Internet DRAFT - draft-boucadair-rtgwg-sdn-and-semantic-routing
draft-boucadair-rtgwg-sdn-and-semantic-routing
IRTF M. Boucadair
Internet-Draft Orange
Intended status: Informational D. Trossen
Expires: 6 November 2023 Huawei
A. Farrel
Old Dog Consulting
5 May 2023
Considerations for the use of SDN in Semantic Routing Networks
draft-boucadair-rtgwg-sdn-and-semantic-routing-00
Abstract
The forwarding of packets in today's networks has long evolved beyond
ensuring mere reachability of the receiving endpoint. Instead, other
'purposes' of communication, e.g., ensuring quality of service of
delivery, ensuring protection against path failures through utilizing
more than one, and others, are realized by many extensions to the
original reachability purpose of IP routing.
Semantic Routing defines an approach to realizing such extended
purposes beyond reachability by instead making routing and forwarding
decisions based, not only on the destination IP address, but on other
information carried in an IP packet. The intent is to facilitate
enhanced routing decisions based on this information in order to
provide differentiated forwarding paths for specific packet flows.
Software Defined Networking (SDN) places control of network elements
(including all or some of their forwarding decisions) within external
software components called controllers and orchestrators. This
approach differs from conventional approaches that solely rely upon
distributed routing protocols for the delivery of advanced
connectivity services. By doing so, SDN aims to enable network
elements to be simplified while still performing forwarding function.
This document examines the applicability of SDN techniques to
Semantic Routing and provides considerations for the development of
Semantic Routing solutions in the context of SDN.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Boucadair, et al. Expires 6 November 2023 [Page 1]
Internet-Draft SDN and Semantic Routing May 2023
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/.
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 6 November 2023.
Copyright Notice
Copyright (c) 2023 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Software Defined Networking (SDN): An Overview . . . . . . . 4
3. Semantic Routing: Summary of Required Technical Elements . . 5
4. Programmable Forwarding . . . . . . . . . . . . . . . . . . . 6
4.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . 6
4.2. SDN for Semantic Routing: The Intended Behavior . . . . . 8
5. Policy-Based Semantic Routing . . . . . . . . . . . . . . . . 10
6. Network-Wide Coordination . . . . . . . . . . . . . . . . . . 11
7. Applying Semantic Information to Packets . . . . . . . . . . 12
8. Benefits and Concerns with the Use of SDN for Semantic
Routing . . . . . . . . . . . . . . . . . . . . . . . . . 13
9. Security Considerations . . . . . . . . . . . . . . . . . . . 14
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14
12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 14
13. Informative References . . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
Boucadair, et al. Expires 6 November 2023 [Page 2]
Internet-Draft SDN and Semantic Routing May 2023
1. Introduction
Service differentiation in the network can be enforced by
manipulating a set of parameters that belong to distinct dimensions
(e.g., forwarding, routing, traffic classification, resource
partitioning). Through this, the resulting system may be able to
realize communication that goes beyond the mere reachability that
original IP routing (and forwarding) aimed at. As pointed out in
[I-D.trossen-rtgwg-routing-beyond-reachability], this differentiation
and its solutions have long found entry into many existing and
deployed Internet technologies.
Among the techniques to achieve such differentiation, this document
focuses on Semantic Routing, which refers to a process that is meant
to provide differentiated forwarding paths for specific packet flows
distinct from simple shortest path first routing and, thus, satisfy
specific service/application requirements.
More concretely, Semantic Routing is the process of making routing
and forwarding decisions based, not only on the destination IP
address of a packet, but also by taking into account other
information that is carried in the packet such as (but not limited
to):
* Other fields of the IP header, e.g., DSCP/Traffic Class.
* The transport header, e.g., transport port numbers [RFC7597] or
subflows [RFC8803].
* Specific transport encapsulation shims, e.g., [RFC8926].
* Specific service headers, e.g., [RFC8300].
* Metadata.
Section 3 provides more details about Semantic Routing.
Software Defined Networking (SDN) places (partial or full) control of
network elements and their forwarding decisions within dedicated
software components called controllers and orchestrators. This
approach differs from those that solely rely upon distributed routing
protocols. An ambition of SDN is to enable network elements to be
simplified while the network is optimized to deliver value-added
connectivity services. Refer to Section 2 for an overview of SDN.
Boucadair, et al. Expires 6 November 2023 [Page 3]
Internet-Draft SDN and Semantic Routing May 2023
This document examines the applicability of SDN to Semantic Routing
though programbale forwarding (see Section 4 and provides
considerations for the development of Semantic Routing solutions in
the context of SDN.
This document does not elaborate on specific SDN protocols: some SDN
protocol solutions may be more or less amenable to use for Semantic
Routing, but that discussion would need detailed analysis which is
better suited to a further and separate document.
2. Software Defined Networking (SDN): An Overview
SDN refers to an approach for network programmability: the capacity
to initialize, control, and manage network behavior dynamically via
open interfaces. Such programmability can facilitate the delivery of
services in a deterministic, dynamic, and scalable manner.
SDN emphasizes the role of software in operational networks by
supporting the separation between data and control planes. Even if
such a separation has been adopted by most routing processes for
decades (Section 2.1 of [RFC7149]), SDN focuses more on the power of
"central" controllers to optimize route computation within a network
before populating the Forwarding Information Base (FIB) of the
network elements.
The separation of the control and data planes allows faster
innovation in both planes, and it enables a dynamic and flexible
approach to implementing new network behaviors as well as to reacting
to changes in network state and traffic demands.
SDN has been discussed in many places during the last decade. For
example, within the IRTF, [RFC7426] provides a concise reference for
the SDN research community to address the questions of what SDN is,
what the layer structure of an SDN architecture is, and how layers
interface with each other within that architecture. [RFC7149]
(published in the IETF stream) offers a service provider's
perspective of the SDN landscape by describing requirements, issues,
and other considerations about SDN. In particular, [RFC7149]
classifies SDN techniques into the following functional domains:
* Techniques for the dynamic discovery of network topology, devices,
and capabilities, along with relevant information and data models
that are meant to precisely document such topology, devices, and
their capabilities.
Boucadair, et al. Expires 6 November 2023 [Page 4]
Internet-Draft SDN and Semantic Routing May 2023
* Techniques for exposing network services and their characteristics
and for dynamically capturing the set of service parameters that
will be used to measure the level of quality associated with the
delivery of a given service or a combination thereof.
* Techniques used by service-requirement-derived dynamic resource
allocation and policy enforcement schemes, so that networks can be
programmed accordingly.
* Dynamic feedback mechanisms that are meant to assess how
efficiently a set of policies are enforced from a service
fulfillment and assurance perspective.
SDN can be deployed in a recursive model that involves dedicated
interfaces for both network and service optimization. Indeed,
[RFC8597] differentiates the control functions associated with
transport (that is, the transfer capabilities offered by a networking
infrastructure) from those related to services in an approach called
Cooperating Layered Architecture for Software-Defined Networking
(CLAS).
To an SDN context, domain-specific controllers can be deployed with
specific interactions as discussed in Section 4 of [RFC8309].
3. Semantic Routing: Summary of Required Technical Elements
As described in [I-D.farrel-irtf-introduction-to-semantic-routing],
Semantic Routing (or, more generally, Semantic Networking) is the
process of achieving enhanced routing and forwarding decisions based
on semantics added to IP packet headers to provide differentiated
paths for different packet flows distinct from simple shortest path
first routing. The additional information or "semantics" may be
placed in existing header fields (such as the IPv6 Traffic Class
field or the destination address) or may be carried by adding fields
to the header. Further, the semantics may be encoded in the payload
or additional headers (such as in the port number fields or in an
IPv6 Extension Header).
The application of Semantic Routing allows packets from different
flows (even those between the same applications on the same devices)
to be marked for different treatment in the network. The packets may
then be routed onto different paths according to the capabilities and
states of the network links in order to meet the requirements of the
flows. For example, one flow may need low latency, while another may
require ultra low jitter, and a third may demand very high bandwidth.
Three elements are needed to achieve Semantic Routing:
Boucadair, et al. Expires 6 November 2023 [Page 5]
Internet-Draft SDN and Semantic Routing May 2023
* The capabilities and state of the network must be discovered.
* The packets must be marked (with semantic information) according
to their required delivery characteristics.
* The routers must be programmed to forward the traffic according to
how the packets are marked.
All these elements can be matched to the SDN functional domains
listed in Section 2. From that standpoint, this document provides
more details on how SDN can be used to satisfy specific Semantic
Routing needs.
4. Programmable Forwarding
Programmable Forwarding is the term applied to the use of control
techniques to instruct network devices how to forward packets in a
programmatic way.
4.1. Motivation
Modern networks are designed to carry traffic that belongs to a
variety of services/applications that have distinct traffic
performance requirements, reliability and robustness expectations,
and service-specific needs [RFC7665][RFC8517]. Such expectations,
and other forwarding requirements that can be captured in a Service
Level Agreement (SLA) [RFC7297], can be considered by providers when
designing their networks in order to be able to deliver
differentiated forwarding behaviors. However, conventional routing
and forwarding procedures do not always offer the required
functionalities for such differentiated service delivery. Thus,
additional means have to be enabled in these networks for the sake of
innovative service delivery while minimizing the induced complexity
to operate such networks. Also, these means should be tweaked to
ensure consistent forwarding behaviors network-wide.
The aforementioned means are not only extensions to routing
protocols, but include other mechanisms that affect the forwarding
behaviors within a network. A non-exhaustive list of sample
capabilities that can be offered by appropriate control of forwarding
elements is provided below:
Resource Pooling: A network may host dedicated functions that
implement resource pooling among many available paths or that
control which path is used to steer traffic as a function of the
observed round-trip time (RTT) (e.g., enable Mutlipath TCP (MPTCP)
converters [RFC8803] in specific network segments, including data
centers as detailed in Section 2.1 of [RFC8041]).
Boucadair, et al. Expires 6 November 2023 [Page 6]
Internet-Draft SDN and Semantic Routing May 2023
There is a need to interact with the underlying forwarding
elements to communicate a set forwarding policies that will ensure
that such service differentiation is provided to the specific
flows. These forwarding policies include, for example, a set of
rules that characterize the flows that are eligible to the
resource pooling service or the scheduling policies (maximize link
utilization, grab extra resources only when needed, etc.).
These polices are then enforced by programmable forwarders.
Performance-based Route Selection: Some applications may have strict
traffic performance requirements (e.g., a low one-way delay
[RFC7679]), however, the underlying network elements might not
support a mechanism to disseminate performance metrics associated
with specific paths and/or perform performance-based route
selection (e.g., [I-D.ietf-idr-performance-routing]).
As an alternative, an off-line Semantic Routing approach could be
used to collect measurement data to reach a given content (e.g.,
one-way delay to reach specific data centers), perform route
selection based on this data, and then program the appropriate
forwarding elements accordingly.
Energy-efficient Forwarding: An important effort was made in the
past to optimize the energy consumption of network elements.
However, such optimization is node-specific and no standard means
to optimize the energy consumption at the scale of the network
have been defined. For example, many nodes (also, service cards)
are deployed as backups.
A controller-based approach can be implemented so that the route
selection process optimizes the overall energy consumption of a
path. Such a process takes into account the current load, avoids
waking nodes/cards for handling "sparse" traffic (i.e., a minor
portion of the total traffic), considers node-specific data (e.g.,
[RFC7460]), etc. This off-line Semantic Routing approach will
transition specific cards/nodes to "idle" and wake them as
appropriate, etc., without breaking service objectives. Moreover,
such an approach will have to maintain an up-to-date topology even
if a node is in an "idle" state (such nodes may be removed from
adjacency tables if they don't participate in routing
advertisements).
Network Partitioning: A network may need to be partitioned in order
to rationalize the delivery of advanced connectivity services, and
to address specific forwarding requirements of groups of services/
applications. Network slicing [I-D.ietf-teas-ietf-network-slices]
can be considered to deliver these services. However, an
Boucadair, et al. Expires 6 November 2023 [Page 7]
Internet-Draft SDN and Semantic Routing May 2023
intelligence is needed to decide the criteria to be used to
partition the available resources, filter them, decide whether
network extensions are needed, ensure whether/how resource
preemption is adequately implemented, etc.
These tasks are better achieved using a central intelligence that
has direct visibility into the intents of applications, underlying
network capabilities, local policies and guidelines, etc. As an
output of processing these various inputs, a set of node-specific
policies is generated, and then pushed using available SDN
interface.
Alternative Forwarding: The programmability of SDN in the form of
forwarding actions defined on packet header fields allows for
realizing forwarding techniques beyond the typical longest-prefix
match used for IP-based reachability. Solutions, like those in
[ICC2016], use a binary representation of links in a network to
realize a path-based forwarding action that acts purely on node-
local state, independent of the nature of the path or the
communications traversing it. As discussed in Section 7, the
limitation of forwarding actions to apply only to defined (IP)
packet header fields results in issues that need special
consideration when realizing such solutions in real-world
deployments.
The next subsection further details which elements are needed when
interacting with programmable forwarders in an SDN context.
4.2. SDN for Semantic Routing: The Intended Behavior
SDN minimizes the required changes to legacy (interior) routing
protocols. More concretely, SDN can be used to provide the intended
Semantic Routing behavior, especially:
* Identify the forwarding elements that can be safely involved in
providing the intended Semantic Routing features.
* Maintain abstract topologies that involve these elements and their
capabilities.
* Capture application-specific intents and derive the corresponding
forwarding requirements and, then, forwarding policies.
* Map these abstract topologies to (groups of) applications with
specific Semantic Routing needs.
Boucadair, et al. Expires 6 November 2023 [Page 8]
Internet-Draft SDN and Semantic Routing May 2023
* Program a subset of nodes (called boundary nodes) with the
required classification and marking policies to bind flows to
their intended Semantic Routing behaviors.
In order to adequately process the application flows that require
specific differentiated forwarding, SDN controllers maintain a
table that allows to unambiguously identify such flows. The
content of that table is used to derive the appropriate
classification/match rules that are then communicated by an SDN
controller to a set of forwarding elements.
When volatile data (e.g., dynamic IP addresses) are used to build
such rules, it is the responsibility of the SDN controllers to
update the rules whenever a new identifier is used. Failure to
maintain "fresh" classification rules will lead to service
failure/degradation.
* Supply intermediate nodes (that is, nodes that are not boundary
nodes) with the appropriate rules to locate and interpret the bits
within the packet to determine and execute forwarding actions as
established by Semantic Routing.
* Automatically adjust, if possible, the network MTU to accommodate
any overhead that is introcuced by any extra bits used to signal
Semantic Routing behavior.
* Instruct egress boundary nodes about the required actions such as
stripping or setting any Semantic Routing bits.
* Interact with the underlying nodes to maintain, retrieve, and
disseminate the data that are used for assuring that Semantic
Routing policies are appropriately fulfilled.
* Configure OAM policies to measure the network behavior and adjust
the forwarding processes.
* Monitor the network and detect parts of the network where policies
are broken or suboptimal.
* Automate the overall procedure [RFC8969].
At least three approaches can be considered by an SDN controller to
accomplish the above tasks:
Boucadair, et al. Expires 6 November 2023 [Page 9]
Internet-Draft SDN and Semantic Routing May 2023
* Compute (centrally) the differentiated paths and install the
required forwarding rules in involved nodes. Strict or loose
paths may be installed. This approach has the merit of
implementing new path selection algorithms without requiring them
to be supported by every involved node.
* Assign (centrally) differentiated link information and install the
required forwarding rules in the involved nodes. End-to-end paths
are constructed without involvement of the SDN controller,
utilizing the link information to establish path identifiers on
which installed forwarding rules can act upon without additional
path-specific knowledge being required. See [ICC2016] for an
example of such an approach.
* Rely upon a distributed routing protocol to customize the route
selection process ([RFC9350], for example). In such cases, the
SDN controller is responsible for communicating the parameters to
be used for the route selection process, selecting the nodes that
will participate in a given topology, and configuring any tunnels
to interconnect these nodes.
A hierarchical SDN design can also be considered, where specific
controllers are enabled in each domain with dedicated interfaces to
share data (e.g., radio bottlenecks, expectations). These domains do
not need to support the same technological implementations. The
interaction between the SDN controllers eases the delivery of
consistent Semantic Routing behaviors without requiring common domain
configuration.
5. Policy-Based Semantic Routing
Policy is a term applied to the application of local or network-wide
operational choices made by the network manager. These may range
from decisions about what traffic to admit to the network, how
network resources should be used to support different traffic flows,
how errors or security violations are handled, and how packets are
routed through the network.
Policies are usually made available to network operators as
configuration elements on network nodes. However, these
configuration actions need to be coordinated across the whole network
if the policies are to be effective. Thus, a mechanism is desired
that allows an operator to set a network-wide policy in one place and
that results in that policy being pushed out to the network nodes
that need to act on the policy.
Boucadair, et al. Expires 6 November 2023 [Page 10]
Internet-Draft SDN and Semantic Routing May 2023
Semantic Routing is particularly amenable to a policy-based approach.
That is, an operator (or their software tools) can make decisions
about how different traffic flows should be handeled in the network.
Those decisions can then be installed on network nodes so that
different traffic is handled differently and according to the
policies.
SDN is a powerly approach to implement a policy-based network
management framework. The operator need only select or configure the
desired policies at the controller: the controller will realize the
policies and install the necessary instructions and behaviors on the
network nodes.
6. Network-Wide Coordination
Critical to the correct functioning of any routing system is proper
network-wide coordination. In many cases, the coordination starts
with the collection and dissemination of network connectivity
information (known as the network topology), the capabilities of the
network nodes and links, and the current state (up, down, degraded,
busy, etc.) of those nodes and links. But an even mode fundamental
element of network-wide coordination is the decision about which
routing algorithms and procedures will be used because, if different
nodes or even different parts of the network) apply different routing
approaches, it is very possible that traffic will loop or be dropped.
Thus, th first elements of coordination are finding out what the
network looks like and agreeing how to route traffic.
These essentials are no less relevant in Semantic Routing. All nodes
that participate in a Semantic Routing network need to have the same
understanding of the additional information carried in packets, and
must make coordinated forwarding decisions based on a coordinated
routing algorithm.
A centralized approach, such as that achieved in an SDN system, is
particularly useful in this context because it allows the
coordination to be applied through a central point of control which
may remove the complexity and "fragility" from the routing system.
This coordination may be considered in parallel with the aspects of
policy-based routing described in Section 5.
Boucadair, et al. Expires 6 November 2023 [Page 11]
Internet-Draft SDN and Semantic Routing May 2023
7. Applying Semantic Information to Packets
Given the focus of Semantic Routing is the use within IP networks,
semantic information that can be used in SDN-based Semantic Routing
is limited to those fields specifically defined for use with Semantic
Routing (see Section 2 for more information). This document
deliberately makes no comment on the specifications that may be
produced to define such fields, their meaning, and their encoding.
SDN aligns with the concept of Semantic Routing in that it allows the
network devices to be programmed for forwarding actions indicated by
a wide range of packet header fields beyond simply the IP destination
addresses.
However, Semantic Routing solutions have also been proposed that
"overwrite" existing protocol fields in order for them to carry
semantic information that can be used to drive a forwarding action
outside their original semantics. [POINT2015] and [POINT2016]
outline an example of such approaches in which semantic information
is used for a path-based forwarding decision; while the absence of
"path" information is foreseen as an actionable packet header field
in IPv6.
Here, the path is constructed by a Path Computation Element (PCE)
[RFC4655] that matches a given service name against previously
announced locations where said service name is located. The path is
represented as a concatenation of individual link information, which
in pushed by the SDN controller to the network nodes so that they can
perform local forwarding actions on packets that arrive. Given the
binary structure of the end-to-end path information, the forwarding
operation can be implemented in a standard-compliant manner with its
realization described in [ICC2016] as an arbitrary wildcard matching
operation.
However, the constraint of acting only on limited packet fields
requires that the path information be carried in one of those
standard-defined packet header fields: thereby overwriting (or
overloading) any existing packet header field. [POINT2016] uses the
IPv6 address fields for this purpose, representing the longest
continuous binary field in the IPv6 header (two addresses make up 256
bits in total) allows the support of topologies with up to 256 links.
Given the approach chosen in [POINT2016], any IPv6 address
information, if needed, cannot be present in the packet header and so
is provided in the encapsulated payload. This leads to repeated
encapsulation with the overhead of carrying two IP headers in a
single packet: one used for path-based forwarding and one for the
operations in arriving endpoint. Only newer SDN-based forwarding
Boucadair, et al. Expires 6 November 2023 [Page 12]
Internet-Draft SDN and Semantic Routing May 2023
plane programming tools, such as P4, would allow for such overhead to
be removed by placing the path information into another packet header
field (or even the payload as an extended header of sort) to act
upon.
8. Benefits and Concerns with the Use of SDN for Semantic Routing
The programmability of SDN provides a fertile ground for forwarding
decision that go beyond the reachability information provided through
IPv4/v6 addresses, e.g., by using other packet header fields. This
not only allows for extending the simple reachability-driven
forwarding decision with richer, e.g., policy-based, decisions (as
discussed in Section 5), it may also enable new forwarding paradigms
per se, such as those in [POINT2016], which in turn may realize
forwarding behaviours like multicast at much lower cost points and
higher efficiency (see [ICC2016]).
However, SDN specifications have limited capabilities when it comes
to the additional (i.e., new) packet header fields that may be used
for forwarding actions. As a consequence, "true" Semantic Routing on
any semantic enhancement, which is included in the packet, is only
possible in a manner limited to those existing fields.
Solutions such as those in [POINT2016], using methods outlined in
[ICC2016], attempt to break this limitation albeit by overwriting
standard-defined packet header fields, thereby changing the semantics
of those fields within the scope (i.e., network domain) where the
"re-defined" semantics are known and understood.
This limits any solution to a limited domain [RFC8799]. More
importantly, the redefinition of packet fields poses the danger of
exposing this (non-standard compliant) semantic to elements outside
the limited domain: semantic leakage may occur, or nodes outside the
domain may misinterpret overwritten fields, requiring methods, such
as dedicated gateways, to preventi such leakage. This can be seen in
[POINT2016], where the boundaries to IP-compliant end devices and
other domains alike are delimited by dedicated gateway elements.
Those gateways usually act at higher layers than the forwarding
layer, thereby incurring complexity and often delay.
See also [I-D.king-irtf-challenges-in-routing] for a discussion of
issues and concerns that need to be examined when applying a new
routing or forwarding paradigm to a self-contained network or
Internet.
Boucadair, et al. Expires 6 November 2023 [Page 13]
Internet-Draft SDN and Semantic Routing May 2023
9. Security Considerations
SDN-related considerations are discussed in Section 5 of [RFC7149].
10. IANA Considerations
This document makes no requests for IANA action.
11. Acknowledgements
Thanks to George Polyzos for helpful comments on this work.
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).
12. Contributors
George Xylomenos
Email: xgeorge@aueb.gr
13. Informative References
[I-D.farrel-irtf-introduction-to-semantic-routing]
Farrel, A. and D. King, "An Introduction to Semantic
Routing", Work in Progress, Internet-Draft, draft-farrel-
irtf-introduction-to-semantic-routing-04, 25 April 2022,
<https://datatracker.ietf.org/doc/html/draft-farrel-irtf-
introduction-to-semantic-routing-04>.
[I-D.ietf-idr-performance-routing]
Xu, X., Hegde, S., Talaulikar, K., Boucadair, M., and C.
Jacquenet, "Performance-based BGP Routing Mechanism", Work
in Progress, Internet-Draft, draft-ietf-idr-performance-
routing-03, 22 December 2020,
<https://datatracker.ietf.org/doc/html/draft-ietf-idr-
performance-routing-03>.
[I-D.ietf-teas-ietf-network-slices]
Farrel, A., Drake, J., Rokui, R., Homma, S., Makhijani,
K., Contreras, L. M., and J. Tantsura, "A Framework for
IETF Network Slices", Work in Progress, Internet-Draft,
draft-ietf-teas-ietf-network-slices-19, 21 January 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-teas-
ietf-network-slices-19>.
Boucadair, et al. Expires 6 November 2023 [Page 14]
Internet-Draft SDN and Semantic Routing May 2023
[I-D.king-irtf-challenges-in-routing]
King, D., Farrel, A., and C. Jacquenet, "Challenges for
the Internet Routing Systems Introduced by Semantic
Routing", Work in Progress, Internet-Draft, draft-king-
irtf-challenges-in-routing-08, 25 April 2022,
<https://datatracker.ietf.org/doc/html/draft-king-irtf-
challenges-in-routing-08>.
[I-D.trossen-rtgwg-routing-beyond-reachability]
Trossen, D., Lou, Z., and S. Jiang, "Continuing to Evolve
Internet Routing Beyond 'Mere' Reachability", Work in
Progress, Internet-Draft, draft-trossen-rtgwg-routing-
beyond-reachability-01, 30 June 2022,
<https://datatracker.ietf.org/doc/html/draft-trossen-
rtgwg-routing-beyond-reachability-01>.
[ICC2016] Reed, M., Al-Naday, M., Thomos, N., Trossen, D.,
Petropoulos, G., and S. Spirou, "Stateless multicast
switching in software defined networks", Paper IEEE ICC
2016, 2016.
[POINT2015]
Trossen, D., Reed, M., Riihijarvi, J., Georgiades, M.,
Xylomenos, G., and S. Fotiou, "IP Over ICN: The Better
IP?", Paper EuCNC (European Conference on Networks and
Communications), Paris, France, 2015.
[POINT2016]
Kim, S.-Y.., Robitzsch, S., Trossen, D., Reed, M., Al-
Naday, M., and J. Riihijarvi, "Realizing IP-based Services
over an Information-Centric Networking Transport Network",
Paper Proceedings of the 3rd ACM Conference on
Information-Centric Networking, Pages 215-216, 2016.
[RFC4655] Farrel, A., Vasseur, J.-P., and J. Ash, "A Path
Computation Element (PCE)-Based Architecture", RFC 4655,
DOI 10.17487/RFC4655, August 2006,
<https://www.rfc-editor.org/info/rfc4655>.
[RFC7149] Boucadair, M. and C. Jacquenet, "Software-Defined
Networking: A Perspective from within a Service Provider
Environment", RFC 7149, DOI 10.17487/RFC7149, March 2014,
<https://www.rfc-editor.org/info/rfc7149>.
[RFC7297] Boucadair, M., Jacquenet, C., and N. Wang, "IP
Connectivity Provisioning Profile (CPP)", RFC 7297,
DOI 10.17487/RFC7297, July 2014,
<https://www.rfc-editor.org/info/rfc7297>.
Boucadair, et al. Expires 6 November 2023 [Page 15]
Internet-Draft SDN and Semantic Routing May 2023
[RFC7426] Haleplidis, E., Ed., Pentikousis, K., Ed., Denazis, S.,
Hadi Salim, J., Meyer, D., and O. Koufopavlou, "Software-
Defined Networking (SDN): Layers and Architecture
Terminology", RFC 7426, DOI 10.17487/RFC7426, January
2015, <https://www.rfc-editor.org/info/rfc7426>.
[RFC7460] Chandramouli, M., Claise, B., Schoening, B., Quittek, J.,
and T. Dietz, "Monitoring and Control MIB for Power and
Energy", RFC 7460, DOI 10.17487/RFC7460, March 2015,
<https://www.rfc-editor.org/info/rfc7460>.
[RFC7597] Troan, O., Ed., Dec, W., Li, X., Bao, C., Matsushima, S.,
Murakami, T., and T. Taylor, Ed., "Mapping of Address and
Port with Encapsulation (MAP-E)", RFC 7597,
DOI 10.17487/RFC7597, July 2015,
<https://www.rfc-editor.org/info/rfc7597>.
[RFC7665] Halpern, J., Ed. and C. Pignataro, Ed., "Service Function
Chaining (SFC) Architecture", RFC 7665,
DOI 10.17487/RFC7665, October 2015,
<https://www.rfc-editor.org/info/rfc7665>.
[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>.
[RFC8041] Bonaventure, O., Paasch, C., and G. Detal, "Use Cases and
Operational Experience with Multipath TCP", RFC 8041,
DOI 10.17487/RFC8041, January 2017,
<https://www.rfc-editor.org/info/rfc8041>.
[RFC8300] Quinn, P., Ed., Elzur, U., Ed., and C. Pignataro, Ed.,
"Network Service Header (NSH)", RFC 8300,
DOI 10.17487/RFC8300, January 2018,
<https://www.rfc-editor.org/info/rfc8300>.
[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>.
[RFC8517] Dolson, D., Ed., Snellman, J., Boucadair, M., Ed., and C.
Jacquenet, "An Inventory of Transport-Centric Functions
Provided by Middleboxes: An Operator Perspective",
RFC 8517, DOI 10.17487/RFC8517, February 2019,
<https://www.rfc-editor.org/info/rfc8517>.
Boucadair, et al. Expires 6 November 2023 [Page 16]
Internet-Draft SDN and Semantic Routing May 2023
[RFC8597] Contreras, LM., Bernardos, CJ., Lopez, D., Boucadair, M.,
and P. Iovanna, "Cooperating Layered Architecture for
Software-Defined Networking (CLAS)", RFC 8597,
DOI 10.17487/RFC8597, May 2019,
<https://www.rfc-editor.org/info/rfc8597>.
[RFC8799] Carpenter, B. and B. Liu, "Limited Domains and Internet
Protocols", RFC 8799, DOI 10.17487/RFC8799, July 2020,
<https://www.rfc-editor.org/info/rfc8799>.
[RFC8803] Bonaventure, O., Ed., Boucadair, M., Ed., Gundavelli, S.,
Seo, S., and B. Hesmans, "0-RTT TCP Convert Protocol",
RFC 8803, DOI 10.17487/RFC8803, July 2020,
<https://www.rfc-editor.org/info/rfc8803>.
[RFC8926] Gross, J., Ed., Ganga, I., Ed., and T. Sridhar, Ed.,
"Geneve: Generic Network Virtualization Encapsulation",
RFC 8926, DOI 10.17487/RFC8926, November 2020,
<https://www.rfc-editor.org/info/rfc8926>.
[RFC8969] Wu, Q., Ed., Boucadair, M., Ed., Lopez, D., Xie, C., and
L. Geng, "A Framework for Automating Service and Network
Management with YANG", RFC 8969, DOI 10.17487/RFC8969,
January 2021, <https://www.rfc-editor.org/info/rfc8969>.
[RFC9350] Psenak, P., Ed., Hegde, S., Filsfils, C., Talaulikar, K.,
and A. Gulko, "IGP Flexible Algorithm", RFC 9350,
DOI 10.17487/RFC9350, February 2023,
<https://www.rfc-editor.org/info/rfc9350>.
Authors' Addresses
Mohamed Boucadair
Orange
Rennes
France
Email: mohamed.boucadair@orange.com
Dirk Trossen
Huawei
Munich
Germany
Email: dirk.trossen@huawei.com
Boucadair, et al. Expires 6 November 2023 [Page 17]
Internet-Draft SDN and Semantic Routing May 2023
Adrian Farrel
Old Dog Consulting
United Kingdom
Email: adrian@olddog.co.uk
Boucadair, et al. Expires 6 November 2023 [Page 18]
