Network Working Group A. Farrel, Ed.
Internet-Draft Old Dog Consulting
Intended status: Informational E. Gray
Expires: October 18, 2021 Ericsson
J. Drake
Juniper Networks
R. Rokui
Nokia
S. Homma
NTT
K. Makhijani
Futurewei
LM. Contreras
Telefonica
J. Tantsura
Juniper Networks
April 16, 2021
Framework for IETF Network Slices
draft-ietf-teas-ietf-network-slices-01
Abstract
This document describes network slicing in the context of networks
built from IETF technologies. It defines the term "IETF Network
Slice" and establishes the general principles of network slicing in
the IETF context.
The document discusses the general framework for requesting and
operating IETF Network Slices, the characteristics of an IETF Network
Slice, the necessary system components and interfaces, and how
abstract requests can be mapped to more specific technologies. The
document also discusses related considerations with monitoring and
security.
This document also provides definitions of related terms to enable
consistent usage in other IETF documents that describe or use aspects
of IETF Network Slices.
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
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working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on October 18, 2021.
Copyright Notice
Copyright (c) 2021 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 Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Background . . . . . . . . . . . . . . . . . . . . . . . 4
2. Terms and Abbreviations . . . . . . . . . . . . . . . . . . . 5
3. IETF Network Slice Objectives . . . . . . . . . . . . . . . . 6
3.1. Definition and Scope of IETF Network Slice . . . . . . . 6
4. IETF Network Slice System Characteristics . . . . . . . . . . 7
4.1. Objectives for IETF Network Slices . . . . . . . . . . . 7
4.1.1. Service Level Objectives . . . . . . . . . . . . . . 8
4.2. IETF Network Slice Endpoints . . . . . . . . . . . . . . 10
4.2.1. IETF Network Slice Connectivity Types . . . . . . . . 12
4.3. IETF Network Slice Decomposition . . . . . . . . . . . . 12
5. Framework . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.1. IETF Network Slice Stakeholders . . . . . . . . . . . . . 12
5.2. Expressing Connectivity Intents . . . . . . . . . . . . . 13
5.3. IETF Network Slice Controller (NSC) . . . . . . . . . . . 15
5.3.1. IETF Network Slice Controller Interfaces . . . . . . 17
5.3.2. Northbound Interface (NBI) . . . . . . . . . . . . . 17
5.4. IETF Network Slice Structure . . . . . . . . . . . . . . 18
5.5. Realizing IETF Network Slice . . . . . . . . . . . . . . 20
5.5.1. Underlying Technology . . . . . . . . . . . . . . . . 20
6. Applicability of ACTN to IETF Network Slices . . . . . . . . 21
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7. Isolation in IETF Network Slices . . . . . . . . . . . . . . 23
7.1. Isolation as a Service Requirement . . . . . . . . . . . 23
7.2. Isolation in IETF Network Slice Realization . . . . . . . 24
8. Management Considerations . . . . . . . . . . . . . . . . . . 24
9. Security Considerations . . . . . . . . . . . . . . . . . . . 24
9.1. Privacy Considerations . . . . . . . . . . . . . . . . . 25
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 26
12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 26
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 27
13.1. Normative References . . . . . . . . . . . . . . . . . . 27
13.2. Informative References . . . . . . . . . . . . . . . . . 27
Appendix A. Unused Material . . . . . . . . . . . . . . . . . . 31
A.1. Abstract . . . . . . . . . . . . . . . . . . . . . . . . 32
A.2. Management Systems or Other Applications . . . . . . . . 32
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 32
1. Introduction
===================== EDITOR'S NOTE =====================
This document is a merge of the text in
[I-D.ietf-teas-ietf-network-slice-definition] and
[I-D.ietf-teas-ietf-network-slice-framework]. In this version, the
text included from the contributing documents has been re-arranged to
rationalise the structure, but no substantive changes have been made.
Additionally, the Editor has made a number of stylistic edits and
fixed further simple editorial and formatting issues.
In the case that the source text is not used within the document, it
is presented in Appendix A.
=================== END EDITOR'S NOTE ===================
A number of use cases benefit from network connections that along
with the connectivity provide assurance of meeting a specific set of
objectives with respect to network resources use. This connectivity
and resource commitment is referred to as a network slice. Since the
term network slice is rather generic, the qualifying term "IETF" is
used in this document to limit the scope of network slice to network
technologies described and standardized by the IETF. This document
defines the concept of IETF Network Slices that provide connectivity
coupled with a set of specific commitments of network resources
between a number of endpoints over a shared network infrastructure.
Services that might benefit from IETF Network Slices include, but are
not limited to:
o 5G services (e.g. eMBB, URLLC, mMTC)(See [TS23501])
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o Network wholesale services
o Network infrastructure sharing among operators
o NFV connectivity and Data Center Interconnect
IETF Network Slices are created and managed within the scope of one
or more network technologies (e.g., IP, MPLS, optical). They are
intended to enable a diverse set of applications that have different
requirements to coexist on the shared network infrastructure. A
request for an IETF Network Slice is technology-agnostic so as to
allow a consumer to describe their network connectivity objectives in
a common format, independent of the underlying technologies used.
This document also provides a framework for discussing IETF Network
Slices. This framework is intended as a structure for discussing
interfaces and technologies. It is not intended to specify a new set
of concrete interfaces or technologies. Rather, the idea is that
existing or under-development IETF technologies (plural) can be used
to realize the concepts expressed herein.
For example, virtual private networks (VPNs) have served the industry
well as a means of providing different groups of users with logically
isolated access to a common network. The common or base network that
is used to provide the VPNs is often referred to as an underlay
network, and the VPN is often called an overlay network. As an
example technology, a VPN may in turn serve as an underlay network
for IETF Network Slices.
Note that it is conceivable that extensions to these IETF
technologies are needed in order to fully support all the ideas that
can be implemented with slices, but at least in the beginning there
is no plan for the creation of new protocols or interfaces.
1.1. Background
Driven largely by needs surfacing from 5G, the concept of network
slicing has gained traction ([NGMN-NS-Concept], [TS23501], [TS28530],
and [BBF-SD406]). In [TS23501], a Network Slice is defined as "a
logical network that provides specific network capabilities and
network characteristics", and a Network Slice Instance is defined as
"A set of Network Function instances and the required resources (e.g.
compute, storage and networking resources) which form a deployed
Network Slice." According to [TS28530], an end-to-end network slice
consists of three major types of network segments: Radio Access
Network (RAN), Transport Network (TN) and Core Network (CN). IETF
Network Slice provides the required connectivity between different
entities in RAN and CN segments of an end-to-end network slice, with
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a specific performance commitment. For each end-to-end network
slice, the topology and performance requirement on a consumer's use
of IETF Network Slice can be very different, which requires the
underlay network to have the capability of supporting multiple
different IETF Network Slices.
While network slices are commonly discussed in the context of 5G, it
is important to note that IETF Network Slices are a narrower concept,
and focus primarily on particular network connectivity aspects.
Other systems, including 5G deployments, may use IETF Network Slices
as a component to create entire systems and concatenated constructs
that match their needs, including end-to-end connectivity.
A IETF Network Slice could span multiple technologies and multiple
administrative domains. Depending on the IETF Network Slice
consumer's requirements, an IETF Network Slice could be isolated from
other, often concurrent IETF Network Slices in terms of data, control
and management planes.
The consumer expresses requirements for a particular IETF Network
Slice by specifying what is required rather than how the requirement
is to be fulfilled. That is, the IETF Network Slice consumer's view
of an IETF Network Slice is an abstract one.
Thus, there is a need to create logical network structures with
required characteristics. The consumer of such a logical network can
require a degree of isolation and performance that previously might
not have been satisfied by traditional overlay VPNs. Additionally,
the IETF Network Slice consumer might ask for some level of control
of their virtual networks, e.g., to customize the service paths in a
network slice.
This document specifies a framework for the use of existing
technologies as components to provide an IETF Network Slice service,
and might also discuss (or reference) modified and potential new
technologies, as they develop (such as candidate technologies
described in section 5 of [I-D.ietf-teas-enhanced-vpn]).
2. Terms and Abbreviations
The terms and abbreviations used in this document are listed below.
o NBI: NorthBound Interface
o NS: Network Slice
o NSC: Network Slice Controller
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o NSE: Network Slice Endpoint
o SBI: SouthBound Interface
o SLA: Service Level Agreement
o SLI: Service Level Indicator
o SLO: Service Level Objective
The above terminology is defined in greater details in the remainder
of this document.
3. IETF Network Slice Objectives
It is intended that IETF Network Slices can be created to meet
specific requirements, typically expressed as bandwidth, latency,
latency variation, and other desired or required characteristics.
Creation is initiated by a management system or other application
used to specify network-related conditions for particular traffic
flows.
It is also intended that, once created, these slices can be
monitored, modified, deleted, and otherwise managed.
It is also intended that applications and components will be able to
use these IETF Network Slices to move packets between the specified
end-points in accordance with specified characteristics.
As an example of requirements that might apply to IETF Network
Slices, see [I-D.ietf-teas-enhanced-vpn] (in particular, section 3).
3.1. Definition and Scope of IETF Network Slice
The definition of a network slice in IETF context is as follows:
An IETF Network Slice is a logical network topology connecting a
number of endpoints using a set of shared or dedicated network
resources that are used to satisfy specific Service Level Objectives
(SLOs).
An IETF Network Slice combines the connectivity resource requirements
and associated network behaviors such as bandwidth, latency, jitter,
and network functions with other resource behaviors such as compute
and storage availability. IETF Network Slices are independent of the
underlying infrastructure connectivity and technologies used. This
is to allow an IETF Network Slice consumer to describe their network
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connectivity and relevant objectives in a common format, independent
of the underlying technologies used.
IETF Network Slices may be combined hierarchically, so that a network
slice may itself be sliced. They may also be combined sequentially
so that various different networks can each be sliced and the network
slices placed into a sequence to provide an end-to-end service. This
form of sequential combination is utilized in some services such as
in 3GPP's 5G network [TS23501].
An IETF Network Slice is technology-agnostic, and the means for IETF
Network Slice realization can be chosen depending on several factors
such as: service requirements, specifications or capabilities of
underlying infrastructure. The structure and different
characteristics of IETF Network Slices are described in the following
sections.
Term "Slice" refers to a set of characteristics and behaviours that
separate one type of user-traffic from another. IETF Network Slice
assumes that an underlying network is capable of changing the
configurations of the network devices on demand, through in-band
signaling or via controller(s) and fulfilling all or some of SLOs to
all of the traffic in the slice or to specific flows.
4. IETF Network Slice System Characteristics
The following subsections describe the characteristics of IETF
Network Slices.
4.1. Objectives for IETF Network Slices
An IETF Network Slice is defined in terms of several quantifiable
characteristics or Service Level Objectives (SLOs). SLOs along with
the terms Service Level Indicator (SLI) and Service Level Agreement
(SLA) are used to define the performance of a service at different
levels.
A Service Level Indicator (SLI) is a quantifiable measure of an
aspect of the performance of a network. For example, it may be a
measure of throughput in bits per second, or it may be a measure of
latency in milliseconds.
A Service Level Objective (SLO) is a target value or range for the
measurements returned by observation of an SLI. For example, an SLO
may be expressed as "SLI <= target", or "lower bound <= SLI <= upper
bound". A network slice is expressed in terms of the set of SLOs
that are to be delivered for the different connections between
endpoints.
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A Service Level Agreement (SLA) is an explicit or implicit contract
between the consumer of an IETF Network Slice and the provider of the
slice. The SLA is expressed in terms of a set of SLOs and may
include commercial terms as well as the consequences of missing/
violating the SLOs they contain.
Additional descriptions of IETF Network Slice attributes is covered
in [I-D.contreras-teas-slice-nbi].
4.1.1. Service Level Objectives
SLOs define a set of network attributes and characteristics that
describe an IETF Network Slice. SLOs do not describe how the IETF
Network Slices are implemented or realized in the underlying network
layers. Instead, they are defined in terms of dimensions of
operation (time, capacity, etc.), availability, and other attributes.
An IETF Network Slice can have one or more SLOs associated with it.
The SLOs are combined in an SLA. The SLOs are defined for sets of
two or more endpoints and apply to specific directions of traffic
flow. That is, they apply to specific source endpoints and specific
connections between endpoints within the set of endpoints and
connections in the IETF Network Slice.
4.1.1.1. Minimal Set of SLOs
This document defines a minimal set of SLOs and later systems or
standards could extend this set as described in Section 4.1.1.2.
SLOs can be categorized in to 'Directly Measurable Objectives' or
'Indirectly Measurable Objectives'. Objectives such as guaranteed
minimum bandwidth, guaranteed maximum latency, maximum permissible
delay variation, maximum permissible packet loss rate, and
availability are 'Directly Measurable Objectives'. While 'Indirectly
Measurable Objectives' include security, geographical restrictions,
maximum occupancy level objectives. The later standard might define
other SLOs as needed.
Editor's Note TODO: replace Minimal set to most commonly used
objectives to describe network behavior. Other directly or
indirectly measurable objectives may be requested by that consumer of
an IETF Network Slice.
The definition of these objectives are as follows:
Guaranteed Minimum Bandwidth
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Minimum guaranteed bandwidth between two endpoints at any time.
The bandwidth is measured in data rate units of bits per second
and is measured unidirectionally.
Guaranteed Maximum Latency
Upper bound of network latency when transmitting between two
endpoints. The latency is measured in terms of network
characteristics (excluding application-level latency).
[RFC2681] and [RFC7679] discuss round trip times and one-way
metrics, respectively.
Maximum Permissible Delay Variation
Packet delay variation (PDV) as defined by [RFC3393], is the
difference in the one-way delay between sequential packets in a
flow. This SLO sets a maximum value PDV for packets between
two endpoints.
Maximum permissible packet loss rate
The ratio of packets dropped to packets transmitted between two
endpoints over a period of time. See [RFC7680].
Availability
The ratio of uptime to the sum of uptime and downtime, where
uptime is the time the IETF Network Slice is available in
accordance with the SLOs associated with it.
Security
An IETF Network Slice consumer may request that the network
applies encryption or other security techniques to traffic
flowing between endpoints.
Note that the use of security or the violation of this SLO is
not directly observable by the IETF Network Slice consumer and
cannot be measured as a quantifiable metric.
Also note that the objective may include request for encryption
(e.g., [RFC4303]) between the two endpoints explicitly to meet
architecture recommendations as in [TS33.210] or for compliance
with [HIPAA] and/or [PCI].
Please see more discussion on security in Section 9.
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4.1.1.2. Other Service Level Objectives
Additional SLOs may be defined to provide additional description of
the IETF Network Slice that a consumer requests.
If the IETF Network Slice consumer service is traffic aware, other
traffic specific characteristics may be valuable including MTU,
traffic-type (e.g., IPv4, IPv6, Ethernet or unstructured), or a
higher-level behavior to process traffic according to user-
application (which may be realized using network functions).
Maximal occupancy for an IETF Network Slice should be provided.
Since it carries traffic for multiple flows between the two
endpoints, the objectives should also say if they are for the entire
connection, group of flows or on per flow basis. Maximal occupancy
should specify the scale of the flows (i.e., maximum number of flows
to be admitted) and optionally a maximum number of countable resource
units, e.g., IP or MAC addresses a slice might consume.
4.2. IETF Network Slice Endpoints
As noted in Section 3.1, an IETF Network Slice describes connectivity
between multiple endpoints across the underlying network. These
connectivity types are: point-to-point, point-to-multipoint,
multipoint-to-point, multipoint-to-point, or multipoint-to-
multipoint.
Figure 1 shows an IETF Network Slice along with its Network Slice
Endpoints (NSEs).
The characteristics of IETF NSEs are as follows:
o The IETF NSE are conceptual points of connection to IETF network
slice. As such, they serve as the IETF Network Slice ingress/
egress points.
o Each endpoint could map to a device, application or a network
function. A non-exhaustive list of devices, applications or
network functions might include but not limited to: routers,
switches, firewalls, WAN, 4G/5G RAN nodes, 4G/5G Core nodes,
application acceleration, Deep Packet Inspection (DPI), server
load balancers, NAT44 [RFC3022], NAT64 [RFC6146], HTTP header
enrichment functions, and TCP optimizers.
o An NSE should be identified by a unique ID in the context of an
IETF Network Slice consumer.
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o In addition to an identifier, each NSE should contain a subset of
attributes such as IPv4/IPv6 addresses, encapsulation type (i.e.,
VLAN tag, MPLS Label etc.), interface/port numbers, node ID etc.
o A combination of NSE unique ID and NSE attributes defines an NSE
in the context of the IETF Network Slice Controller (NSC).
o During the realization of the IETF Network Slice, in addition to
SLOs, all or subset of IETF NSE attributes will be utilized by the
IETF NSC to find the optimal realization in the IETF network.
o Similarly to IETF Network Slices, the IETF Network Slice Endpoints
are logical entities that are mapped to services/tunnels/paths
endpoints in IETF Network Slice during its initialization and
realization.
Note that there are various IETF TE terms such as access points (AP)
defined in [RFC8453], Termination Point (TP) defined in [RFC8345],
and Link Termination Point (LTP) defined in [RFC8795] which are
tightly coupled with TE network type and various realization
techniques. At the time of realization of the IETF Network Slice,
the NSE could be mapped to one or more of these based on the network
slice realization technique in use.
|----------------------------------|
NSE1 | | NSE2
O.....| |.....O
. | | .
. | | .
. | | .
| |
NSEm | | NSEn
O.....| |.....O
| |
|----------------------------------|
<------------ IETF Network Slice -------------->
between endpoints NSE1 to NSEn
Legend:
NSE: IETF Network Slice Endpoint
O: Represents IETF Network Slice Endpoints
Figure 1: An IETF Network Slice Endpoints (NSE)
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4.2.1. IETF Network Slice Connectivity Types
The IETF Network Slice connection types can be point to point (P2P),
point to multipoint (P2MP), multi-point to point (MP2P), or multi-
point to multi-point (MP2MP). They will requested by the higher
level operation system.
4.3. IETF Network Slice Decomposition
Operationally, an IETF Network Slice may be decomposed in two or more
IETF Network Slices as specified below. Decomposed network slices
are then independently realized and managed.
o Hierarchical (i.e., recursive) composition: An IETF Network Slice
can be further sliced into other network slices. Recursive
composition allows an IETF Network Slice at one layer to be used
by the other layers. This type of multi-layer vertical IETF
Network Slice associates resources at different layers.
o Sequential composition: Different IETF Network Slices can be
placed into a sequence to provide an end-to-end service. In
sequential composition, each IETF Network Slice would potentially
support different dataplanes that need to be stitched together.
5. Framework
A number of IETF Network Slice services will typically be provided
over a shared underlying network infrastructure. Each IETF Network
Slice consists of both the overlay connectivity and a specific set of
dedicated network resources and/or functions allocated in a shared
underlay network to satisfy the needs of the IETF Network Slice
consumer. In at least some examples of underlying network
technologies, the integration between the overlay and various
underlay resources is needed to ensure the guaranteed performance
requested for different IETF Network Slices.
Section 3 of [I-D.ietf-teas-enhanced-vpn] provides an example
architecture that might apply in using the technology described in
this document.
5.1. IETF Network Slice Stakeholders
An IETF Network Slice and its realization involves the following
stakeholders and it is relevant to define them for consistent
terminology.
Consumer: A consumer is the requester of an IETF Network Slice.
Consumers may request monitoring of SLOs. A consumer may manage
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the IETF Network Slice service directly by interfacing with the
IETF NSC or indirectly through an orchestrator.
Orchestrator: An orchestrator is an entity that composes different
services, resource and network requirements. It interfaces with
the IETF NSC.
IETF Network Slice Controller (NSC): It realizes an IETF Network
Slice in the underlying network, maintains and monitors the run-
time state of resources and topologies associated with it. A
well-defined interface is needed between different types of IETF
NSCs and different types of orchestrators. An IETF Network Slice
operator (or slice operator for short) manages one or more IETF
Network Slices using the IETF NSCs.
Network Controller: is a form of network infrastructure controller
that offers network resources to the NSC to realize a particular
network slice. These may be existing network controllers
associated with one or more specific technologies that may be
adapted to the function of realizing IETF Network Slices in a
network.
5.2. Expressing Connectivity Intents
The NSC northbound interface (NBI) can be used to communicate between
IETF Network Slice users (or consumers) and the NSC.
An IETF Network Slice user may be a network operator who, in turn,
provides the IETF Network Slice to another IETF Network Slice user or
consumer.
Using the NBI, a consumer expresses requirements for a particular
slice by specifying what is required rather than how that is to be
achieved. That is, the consumer's view of a slice is an abstract
one. Consumers normally have limited (or no) visibility into the
provider network's actual topology and resource availability
information.
This should be true even if both the consumer and provider are
associated with a single administrative domain, in order to reduce
the potential for adverse interactions between IETF Network Slice
consumers and other users of the underlay network infrastructure.
The benefits of this model can include:
o Security: because the underlay network (or network operator) does
not need to expose network details (topology, capacity, etc.) to
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IETF Network Slice consumers the underlay network components are
less exposed to attack;
o Layered Implementation: the underlay network comprises network
elements that belong to a different layer network than consumer
applications, and network information (advertisements, protocols,
etc.) that a consumer cannot interpret or respond to (note - a
consumer should not use network information not exposed via the
NSC NBI, even if that information is available);
o Scalability: consumers do not need to know any information beyond
that which is exposed via the NBI.
The general issues of abstraction in a TE network is described more
fully in [RFC7926].
This framework document does not assume any particular layer at which
IETF Network Slices operate as a number of layers (including virtual
L2, Ethernet or IP connectivity) could be employed.
Data models and interfaces are of course needed to set up IETF
Network Slices, and specific interfaces may have capabilities that
allow creation of specific layers.
Layered virtual connections are comprehensively discussed in IETF
documents and are widely supported. See, for instance, GMPLS-based
networks ([RFC5212] and [RFC4397]), or ACTN ([RFC8453] and
[RFC8454]). The principles and mechanisms associated with layered
networking are applicable to IETF Network Slices.
There are several IETF-defined mechanisms for expressing the need for
a desired logical network. The NBI carries data either in a
protocol-defined format, or in a formalism associated with a modeling
language.
For instance:
o Path Computation Element (PCE) Communication Protocol (PCEP)
[RFC5440] and GMPLS User-Network Interface (UNI) using RSVP-TE
[RFC4208] use a TLV-based binary encoding to transmit data.
o Network Configuration Protocol (NETCONF) [RFC6241] and RESTCONF
Protocol [RFC8040] use XML abnd JSON encoding.
o gRPC/GNMI [I-D.openconfig-rtgwg-gnmi-spec] uses a binary encoded
programmable interface;
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o SNMP ([RFC3417], [RFC3412] and [RFC3414] uses binary encoding
(ASN.1).
o For data modeling, YANG ([RFC6020] and [RFC7950]) may be used to
model configuration and other data for NETCONF, RESTCONF, and GNMI
- among others; ProtoBufs can be used to model gRPC and GNMI data;
Structure of Management Information (SMI) [RFC2578] may be used to
define Management Information Base (MIB) modules for SNMP, using
an adapted subset of OSI's Abstract Syntax Notation One (ASN.1,
1988).
While several generic formats and data models for specific purposes
exist, it is expected that IETF Network Slice management may require
enhancement or augmentation of existing data models.
5.3. IETF Network Slice Controller (NSC)
The IETF NSC takes abstract requests for IETF Network Slices and
implements them using a suitable underlying technology. An IETF NSC
is the key building block for control and management of the IETF
Network Slice. It provides the creation/modification/deletion,
monitoring and optimization of IETF Network Slices in a multi-domain,
a multi-technology and multi-vendor environment.
The main task of the IETF NSC is to map abstract IETF Network Slice
requirements to concrete technologies and establish required
connectivity, and ensuring that required resources are allocated to
the IETF Network Slice.
A NSC northbound interface (NBI) is needed for communicating details
of a IETF Network Slice (configuration, selected policies,
operational state, etc.), as well as providing information to a slice
requester/consumer about IETF Network Slice status and performance.
The details for this NBI are not in scope for this document.
The controller provides the following functions:
o Provides a technology-agnostic NBI for creation/modification/
deletion of the IETF Network Slices. The API exposed by this NBI
communicates the endpoints of the IETF network slice, IETF Network
Slice SLO parameters (and possibly monitoring thresholds),
applicable input selection (filtering) and various policies, and
provides a way to monitor the slice.
o Determines an abstract topology connecting the endpoints of the
IETF Network Slice that meets criteria specified via the NBI. The
NSC also retains information about the mapping of this abstract
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topology to underlying components of the IETF network slice as
necessary to monitor IETF Network Slice status and performance.
o Provides "Mapping Functions" for the realization of IETF Network
Slices. In other words, it will use the mapping functions that:
* map technology-agnostic NBI request to technology-specific SBIs
* map filtering/selection information as necessary to entities in
the underlay network.
o Via an SBI, the controller collects telemetry data (e.g., OAM
results, statistics, states, etc.) for all elements in the
abstract topology used to realize the IETF Network Slice.
o Using the telemetry data from the underlying realization of a IETF
Network Slice (i.e., services/paths/tunnels), evaluates the
current performance against IETF Network Slice SLO parameters and
exposes them to the IETF Network Slice consumer via the NBI. The
NSC NBI may also include a capability to provide notification in
case the IETF Network Slice performance reaches threshold values
defined by the IETF Network Slice consumer.
An IETF Network Slice user is served by the IETF Network Slice
Controller (NSC), as follows:
o The NSC takes requests from a management system or other
application, which are then communicated via an NBI. This
interface carries data objects the IETF Network Slice user
provides, describing the needed IETF Network Slices in terms of
topology, applicable service level objectives (SLO), and any
monitoring and reporting requirements that may apply. Note that -
in this context - "topology" means what the IETF Network Slice
connectivity is meant to look like from the user's perspective; it
may be as simple as a list of mutually (and symmetrically)
connected end points, or it may be complicated by details of
connection asymmetry, per-connection SLO requirements, etc.
o These requests are assumed to be translated by one or more
underlying systems, which are used to establish specific IETF
Network Slice instances on top of an underlying network
infrastructure.
o The NSC maintains a record of the mapping from user requests to
slice instantiations, as needed to allow for subsequent control
functions (such as modification or deletion of the requested
slices), and as needed for any requested monitoring and reporting
functions.
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5.3.1. IETF Network Slice Controller Interfaces
The interworking and interoperability among the different
stakeholders to provide common means of provisioning, operating and
monitoring the IETF Network Slices is enabled by the following
communication interfaces (see Figure 2).
NSC Northbound Interface (NBI): The NSC Northbound Interface is an
interface between a consumer's higher level operation system
(e.g., a network slice orchestrator) and the NSC. It is a
technology agnostic interface. The consumer can use this
interface to communicate the requested characteristics and other
requirements (i.e., the SLOs) for the IETF Network Slice, and the
NSC can use the interface to report the operational state of an
IETF Network Slice to the consumer.
NSC Southbound Interface (SBI): The NSC Southbound Interface is an
interface between the NSC and network controllers. It is
technology-specific and may be built around the many network
models defined within the IETF.
+------------------------------------------+
| Consumer higher level operation system |
| (e.g E2E network slice orchestrator) |
+------------------------------------------+
A
| NSC NBI
V
+------------------------------------------+
| IETF Network Slice Controller (NSC) |
+------------------------------------------+
A
| NSC SBI
V
+------------------------------------------+
| Network Controllers |
+------------------------------------------+
Figure 2: Interface of IETF Network Slice Controller
5.3.2. Northbound Interface (NBI)
The IETF Network Slice Controller provides a Northbound Interface
(NBI) that allows consumers of network slices to request and monitor
IETF Network Slices. Consumers operate on abstract IETF Network
Slices, with details related to their realization hidden.
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The NBI complements various IETF services, tunnels, path models by
providing an abstract layer on top of these models.
The NBI is independent of type of network functions or services that
need to be connected, i.e., it is independent of any specific
storage, software, protocol, or platform used to realize physical or
virtual network connectivity or functions in support of IETF Network
Slices.
The NBI uses protocol mechanisms and information passed over those
mechanisms to convey desired attributes for IETF Network Slices and
their status. The information is expected to be represented as a
well-defined data model, and should include at least endpoint and
connectivity information, SLO specification, and status information.
To accomplish this, the NBI needs to convey information needed to
support communication across the NBI, in terms of identifying the
IETF Network Slices, as well providing the above model information.
5.4. IETF Network Slice Structure
An IETF Network Slice is a set of connections among various endpoints
to form a logical network that meets the SLOs agreed upon.
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|------------------------------------------|
NSE1 O....| |....O NSE2
. | | .
. | IETF Network Slice | .
. | (SLOs e.g. B/W > x bps, Delay < y ms) | .
NSEm O....| |....O NSEn
|------------------------------------------|
== == == == == == == == == == == == == == == == == == == == == ==
.--. .--.
[EP1] ( )- . ( )- . [EP2]
. .' IETF ' SLO .' IETF ' .
. ( Network-1 ) ... ( Network-p ) .
`-----------' `-----------'
[EPm] [EPn]
Legend
NSE: IETF Network Slice Endpoints
EP: Serivce/tunnels/path Endpoints used to realize the
IETF Network Slice
Figure 3: IETF Network Slice
Figure 3 illustrates a case where an IETF Network Slice provides
connectivity between a set of IEFT network slice endpoints (NSE)
pairs with specific SLOs (e.g., guaranteed minimum bandwidth of x bps
and guaranteed delay of no more than y ms). The IETF Network Slice
endpoints are mapped to the underlay IETF Network Slice Endpoints
(NEPs). Also, the IETF NSEs on the same IETF network slice may
belong to the same or different address spaces.
IETF Network Slice structure fits into a broader concept of end-to-
end network slices. A network operator may be responsible for
delivering services over a number of technologies (such as radio
networks) and for providing specific and fine-grained services (such
as CCTV feed or High definition realtime traffic data). That
operator may need to combine slices of various networks to produce an
end-to-end network service. Each of these networks may include
multiple physical or virtual nodes and may also provide network
functions beyond simply carrying of technology-specific protocol data
units. An end-to-end network slice is defined by the 3GPP as a
complete logical network that provides a service in its entirety with
a specific assurance to the consumer [TS23501].
An end-to-end network slice may be composed from other network slices
that include IETF Network Slices. This composition may include the
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hierarchical (or recursive) use of underlying network slices and the
sequential (or stitched) combination of slices of different networks.
5.5. Realizing IETF Network Slice
Realization of IETF Network Slices is out of scope of this document.
It is a mapping of the definition of the IETF Network Slice to the
underlying infrastructure and is necessarily technology-specific and
achieved by the NSC over the SBI.
The realization can be achieved in a form of either physical or
logical connectivity through VPNs (see, for example,
[I-D.ietf-teas-enhanced-vpn], a variety of tunneling technologies
such as Segment Routing, MPLS, etc. Accordingly, endpoints may be
realized as physical or logical service or network functions.
5.5.1. Underlying Technology
There are a number of different technologies that can be used,
including physical connections, MPLS, TSN, Flex-E, etc.
See Section 5 of [I-D.ietf-teas-enhanced-vpn] for instance, for
example underlying technologies.
Also, as outlined in "applicability of ACTN to IETF Network Slices"
below, ACTN ([RFC8453]) offers a framework that is used elsewhere in
IETF specifications to create virtual network (VN) services similar
to IETF Network Slices.
A IETF Network Slice can be realized in a network, using specific
underlying technology or technologies. The creation of a new IETF
Network Slice will be initiated with following three steps:
o Step 1: A higher level system requests connections with specific
characteristics via NBI.
o Step 2: This request will be processed by an IETF NSC which
specifies a mapping between northbound request to any IETF
Services, Tunnels, and paths models.
o Step 3: A series of requests for creation of services, tunnels and
paths will be sent to the network to realize the trasport slice.
It is very clear that regardless of how IETF Network Slice is
realized in the network (i.e., using tunnels of type RSVP or SR), the
definition of IETF Network Slice does not change at all but rather
its realization.
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6. Applicability of ACTN to IETF Network Slices
Abstraction and Control of TE Networks (ACTN - [RFC8453]) is an
example of similar IETF work. ACTN defines three controllers to
support virtual network (VN) services -
o Customer Network Controller (CNC),
o Multi-Domain Service Coordinator (MDSC) and
o Provisioning Network Controller (PNC).
A CNC is responsible for communicating a customer's VN requirements.
A MDSC is responsible for multi-domain coordination, virtualization
(or abstraction), customer mapping/translation and virtual service
coordination to realize the VN requirement. Its key role is to
detach the network/service requirements from the underlying
technology.
A PNC oversees the configuration, monitoring and collection of the
network topology. The PNC is a underlay technology specific
controller.
While the ACTN framework is a generic VN framework that is used for
various VN service beyond the IETF Network Slice, it is still a
suitable basis to understand how the various controllers interact to
realize a IETF Network Slice.
One possible mapping between the IETF Network Slice, and ACTN,
definitions is as shown in Figure 4.
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IETF Network Slice | ACTN analogous
Terminology / Concepts Terminology
| and Concepts
+--------------------------------------+
|Consumer higher level operation system| | +-----+
| (e.g E2E network slice orchestrator) | =====> | CNC |
+--------------------------------------+ | +-----+
^ ^
| NSC NBI | | CMI
v v
+-------------------------------------+ | +------+
| IETF Network Slice Controller (NSC) | =====> | MDSC |
+-------------------------------------+ | +------+
^ ^
| NSC SBI | | MPI
v v
+-------------------------------------+ | +-----+
| Network Controller(s) | =====> | PNC |
+-------------------------------------+ | +-----+
Figure 4: Mapping between IETF Network Slices and ACTN
The NSC NBI conveys the generic IETF Network Slice requirements.
These may then be realized using an SBI within the NSC.
As per [RFC8453] and [I-D.ietf-teas-actn-yang], the CNC-MDSC
Interface (CMI) is used to convey the virtual network service
requirements along with the service models and the MDSC-PNC Interface
(MPI) is used to realize the service along network configuration
models. [I-D.ietf-teas-te-service-mapping-yang] further describe how
the VPN services can be mapped to the underlying TE resources.
The Network Controller is depicted as a single block, analogous to a
Provisioning Network Controller (PNC - in this example). In the ACTN
framework, however, it is also possible that the NC function is
decomposed into MDSC and PNC - that is, the NC may comprise hierarchy
as needed to handle the multiple domains and various underlay
technologies, whereas a PNC in ACTN is intended to be specific to at
most a single underlay technology and (likely) to individual devices
(or functional components).
Note that the details of potential implementations of everything that
is below the NSC in Section 6 are out of scope in this document -
hence the specifics of the relationship between NC and PNC, and the
possibility that the MDSC and PNC may be combined are at most
academically interesting in this context. Another way to view this
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is that, in the same way that ACTN might combine MDSC and PNC, the
NSC might also directly include NC functionality.
[RFC8453] also describes TE Network Slicing in the context of ACTN as
a collection of resources that is used to establish a logically
dedicated virtual network over one or more TE networks. In case of
TE enabled underlying network, ACTN VN can be used as a base to
realize the IETF Network Slicing by coordination among multiple peer
domains as well as underlay technology domains.
Section 6 shows only one possible mapping as each ACTN component (or
interface) in the figure may be a composed differently in other
mappings, and the exact role of both components and subcomponents
will not be always an exact analogy between the concepts used in this
document and those defined in ACTN.
This is - in part - shown in a previous paragraph in this section
where it is pointed out that the NC may actually subsume some aspects
of both the MDSC and PNC.
Similarly, in part depending on how "customer" is interpreted, CNC
might merge some aspects of the higher level system and the NSC. As
in the NC/PNC case, this way of comparing ACTN to this work is not
useful as the NSC and NSC NBI are the focus on this document.
7. Isolation in IETF Network Slices
An IETF Network Slice consumer may request, that the IETF Network
Slice delivered to them is isolated from any other network slices of
services delivered to any other consumers. It is expected that the
changes to the other network slices of services do not have any
negative impact on the delivery of the IETF Network Slice.
7.1. Isolation as a Service Requirement
Isolation may be an important requirement of IETF Network Slices for
some critical services. A consumer may express this request as an
SLO.
This requirement can be met by simple conformance with other SLOs.
For example, traffic congestion (interference from other services)
might impact on the latency experienced by an IETF Network Slice.
Thus, in this example, conformance to a latency SLO would be the
primary requirement for delivery of the IETF Network Slice service,
and isolation from other services might be only a means to that end.
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It should be noted that some aspects of isolation may be measurable
by a consumer who have the information about the traffic on a number
of IETF Network Slices or other services.
7.2. Isolation in IETF Network Slice Realization
Delivery of isolation is achieved in the realization of IETF Network
Slices, with existing, in-development, and potential new technologies
in IETF. It depends on how a network operator decides to operate
their network and deliver services.
Isolation may be achieved in the underlying network by various forms
of resource partitioning ranging from dedicated allocation of
resources for a specific IETF Network Slice, to sharing or resources
with safeguards. For example, traffic separation between different
IETF Network Slices may be achieved using VPN technologies, such as
L3VPN, L2VPN, EVPN, etc. Interference avoidance may be achieved by
network capacity planning, allocating dedicated network resources,
traffic policing or shaping, prioritizing in using shared network
resources, etc. Finally, service continuity may be ensured by
reserving backup paths for critical traffic, dedicating specific
network resources for a selected number of network slices, etc.
8. Management Considerations
IETF Network Slice realization needs to be instrumented in order to
track how it is working, and it might be necessary to modify the IETF
Network Slice as requirements change. Dynamic reconfiguration might
be needed.
9. Security Considerations
This document specifies terminology and has no direct effect on the
security of implementations or deployments. In this section, a few
of the security aspects are identified.
o Conformance to security constraints: Specific security requests
from consumer defined IETF Network Slices will be mapped to their
realization in the unerlay networks. It will be required by
underlay networks to have capabilities to conform to consumer's
requests as some aspects of security may be expressed in SLOs.
o IETF NSC authentication: Unerlying networks need to be protected
against the attacks from an adversary NSC as they can destablize
overall network operations. It is particularly critical since an
IETF Network Slice may span across different networks, therefore,
IETF NSC should have strong authentication with each those
networks. Futhermore, both SBI and NBI need to be secured.
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o Specific isolation criteria: The nature of conformance to
isolation requests means that it should not be possible to attack
an IETF Network Slice service by varying the traffic on other
services or slices carried by the same underlay network. In
general, isolation is expected to strengthen the IETF Network
Slice security.
o Data Integrity of an IETF Network Slice: A consumer wanting to
secure their data and keep it private will be responsible for
applying appropriate security measures to their traffic and not
depending on the network operator that provides the IETF Network
Slice. It is expected that for data integrity, a consumer is
responsible for end-to-end encryption of its own traffic.
Note: see NGMN document[NGMN_SEC] on 5G network slice security for
discussion relevant to this section.
IETF Network Slices might use underlying virtualized networking. All
types of virtual networking require special consideration to be given
to the separation of traffic between distinct virtual networks, as
well as some degree of protection from effects of traffic use of
underlying network (and other) resources from other virtual networks
sharing those resources.
For example, if a service requires a specific upper bound of latency,
then that service can be degraded by added delay in transmission of
service packets through the activities of another service or
application using the same resources.
Similarly, in a network with virtual functions, noticeably impeding
access to a function used by another IETF Network Slice (for
instance, compute resources) can be just as service degrading as
delaying physical transmission of associated packet in the network.
While a IETF Network Slice might include encryption and other
security features as part of the service, consumers might be well
advised to take responsibility for their own security needs, possibly
by encrypting traffic before hand-off to a service provider.
9.1. Privacy Considerations
Privacy of IETF Network Slice service consumers must be preserved.
It should not be possible for one IETF Network Slice consumer to
discover the presence of other consumers, nor should sites that are
members of one IETF Network Slice be visible outside the context of
that IETF Network Slice.
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In this sense, it is of paramount importance that the system use the
privacy protection mechanism defined for the specific underlying
technologies used, including in particular those mechanisms designed
to preclude acquiring identifying information associated with any
IETF Network Slice consumer.
10. IANA Considerations
There are no requests to IANA in this framework document.
11. Acknowledgments
The entire TEAS NS design team and everyone participating in related
discussions has contributed to this document. Some text fragments in
the document have been copied from the [I-D.ietf-teas-enhanced-vpn],
for which we are grateful.
Significant contributions to this document were gratefully received
from the contributing authors listed in the "Contributors" section.
In addition we would like to also thank those others who have
attended one or more of the design team meetings, including the
following people not listed elsewhere:
o Aihua Guo
o Bo Wu
o Greg Mirsky
o Lou Berger
o Rakesh Gandhi
o Ran Chen
o Sergio Belotti
o Stewart Bryant
o Tomonobu Niwa
o Xuesong Geng
12. Contributors
The following authors contributed significantly to this document:
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Jari Arkko
Ericsson
Email: jari.arkko@piuha.net
Dhruv Dhody
Huawei, India
Email: dhruv.ietf@gmail.com
Jie Dong
Huawei
Email: jie.dong@huawei.com
Xufeng Liu
Volta Networks
Email: xufeng.liu.ietf@gmail.com
13. References
13.1. Normative References
[I-D.ietf-teas-ietf-network-slice-definition]
Rokui, R., Homma, S., Makhijani, K., Contreras, L., and J.
Tantsura, "Definition of IETF Network Slices", draft-ietf-
teas-ietf-network-slice-definition-00 (work in progress),
January 2021.
[I-D.ietf-teas-ietf-network-slice-framework]
Gray, E. and J. Drake, "Framework for IETF Network
Slices", draft-ietf-teas-ietf-network-slice-framework-00
(work in progress), March 2021.
13.2. Informative References
[BBF-SD406]
Broadband Forum, ., "End-to-end network slicing", BBF
SD-406 , n.d..
[HIPAA] HHS, "Health Insurance Portability and Accountability Act
- The Security Rule", February 2003,
<https://www.hhs.gov/hipaa/for-professionals/security/
index.html>.
[I-D.contreras-teas-slice-nbi]
Contreras, L., Homma, S., and J. Ordonez-Lucena, "IETF
Network Slice use cases and attributes for Northbound
Interface of controller", draft-contreras-teas-slice-
nbi-03 (work in progress), October 2020.
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[I-D.ietf-teas-actn-yang]
Lee, Y., Zheng, H., Ceccarelli, D., Yoon, B., Dios, O.,
Shin, J., and S. Belotti, "Applicability of YANG models
for Abstraction and Control of Traffic Engineered
Networks", draft-ietf-teas-actn-yang-06 (work in
progress), August 2020.
[I-D.ietf-teas-enhanced-vpn]
Dong, J., Bryant, S., Li, Z., Miyasaka, T., and Y. Lee, "A
Framework for Enhanced Virtual Private Networks (VPN+)
Service", draft-ietf-teas-enhanced-vpn-06 (work in
progress), July 2020.
[I-D.ietf-teas-te-service-mapping-yang]
Lee, Y., Dhody, D., Fioccola, G., WU, Q., Ceccarelli, D.,
and J. Tantsura, "Traffic Engineering (TE) and Service
Mapping Yang Model", draft-ietf-teas-te-service-mapping-
yang-05 (work in progress), November 2020.
[I-D.openconfig-rtgwg-gnmi-spec]
Shakir, R., Shaikh, A., Borman, P., Hines, M., Lebsack,
C., and C. Morrow, "gRPC Network Management Interface
(gNMI)", draft-openconfig-rtgwg-gnmi-spec-01 (work in
progress), March 2018.
[NGMN-NS-Concept]
NGMN Alliance, ., "Description of Network Slicing
Concept", https://www.ngmn.org/uploads/
media/161010_NGMN_Network_Slicing_framework_v1.0.8.pdf ,
2016.
[NGMN_SEC]
NGMN Alliance, "NGMN 5G Security - Network Slicing", April
2016, <https://www.ngmn.org/wp-content/uploads/Publication
s/2016/160429_NGMN_5G_Security_Network_Slicing_v1_0.pdf>.
[PCI] PCI Security Standards Council, "PCI DSS", May 2018,
<https://www.pcisecuritystandards.org>.
[RFC2578] McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Structure of Management Information
Version 2 (SMIv2)", STD 58, RFC 2578,
DOI 10.17487/RFC2578, April 1999,
<https://www.rfc-editor.org/info/rfc2578>.
[RFC2681] Almes, G., Kalidindi, S., and M. Zekauskas, "A Round-trip
Delay Metric for IPPM", RFC 2681, DOI 10.17487/RFC2681,
September 1999, <https://www.rfc-editor.org/info/rfc2681>.
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[RFC3022] Srisuresh, P. and K. Egevang, "Traditional IP Network
Address Translator (Traditional NAT)", RFC 3022,
DOI 10.17487/RFC3022, January 2001,
<https://www.rfc-editor.org/info/rfc3022>.
[RFC3393] Demichelis, C. and P. Chimento, "IP Packet Delay Variation
Metric for IP Performance Metrics (IPPM)", RFC 3393,
DOI 10.17487/RFC3393, November 2002,
<https://www.rfc-editor.org/info/rfc3393>.
[RFC3412] Case, J., Harrington, D., Presuhn, R., and B. Wijnen,
"Message Processing and Dispatching for the Simple Network
Management Protocol (SNMP)", STD 62, RFC 3412,
DOI 10.17487/RFC3412, December 2002,
<https://www.rfc-editor.org/info/rfc3412>.
[RFC3414] Blumenthal, U. and B. Wijnen, "User-based Security Model
(USM) for version 3 of the Simple Network Management
Protocol (SNMPv3)", STD 62, RFC 3414,
DOI 10.17487/RFC3414, December 2002,
<https://www.rfc-editor.org/info/rfc3414>.
[RFC3417] Presuhn, R., Ed., "Transport Mappings for the Simple
Network Management Protocol (SNMP)", STD 62, RFC 3417,
DOI 10.17487/RFC3417, December 2002,
<https://www.rfc-editor.org/info/rfc3417>.
[RFC4208] Swallow, G., Drake, J., Ishimatsu, H., and Y. Rekhter,
"Generalized Multiprotocol Label Switching (GMPLS) User-
Network Interface (UNI): Resource ReserVation Protocol-
Traffic Engineering (RSVP-TE) Support for the Overlay
Model", RFC 4208, DOI 10.17487/RFC4208, October 2005,
<https://www.rfc-editor.org/info/rfc4208>.
[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)",
RFC 4303, DOI 10.17487/RFC4303, December 2005,
<https://www.rfc-editor.org/info/rfc4303>.
[RFC4397] Bryskin, I. and A. Farrel, "A Lexicography for the
Interpretation of Generalized Multiprotocol Label
Switching (GMPLS) Terminology within the Context of the
ITU-T's Automatically Switched Optical Network (ASON)
Architecture", RFC 4397, DOI 10.17487/RFC4397, February
2006, <https://www.rfc-editor.org/info/rfc4397>.
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[RFC5212] Shiomoto, K., Papadimitriou, D., Le Roux, JL., Vigoureux,
M., and D. Brungard, "Requirements for GMPLS-Based Multi-
Region and Multi-Layer Networks (MRN/MLN)", RFC 5212,
DOI 10.17487/RFC5212, July 2008,
<https://www.rfc-editor.org/info/rfc5212>.
[RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
Element (PCE) Communication Protocol (PCEP)", RFC 5440,
DOI 10.17487/RFC5440, March 2009,
<https://www.rfc-editor.org/info/rfc5440>.
[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>.
[RFC6146] Bagnulo, M., Matthews, P., and I. van Beijnum, "Stateful
NAT64: Network Address and Protocol Translation from IPv6
Clients to IPv4 Servers", RFC 6146, DOI 10.17487/RFC6146,
April 2011, <https://www.rfc-editor.org/info/rfc6146>.
[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>.
[RFC7679] Almes, G., Kalidindi, S., Zekauskas, M., and A. Morton,
Ed., "A One-Way Delay Metric for IP Performance Metrics
(IPPM)", STD 81, RFC 7679, DOI 10.17487/RFC7679, January
2016, <https://www.rfc-editor.org/info/rfc7679>.
[RFC7680] Almes, G., Kalidindi, S., Zekauskas, M., and A. Morton,
Ed., "A One-Way Loss Metric for IP Performance Metrics
(IPPM)", STD 82, RFC 7680, DOI 10.17487/RFC7680, January
2016, <https://www.rfc-editor.org/info/rfc7680>.
[RFC7926] Farrel, A., Ed., Drake, J., Bitar, N., Swallow, G.,
Ceccarelli, D., and X. Zhang, "Problem Statement and
Architecture for Information Exchange between
Interconnected Traffic-Engineered Networks", BCP 206,
RFC 7926, DOI 10.17487/RFC7926, July 2016,
<https://www.rfc-editor.org/info/rfc7926>.
[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>.
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[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>.
[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>.
[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>.
[RFC8454] Lee, Y., Belotti, S., Dhody, D., Ceccarelli, D., and B.
Yoon, "Information Model for Abstraction and Control of TE
Networks (ACTN)", RFC 8454, DOI 10.17487/RFC8454,
September 2018, <https://www.rfc-editor.org/info/rfc8454>.
[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>.
[TS23501] 3GPP, ., "System architecture for the 5G System (5GS)",
3GPP TS 23.501 , 2019.
[TS28530] 3GPP, ., "Management and orchestration; Concepts, use
cases and requirements", 3GPP TS 28.530 , 2019.
[TS33.210]
3GPP, "3G security; Network Domain Security (NDS); IP
network layer security (Release 14).", December 2016,
<https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=2279>.
Appendix A. Unused Material
This section includes material from the source documents that is not
used in the body of this document. It is intended for deletion.
For this purpose, the text is tagged to show its origin using the
format <D1.3> or <F2.4> where the letters 'D' and 'F' indicate the
definitions draft [I-D.ietf-teas-ietf-network-slice-definition] and
the framework draft [I-D.ietf-teas-ietf-network-slice-framework]
respectively, and the subsequent numbers indicate the the section of
the source document.
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A.1. Abstract
<FAb>
This memo is intended for discussing interfaces and technologies. It
is not intended to be a new set of concrete interfaces or
technologies. Rather, it should be seen as an explanation of how
some existing, concrete IETF VPN and traffic-engineering technologies
can be used to create IETF network slices. Note that there are a
number of these technologies, and new technologies or capabilities
keep being added. This memo is also not intended presume any
particular technology choice.
A.2. Management Systems or Other Applications
<F3.1.>
The IETF Network Slice system is used by a management system or other
application. These systems and applications may also be a part of a
higher level function in the system, e.g., putting together network
functions, access equipment, application specific components, as well
as the IETF Network Slices.
Authors' Addresses
Adrian Farrel (editor)
Old Dog Consulting
Email: adrian@olddog.co.uk
Eric Gray
Ericsson
Email: ewgray@graiymage.com
John Drake
Juniper Networks
Email: jdrake@juniper.net
Reza Rokui
Nokia
Email: reza.rokui@nokia.com
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Shunsuke Homma
NTT
Email: shunsuke.homma.ietf@gmail.com
Kiran Makhijani
Futurewei
Email: kiranm@futurewei.com
Luis M. Contreras
Telefonica
Spain
Email: luismiguel.contrerasmurillo@telefonica.com
Jeff Tantsura
Juniper Networks
Email: jefftant.ietf@gmail.com
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