YANG Data Model for DetNet Mapping with Network Slice ZTE Corp.NanjingChina+86 25 88013062song.xueyan2@zte.com.cnZTE Corp.NanjingChinawu.haisheng@zte.com.cn
Routing
DetNet Working GroupThe convergence of IETF Network Slicing with DetNet achieves adequate network resource allocation and reservation to each node along the way
of DetNet flows for latency-sensitive services. This document introduces the applicability of DetNet to network slice , DetNet mapping with Network
Slice requirements and YANG data models extensions in the context of IP/ MPLS network. Deterministic Networking (DetNet) is a service that can be offered by a network to DetNet flows. As defined in , DetNet flows
provide deterministic services with guaranteed performance such as end-to-end delay and low packet loss rate for unicast or multicast data
streams. The adequate network resource allocation and reservation are required for DetNet flows. DetNet assumes that DetNet control plane
using traditional technologies such as RSVP-TE, SR to achieve bandwidth and buffer resources allocation at each DetNet node along the path
of DetNet flows. The DetNet data plane according to the existing DetNet mechanism makes best effort to forward data packets with no network
resource reservation and occupation guarantee. provides the definition of network slice in the context of IETF network and discusses the
main characteristics, necessary components and interfaces for the general framework of IETF Network Slice. An IETF Network Slice delivers a service
to a customer by meeting connectivity resource requirements and associated network capabilities identified as SLOs and SLEs. The parameters for SLOs
include guaranteed minimum bandwidth, guaranteed maximum latency, maximum permissible delay variation and Maximum Permissible Packet Loss Rate.
In order to support SLOs guarantee for slice flows, the network resources need to be partitioned in both control plane and data plane.
provides a solution to resolve this problem. It introduces NRP (Network Resource Partition) and NRP policy
to construct IETF Network Slice to address the requirements of network slicing in packet networks. To realize the adequate network resource
allocation at control plane and necessary network resource reservation at data plane, the resource reservation on each link needs to be NRP aware,
e.g., the traditional technology such as RSVP-TE used at control plane is not enough, the NRP state aware Traffic Engineering (NRP-TE) is needed. This document describes the applicability of DetNet to IETF Network Slice. The convergence of DetNet with IETF Network Slice helps the deterministic
service delivery with adequate network resource allocation and reservation on each node along the path of DetNet flows. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED",
"MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14
when, and only when, they appear in all capitals, as shown here. Refer to , and , for the key terms
used in this document. The terminology for describing YANG data models is found in . DetNet: Deterministic Networking IETF NS: IETF Network Slice MPLS: Multi-Protocol Label Switching NETCONF: Network Configuration Protocol NRP: Network Resource Partition PREOF: Packet Replication, Elimination, and Ordering Functions SDP: Service Demarcation Point SLE: Service Level Expectation SLO: Service Level Objective SSH: transport Secure Shell TLS: Transport Layer Security Refer to the use case of DetNet applied to Network Slicing is described in section 10:
Resource distribution across slices.
Deterministic services within slices.
The IETF Network Slicing enables a diverse set of applications with different SLOs (Service Level Objectives) guarantee to coexist over a
shared underlay network. The NRP defined in provides one solution to address SLO guarantee problem. With the use of
NRP and NRP policy network resource allocation and reservation are achieved at each node in IP/MPLS network. Through the applicability of IETF
Network Slice to DetNet the sufficient network bandwidth and buffer resources are allocated and reserved at each node along the path of the
DetNet flow to deliver deterministic service. The following figure shows an example for the applicability of DetNet to Network Slice. The App-flow user applies for low-latency deterministic service. The packets belonging to the flow are filtered and classified to
DetNet-specific flows. The DetNet Service Instance (DSI-1) is terminated at end system A and B. In order to meet the network resource
guarantee the user of the DetNet-specific flow applies for necessary network resources. The IETF NSC after received the request sends NRP
profile/policy to the underlying network nodes and the underling PE and P nodes make corresponding network resource reservation at the right
path based on path computation of NRP profile/policy. In order to achieve adequate network resource allocation, the edge routers (e.g., PE)
should be able to identify a packet belonging to DetNet-specific flow and its mapping with the IETF Network Slice instance. The DetNet flow
should has slice-aware capability to realize necessary network resources allocation and reservation on each node between the end systems A
and B. At data plane the DetNet nodes should support the NRP-ID and NRP-Label field encapsulation. Then the added NRP-ID and NRP-Label
fields parsed and processed by each node along the path direction of the DetNet flow for the distribution of the local NRP strategy and
the reservation of network resources.This document provides three modes of IETF Network Slice selection operations as associated with DetNet follows. Additional modes may be
defined in the future.New IETF Network Slice Binding - A customer may request a DetNet service with requirements guarantee, e.g., end-to-end latency, latency
variation, jitter, etc. To satisfy the customer's requirements on network resource it's recommended to bind DetNet flows with an IETF Network
Slice instance. The YANG model described in Section 5 of this document provides the mapping between DetNet flows with a new IETF Network Slice.IETF Network Slice Sharing - A customer may request a DetNet service with requirement guarantee where a new IETF Network Slice do not need to
be created but be shared with other multiple DetNet flows. The mapping YANG model described in Section 5 of this document provides the mapping
between DetNet flows with an IETF Network Slice in use. No modification of the properties of an IETF Network Slice is allowed in this mode.IETF Network Slice Modification - This mode allows the modification of the properties of the existing IETF Network Slice
(e.g., bandwidth, latency, etc.).IETF Network Slice Mapping Template - A policy profile which contains network constraints and optimization criteria is used for mapping
DetNet flows to one/more certain IETF Network Slice instance. DetNet service is per flow (including app-layer, service-layer and forwarding-layer flow), performs traffic processing based on the
identification for flow/flow aggregation. Differences in IETF Network Slice service are considered in terms of Network Resource Partition.
introduces a mechanism to associate Network Resource Partition (NRP) with Slice-Flow Aggregate.
If DetNet applied to IETF Network Slice, the DetNet-flow/flow aggregation is considered as the slice-flow/flow aggregation over the underlying NRP. Requirements for Network Slice mapping with deterministic networking services:
The mapping of deterministic services with underlying network slice resources is necessary. It may include:
Service endpoint mapping between DetNet Edge Node and IETF Network Slice SDP.
Access service mapping between DetNet UNI and IETF Network Slice AC.
Instance mapping between DetNet-flow/flow aggregations with IETF Network Slice.
The creation request for network slice instance to be bounded with one specific deterministic flow/flow aggregation instances should be supported.
The sharing of network slice instance for one or more deterministic flow/flow aggregation instances SHOULD be supported.
Configurations for a new network slice instance to provide necessary underlying resource to deterministic services is necessary.
Modification for an existing network slice instance applied to one or more DetNet flow SHOULD be supported.
APP-flow packets is instantiated as DetNet service awareness flow.
If there is an existing IETF Network Slice instance which satisfies the network resource requirements of the DetNet customer.
After check the feasibility of the IETF Network Slice instance bound to DetNet flows, request mapping DetNet-flow/flow aggregations with
IETF Network Slice instance.
If there is no IETF Network Slice available, a new IETF Network Slice instance creation is required.
The mapping of DetNet flow with IETF Network Slice is configured and stored in management plane. The mapping policy of DetNet flow associated
with underlying network resource partition (NRP) is programmed to the DetNet or IETF Network Slice Nodes (such as SDP, P nodes, etc.) through
YANG data models.
In data plane, the DetNet or IETF Network Slice Nodes complete the identification of deterministic service flows (such as IP 6-tuple,
MPLS labels, etc.) and correspond with one specific network slice instance , realize the slice awareness of DetNet flow/flow aggregation.
Through the network resource occupation of hop-by-hop nodes along the path, network resources required by the deterministic networking service
flow is guaranteed.
This section provides how the DetNet and IETF Network Slice Service mapping parameters are supported using augmentation of the existing
DetNet service models (i.e., ). It identifies the YANG data models being defined by the IETF to support this deployment
architecture and specific scenarios relevant for Service Providers. The below figure shows the modeling approach of the Augmented DetNet Model. | |
| Mapping Types| import | |
+--------------+ | |
+----------------------+
]]> /ns:slice-template/ns-slo-sle-templates/id
]]> /nsdmt:ns-mapping-templates/ns-mapping-template/id
{template}?
]]> file "ietf-ns-detnet-mapping-types@2023-02-25.yang"
module ietf-ns-detnet-mapping-types {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-ns-detnet-mapping-types";
prefix nsdmt;
import ietf-network-slice {
prefix ietf-ns;
reference
"I-D.ietf-teas-ietf-network-slice-nbi-yang-01: A YANG Data Model for the IETF Network Slice";
}
organization
"IETF DetNet Working Group";
contact
"WG Web:
WG List:
Editor: Xueyan Song
Editor: Haisheng Wu
";
description
"This module contains a YANG module for IETF Network Slice & Detnet mapping
parameters.
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 2022-03-27 {
description
"Initial revision.";
reference
"RFC XXXX: YANG Data Model for DetNet Mapping with Network Slice";
}
/*
* Features
*/
feature template {
description
"Support Network Slice mapping templates.";
}
/*
* Identity for map-type
*/
identity map-type {
description
"Base identity from which specific map types are derived.";
}
identity new {
base map-type;
description
"The new Network Slice are binded to the service.";
}
identity select {
base map-type;
description
"The Detnet service selects an existing Network Slice with no
modification.";
}
identity modify {
base map-type;
description
"The Detnet service selects an existing Network Slice and allows to modify
the properties of the Network Slice (e.g., SLO)";
}
identity none {
base map-type;
description
"The Detnet service is not mapped to any underlying Network Slice";
}
/*
* Typedef
*/
typedef ns-mapping-template-id {
type string;
description
"Identifier for Network Slice mapping template.";
}
/*
* Groupings
*/
grouping ns-ref {
description
"The reference to Network Slice.";
leaf ns-mapping-slice-id{
type int;
description
"Identifier for a Network Slice.";
}
leaf ns-mapping-template-ref {
if-feature "template";
type leafref {
path "/nsdmt:ns-mapping-templates/"
+ "nsdmt:ns-mapping-template/nsdmt:id";
}
description
"An identifier to the Network Slice Mapping Template where the Network Slice
constraints and optimization criteria are specified.";
}
}
grouping ns-mapping {
description
"Mapping between Services and network-slice";
container ns-mapping {
description
"Mapping between Services and network-slice";
leaf map-type {
type identityref {
base map-type;
}
description
"Isolation Requirements";
}
uses ns-ref;
}
}
//grouping
container ns-mapping-templates {
description
"The network-slice constraints and optimization criteria";
list ns-mapping-template {
key "id";
leaf id {
type ns-mapping-template-id;
description
"Identification of the Template to be used.";
}
leaf description {
type string;
description
"Description of the template.";
}
leaf map-type {
type identityref {
base map-type;
}
must "0 = derived-from-or-self(.,'none')" {
error-message "The map-type must be other than "
+ "none";
}
description
"Map type for Network Slice creation/
selection.";
}
leaf ns-slo-ref{
type leafref {
path "/ns:ns-slo-sle-templates/ns-slo-sle-template/id";
}
description
"List for templates.";
}
}
}
}
]]> file "ietf-ns-detnet-service-mapping@2022-03-27.yang"
module ietf-ns-detnet-service-mapping {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-ns-detnet-service-mapping";
prefix detnet-nssm;
import ietf-ns-detnet-mapping-types {
prefix nsdmt;
reference
"RFC XXXX: YANG Data Model for DetNet Mapping with Network Slice";
}
import ietf-detnet {
prefix dnet;
reference
"draft-ietf-detnet-yang-16.txt: YANG Data Model for Detnet";
}
organization
"IETF DetNet Working Group";
contact
"WG Web:
WG List:
Editor: Xueyan Song
Editor: Haisheng Wu
";
description
"This module contains a YANG module for the mapping of DetNet to the Network Slice.
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 2022-03-27 {
description
"Initial revision.";
reference
"RFC XXXX: YANG Data Model for DetNet Mapping with Network Slice";
}
/*
* Augmentation to Detnet
*/
augment "/dnet:detnet:detnet/service:sub-layer"
+ "/service:sub-layer" {
description
"Detnet augmented to include Network Slice parameters and mapping";
container ns-detnet-mapping {
presence "Indicates Detnet service to Network Slice mapping";
description
"Container to augment detnet to Network Slice parameters and mapping";
uses nsdmt:ns-mapping;
}
}
//augment
}
]]> This document requests the IANA to register the following URIs in the "IETF XML Registry" . This document requests the IANA to register the following YANG modules in the YANG Module Names registry . Security considerations for DetNet are covered in the DetNet Architecture and DetNet Security Considerations
The YANG data model specified in this document defines a schema for mapping of DetNet with IETF Network Slice via NETCONF
or RESTCONF . For NETCONF to support secure transport Secure Shell (SSH)
is mandatory. For RESTCONF to support secure transport TLS is mandatory. The authors appreciate Peng Shaofu and Liu Aihua for useful discussions and motivations for this work.