix1"
                    }
                  ]
                },
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "AC-SDP3",
                      "ac-description": "Device 3 to PE-C",
                      "ac-node-id": "PE-C",
                      "ac-tp-id": "GigabitEthernet3/0/0/0",
                      "ac-ip-address": "192.0.3.1",
                      "ac-ip-prefix-length": 24,
                      "ac-qos-policy-name": "QoS-Gold",
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ],
                        "ac-tag-opaque": [
                          {
                            "tag-name": "VRF",
                            "value": ["FOO"]
                          }
                        ]
                      },
                      "sdp-peering": {
                        "protocol": [
                          {
                            "protocol-type": "ietf-nss:peering-protocol-bgp",
                            "attribute": [
                              {
                                "attribute-type": "ietf-nss:neighbor",
                                "value": ["192.0.3.2"]
                              }
                            ]
                          }
                        ],
                        "opaque": [
                          {
                            "attribute-name": "color",
                            "value": ["10"]
                          }
                        ]
                      },
                      "incoming-rate-limits": {
                        "cir": "1000000",
                        "cbs": "1000",
                        "pir": "5000000",
                        "pbs": "1000"
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "SDP4",
                "sdp-description": "Remote Office 2 at location PE-D",
                "node-id": "PE-D",
                "sdp-ip": "192.0.4.1",
                "service-match-criteria": {
                  "match-criterion": [
                    {
                      "index": 1,
                      "match-type": "ietf-network-slice-service:service-vlan-match",
                      "value": ["100"],
                      "target-connection-group-id": "matrix1"
                    }
                  ]
                },
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "AC-SDP4",
                      "ac-description": "Device 4 to PE-D",
                      "ac-node-id": "PE-A",
                      "ac-tp-id": "GigabitEthernet4/0/0/0",
                      "ac-ip-address": "192.0.4.1",
                      "ac-ip-prefix-length": 24,
                      "ac-qos-policy-name": "QoS-Gold",
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ],
                        "ac-tag-opaque": [
                          {
                            "tag-name": "VRF",
                            "value": ["FOO"]
                          }
                        ]
                      },
                      "sdp-peering": {
                        "protocol": [
                          {
                            "protocol-type": "ietf-nss:peering-protocol-bgp",
                            "attribute": [
                              {
                                "attribute-type": "ietf-nss:neighbor",
                                "value": ["192.0.4.2"]
                              }
                            ]
                          }
                        ],
                        "opaque": [
                          {
                            "attribute-name": "color",
                            "value": ["10"]
                          }
                        ]
                      },
                      "incoming-rate-limits": {
                        "cir": "1000000",
                        "cbs": "1000",
                        "pir": "5000000",
                        "pbs": "1000"
                      }
                    }
                  ]
                },
                "status": {
                }
              }
            ]
          },
          "connection-groups": {
            "connection-group": [
              {
                "connection-group-id": "matrix1",
                "slo-sle-template": "low-BW-template",
                "connectivity-construct": [
                  {
                    "cc-id": 1,
                    "a2a-sdp": [
                      {
                        "sdp-id": "SDP1",
                        "slo-sle-template": "high-BW-template"
                      },
                      {
                        "sdp-id": "SDP2",
                        "slo-sle-template": "high-BW-template"
                      },
                      {
                        "sdp-id": "SDP3"
                      },
                      {
                        "sdp-id": "SDP4"
                      }
                    ]
                  }
                ]
              }
            ]
          }
        }
      ]
    }
  }
}

The method of Two A2A connectivity construct
The service is realized using two any-to-any connectivity constructs:
- any-to-any cc-id=1 enables SDP1 and SDP2 to communicate using the high-bandwidth slo-sle-template policy between SDPs.
- any-to-any cc-id=2 enables all SDPs to communicate using the low-bandwidth slo-sle-template policy between SDPs.
{
  "data": {
    "ietf-network-slice-service:network-slice-services": {
      "slo-sle-templates": {
        "slo-sle-template": [
          {
            "id": "high-BW-template",
            "template-description": "take the highest BW forwarding path"
          },
          {
            "id": "low-BW-template",
            "template-description": "lowest BW forwarding behavior"
          }
        ]
      },
      "slice-service": [
        {
          "service-id": "NS1",
          "service-description": "URLLC",
          "service-tags": {
            "tag-type": [
              {
                "tag-type": "ietf-nss:service-tag-customer",
                "value": ["Customer-FOO"]
              },
              {
                "tag-type": "ietf-nss:service-tag-service",
                "value": ["L3"]
              }
            ]
          },
          "status": {
          },
          "sdps": {
            "sdp": [
              {
                "sdp-id": "SDP1",
                "sdp-description": "Central Office 1 at location PE-A",
                "node-id": "PE-A",
                "sdp-ip": "192.0.1.1",
                "service-match-criteria": {
                  "match-criterion": [
                    {
                      "index": 1,
                      "match-type": "ietf-network-slice-service:service-vlan-match",
                      "value": ["100"],
                      "target-connection-group-id": "matrix1"
                    }
                  ]
                },
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "AC-SDP1",
                      "ac-description": "Device 1 to PE-A",
                      "ac-node-id": "PE-A",
                      "ac-tp-id": "GigabitEthernet1/0/0/0",
                      "ac-ip-address": "192.0.1.1",
                      "ac-ip-prefix-length": 24,
                      "ac-qos-policy-name": "QoS-Gold",
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ],
                        "ac-tag-opaque": [
                          {
                            "tag-name": "VRF",
                            "value": ["FOO"]
                          }
                        ]
                      },
                      "sdp-peering": {
                        "protocol": [
                          {
                            "protocol-type": "ietf-nss:peering-protocol-bgp",
                            "attribute": [
                              {
                                "attribute-type": "ietf-nss:neighbor",
                                "value": ["192.0.1.2"]
                              }
                            ]
                          }
                        ],
                        "opaque": [
                          {
                            "attribute-name": "color",
                            "value": ["10"]
                          }
                        ]
                      },
                      "incoming-rate-limits": {
                        "cir": "1000000",
                        "cbs": "1000",
                        "pir": "5000000",
                        "pbs": "1000"
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "SDP2",
                "sdp-description": "Central Office 2 at location PE-B",
                "node-id": "PE-B",
                "sdp-ip": "192.0.2.1",
                "service-match-criteria": {
                  "match-criterion": [
                    {
                      "index": 1,
                      "match-type": "ietf-network-slice-service:service-vlan-match",
                      "value": ["100"],
                      "target-connection-group-id": "matrix1"
                    }
                  ]
                },
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "AC-SDP2",
                      "ac-description": "Device 2 to PE-B",
                      "ac-node-id": "PE-B",
                      "ac-tp-id": "GigabitEthernet2/0/0/0",
                      "ac-ip-address": "192.0.2.1",
                      "ac-ip-prefix-length": 24,
                      "ac-qos-policy-name": "QoS-Gold",
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ],
                        "ac-tag-opaque": [
                          {
                            "tag-name": "VRF",
                            "value": ["FOO"]
                          }
                        ]
                      },
                      "sdp-peering": {
                        "protocol": [
                          {
                            "protocol-type": "ietf-nss:peering-protocol-bgp",
                            "attribute": [
                              {
                                "attribute-type": "ietf-nss:neighbor",
                                "value": ["192.0.2.2"]
                              }
                            ]
                          }
                        ],
                        "opaque": [
                          {
                            "attribute-name": "color",
                            "value": ["10"]
                          }
                        ]
                      },
                      "incoming-rate-limits": {
                        "cir": "1000000",
                        "cbs": "1000",
                        "pir": "5000000",
                        "pbs": "1000"
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "SDP3",
                "sdp-description": "Remote Office 1 at location PE-C",
                "node-id": "PE-C",
                "sdp-ip": "192.0.3.1",
                "service-match-criteria": {
                  "match-criterion": [
                    {
                      "index": 1,
                      "match-type": "ietf-network-slice-service:service-vlan-match",
                      "value": ["100"],
                      "target-connection-group-id": "matrix1"
                    }
                  ]
                },
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "AC-SDP3",
                      "ac-description": "Device 3 to PE-C",
                      "ac-node-id": "PE-C",
                      "ac-tp-id": "GigabitEthernet3/0/0/0",
                      "ac-ip-address": "192.0.3.1",
                      "ac-ip-prefix-length": 24,
                      "ac-qos-policy-name": "QoS-Gold",
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ],
                        "ac-tag-opaque": [
                          {
                            "tag-name": "VRF",
                            "value": ["FOO"]
                          }
                        ]
                      },
                      "sdp-peering": {
                        "protocol": [
                          {
                            "protocol-type": "ietf-nss:peering-protocol-bgp",
                            "attribute": [
                              {
                                "attribute-type": "ietf-nss:neighbor",
                                "value": ["192.0.3.2"]
                              }
                            ]
                          }
                        ],
                        "opaque": [
                          {
                            "attribute-name": "color",
                            "value": ["10"]
                          }
                        ]
                      },
                      "incoming-rate-limits": {
                        "cir": "1000000",
                        "cbs": "1000",
                        "pir": "5000000",
                        "pbs": "1000"
                      }
                    }
                  ]
                },
                "status": {
                }
              },
              {
                "sdp-id": "SDP4",
                "sdp-description": "Remote Office 2 at location PE-D",
                "node-id": "PE-D",
                "sdp-ip": "192.0.4.1",
                "service-match-criteria": {
                  "match-criterion": [
                    {
                      "index": 1,
                      "match-type": "ietf-network-slice-service:service-vlan-match",
                      "value": ["100"],
                      "target-connection-group-id": "matrix1"
                    }
                  ]
                },
                "attachment-circuits": {
                  "attachment-circuit": [
                    {
                      "ac-id": "AC-SDP4",
                      "ac-description": "Device 4 to PE-D",
                      "ac-node-id": "PE-A",
                      "ac-tp-id": "GigabitEthernet4/0/0/0",
                      "ac-ip-address": "192.0.4.1",
                      "ac-ip-prefix-length": 24,
                      "ac-qos-policy-name": "QoS-Gold",
                      "ac-tags": {
                        "ac-tags": [
                          {
                            "ac-tag-type": "ietf-nss:attachment-circuit-tag-vlan-id",
                            "value": ["100"]
                          }
                        ],
                        "ac-tag-opaque": [
                          {
                            "tag-name": "VRF",
                            "value": ["FOO"]
                          }
                        ]
                      },
                      "sdp-peering": {
                        "protocol": [
                          {
                            "protocol-type": "ietf-nss:peering-protocol-bgp",
                            "attribute": [
                              {
                                "attribute-type": "ietf-nss:neighbor",
                                "value": ["192.0.4.2"]
                              }
                            ]
                          }
                        ],
                        "opaque": [
                          {
                            "attribute-name": "color",
                            "value": ["10"]
                          }
                        ]
                      },
                      "incoming-rate-limits": {
                        "cir": "1000000",
                        "cbs": "1000",
                        "pir": "5000000",
                        "pbs": "1000"
                      }
                    }
                  ]
                },
                "status": {
                }
              }
            ]
          },
          "connection-groups": {
            "connection-group": [
              {
                "connection-group-id": "matrix1",
                "connectivity-construct": [
                  {
                    "cc-id": 1,
                    "a2a-sdp": [
                      {
                        "sdp-id": "SDP1"
                      },
                      {
                        "sdp-id": "SDP2"
                      }
                    ],
                    "slo-sle-template": "high-BW-template"
                  },
                  {
                    "cc-id": 2,
                    "a2a-sdp": [
                      {
                        "sdp-id": "SDP1"
                      },
                      {
                        "sdp-id": "SDP2"
                      },
                      {
                        "sdp-id": "SDP3"
                      },
                      {
                        "sdp-id": "SDP4"
                      }
                    ],
                    "slo-sle-template": "low-BW-template"
                  }
                ]
              }
            ]
          }
        }
      ]
    }
  }
}

Comparison with Other Possible Design choices for IETF Network Slice Service Interface
According to the 5.3.1 IETF Network Slice Service Interface [I-D.ietf-teas-ietf-network-slices], the Network Slice service Interface is a technology-agnostic interface, which is used for a customer to express requirements for a particular IETF Network Slice. Customers operate on abstract IETF Network Slices, with details related to their realization hidden. As classified by [RFC8309], the Network Slice service Interface is classified as Customer Service Model.
This draft analyzes the following existing IETF models to identify the gap between the IETF Network Slice service Interface requirements.

ACTN VN Model Augmentation
The difference between the ACTN VN model and the IETF Network Slice service requirements is that the IETF Network Slice service interface 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 customer view of the TE network. Its YANG structure includes four components:
- 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.
- AP: An AP is a logical identifier used to identify the access link which is shared between the customer and the IETF scoped Network.
- VN-AP: A VN-AP is a logical binding between an AP and a given VN.
- 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 SDP 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 "service-match-criteria“ to specify a specific SDP belonging to an IETF Network Slice service.

RFC8345 Augmentation Model
The difference between the IETF Network Slice service requirements and the IETF basic network model is that the IETF Network Slice service requests abstract customer 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 includes three major parts:
- Network: a transport network list and an list of nodes contained in the network
- Link: "links" list and "termination points" list describe how nodes in a network are connected to each other
- 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.