Internet DRAFT - draft-liu-teas-transport-network-slice-yang
draft-liu-teas-transport-network-slice-yang
TEAS Working Group X. Liu
Internet-Draft IBM Corporation
Intended status: Standards Track J. Tantsura
Expires: 14 September 2023 Microsoft
I. Bryskin
Individual
L.M. Contreras
Telefonica
Q. Wu
Huawei
S. Belotti
Nokia
R. Rokui
Ciena
A. Guo
Futurewei
I. Busi
Huawei
13 March 2023
IETF Network Slice Topology YANG Data Model
draft-liu-teas-transport-network-slice-yang-06
Abstract
An IETF network slice may use an abstract topology to describe
intended underlay for connectivities between slice endpoints.
Abstract topologies help the customer to request network slices with
shared resources amongst connections, and connections can be
activated within the slice as needed.
This document describes a YANG data model for managing and
controlling abstract topologies for IETF network slices defined in
RFC YYYY.
[RFC EDITOR NOTE: Please replace RFC YYYY with the RFC number of
draft-ietf-teas-ietf-network-slices once it has been published.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Liu, et al. Expires 14 September 2023 [Page 1]
Internet-Draft Network Slice Topology Data Model March 2023
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 14 September 2023.
Copyright Notice
Copyright (c) 2023 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Prefixes in Data Node Names . . . . . . . . . . . . . . . 3
2. Modeling Considerations . . . . . . . . . . . . . . . . . . . 4
2.1. Relationships to Related Topology Models . . . . . . . . 4
2.2. ACTN for Network Slicing . . . . . . . . . . . . . . . . 5
3. Model Applicability . . . . . . . . . . . . . . . . . . . . . 5
4. YANG Model Overview . . . . . . . . . . . . . . . . . . . . . 8
5. Model Tree Structure . . . . . . . . . . . . . . . . . . . . 8
6. YANG Modules . . . . . . . . . . . . . . . . . . . . . . . . 10
7. Manageability Considerations . . . . . . . . . . . . . . . . 16
8. Security Considerations . . . . . . . . . . . . . . . . . . . 17
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 18
10.1. Normative References . . . . . . . . . . . . . . . . . . 18
10.2. Informative References . . . . . . . . . . . . . . . . . 19
Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 20
Appendix B. Data Tree for the Example in Section 3.1 . . . . . . 20
B.1. Native Topology . . . . . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 26
Liu, et al. Expires 14 September 2023 [Page 2]
Internet-Draft Network Slice Topology Data Model March 2023
1. Introduction
This document defines a YANG [RFC7950] data model for representing,
managing, and controlling IETF network slices as abstract network
topologies, where the network slices are defined in
[I-D.ietf-teas-ietf-network-slices].
The defined data model is an interface between customers and
providers for configurations and state retrievals, so as to support
network slicing as a service. Through this model, a customer can
learn the slicing capabilities and the available resources of the
provider. A customer can request or negotiate with a network slicing
provider to create an instance. The customer can incrementally
update its requirements on individual topology elements in the slice
instance, e.g., adding or removing a node or link, updating desired
bandwidth of a link, and retrieve the operational states of these
elements. With the help of other mechanisms and data models defined
in IETF, the telemetry information can be published to the customer.
The YANG model defines technology-agnostic constructs common to
network slicing at network layers of different technologies, e.g.
IP/MPLS(-TP), OTN and WDM. Therefore, this model may be used as a
common base model on which other network slicing models, such as
[I-D.ietf-ccamp-yang-otn-slicing], may augments with technology-
specific constructs.
As described in Section 3 of
[I-D.contreras-teas-slice-controller-models], the data model defined
in this document complements the data model defined in
[I-D.ietf-teas-ietf-network-slice-nbi-yang]. In addition to the
provider's view, the data model defined in this document models the
Type 2 service defined in [RFC8453].
The YANG data model in this document conforms to the Network
Management Datastore Architecture (NMDA) [RFC8342].
1.1. Tree Diagram
Tree diagrams used in this document follow the notation defined in
[RFC8340].
1.2. Prefixes in Data Node Names
In this document, names of data nodes and other data model objects
are prefixed using the standard prefix associated with the
corresponding YANG imported modules, as shown in Table 1.
Liu, et al. Expires 14 September 2023 [Page 3]
Internet-Draft Network Slice Topology Data Model March 2023
+==========+=======================+===========+
| Prefix | YANG Module | Reference |
+==========+=======================+===========+
| yang | ietf-yang-types | [RFC6991] |
+----------+-----------------------+-----------+
| inet | ietf-inet-types | [RFC6991] |
+----------+-----------------------+-----------+
| nt | ietf-network-topology | [RFC8345] |
+----------+-----------------------+-----------+
| nw | ietf-network-topology | [RFC8345] |
+----------+-----------------------+-----------+
| tet | ietf-te-topology | [RFC8795] |
+----------+-----------------------+-----------+
| te-types | ietf-te-types | [RFC8776] |
+----------+-----------------------+-----------+
| ns-topo | ietf-ns-topo | RFCXXXX |
+----------+-----------------------+-----------+
Table 1: Prefixes and Corresponding YANG Modules
RFC Editor Note: Please replace XXXX with the RFC number assigned to
this document. Please remove this note.
2. Modeling Considerations
An IETF network slice topology is modeled as network topology defined
in [RFC8345], with augmentations. A new network type "network-slice"
is defined in this document. When a network topology data instance
contains the network-slice network type, it represents an instance of
an IETF network slice topology.
2.1. Relationships to Related Topology Models
There are several related YANG data models that have been defined in
IETF. Some of these are:
Network Topology Model: Defined in [RFC8345].
Network Slicing Model: Defined in
[I-D.ietf-teas-ietf-network-slice-nbi-yang].
OTN Slicing: Defined in [I-D.ietf-ccamp-yang-otn-slicing].
Figure 1 shows the relationships among these models. The box of
dotted lines denotes the model defined in this document.
Liu, et al. Expires 14 September 2023 [Page 4]
Internet-Draft Network Slice Topology Data Model March 2023
+----------+ +----------+
| Network | | Network |
| Slice | | Topology +
| NBI YANG >------+ | Model |
| Model | | | RFC 8345 |
+----+-----+ | +-----+----+
| | |
|augments |references |augments
| | |
+----^-----+ | ......^.....
| OTN | +----------: Network :
| Slicing | augments : Slice :
| Model >-----------------: Topology :
| | : Model :
+----------+ ''''''''''''
Figure 1: Model Relationships
2.2. ACTN for Network Slicing
Since ACTN topology data models are based on the network topology
model defined in [RFC8345], the augmentations defined in this
document are effective augmentations to the ACTN topology data
models, resulting in making the ACTN framework [RFC8453] and data
models [I-D.ietf-teas-actn-yang] capable of slicing networks with the
required network characteristics.
3. Model Applicability
There are many technologies to achieve network slicing. The data
model defined in this document can be used to configure resource-
based network slices, where the resources of a network slice is
represented in the form of an abstract network topology, which can
then be mapped to a network resource partition (NRP) according to the
scenarios defined in [I-D.ietf-teas-ietf-network-slices].
Network slices may be abstracted differently depending on the
requirement contained in the configuration provided by the slice
customer. A customer may request a network slice to provide just
connectivity between specified endpoints, in which case the network
slice can be represented as a set of endpoint-to-endpoint links, with
each link formed by an end-to-end tunnel across the underlying
transport networks. The resources associated with each link of the
slice is reserved and commissioned in the underlying physical network
upon the completion of configuring the network slice and all the
links are active.
Liu, et al. Expires 14 September 2023 [Page 5]
Internet-Draft Network Slice Topology Data Model March 2023
Alternatively a network slice can also be represented as an abstract
topology when the customer requests the slice to share resources
between multiple endpoints and to use the resources on demand. The
abstract topology may consist of virtual nodes and virtual links, and
their associated resources are reserved but not commissioned across
the underlying transport networks. The customer can later commission
resources within the slice dynamically using the NBI provided by the
service provider.
According to [I-D.ietf-teas-ietf-network-slices], the IETF Network
Slice service customer might ask for some level of control of, e.g.,
to customize the service paths in a network slice. The abstract
topology defined in this draft could serve to enable this capability
and optimize the resource utilization for network slice connections
activated on top of the abstract topology.
In the example shown in Figure 2, two network resource partitions are
created by the provider to support the two network slice topology
requests from the customers. In realizing the network resource
partitions, node virtualization is used to separate and allocate
resources in physical devices. Two virtual routers VR1 and VR2 are
created over physical router R1, and two virtual routers VR3 and VR4
are created over physical router R2, respectively. Each of the
virtual routers,as a partition of the physical router, takes a
portion of the resources such as ports and memory in the physical
router.
Depending on the requirements and the implementations, they may share
certain resources such as processors, ASICs, and switch fabric.
The network slice topology intent requested by the customers is then
mapped to a corresponding network resource partition. The provider
also reports the operational state of the topology, which shows the
resources that are allocated. Customers can process the requested
topology and integrate it with their own topology.
As an example, Appendix B. shows the JSON encoded data instances of
the customer topology intent for Network Slice Blue.
Customer Topology (Merged) Customer Topology (Merged)
Network Slice Blue Network Slice Red
+---+ +---+ +---+
-----|R3 |--- ---|R2 |------|R3 |
/ +---+ +---+ +---+
+---+ +---+ ^ ^ ^ \ +---+
---|R1 |------|R2 | | | | -----|R4 |---
+---+ +---+ | | | +---+
^ ^ v v v ^
| | +---+ +---+ +---+ |
Liu, et al. Expires 14 September 2023 [Page 6]
Internet-Draft Network Slice Topology Data Model March 2023
| | -----|VR5|--- ---|VR2|------|VR4| |
v v / +---+ +---+ +---+ v
+---+ +---+ \ +---+
---|VR1|------|VR3| -----|VR6|---
+---+ +---+ +---+
Customer Topology (Intended) Customer Topology (Intended)
Network Slice Blue Network Slice Red
Customers
---------------------------------------------------------------------
Provider
Customized Topology (Network Resouce Partition)
Provider Network with Virtual Devices
Network Slice Blue: VR1, VR3, VR5 +---+
----------|VR5|------
/ +---+
+---+ +---+
------|VR1|---------|VR3|
+---+ +---+
------|VR2|---------|VR4|
+---+ +---+
\ +---+
----------|VR6|------
Network Slice Red: VR2, VR4, VR6 +---+
Virtual Devices
---------------------------------------------------------------------
Physical Devices
Native Topology
Provider Network with Physical Devices
+---+
----------|R3 |------
/ +---+
+---+ +---+
======|R1 |=========|R2 |
+---+ +---+
\ +---+
----------|R4 |------
+---+
Figure 2: Network Slicing Topologies for Virtualization
Liu, et al. Expires 14 September 2023 [Page 7]
Internet-Draft Network Slice Topology Data Model March 2023
4. YANG Model Overview
The following constructs and attributes are defined within the YANG
model:
* Network topology, which represent set of shared, reserved
resources organized as a virtual topology between all of the
endpoints. A customer could use such network topology to define
detailed connectivity path traversing the topology, and allow
sharing of resources between its multiple endpoint pairs.
* Service-level objectives (SLOs) associated with different objects,
including node, link, termination point of the topology.
5. Model Tree Structure
module: ietf-ns-topo
augment /nw:networks/nw:network/nw:network-types:
+--rw network-slice!
augment /nw:networks/nw:network:
+--rw (slo-sle-policy)?
+--:(standard)
| +--rw slo-sle-template? leafref
+--:(custom)
+--rw service-slo-sle-policy
+--rw description? string
+--rw metric-bounds
| +--rw metric-bound* [metric-type]
| +--rw metric-type identityref
| +--rw metric-unit string
| +--rw value-description? string
| +--rw percentile-value? percentile
| +--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 disjointness?
| te-types:te-path-disjointness
+--rw optimization-criterion? identityref
+--rw resize-requirement? identityref
+--rw service-info? string
augment /nw:networks/nw:network/nw:node:
+--rw (slo-sle-policy)?
Liu, et al. Expires 14 September 2023 [Page 8]
Internet-Draft Network Slice Topology Data Model March 2023
+--:(standard)
| +--rw slo-sle-template? leafref
+--:(custom)
+--rw service-slo-sle-policy
+--rw description? string
+--rw metric-bounds
| +--rw metric-bound* [metric-type]
| +--rw metric-type identityref
| +--rw metric-unit string
| +--rw value-description? string
| +--rw percentile-value? percentile
| +--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 disjointness?
| te-types:te-path-disjointness
+--rw optimization-criterion? identityref
+--rw resize-requirement? identityref
+--rw service-info? string
augment /nw:networks/nw:network/nw:node/nt:termination-point:
+--rw (slo-sle-policy)?
+--:(standard)
| +--rw slo-sle-template? leafref
+--:(custom)
+--rw service-slo-sle-policy
+--rw description? string
+--rw metric-bounds
| +--rw metric-bound* [metric-type]
| +--rw metric-type identityref
| +--rw metric-unit string
| +--rw value-description? string
| +--rw percentile-value? percentile
| +--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 optimization-criterion? identityref
+--rw resize-requirement? identityref
+--rw service-info? string
Liu, et al. Expires 14 September 2023 [Page 9]
Internet-Draft Network Slice Topology Data Model March 2023
augment /nw:networks/nw:network/nt:link:
+--rw (slo-sle-policy)?
+--:(standard)
| +--rw slo-sle-template? leafref
+--:(custom)
+--rw service-slo-sle-policy
+--rw description? string
+--rw metric-bounds
| +--rw metric-bound* [metric-type]
| +--rw metric-type identityref
| +--rw metric-unit string
| +--rw value-description? string
| +--rw percentile-value? percentile
| +--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 disjointness?
| te-types:te-path-disjointness
+--rw optimization-criterion? identityref
+--rw resize-requirement? identityref
+--rw service-info? string
Figure 3: Tree diagram for network slice topology
6. YANG Modules
<CODE BEGINS> file "ietf-ns-topo@2023-03-11.yang"
module ietf-ns-topo {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-ns-topo";
prefix "ns-topo";
import ietf-network {
prefix "nw";
reference
"RFC 8345: A YANG Data Model for Network Topologies";
}
import ietf-network-topology {
prefix "nt";
reference
"RFC 8345: A YANG Data Model for Network Topologies";
}
Liu, et al. Expires 14 September 2023 [Page 10]
Internet-Draft Network Slice Topology Data Model March 2023
import ietf-te-types {
prefix "te-types";
reference
"RFC 8776: Traffic Engineering Common YANG Types";
}
import ietf-network-slice-service {
prefix "ietf-nss";
reference
"draft-ietf-teas-ietf-network-slice-nbi-yang-00:
IETF Network Slice Service YANG Model";
}
organization
"IETF CCAMP Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/ccamp/>
WG List: <mailto:ccamp@ietf.org>
Editor: Xufeng Liu
<mailto:xufeng.liu.ietf@gmail.com>
Editor: Italo Busi
<mailto:italo.busi@huawei.com>
Editor: Aihua Guo
<mailto:aihuaguo.ietf@gmail.com>
Editor: Sergio Belotti
<mailto:sergio.belotti@nokia.com>
Editor: Luis M. Contreras
<mailto:luismiguel.contrerasmurillo@telefonica.com>";
description
"This module defines a base YANG data model for configuring
generic network slices in optical transport networks, e.g.,
Optical Transport Network (OTN).
The model fully conforms to the Network Management Datastore
Architecture (NMDA).
Copyright (c) 2023 IETF Trust and the persons
identified as authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with
or without modification, is permitted pursuant to, and
subject to the license terms contained in, the Revised
Liu, et al. Expires 14 September 2023 [Page 11]
Internet-Draft Network Slice Topology Data Model March 2023
BSD License set forth in Section 4.c of the IETF Trust's
Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision 2023-03-11 {
description "Initial revision";
reference
"RFC XXXX: IETF Network Slice Topology YANG Data Model";
}
/*
* Identities
*/
identity resize-option {
description
"Base identity for link or connectivity resizing options";
}
identity resize-none {
base resize-option;
description
"Not resizable";
}
identity resize-with-hit {
base resize-option;
description
"Resizable with traffic hits";
}
identity resize-hitless {
base resize-option;
description
"Hitless resizable";
}
/*
* Groupings
*/
grouping ns-topo-slo-sle-policy {
description
"Policy grouping for Transport Network Slices.";
Liu, et al. Expires 14 September 2023 [Page 12]
Internet-Draft Network Slice Topology Data Model March 2023
leaf optimization-criterion {
type identityref {
base te-types:objective-function-type;
}
description
"Optimization criterion applied to this topology.";
}
leaf resize-requirement {
type identityref {
base resize-option;
}
description
"Indicates resizing requirments";
}
leaf service-info {
type string;
description
"Describe type of services running on the slice. It may be
useful information to help the slice controller to
optimize resource allocation";
}
}
grouping ns-topo-steering-constraints {
description
"Policy grouping for specifying steering constraints for
Transport Network Slices.";
leaf disjointness {
type te-types:te-path-disjointness;
description
"Indicate the level of disjointness for slice
resources.";
}
}
/*
* Augmented data nodes
*/
/* network type augments */
augment "/nw:networks/nw:network/nw:network-types" {
description
"Defines the Network Slice topology type.";
container network-slice {
presence "Indicates Network Slice topology";
description
"Its presence identifies the Network Slice type.";
}
Liu, et al. Expires 14 September 2023 [Page 13]
Internet-Draft Network Slice Topology Data Model March 2023
}
/* network topology augments */
augment "/nw:networks/nw:network" {
when "./nw:network-types/ns-topo:network-slice" {
description "Augment only for Network Slice topology.";
}
description "Augment topology configuration and state.";
uses ietf-nss:service-slo-sle-policy;
}
augment "/nw:networks/nw:network" +
"/ns-topo:slo-sle-policy" +
"/ns-topo:custom" +
"/ns-topo:service-slo-sle-policy" {
when "../nw:network-types/ns-topo:network-slice" {
description "Augment only for Network Slice topology.";
}
description "Augment topology configuration and state.";
uses ns-topo-slo-sle-policy;
}
augment "/nw:networks/nw:network" +
"/ns-topo:slo-sle-policy" +
"/ns-topo:custom" +
"/ns-topo:service-slo-sle-policy" +
"/ns-topo:steering-constraints" {
when "../../nw:network-types/ns-topo:network-slice" {
description "Augment only for Network Slice topology.";
}
description "Augment topology configuration and state.";
uses ns-topo-steering-constraints;
}
/* network node augments */
augment "/nw:networks/nw:network/nw:node" {
when "../nw:network-types/ns-topo:network-slice" {
description "Augment only for Network Slice topology.";
}
description "Augment node configuration and state.";
uses ietf-nss:service-slo-sle-policy;
}
augment "/nw:networks/nw:network/nw:node" +
"/ns-topo:slo-sle-policy" +
"/ns-topo:custom" +
"/ns-topo:service-slo-sle-policy" {
when "../../nw:network-types/ns-topo:network-slice" {
Liu, et al. Expires 14 September 2023 [Page 14]
Internet-Draft Network Slice Topology Data Model March 2023
description "Augment only for Network Slice topology.";
}
description "Augment node configuration and state.";
uses ns-topo-slo-sle-policy;
}
augment "/nw:networks/nw:network/nw:node" +
"/ns-topo:slo-sle-policy" +
"/ns-topo:custom" +
"/ns-topo:service-slo-sle-policy" +
"/ns-topo:steering-constraints" {
when "../../../nw:network-types/ns-topo:network-slice" {
description "Augment only for Network Slice topology.";
}
description
"Augment IETF network slice services to include steering
constraints for nodes.";
uses ns-topo-steering-constraints;
}
/* network node's termination point augments */
augment "/nw:networks/nw:network/nw:node" +
"/nt:termination-point" {
when "../../nw:network-types/ns-topo:network-slice" {
description "Augment only for Network Slice topology.";
}
description "Augment node configuration and state.";
uses ietf-nss:service-slo-sle-policy;
}
augment "/nw:networks/nw:network/nw:node" +
"/nt:termination-point" +
"/ns-topo:slo-sle-policy" +
"/ns-topo:custom" +
"/ns-topo:service-slo-sle-policy" {
when "../../../nw:network-types/ns-topo:network-slice" {
description "Augment only for Network Slice topology.";
}
description "Augment node configuration and state.";
uses ns-topo-slo-sle-policy;
}
/* network link augments */
augment "/nw:networks/nw:network/nt:link" {
when "../nw:network-types/ns-topo:network-slice" {
description "Augment only for Network Slice topology.";
Liu, et al. Expires 14 September 2023 [Page 15]
Internet-Draft Network Slice Topology Data Model March 2023
}
description "Augment link configuration and state.";
uses ietf-nss:service-slo-sle-policy;
}
augment "/nw:networks/nw:network/nt:link" +
"/ns-topo:slo-sle-policy" +
"/ns-topo:custom" +
"/ns-topo:service-slo-sle-policy" {
when "../../nw:network-types/ns-topo:network-slice" {
description "Augment only for Network Slice topology.";
}
description "Augment link configuration and state.";
uses ns-topo-slo-sle-policy;
}
augment "/nw:networks/nw:network/nt:link" +
"/ns-topo:slo-sle-policy" +
"/ns-topo:custom" +
"/ns-topo:service-slo-sle-policy" +
"/ns-topo:steering-constraints" {
when "../../../nw:network-types/ns-topo:network-slice" {
description "Augment only for Network Slice topology.";
}
description
"Augment IETF network slice services to include steering
constraints for links within a resource-based transport
network slice.";
uses ns-topo-steering-constraints;
}
}
<CODE ENDS>
Figure 4: YANG model for network slice topology
7. Manageability Considerations
To ensure the security and controllability of physical resource
isolation, slice-based independent operation and management are
required to achieve management isolation. Each network slice
typically requires dedicated accounts, permissions, and resources for
independent access and O&M. This mechanism is to guarantee the
information isolation among slice tenants and to avoid resource
conflicts. The access to slice management functions will only be
permitted after successful security checks.
Liu, et al. Expires 14 September 2023 [Page 16]
Internet-Draft Network Slice Topology Data Model March 2023
8. Security Considerations
The YANG module specified in this document defines a schema for data
that is designed to be accessed via network management protocols such
as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer
is the secure transport layer, and the mandatory-to-implement secure
transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer
is HTTPS, and the mandatory-to-implement secure transport is TLS
[RFC8446].
The 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. Considerations in Section 8 of
[RFC8795] are also applicable to their subtrees in the module defined
in this document.
Some of the readable data nodes in this YANG module may be considered
sensitive or vulnerable in some network environments. It is thus
important to control read access (e.g., via get, get-config, or
notification) to these data nodes. Considerations in Section 8 of
[RFC8795] are also applicable to their subtrees in the module defined
in this document.
9. IANA Considerations
It is proposed to IANA to assign new URIs from the "IETF XML
Registry" [RFC3688] as follows:
URI: urn:ietf:params:xml:ns:yang:ietf-ns-topo
Registrant Contact: The IESG
XML: N/A; the requested URI is an XML namespace.
This document registers a YANG module in the YANG Module Names
registry [RFC6020].
name: ietf-ns-topo
namespace: urn:ietf:params:xml:ns:yang:ietf-ns-topo
prefix: ns-topo
reference: RFC XXXX
Liu, et al. Expires 14 September 2023 [Page 17]
Internet-Draft Network Slice Topology Data Model March 2023
10. References
10.1. Normative References
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<https://www.rfc-editor.org/info/rfc6020>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<https://www.rfc-editor.org/info/rfc6242>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/info/rfc6991>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
[RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG",
RFC 7951, DOI 10.17487/RFC7951, August 2016,
<https://www.rfc-editor.org/info/rfc7951>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>.
[RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
<https://www.rfc-editor.org/info/rfc8340>.
[RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration
Access Control Model", STD 91, RFC 8341,
DOI 10.17487/RFC8341, March 2018,
<https://www.rfc-editor.org/info/rfc8341>.
Liu, et al. Expires 14 September 2023 [Page 18]
Internet-Draft Network Slice Topology Data Model March 2023
[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
and R. Wilton, "Network Management Datastore Architecture
(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
<https://www.rfc-editor.org/info/rfc8342>.
[RFC8345] Clemm, A., Medved, J., Varga, R., Bahadur, N.,
Ananthakrishnan, H., and X. Liu, "A YANG Data Model for
Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March
2018, <https://www.rfc-editor.org/info/rfc8345>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[RFC8776] Saad, T., Gandhi, R., Liu, X., Beeram, V., and I. Bryskin,
"Common YANG Data Types for Traffic Engineering",
RFC 8776, DOI 10.17487/RFC8776, June 2020,
<https://www.rfc-editor.org/info/rfc8776>.
[RFC8795] Liu, X., Bryskin, I., Beeram, V., Saad, T., Shah, H., and
O. Gonzalez de Dios, "YANG Data Model for Traffic
Engineering (TE) Topologies", RFC 8795,
DOI 10.17487/RFC8795, August 2020,
<https://www.rfc-editor.org/info/rfc8795>.
10.2. Informative References
[I-D.contreras-teas-slice-controller-models]
Contreras, L. M., Rokui, R., Tantsura, J., Wu, B., Liu,
X., Dhody, D., and S. Belotti, "IETF Network Slice
Controller and its associated data models", Work in
Progress, Internet-Draft, draft-contreras-teas-slice-
controller-models-04, 24 October 2022,
<https://datatracker.ietf.org/doc/html/draft-contreras-
teas-slice-controller-models-04>.
[I-D.ietf-ccamp-yang-otn-slicing]
Guo, A., Contreras, L. M., Belotti, S., Rokui, R., Xu, Y.,
Zhao, Y., and X. Liu, "Framework and Data Model for OTN
Network Slicing", Work in Progress, Internet-Draft, draft-
ietf-ccamp-yang-otn-slicing-03, 24 October 2022,
<https://datatracker.ietf.org/doc/html/draft-ietf-ccamp-
yang-otn-slicing-03>.
[I-D.ietf-teas-actn-yang]
Lee, Y., Zheng, H., Ceccarelli, D., Yoon, B. Y., and S.
Belotti, "Applicability of YANG models for Abstraction and
Control of Traffic Engineered Networks", Work in Progress,
Liu, et al. Expires 14 September 2023 [Page 19]
Internet-Draft Network Slice Topology Data Model March 2023
Internet-Draft, draft-ietf-teas-actn-yang-11, 7 March
2023, <https://datatracker.ietf.org/doc/html/draft-ietf-
teas-actn-yang-11>.
[I-D.ietf-teas-ietf-network-slice-nbi-yang]
Wu, B., Dhody, D., Rokui, R., Saad, T., Han, L., and J.
Mullooly, "A YANG Data Model for the IETF Network Slice
Service", Work in Progress, Internet-Draft, draft-ietf-
teas-ietf-network-slice-nbi-yang-04, 13 March 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-teas-
ietf-network-slice-nbi-yang-04>.
[I-D.ietf-teas-ietf-network-slices]
Farrel, A., Drake, J., Rokui, R., Homma, S., Makhijani,
K., Contreras, L. M., and J. Tantsura, "A Framework for
IETF Network Slices", Work in Progress, Internet-Draft,
draft-ietf-teas-ietf-network-slices-19, 21 January 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-teas-
ietf-network-slices-19>.
[RFC8453] Ceccarelli, D., Ed. and Y. Lee, Ed., "Framework for
Abstraction and Control of TE Networks (ACTN)", RFC 8453,
DOI 10.17487/RFC8453, August 2018,
<https://www.rfc-editor.org/info/rfc8453>.
Appendix A. Acknowledgments
The TEAS Network Slicing Design Team (NSDT) members included Aijun
Wang, Dong Jie, Eric Gray, Jari Arkko, Jeff Tantsura, John E Drake,
Luis M. Contreras, Rakesh Gandhi, Ran Chen, Reza Rokui, Ricard
Vilalta, Ron Bonica, Sergio Belotti, Tomonobu Niwa, Xuesong Geng, and
Xufeng Liu.
Appendix B. Data Tree for the Example in Section 3.1
B.1. Native Topology
This section contains an example of an instance data tree in the JSON
encoding [RFC7951]. The example instantiates "ietf-network" for the
topology of Network Slice Blue depicted in Figure 2.
=============== NOTE: '\' line wrapping per RFC 8792 ================
{
"ietf-network:networks": {
"network": [
{
"network-id": "example-customized-blue-topology",
Liu, et al. Expires 14 September 2023 [Page 20]
Internet-Draft Network Slice Topology Data Model March 2023
"network-types": {
"ietf-ns-topo:network-slice": {
}
},
"node": [
{
"node-id": "VR1",
"ietf-ns-topo:service-slo-sle-policy": {
"isolation": "ietf-network-slice-service:service-isola\
tion-dedicated",
"resize-requirement": "resize-hitless"
},
"ietf-network-topology:termination-point": [
{
"tp-id": "1-0-1"
},
{
"tp-id": "1-3-1"
}
]
},
{
"node-id": "VR3",
"ietf-ns-topo:service-slo-sle-policy": {
"isolation": "ietf-network-slice-service:service-isola\
tion-shared",
"resize-requirement": "resize-hitless"
},
"ietf-network-topology:termination-point": [
{
"tp-id": "3-1-1"
},
{
"tp-id": "3-5-1"
}
]
},
{
"node-id": "VR5",
"ietf-ns-topo:service-slo-sle-policy": {
"isolation": "ietf-network-slice-service:service-isola\
tion-shared",
"resize-requirement": "resize-hitless"
},
"ietf-network-topology:termination-point": [
{
"tp-id": "5-3-1"
},
Liu, et al. Expires 14 September 2023 [Page 21]
Internet-Draft Network Slice Topology Data Model March 2023
{
"tp-id": "5-0-1"
}
]
}
],
"ietf-network-topology:link": [
{
"link-id": "VR1,1-0-1,,",
"source": {
"source-node": "VR1",
"source-tp": "1-0-1"
},
"ietf-ns-topo:service-slo-sle-policy": {
"metric-bounds": {
"metric-bound": [
{
"metric-type": "ietf-network-slice-service:servi\
ce-slo-two-way-delay",
"metric-unit": "ms",
"bound": 60
}
]
},
"isolation": "ietf-network-slice-service:service-isola\
tion-shared"
}
},
{
"link-id": ",,VR1,1-0-1",
"destination": {
"dest-node": "VR1",
"dest-tp": "1-0-1"
},
"ietf-ns-topo:service-slo-sle-policy": {
"metric-bounds": {
"metric-bound": [
{
"metric-type": "ietf-network-slice-service:servi\
ce-slo-two-way-delay",
"metric-unit": "ms",
"bound": 60
}
]
},
"isolation": "ietf-network-slice-service:service-isola\
tion-dedicated"
}
Liu, et al. Expires 14 September 2023 [Page 22]
Internet-Draft Network Slice Topology Data Model March 2023
},
{
"link-id": "VR1,1-3-1,VR3,3-1-1",
"source": {
"source-node": "VR1",
"source-tp": "1-3-1"
},
"destination": {
"dest-node": "VR3",
"dest-tp": "3-1-1"
},
"ietf-ns-topo:service-slo-sle-policy": {
"metric-bounds": {
"metric-bound": [
{
"metric-type": "ietf-network-slice-service:servi\
ce-slo-two-way-delay",
"metric-unit": "ms",
"bound": 30
}
]
},
"isolation": "ietf-network-slice-service:service-isola\
tion-dedicated"
}
},
{
"link-id": "VR3,3-1-1,VR1,1-3-1",
"source": {
"source-node": "VR3",
"source-tp": "3-1-1"
},
"destination": {
"dest-node": "R1",
"dest-tp": "1-3-1"
},
"ietf-ns-topo:service-slo-sle-policy": {
"metric-bounds": {
"metric-bound": [
{
"metric-type": "ietf-network-slice-service:servi\
ce-slo-two-way-delay",
"metric-unit": "ms",
"bound": 30
}
]
},
"isolation": "ietf-network-slice-service:service-isola\
Liu, et al. Expires 14 September 2023 [Page 23]
Internet-Draft Network Slice Topology Data Model March 2023
tion-dedicated"
}
},
{
"link-id": "VR3,3-5-1,VR5,5-3-1",
"source": {
"source-node": "VR3",
"source-tp": "3-5-1"
},
"destination": {
"dest-node": "VR5",
"dest-tp": "5-3-1"
},
"ietf-ns-topo:service-slo-sle-policy": {
"metric-bounds": {
"metric-bound": [
{
"metric-type": "ietf-network-slice-service:servi\
ce-slo-two-way-delay",
"metric-unit": "ms",
"bound": 35
}
]
},
"isolation": "ietf-network-slice-service:service-isola\
tion-dedicated"
}
},
{
"link-id": "VR5,5-3-1,VR3,3-5-1",
"source": {
"source-node": "VR5",
"source-tp": "5-3-1"
},
"destination": {
"dest-node": "VR3",
"dest-tp": "3-5-1"
},
"ietf-ns-topo:service-slo-sle-policy": {
"metric-bounds": {
"metric-bound": [
{
"metric-type": "ietf-network-slice-service:servi\
ce-slo-two-way-delay",
"metric-unit": "ms",
"bound": 35
}
]
Liu, et al. Expires 14 September 2023 [Page 24]
Internet-Draft Network Slice Topology Data Model March 2023
},
"isolation": "ietf-network-slice-service:service-isola\
tion-dedicated"
}
},
{
"link-id": "VR5,5-0-1,,",
"source": {
"source-node": "VR5",
"source-tp": "5-0-1"
},
"ietf-ns-topo:service-slo-sle-policy": {
"metric-bounds": {
"metric-bound": [
{
"metric-type": "ietf-network-slice-service:servi\
ce-slo-two-way-delay",
"metric-unit": "ms",
"bound": 25
}
]
},
"isolation": "ietf-network-slice-service:service-isola\
tion-dedicated"
}
},
{
"link-id": ",,VR5,5-0-1",
"destination": {
"dest-node": "VR5",
"dest-tp": "5-0-1"
},
"ietf-ns-topo:service-slo-sle-policy": {
"metric-bounds": {
"metric-bound": [
{
"metric-type": "ietf-network-slice-service:servi\
ce-slo-two-way-delay",
"metric-unit": "ms",
"bound": 25
}
]
},
"isolation": "ietf-network-slice-service:service-isola\
tion-dedicated"
}
}
],
Liu, et al. Expires 14 September 2023 [Page 25]
Internet-Draft Network Slice Topology Data Model March 2023
"ietf-ns-topo:service-slo-sle-policy": {
"isolation": "ietf-network-slice-service:service-isolation\
-dedicated",
"optimization-criterion": "ietf-te-types:of-minimize-cost-\
path"
}
}
]
}
}
Authors' Addresses
Xufeng Liu
IBM Corporation
Email: xufeng.liu.ietf@gmail.com
Jeff Tantsura
Microsoft
Email: jefftant.ietf@gmail.com
Igor Bryskin
Individual
Email: i_bryskin@yahoo.com
Luis M. Contreras
Telefonica
Email: luismiguel.contrerasmurillo@telefonica.com
Qin Wu
Huawei
Email: bill.wu@huawei.com
Sergio Belotti
Nokia
Email: Sergio.belotti@nokia.com
Reza Rokui
Ciena
Email: rrokui@ciena.com
Liu, et al. Expires 14 September 2023 [Page 26]
Internet-Draft Network Slice Topology Data Model March 2023
Aihua Guo
Futurewei
Email: aihuaguo.ietf@gmail.com
Italo Busi
Huawei
Email: italo.busi@huawei.com
Liu, et al. Expires 14 September 2023 [Page 27]
