Framework for IETF Network Slices
draft-ietf-teas-ietf-network-slices-07
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 9543.
|
|
|---|---|---|---|
| Authors | Adrian Farrel , John Drake , Reza Rokui , Shunsuke Homma , Kiran Makhijani , Luis M. Contreras , Jeff Tantsura | ||
| Last updated | 2022-03-04 | ||
| Replaces | draft-ietf-teas-ietf-network-slice-definition, draft-ietf-teas-ietf-network-slice-framework | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Reviews |
INTDIR Telechat review
(of
-21)
by Dirk Von Hugo
Ready w/nits
GENART Last Call review
(of
-21)
by Reese Enghardt
Ready w/nits
|
||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | Became RFC 9543 (Informational) | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-teas-ietf-network-slices-07
Network Working Group A. Farrel, Ed.
Internet-Draft Old Dog Consulting
Intended status: Informational J. Drake
Expires: 5 September 2022 Juniper Networks
R. Rokui
Ciena
S. Homma
NTT
K. Makhijani
Futurewei
L.M. Contreras
Telefonica
J. Tantsura
Microsoft
4 March 2022
Framework for IETF Network Slices
draft-ietf-teas-ietf-network-slices-07
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
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Farrel, et al. Expires 5 September 2022 [Page 1]
Internet-Draft IETF Network Slices March 2022
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 5 September 2022.
Copyright Notice
Copyright (c) 2022 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. Background . . . . . . . . . . . . . . . . . . . . . . . 4
2. Terms and Abbreviations . . . . . . . . . . . . . . . . . . . 5
2.1. Core Terminology . . . . . . . . . . . . . . . . . . . . 5
3. IETF Network Slice Objectives . . . . . . . . . . . . . . . . 7
3.1. Definition and Scope of IETF Network Slice . . . . . . . 7
3.2. IETF Network Slice Service . . . . . . . . . . . . . . . 8
3.2.1. Ancillary SDPs . . . . . . . . . . . . . . . . . . . 11
4. IETF Network Slice System Characteristics . . . . . . . . . . 11
4.1. Objectives for IETF Network Slices . . . . . . . . . . . 11
4.1.1. Service Level Objectives . . . . . . . . . . . . . . 12
4.1.2. Service Level Expectations . . . . . . . . . . . . . 14
4.2. IETF Network Slice Service Demarcation Points . . . . . . 16
4.3. IETF Network Slice Decomposition . . . . . . . . . . . . 18
5. Framework . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.1. IETF Network Slice Stakeholders . . . . . . . . . . . . . 19
5.2. Expressing Connectivity Intents . . . . . . . . . . . . . 19
5.3. IETF Network Slice Controller (NSC) . . . . . . . . . . . 21
5.3.1. IETF Network Slice Controller Interfaces . . . . . . 23
5.3.2. Management Architecture . . . . . . . . . . . . . . . 25
5.4. IETF Network Slice Structure . . . . . . . . . . . . . . 25
6. Realizing IETF Network Slices . . . . . . . . . . . . . . . . 27
6.1. Architecture to Realize IETF Network Slices . . . . . . . 27
6.2. Procedures to Realize IETF Network Slices . . . . . . . . 30
6.3. Applicability of ACTN to IETF Network Slices . . . . . . 31
Farrel, et al. Expires 5 September 2022 [Page 2]
Internet-Draft IETF Network Slices March 2022
6.4. Applicability of Enhanced VPNs to IETF Network Slices . . 31
6.5. Network Slicing and Aggregation in IP/MPLS Networks . . . 32
7. Isolation in IETF Network Slices . . . . . . . . . . . . . . 32
7.1. Isolation as a Service Requirement . . . . . . . . . . . 32
7.2. Isolation in IETF Network Slice Realization . . . . . . . 33
8. Management Considerations . . . . . . . . . . . . . . . . . . 33
9. Security Considerations . . . . . . . . . . . . . . . . . . . 33
10. Privacy Considerations . . . . . . . . . . . . . . . . . . . 34
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 35
12. Informative References . . . . . . . . . . . . . . . . . . . 35
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 38
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 40
1. Introduction
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 (known as Service Demarcation Points
(SDPs) - see Section 2.1) over a shared underlay network. Services
that might benefit from IETF Network Slices include, but are not
limited to:
* 5G services (e.g. eMBB, URLLC, mMTC)(See [TS23501])
* Network wholesale services
* Network infrastructure sharing among operators
* 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 underlay network. A request
for an IETF Network Slice is agnostic to the technology in the
underlying network so as to allow a customer to describe their
network connectivity objectives in a common format, independent of
the underlying technologies used.
Farrel, et al. Expires 5 September 2022 [Page 3]
Internet-Draft IETF Network Slices March 2022
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 support the VPNs is often referred to as an underlay
network, and the VPN is often called an overlay network. An overlay
network may, in turn, serve as an underlay network to support another
overlay network.
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. Evaluation of existing technologies,
proposed extensions to existing protocols and interfaces, and the
creation of new protocols or interfaces is outside the scope of this
document.
1.1. Background
Driven largely by needs surfacing from 5G, the concept of network
slicing has gained traction ([NGMN-NS-Concept], [TS23501], and
[TS28530]). 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). An IETF
Network Slice provides the required connectivity between different
entities in RAN and CN segments of an end-to-end network slice, with
a specific performance commitment. For each end-to-end network
slice, the topology and performance requirement on a customer'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.
Farrel, et al. Expires 5 September 2022 [Page 4]
Internet-Draft IETF Network Slices March 2022
A IETF Network Slice could span multiple technologies and multiple
administrative domains. Depending on the IETF Network Slice
customer'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 customer 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 customer'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 customer of such a logical network can
require a degree of isolation and performance that previously might
not have been satisfied by overlay VPNs. Additionally, the IETF
Network Slice customer 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 definitions and a framework for the provision
of an IETF Network Slice service. Section 6 briefly indicates some
candidate technologies for realizing IETF Network Slices.
2. Terms and Abbreviations
The following abbreviations are used in this document.
* NSC: Network Slice Controller
* SLA: Service Level Agreement
* SLI: Service Level Indicator
* SLO: Service Level Objective
The meaning of these abbreviations is defined in greater details in
the remainder of this document.
2.1. Core Terminology
The following terms are presented here to give context. Other
terminology is defined in the remainder of this document.
Customer: A customer is the requester of an IETF Network Slice
service. Customers may request monitoring of SLOs. A customer
may be an entity such as an enterprise network or a network
operator, an individual working at such an entity, a private
individual contracting for a service, or an application or
Farrel, et al. Expires 5 September 2022 [Page 5]
Internet-Draft IETF Network Slices March 2022
software component. A customer may be an external party
(classically a paying customer) or a division of a network
operator that uses the service provided by another division of the
same operator. Other terms that have been applied to the customer
role are "client" and "consumer".
Provider: A provider is the organization that delivers an IETF
Network Slice service. A provider is the network operator that
controls the network resources used to construct the network slice
(that is, the network that is sliced). The provider's network
maybe a physical network or may be a virtual network supplied by
another service provider.
Customer Edge (CE): The customer device that provides connectivity
to a service provider. Examples include routers, Ethernet
switches, firewalls, 4G/5G RAN or Core nodes, application
accelerators, server load balancers, HTTP header enrichment
functions, and PEPs (Performance Enhancing Proxy). In some
circumstances CEs are provided to the customer and managed by the
provider.
Provider Edge: The device within the provider network to which a CE
is attached. A CE may be attached to multiple PEs, and multiple
CEs may be attached to a given PE.
Attachment Circuit (AC): A channel connecting a CE and a PE over
which packets that belong to an IETF Network Slice service are
exchanged. The customer and provider agree (through
configuration) on which values in which combination of layer 2 and
layer 3 header and payload fields within a packet identify to
which {IETF Network Slice service, connectivity construct, and
SLOs/SLEs} that packet is assigned. The customer and provider may
agree on a per {IETF Network Slice service, connectivity
construct, and SLOs/SLEs} basis to police or shape traffic on the
AC in both the ingress (CE to PE) direction and egress (PE to CE)
direction, This ensures that the traffic is within the capacity
profile that is agreed in an IETF Network Slice service. Excess
traffic is dropped by default, unless specific out-of-profile
policies are agreed between the customer and the provider. As
described in Section 4.2 the AC may be part of the IETF Network
Slice service or may be external to it.
Service Demarcation Point (SDP): The point at which an IETF Network
Slice service is delivered by a service provider to a customer.
Depending on the service delivery model (see Section 4.2 this may
be a CE or a PE, and could be a device, a software component, or
in the case of network functions virtualization (for example), be
an abstract function supported within the provider's network.
Farrel, et al. Expires 5 September 2022 [Page 6]
Internet-Draft IETF Network Slices March 2022
Each SDP must have a unique identifier (e.g., an IP address or MAC
address) within a given IETF Network Slice service and may use the
same identifier in multiple IETF Network Slice services.
An SDP may be abstracted as a Service Attachment Point (SAP)
[I-D.ietf-opsawg-sap] for the purpose generalizing the concept
across multiple service types and representing it in management
and configuration systems.
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 of the service in accordance with specified
characteristics.
3.1. Definition and Scope of IETF Network Slice
An IETF Network Slice service enables connectivity between a set of
Service Demarcation Points (SDPs) with specific Service Level
Objectives (SLOs) and Service Level Expectations (SLEs) over a common
underlay network.
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. The definition of an IETF Network Slice
service is independent of the connectivity and technologies used in
the underlay network. This allows an IETF Network Slice service
customer to describe their network connectivity and relevant
objectives in a common format, independent of the underlying
technologies used.
Farrel, et al. Expires 5 September 2022 [Page 7]
Internet-Draft IETF Network Slices March 2022
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 service is agnostic to the technology of the
underlying network, and its realization may be selected based upon
multiple considerations including its service requirements and the
capabilities of the underlay network.
The term "Slice" refers to a set of characteristics and behaviours
that separate one type of user-traffic from another. An IETF Network
Slice assumes that an underlay 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/
SLEs to all of the traffic in the slice or to specific flows.
3.2. IETF Network Slice Service
A service provider delivers an IETF Network Slice service for a
customer. The IETF Network Slice service is specified in terms of a
set of SDPs, a set of one or more connectivity constructs between
subsets of these SDPs, and a set of SLOs and SLEs for each SDP
sending to each connectivity construct. A communication type (point-
to-point (P2P) both unidirectional and bidirectional, point-to-
multipoint (P2MP), multipoint-to-point (MP2P), multipoint-to-
multipoint (MP2MP), or any-to-any (A2A)) is specified for each
connectivity construct. That is, in a given IETF Network Slice
service there may be one or more connectivity constructs of the same
or different type, each connectivity construct may be between a
different subset of SDPs, and for a given connectivity construct each
sending SDP has its own set of SLOs and SLEs, and the SLOs and SLEs
in each set may be different. Note that a service provider may
decide how many connectivity constructs per IETF Network Slice
service it wishes to support.
This approach results in the following possible connectivity
constructs:
* For a P2P connectivity construct, there is one sending SDP and one
receiving SDP. This construct is like a private wire or a tunnel.
All traffic injected at the sending SDP is intended to be received
by the receiving SDP. The SLOs and SLEs apply at the sender (and
implicitly at the receiver).
Farrel, et al. Expires 5 September 2022 [Page 8]
Internet-Draft IETF Network Slices March 2022
* A bidirectional P2P connectivity construct may also be defined,
with two SDPs each of which may send to the other. There are two
sets of SLOs and SLEs which may be different and each of which
applies to one of the SDPs as a sender.
* For a P2MP connectivity construct, there is only one sending SDP
and more than one receiving SDP. This is like a P2MP tunnel or
multi-access VLAN segment. All traffic from the sending SDP is
intended to be received by all the receiving SDPs. There is one
set of SLOs and SLEs that apply at the sending SDP (and implicitly
at all receiving SDPs). Activating unicast or multicast
capabilities to deliver an IETF Slice service can be explicitly
requested by a customer or can be an engineering decision of a
service provider based on capabilities of the network and
operational choices.
* An MP2P connectivity construct has N SDPs: there is one receiving
SDP and (N - 1) sending SDPs. This is like a set of P2P
connections all with a common receiver. All traffic injected at
any sending SDP is received by the single receiving SDP. Each
sending SDP has its own set of SLOs and SLEs, and they may all be
different (the combination of those SLOs and SLEs gives the
implicit SLOs and SLEs for the receiving SDP - that is, the
receiving SDP is expected to receive all traffic from all
senders).
* In an MP2MP connectivity construct each of the N SDPs can be a
sending SDP such that its traffic is delivered to all of the other
SDPs. Each sending SDP has its own set of SLOs and SLEs and they
may all be different. The combination of those SLOs/SLEs gives
the implicit SLOs/SLEs for each/all of the receiving SDPs since
each receiving SDP is expect to receive all traffic from all/any
sender.
Farrel, et al. Expires 5 September 2022 [Page 9]
Internet-Draft IETF Network Slices March 2022
* With an A2A construct, any sending SDP may send to any one
receiving SDP or any set of receiving SDPs in the construct.
There is an implicit level of routing in this connectivity
construct that is not present in the other connectivity constructs
as the construct must determine to which receiving SDPs to deliver
each packet. The SLOs/SLEs apply to individual sending SDPs and
individual receiving SDPs, but there is no implicit linkage and a
sending SDP may be "disappointed" if the receiver is over-
subscribed. This construct may be used to support P2P traffic
between any pair of SDPs or to support multicast or broadcast
traffic from one SDP to a set of other SDPs. In the latter case,
whether the service is delivered using multicast within the
provider's network or using "ingress replication" or some other
means is out of scope of the specification of the service. A
service provider may choose to support A2A constructs but limit
the traffic to P2P.
If an SDP has multiple attachment circuits to a given IETF Network
Slice service and they are operating in single-active mode, then all
traffic between the SDP and its attached PEs transits a single
attachment circuit; if they are operating in in all-active mode, then
traffic between the SDP and its attached PEs is distributed across
all of the active attachment circuits.
A given sending SDP may be part of multiple connectivity constructs
within a single IETF Network Slice service, and the SDP may have
different SLOs and SLEs for each connectivity construct to which it
is sending. Note that a given sending SDP's SLOs and SLEs for a
given connectivity construct apply between it and each of the
receiving SDPs for that connectivity construct.
An IETF Network Slice service provider may freely make a deployment
choice as to whether to offer a 1:1 relationship between IETF Network
Slice service and connectivity construct, or to support multiple
connectivity constructs in a single IETF Network Slice service. In
the former case, the provider might need to deliver multiple IETF
Network Slice services to achieve the function of the second case.
It should be noted that per Section 9 of [RFC4364] an IETF Network
Slice service customer may actually provide IETF Network Slice
services to other customers in a mode sometimes referred to as
"carrier's carrier". In this case, the underlying IETF Network Slice
service provider may be owned and operated by the same or a different
provider network. As noted in Section 3.1, network slices may be
composed hierarchically or serially.
Farrel, et al. Expires 5 September 2022 [Page 10]
Internet-Draft IETF Network Slices March 2022
Section 4.2 provides a description of endpoints in the context of
IETF network slicing. These are known as Service Demarcation Points
(SDPs). For a given IETF Network Slice service, the customer and
provider agree, on a per-SDP basis which end of the attachment
circuit provides the service demarcation point (i.e., whether the
attachment circuit is inside or outside the IETF Network Slice
service). This determines whether the attachment circuit is subject
to the set of SLOs and SLEs at the specific SDP.
3.2.1. Ancillary SDPs
It may be the case that the set of SDPs needs to be supplemented with
additional senders or receivers. An additional sender could be, for
example, an IPTV or DNS server either within the provider's network
or attached to it, while an extra receiver could be, for example, a
node reachable via the Internet. This will be modelled as a set of
ancillary SDPs which supplement the other SDPs in one or more
connectivity constructs, or which have their own connectivity
constructs. Note that an ancillary SDP can either have a resolvable
address, e.g., an IP address or MAC address, or it may be a
placeholder, e.g., IPTV or DNS server, which is resolved within the
provider's network when the IETF Network Slice service is
instantiated.
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 service is defined in terms of quantifiable
characteristics known as Service Level Objectives (SLOs) and
unquantifiable characteristics known as Service Level Expectations
(SLEs). SLOs are expressed in terms Service Level Indicators (SLIs),
and together with the SLEs form the contractual agreement between
service customer and service provider known as a Service Level
Agreement (SLA).
The terms are defined as follows:
* 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.
Farrel, et al. Expires 5 September 2022 [Page 11]
Internet-Draft IETF Network Slices March 2022
* 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 customer can determine whether the provider is
meeting the SLOs by performing measurements on the traffic.
* A Service Level Expectation (SLE) is an expression of an
unmeasurable service-related request that a customer of an IETF
Network Slice makes of the provider. An SLE is distinct from an
SLO because the customer may have little or no way of determining
whether the SLE is being met, but they still contract with the
provider for a service that meets the expectation.
* A Service Level Agreement (SLA) is an explicit or implicit
contract between the customer of an IETF Network Slice service and
the provider of the slice. The SLA is expressed in terms of a set
of SLOs and SLEs that are to be applied for a given connectivity
construct between a sending SDP and the set of receiving SDPs, and
may describe the extent to which divergence from individual SLOs
and SLEs can be tolerated, and commercial terms as well as any
consequences for violating these SLOs and SLEs.
4.1.1. Service Level Objectives
SLOs define a set of measurable network attributes and
characteristics that describe an IETF Network Slice service. SLOs do
not describe how an IETF Network Slice service is 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 service may include multiple connection
constructs that associate sets of endpoints (SDPs). SLOs apply to a
given connectivity construct and apply to specific directions of
traffic flow. That is, they apply to a specific sending SDP and the
connection to specific receiving SDPs.
The SLOs are combined with Service Level Expectations in an SLA.
4.1.1.1. Some Common SLOs
SLOs can be described as 'Directly Measurable Objectives': they are
always measurable. See Section 4.1.2 for the description of Service
Level Expectations which are unmeasurable service-related requests
sometimes known as 'Indirectly Measurable Objectives'.
Farrel, et al. Expires 5 September 2022 [Page 12]
Internet-Draft IETF Network Slices March 2022
Objectives such as guaranteed minimum bandwidth, guaranteed maximum
latency, maximum permissible delay variation, maximum permissible
packet loss rate, and availability are 'Directly Measurable
Objectives'. Future specifications (such as IETF Network Slice
service YANG models) may precisely define these SLOs, and other SLOs
may be introduced as described in Section 4.1.1.2.
The definition of these objectives are as follows:
Guaranteed Minimum Bandwidth: 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.
4.1.1.2. Other Service Level Objectives
Additional SLOs may be defined to provide additional description of
the IETF Network Slice service that a customer requests. These would
be specified in further documents.
If the IETF Network Slice 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).
Farrel, et al. Expires 5 September 2022 [Page 13]
Internet-Draft IETF Network Slices March 2022
4.1.2. Service Level Expectations
SLEs define a set of network attributes and characteristics that
describe an IETF Network Slice service, but which are not directly
measurable by the customer. Even though the delivery of an SLE
cannot usually be determined by the customer, the SLEs form an
important part of the contract between customer and provider.
Quite often, an SLE will imply some details of how an IETF Network
Slice service is realized by the provider, although most aspects of
the implementation in the underlying network layers remain a free
choice for the provider.
SLEs may be seen as aspirational on the part of the customer, and
they are expressed as behaviors that the provider is expected to
apply to the network resources used to deliver the IETF Network Slice
service. The SLEs are combined with SLOs in an SLA.
An IETF Network Slice service may include multiple connection
constructs that associate sets of endpoints (SDPs). SLEs apply to a
given connectivity construct and apply to specific directions of
traffic flow. That is, they apply to a specific sending SDP and the
connection to specific receiving SDPs. However, being more general
in nature that SLOs, SLEs may commonly be applied to all connection
constructs in an IETF Network Slice service.
4.1.2.1. Some Common SLEs
SLEs can be described as 'Indirectly Measurable Objectives': they are
not generally directly measurable by the customer.
Security, geographic restrictions, maximum occupancy level, and
isolation are example SLEs as follows.
Security: A customer may request that the provider applies
encryption or other security techniques to traffic flowing between
SDPs of an IETF Network Slice service. For example, the customer
could request that only network links that have MACsec [MACsec]
enabled are used to realize the IETF Network Slice service.
This SLE may include the request for encryption (e.g., [RFC4303])
between the two SDPs explicitly to meet architecture
recommendations as in [TS33.210] or for compliance with [HIPAA] or
[PCI].
Whether or not the provider has met this SLE is generally not
directly observable by the customer and cannot be measured as a
quantifiable metric.
Farrel, et al. Expires 5 September 2022 [Page 14]
Internet-Draft IETF Network Slices March 2022
Please see further discussion on security in Section 9.
Geographic Restrictions: A customer may request that certain
geographic limits are applied to how the provider routes traffic
for the IETF Network Slice service. For example, the customer may
have a preference that its traffic does not pass through a
particular country for political or security reasons.
Whether or not the provider has met this SLE is generally not
directly observable by the customer and cannot be measured as a
quantifiable metric.
Maximal Occupancy Level: The maximal occupancy level specifies the
number of flows to be admitted and optionally a maximum number of
countable resource units (e.g., IP or MAC addresses) an IETF
Network Slice service can consume. Since an IETF Network Slice
service may include multiple connection constructs, this SLE
should also say whether it applies for the entire IETF Network
Slice service, for group of connections, or on a per connection
basis.
Again, a customer may not be able to fully determine whether this
SLE is being met by the provider.
Isolation: As described in Section 7, a customer may request that
its traffic within its IETF Network Slice service is isolated from
the effects of other network services supported by the same
provider. That is, if another service exceeds capacity or has a
burst of traffic, the customer's IETF Network Slice service should
remain unaffected and there should be no noticeable change to the
quality of traffic delivered.
In general, a customer cannot tell whether a service provider is
meeting this SLE. They cannot tell whether the variation of an
SLI is because of changes in the underlying network or because of
interference from other services carried by the network. And if
the service varies within the allowed bounds of the SLOs, there
may be no noticeable indication that this SLE has been violated.
Diversity: A customer may request that traffic on the connection
between one set of SDPs should use different network resources
from the traffic between another set of SDPs. This might be done
to enhance the availability of the IETF Network Slice service.
While availability is a measurable objective (see Section 4.1.1.1)
this SLE requests a finer grade of control and is not directly
measurable (although the customer might become suspicious if two
connections fail at the same time).
Farrel, et al. Expires 5 September 2022 [Page 15]
Internet-Draft IETF Network Slices March 2022
4.2. IETF Network Slice Service Demarcation Points
As noted in Section 3.1, an IETF Network Slice is a logical network
topology connecting a number of endpoints. Section 3.2 goes on to
describe how the IETF Network Slice service is composed of a set of
one or more connectivity constructs that describe connectivity
between the service demarcation points across the underlying network.
The characteristics of IETF Network Slice Service Demarcation Points
(SDPs) are as follows:
* SDPs are conceptual points of connection to an IETF Network Slice.
As such, they serve as the IETF Network Slice ingress/ egress
points.
* Each SDP maps to a device, application, or a network function,
such as (but not limited to) routers, switches, firewalls, WAN,
4G/5G RAN nodes, 4G/5G Core nodes, application accelerators,
server load balancers, NAT44 [RFC3022], NAT64 [RFC6146], HTTP
header enrichment functions, and Performance Enhancing Proxies
(PEPs) [RFC3135].
* An SDP is identified by a unique identifier in the context of an
IETF Network Slice customer.
* Each SDP is associated with a set of provider-scope identifiers
such as IP addresses, encapsulation-specific identifiers (e.g.,
VLAN tag, MPLS Label), interface/port numbers, node ID, etc.
* SDPs are mapped to endpoints of services/tunnels/paths within the
IETF Network Slice during its initialization and realization.
- A combination of the SDP identifier and SDP provider-network-
scope identifiers define an SDP in the context of the Network
Slice Controller (NSC).
- The NSC will use the SDP provider-network-scope identifiers as
part of the process of realizing the IETF Network Slice.
For a given IETF Network Slice service, the IETF Network Slice
customer and provider agree where the endpoint (i.e., the service
demarcation point) is located. This determines what resources at the
edge of the network form part of the IETF Network Slice and are
subject to the set of SLOs and SLEs for a specific endpoint.
Figure 1 shows different potential scopes of an IETF Network Slice
that are consistent with the different SDP positions. For the
purpose of example and without loss of generality, the figure shows
Farrel, et al. Expires 5 September 2022 [Page 16]
Internet-Draft IETF Network Slices March 2022
customer edge (CE) and provider edge (PE) nodes connected by
attachment circuits (ACs). Notes after the figure give some
explanations.
|<---------------------- (1) ---------------------->|
| |
| |<-------------------- (2) -------------------->| |
| | | |
| | |<----------- (3) ----------->| | |
| | | | | |
| | | |<-------- (4) -------->| | | |
| | | | | | | |
V V AC V V V V AC V V
+-----+ | +-----+ +-----+ | +-----+
| |--------| | | |--------| |
| CE1 | | | PE1 |. . . . . . . . .| PE2 | | | CE2 |
| |--------| | | |--------| |
+-----+ | +-----+ +-----+ | +-----+
^ ^ ^ ^
| | | |
| | | |
Customer Provider Provider Customer
Edge 1 Edge 1 Edge 2 Edge 2
Figure 1: Positioning IETF Service Demarcation Points
Explanatory notes for Figure 1 are as follows:
1. If the CE is operated by the IETF Network Slice service provider,
then the edge of the IETF Network Slice may be within the CE. In
this case the slicing process may utilize resources from within
the CE such as buffers and queues on the outgoing interfaces.
2. The IETF Network Slice may be extended as far as the CE, to
include the AC, but not to include any part of the CE. In this
case, the CE may be operated by the customer or the provider.
Slicing the resources on the AC may require the use of traffic
tagging (such as through Ethernet VLAN tags) or may require
traffic policing at the AC link ends.
3. In another model, the SDPs of the IETF Network Slice are the
customer-facing ports on the PEs. This case can be managed in a
way that is similar to a port-based VPN: each port (AC) or
virtual port (e.g., VLAN tag) identifies the IETF Network Slice
and maps to an IETF Network Slice SDP.
Farrel, et al. Expires 5 September 2022 [Page 17]
Internet-Draft IETF Network Slices March 2022
4. Finally, the SDP may be within the PE. In this mode, the PE
classifies the traffic coming from the AC according to
information (such as the source and destination IP addresses,
payload protocol and port numbers, etc.) in order to place it
onto an IETF Network Slice.
The choice of which of these options to apply is entirely up to the
network operator. It may limit or enable the provisioning of
particular managed services and the operator will want to consider
how they want to manage CEs and what control they wish to offer the
customer over AC resources.
Note that Figure 1 shows a symmetrical positioning of SDP, but this
decision can be taken on a per-SDP basis through agreement between
the customer and provider.
In practice, it may be necessary to map traffic not only onto an IETF
Network Slice, but also onto a specific connectivity construct if the
IETF Network Slice supports more than one connectivity construct with
a source at the specific SDP. The mechanism used will be one of the
mechanisms described above, dependent on how the SDP is realized.
Finally, note (as described in Section 2.1) that an SDP is an
abstract endpoint of an IETF Network Slice service and as such may be
a device or software component and may, in the case of netork
functions virtualization (for example), be an abstract function
supported within the provider's network.
4.3. IETF Network Slice Decomposition
Operationally, an IETF Network Slice may be composed of two or more
IETF Network Slices as specified below. Decomposed network slices
are independently realized and managed.
* 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.
* 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.
Farrel, et al. Expires 5 September 2022 [Page 18]
Internet-Draft IETF Network Slices March 2022
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
customer. 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.
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. The IETF Network Slice customer and IETF Network Slice
provider (see Section 2.1) are also stakeholders.
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): The NSC realizes an IETF
Network Slice in the underlying network, and maintains and
monitors the run-time state of resources and topologies associated
with it. A well-defined interface is needed to support
interworking between different NSC implementations and different
orchestrator implementations.
Network Controller: The 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
An IETF Network Slice customer communicates with the NSC using the
IETF Network Slice Service Interface.
An IETF Network Slice customer may be a network operator who, in
turn, provides the IETF Network Slice to another IETF Network Slice
customer.
Farrel, et al. Expires 5 September 2022 [Page 19]
Internet-Draft IETF Network Slices March 2022
Using the IETF Network Slice Service Interface, a customer expresses
requirements for a particular slice by specifying what is required
rather than how that is to be achieved. That is, the customer's view
of a slice is an abstract one. Customers 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 customer and provider are
associated with a single administrative domain, in order to reduce
the potential for adverse interactions between IETF Network Slice
customers and other users of the underlay network infrastructure.
The benefits of this model can include:
* Security: because the underlay network (or network operator) does
not need to expose network details (topology, capacity, etc.) to
IETF Network Slice customers the underlay network components are
less exposed to attack;
* Layered Implementation: the underlay network comprises network
elements that belong to a different layer network than customer
applications, and network information (advertisements, protocols,
etc.) that a customer cannot interpret or respond to (note - a
customer should not use network information not exposed via the
IETF Network Slice Service Interface, even if that information is
available);
* Scalability: customers do not need to know any information beyond
that which is exposed via the IETF Network Slice Service
Interface.
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 other
IETF documents. See, for instance, GMPLS-based networks [RFC5212]
and [RFC4397], or Abstraction and Control of TE Networks (ACTN)
[RFC8453] and [RFC8454]. The principles and mechanisms associated
with layered networking are applicable to IETF Network Slices.
Farrel, et al. Expires 5 September 2022 [Page 20]
Internet-Draft IETF Network Slices March 2022
There are several IETF-defined mechanisms for expressing the need for
a desired logical network. The IETF Network Slice Service Interface
carries data either in a protocol-defined format, or in a formalism
associated with a modeling language.
For instance:
* 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.
* Network Configuration Protocol (NETCONF) [RFC6241] and RESTCONF
Protocol [RFC8040] use XML and JSON encoding.
* gRPC/GNMI [I-D.openconfig-rtgwg-gnmi-spec] uses a binary encoded
programmable interface;
* 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.
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. Further, it is
possible that mechanisms will be needed to determine the feasibility
of service requests before they are actually made.
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.
The IETF Network Slice Service Interface 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/customer about IETF Network Slice status and performance.
The details for this IETF Network Slice Service Interface are not in
scope for this document.
Farrel, et al. Expires 5 September 2022 [Page 21]
Internet-Draft IETF Network Slices March 2022
The controller provides the following functions:
* Provides an IETF Network Slice Service Interface for
creation/modification/deletion of the IETF Network Slices tht is
agnostic to the technology of the underlying network. The API
exposed by this interface communicates the Service Demarcation
Points 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.
* Determines an abstract topology connecting the SDPs of the IETF
Network Slice that meets criteria specified via the IETF Network
Slice Service Interface. The NSC also retains information about
the mapping of this abstract topology to underlying components of
the IETF Network Slice as necessary to monitor IETF Network Slice
status and performance.
* Provides "Mapping Functions" for the realization of IETF Network
Slices. In other words, it will use the mapping functions that:
- map IETF Network Slice Service Interface requests that are
agnostic to the technology of the underlying network to
technology-specific network configuration interfaces
- map filtering/selection information as necessary to entities in
the underlay network.
* Via a network configuration interface, 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.
* 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 customer via the IETF
Network Slice Service Interface. The IETF Network Slice Service
Interface may also include a capability to provide notification in
case the IETF Network Slice performance reaches threshold values
defined by the IETF Network Slice customer.
An IETF Network Slice customer is served by the IETF Network Slice
Controller (NSC), as follows:
* The NSC takes requests from a management system or other
application, which are then communicated via the IETF Network
Slice Service Interface. This interface carries data objects the
Farrel, et al. Expires 5 September 2022 [Page 22]
Internet-Draft IETF Network Slices March 2022
IETF Network Slice customer 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 customer's perspective; it may be as simple as a list of
mutually (and symmetrically) connected SDPs, or it may be
complicated by details of connection asymmetry, per-connection SLO
requirements, etc.
* 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.
* The NSC maintains a record of the mapping from customer 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.
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).
IETF Network Slice Service Interface: The IETF Network Slice Service
Interface is an interface between a customer's higher level
operation system (e.g., a network slice orchestrator) and the NSC.
It is agnostic to the technology of the underlying network. The
customer 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 customer.
Network Configuration Interface: The Network Configuration 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.
These interfaces can be considered in the context of the Service
Model and Network Model described in [RFC8309] and, together with the
Device Configuration Interface used by the Network Controllers,
provides a consistent view of service delivery and realization.
Farrel, et al. Expires 5 September 2022 [Page 23]
Internet-Draft IETF Network Slices March 2022
+------------------------------------------+
| Customer higher level operation system |
| (e.g E2E network slice orchestrator) |
+------------------------------------------+
A
| IETF Network Slice Service Interface
V
+------------------------------------------+
| IETF Network Slice Controller (NSC) |
+------------------------------------------+
A
| Network Configuration Interface
V
+------------------------------------------+
| Network Controllers |
+------------------------------------------+
Figure 2: Interface of IETF Network Slice Controller
5.3.1.1. IETF Network Slice Service Interface
The IETF Network Slice Controller provides an IETF Network Slice
Service Interface that allows customers of network slices to request
and monitor IETF Network Slices. Customers operate on abstract IETF
Network Slices, with details related to their realization hidden.
The IETF Network Slice Service Interface complements various IETF
services, tunnels, path models by providing an abstract layer on top
of these models.
The IETF Network Slice Service Interface 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 IETF Network Slice Service Interface 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 SDP and connectivity information, SLO specification,
and status information.
To accomplish this, the IETF Network Slice Service Interface needs to
convey information needed to support communication across the
interface, in terms of identifying the IETF Network Slices, as well
providing the above model information.
Farrel, et al. Expires 5 September 2022 [Page 24]
Internet-Draft IETF Network Slices March 2022
5.3.2. Management Architecture
The management architecture described in Figure 2 may be further
decomposed as shown in Figure 3. This should also be seen in the
context of the component architecture shown in Figure 5.
--------------
| Network |
| Slice |
| Orchestrator |
--------------
| IETF Network Slice
| Service Request
| Customer view
..|................................
-v------------------- Operator view
|Controller |
| ------------ |
| | IETF | |
| | Network | |
| | Slice | |
| | Controller | |
| | (NSC) | |
| ------------ |--> Virtual Network
| | Network |
| | Configuration |
| v |
| ------------ |
| | Network | |
| | Controller | |
| | (NC) | |
| ------------ |
---------------------
| Device Configuration
..|................................
v Underlay Network
Figure 3: Interface of IETF Network Slice Management Architecture
5.4. IETF Network Slice Structure
An IETF Network Slice is a set of connections among various SDPs to
form a logical network that meets the SLOs agreed upon.
Farrel, et al. Expires 5 September 2022 [Page 25]
Internet-Draft IETF Network Slices March 2022
|------------------------------------------|
SDP1 O....| |....O SDP2
. | | .
. | IETF Network Slice | .
. | (SLOs e.g. B/W > x bps, Delay < y ms) | .
SDPm O....| |....O SDPn
|------------------------------------------|
== == == == == == == == == == == == == == == == == == == == == ==
.--. .--.
[EP1] ( )- . ( )- . [EP2]
. .' IETF ' SLO .' IETF ' .
. ( Network-1 ) ... ( Network-p ) .
`-----------' `-----------'
[EPm] [EPn]
Legend
SDP: IETF Network Slice Service Demarcation Point
EP: Serivce/tunnel/path Endpoint used to realize the
IETF Network Slice
Figure 4: IETF Network Slice
Figure 4 illustrates a case where an IETF Network Slice provides
connectivity between a set of IETF Network Slice Service Demarcation
Point (SDP) 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 service/tunnel/path
Endpoints (EPs) in the underlay network. Also, the SDPs in 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 customer [TS23501].
Farrel, et al. Expires 5 September 2022 [Page 26]
Internet-Draft IETF Network Slices March 2022
An end-to-end network slice may be composed from other network slices
that include IETF Network Slices. This composition may include the
hierarchical (or recursive) use of underlying network slices and the
sequential (or stitched) combination of slices of different networks.
6. Realizing IETF Network Slices
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 Network Configuration Interface.
However, this section provides an overview of the components and
processes involved in realizing an IETF Network Slice.
The realization can be achieved in a form of either physical or
logical connectivity using VPNs, virtual networks (VNs), or a variety
of tunneling technologies such as Segment Routing, MPLS, etc.
Accordingly, SDPs may be realized as physical or logical service or
network functions.
6.1. Architecture to Realize IETF Network Slices
The architecture described in this section is deliberately at a high
level. It is not intended to be prescriptive: implementations and
technical solutions may vary freely. However, this approach provides
a common framework that other documents may reference in order to
facilitate a shared understanding of the work.
Figure 5 shows the architectural components of a network managed to
provide IETF Network Slices. The customer's view is of individual
IETF Network Slices with their CEs, PEs, and connectivity constructs.
Requests for IETF Network Slices are delivered to the NSC.
The figure shows, without loss of generality, the CEs, ACs, and PEs,
that exist in the network. The SDPs are not shown and can be placed
in any of the ways described in Section 4.2.
Farrel, et al. Expires 5 September 2022 [Page 27]
Internet-Draft IETF Network Slices March 2022
-- -- --
|CE| |CE| |CE|
-- -- --
AC : AC : AC :
---------------------- -------
( |PE|....|PE|....|PE| ) ( IETF )
IETF Network ( --: -- :-- ) ( Network )
Slice Service ( :............: ) ( Slice )
Request ( IETF Network Slice ) ( ) Customer
v ---------------------- ------- View
v ............................\........./...............
v \ / Provider
v >>>>>>>>>>>>>>> Grouping/Mapping v v View
v ^ -----------------------------------------
v ^ ( |PE|.......|PE|........|PE|.......|PE| )
--------- ( --: -- :-- -- )
| | ( :...................: )
| NSC | ( Network Resource Partition )
| | -----------------------------------------
| | ^
| |>>>>> Resource Partitioning |
--------- of Filter Topology |
v v |
v v ----------------------------- --------
v v (|PE|..-..|PE|... ..|PE|..|PE|) ( )
v v ( :-- |P| -- :-: -- :-- ) ( Filter )
v v ( :.- -:.......|P| :- ) ( Topology )
v v ( |P|...........:-:.......|P| ) ( )
v v ( - Filter Topology ) --------
v v ----------------------------- ^
v >>>>>>>>>>>> Topology Filter ^ /
v ...........................\............../...........
v \ / Underlay
---------- \ / (Physical)
| | \ / Network
| Network | ----------------------------------------------
|Controller| ( |PE|.....-.....|PE|...... |PE|.......|PE| )
| | ( -- |P| -- :-...:-- -..:-- )
---------- ( : -:.............|P|.........|P| )
v ( -......................:-:..- - )
>>>>>>> ( |P|.........................|P|......: )
Program the ( - - )
Network ----------------------------------------------
Figure 5: Architecture of an IETF Network Slice
Farrel, et al. Expires 5 September 2022 [Page 28]
Internet-Draft IETF Network Slices March 2022
The network itself (at the bottom of the figure) comprises an
underlay network. This could be a physical network, but may be a
virtual network. The underlay network is provisioned through network
controllers.
The underlay network may optionally be filtered or customized by the
network operator to produce a number of network topologies that we
call Filter Topologies. Customization is just a way of selecting
specific resources (e.g., nodes and links) from the underlay network
according to their capabilities and connectivity in the underlay
network. These actions are configuration options or operator
policies. The resulting topologies can be used as candidates to host
IETF Network Slices and provide a useful way for the network operator
to know in advance that all of the resources they are using to plan
an IETF Network Slice would be able to meet specific SLOs and SLEs.
The creation of a Filter Topology could be an offline planning
activity or could be performed dynamically as new demands arise. The
use of Filter Topologies is entirely optional in the architecture,
and IETF Network Slices could be hosted directly on the underlay
network.
Recall that an IETF Network Slice is a service requested by /
provided for the customer. The IETF Network Slice service is
expressed in terms of one or more connectivity constructs. An
implementation or operator is free to limit the number of
connectivity constructs in a slice to exactly one. Each connectivity
construct is associated within the IETF Network Slice service request
with a set of SLOs and SLEs. The set of SLOs and SLEs does not need
to be the same for every connectivity construct in the slice, but an
implementation or operator is free to require that all connectivity
constructs in a slice have the same set of SLOs and SLEs.
One or more connectivity constructs from one or more slices are
mapped to a set of network resources called a Network Resource
Partition (NRP). A single connectivity construct is mapped to only
one NRP (that is, the relationship is many to one). An NRP may be
chosen to support a specific connectivity construct because of its
ability to support a specific set of SLOs and SLEs, or its ability to
support particular connectivity types, or for any administrative or
operational reason. An implementation or operator is free to map
each connectivity construct to a separate NRP, although there may be
scaling implications depending on the solution implemented. Thus,
the connectivity constructs in one slice may be mapped to one or more
NRPs. By implication from the above, an implementation or operator
is free to map all the connectivity constructs in a slice to a single
NRP, and to not share that NRP with connectivity constructs from
another slice.
Farrel, et al. Expires 5 September 2022 [Page 29]
Internet-Draft IETF Network Slices March 2022
An NRP is simply a collection of resources identified in the underlay
network. The process of determining the NRP may be made easier if
the underlay network topology is first filtered into a Filter
Topology in order to be aware of the subset of network resources that
are suitable for specific NRPs, but this is optional.
The steps described here can be applied in a variety of orders
according to implementation and deployment preferences. Furthermore,
the steps may be iterative so that the components are continually
refined and modified as network conditions change and as service
requests are received or relinquished, and even the underlay network
could be extended if necessary to meet the customers' demands.
6.2. Procedures to Realize IETF Network Slices
There are a number of different technologies that can be used in the
underlay, including physical connections, MPLS, time-sensitive
networking (TSN), Flex-E, etc.
An 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 realized with following steps:
* The NSC exposes the network slicing capabilities that it offers
for the network it manages.
* The customer may issue a request to determine whether a specific
IETF Network Slice could be supported by the network. The NSC may
respond indicating a simple yes or no, and may supplement a
negative response with information about what it could support
were the customer to change some requirements.
* The customer requests an IETF Network Slice. The NSC may respond
that the slice has or has not been created, and may supplement a
negative response with information about what it could support
were the customer to change some requirements.
* When processing a customer request for an IETF Network Slice, the
NSC maps the request to the network capabilities and applies
provider policies before creating or supplementing the resource
partition.
Regardless of how IETF Network Slice is realized in the network
(i.e., using tunnels of different types), the definition of the IETF
Network Slice does not change at all. The only difference is how the
slice is realized. The following sections briefly introduce how some
existing architectural approaches can be applied to realize IETF
Network Slices.
Farrel, et al. Expires 5 September 2022 [Page 30]
Internet-Draft IETF Network Slices March 2022
6.3. Applicability of ACTN to IETF Network Slices
Abstraction and Control of TE Networks (ACTN - [RFC8453]) is a
management architecture and toolkit used to create virtual networks
(VNs) on top of a TE underlay network. The VNs can be presented to
customers for them to operate as private networks.
In many ways, the function of ACTN is similar to IETF network
slicing. Customer requests for connectivity-based overlay services
are mapped to dedicated or shared resources in the underlay network
in a way that meets customer guarantees for service level objectives
and for separation from other customers' traffic. [RFC8453] the
function of ACTN as collecting resources to establish a logically
dedicated virtual network over one or more TE networks. Thus, in the
case of a TE-enabled underlying network, the ACTN VN can be used as a
basis to realize an IETF network slicing.
While the ACTN framework is a generic VN framework that can be used
for VN services beyond the IETF Network Slice, it also a suitable
basis for delivering and realizing IETF Network Slices.
Further discussion of the applicability of ACTN to IETF Network
Slices including a discussion of the relevant YANG models can be
found in [I-D.king-teas-applicability-actn-slicing].
6.4. Applicability of Enhanced VPNs to IETF Network Slices
An enhanced VPN (VPN+) is designed to support the needs of new
applications, particularly applications that are associated with 5G
services, by utilizing an approach that is based on existing VPN and
TE technologies and adds characteristics that specific services
require over and above VPNs as they have previously been specified.
An enhanced VPN can be used to provide enhanced connectivity services
between customer sites and can be used to create the infrastructure
to underpin a network slicing service.
It is envisaged that enhanced VPNs will be delivered using a
combination of existing, modified, and new networking technologies.
[I-D.ietf-teas-enhanced-vpn] describes the framework for Enhanced
Virtual Private Network (VPN+) services.
Farrel, et al. Expires 5 September 2022 [Page 31]
Internet-Draft IETF Network Slices March 2022
6.5. Network Slicing and Aggregation in IP/MPLS Networks
Network slicing provides the ability to partition a physical network
into multiple isolated logical networks of varying sizes, structures,
and functions so that each slice can be dedicated to specific
services or customers.
Many approaches are currently being worked on to support IETF Network
Slices in IP and MPLS networks with or without the use of Segment
Routing. Most of these approaches utilize a way of marking packets
so that network nodes can apply specific routing and forwarding
behaviors to packets that belong to different IETF Network Slices.
Different mechanisms for marking packets have been proposed
(including using MPLS labels and Segment Routing segment IDs) and
those mechanisms are agnostic to the path control technology used
within the underlay network.
These approaches are also sensitive to the scaling concerns of
supporting a large number of IETF Network Slices within a single IP
or MPLS network, and so offer ways to aggregate the connectivity
constructs of slices (or whole slices) so that the packet markings
indicate an aggregate or grouping where all of the packets are
subject to the same routing and forwarding behavior.
At this stage, it is inappropriate to mention any of these proposed
solutions that are currently work in progress and not yet adopted as
IETF work.
7. Isolation in IETF Network Slices
7.1. Isolation as a Service Requirement
An IETF Network Slice customer may request that the IETF Network
Slice delivered to them is delivered such that changes to other IETF
Network Slices or services do not have any negative impact on the
delivery of the IETF Network Slice. The IETF Network Slice customer
may specify the degree to which their IETF Network Slice is
unaffected by changes in the provider network or by the behavior of
other IETF Network Slice customers. The customer may express this
via an SLE it agrees with the provider. This concept is termed
'isolation'
Farrel, et al. Expires 5 September 2022 [Page 32]
Internet-Draft IETF Network Slices March 2022
7.2. Isolation in IETF Network Slice Realization
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 of 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 IETF Network Slices.
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.
* Conformance to security constraints: Specific security requests
from customer defined IETF Network Slices will be mapped to their
realization in the underlay networks. It will be required by
underlay networks to have capabilities to conform to customer's
requests as some aspects of security may be expressed in SLEs.
* IETF NSC authentication: Underlying networks need to be protected
against the attacks from an adversary NSC as they can destabilize
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. Furthermore, both the IETF Network Slice Service
Interface and the Network Configuration Interface need to be
secured.
* 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.
Farrel, et al. Expires 5 September 2022 [Page 33]
Internet-Draft IETF Network Slices March 2022
* Data Integrity of an IETF Network Slice: A customer 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 customer 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, customers might be well
advised to take responsibility for their own security needs, possibly
by encrypting traffic before hand-off to a service provider.
10. Privacy Considerations
Privacy of IETF Network Slice service customers must be preserved.
It should not be possible for one IETF Network Slice customer to
discover the presence of other customers, nor should sites that are
members of one IETF Network Slice be visible outside the context of
that IETF Network Slice.
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 customer.
Farrel, et al. Expires 5 September 2022 [Page 34]
Internet-Draft IETF Network Slices March 2022
11. IANA Considerations
This document makes no requests for IANA action.
12. Informative References
[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.ietf-opsawg-sap]
Boucadair, M., Dios, O. G. D., Barguil, S., Wu, Q., and V.
Lopez, "A Network YANG Model for Service Attachment Points
(SAPs)", Work in Progress, Internet-Draft, draft-ietf-
opsawg-sap-02, 22 February 2022,
<https://datatracker.ietf.org/doc/html/draft-ietf-opsawg-
sap-02>.
[I-D.ietf-teas-enhanced-vpn]
Dong, J., Bryant, S., Li, Z., Miyasaka, T., and Y. Lee, "A
Framework for Enhanced Virtual Private Network (VPN+)
Services", Work in Progress, Internet-Draft, draft-ietf-
teas-enhanced-vpn-09, 25 October 2021,
<https://datatracker.ietf.org/doc/html/draft-ietf-teas-
enhanced-vpn-09>.
[I-D.king-teas-applicability-actn-slicing]
King, D., Drake, J., Zheng, H., and A. Farrel,
"Applicability of Abstraction and Control of Traffic
Engineered Networks (ACTN) to Network Slicing", Work in
Progress, Internet-Draft, draft-king-teas-applicability-
actn-slicing-10, 31 March 2021,
<https://datatracker.ietf.org/doc/html/draft-king-teas-
applicability-actn-slicing-10>.
[I-D.openconfig-rtgwg-gnmi-spec]
Shakir, R., Shaikh, A., Borman, P., Hines, M., Lebsack,
C., and C. Morrow, "gRPC Network Management Interface
(gNMI)", Work in Progress, Internet-Draft, draft-
openconfig-rtgwg-gnmi-spec-01, 5 March 2018,
<https://datatracker.ietf.org/doc/html/draft-openconfig-
rtgwg-gnmi-spec-01>.
[MACsec] IEEE, "IEEE Standard for Local and metropolitan area
networks - Media Access Control (MAC) Security", 2018,
<https://1.ieee802.org/security/802-1ae>.
Farrel, et al. Expires 5 September 2022 [Page 35]
Internet-Draft IETF Network Slices March 2022
[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>.
[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>.
[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>.
[RFC3135] Border, J., Kojo, M., Griner, J., Montenegro, G., and Z.
Shelby, "Performance Enhancing Proxies Intended to
Mitigate Link-Related Degradations", RFC 3135,
DOI 10.17487/RFC3135, June 2001,
<https://www.rfc-editor.org/info/rfc3135>.
[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>.
[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>.
[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
2006, <https://www.rfc-editor.org/info/rfc4364>.
Farrel, et al. Expires 5 September 2022 [Page 36]
Internet-Draft IETF Network Slices March 2022
[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>.
[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>.
Farrel, et al. Expires 5 September 2022 [Page 37]
Internet-Draft IETF Network Slices March 2022
[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>.
[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>.
[RFC8309] Wu, Q., Liu, W., and A. Farrel, "Service Models
Explained", RFC 8309, DOI 10.17487/RFC8309, January 2018,
<https://www.rfc-editor.org/info/rfc8309>.
[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>.
[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>.
Acknowledgments
The entire TEAS Network Slicing 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.
Farrel, et al. Expires 5 September 2022 [Page 38]
Internet-Draft IETF Network Slices March 2022
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:
* Aihua Guo
* Bo Wu
* Greg Mirsky
* Lou Berger
* Rakesh Gandhi
* Ran Chen
* Sergio Belotti
* Stewart Bryant
* Tomonobu Niwa
* Xuesong Geng
Further useful comments were received from Daniele Ceccarelli, Uma
Chunduri, Pavan Beeram, Tarek Saad, Kenichi Ogaki, Oscar Gonzalez de
Dios, Xiaobing Niu, Dan Voyer, Igor Bryskin, Luay Jalil, Joel
Halpern, and John Scudder.
This work is partially supported by the European Commission under
Horizon 2020 grant agreement number 101015857 Secured autonomic
traffic management for a Tera of SDN flows (Teraflow).
Contributors
The following authors contributed significantly to this document:
Farrel, et al. Expires 5 September 2022 [Page 39]
Internet-Draft IETF Network Slices March 2022
Eric Gray (The original editor of the foundation documents)
Independent
Email: ewgray@graiymage.com
Jari Arkko
Ericsson
Email: jari.arkko@piuha.net
Mohamed Boucadair
Orange
Email: mohamed.boucadair@orange.com
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
Authors' Addresses
Adrian Farrel (editor)
Old Dog Consulting
United Kingdom
Email: adrian@olddog.co.uk
John Drake
Juniper Networks
United States of America
Email: jdrake@juniper.net
Reza Rokui
Ciena
Email: rrokui@ciena.com
Shunsuke Homma
NTT
Japan
Email: shunsuke.homma.ietf@gmail.com
Farrel, et al. Expires 5 September 2022 [Page 40]
Internet-Draft IETF Network Slices March 2022
Kiran Makhijani
Futurewei
United States of America
Email: kiranm@futurewei.com
Luis M. Contreras
Telefonica
Spain
Email: luismiguel.contrerasmurillo@telefonica.com
Jeff Tantsura
Microsoft Inc.
Email: jefftant.ietf@gmail.com
Farrel, et al. Expires 5 September 2022 [Page 41]