IRTF D. King
Internet-Draft Lancaster University
Intended status: Informational A. Farrel
Expires: December 16, 2021 Old Dog Consulting
June 14, 2021
Challenges for the Internet Routing Infrastructure Introduced by Changes
in Address Semantics
draft-king-irtf-challenges-in-routing-03
Abstract
Historically, the meaning of an IP address has been to identify an
interface on a network device. Routing protocols were developed
based on the assumption that a destination address had this semantic.
Over time, routing decisions were enhanced to route packets according
to additional information carried within the packets and dependent on
policy coded in, configured at, or signaled to the routers.
Many proposals have been made to add semantics to IP addresses. The
intent is usually to facilitate routing decisions based solely on the
address and without the need to find and process information carried
in other fields within the packets.
This document describes the challenges to the existing routing system
that are introduced by the addition of semantics to IP addresses. It
then summarizes the opportunities for research into new or modified
routing protocols to make use of new address semantics.
This document is presented as study to support further research into
clarifying and understanding the issues. It does not pass comment on
the advisability or practicality of any of the proposals and does not
define any technical solutions.
Status of This Memo
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and may be updated, replaced, or obsoleted by other documents at any
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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 December 16, 2021.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Current Challenges to IP Routing . . . . . . . . . . . . . . 4
3. What is Semantic Routing? . . . . . . . . . . . . . . . . . . 6
3.1. Architectural Considerations . . . . . . . . . . . . . . 8
3.1.1. Isolated Domains . . . . . . . . . . . . . . . . . . 8
3.1.2. Bridged Domains . . . . . . . . . . . . . . . . . . . 9
3.1.3. Semantic Prefix Domains . . . . . . . . . . . . . . . 9
4. Challenges for Internet Routing Research . . . . . . . . . . 11
4.1. Research Principles . . . . . . . . . . . . . . . . . . . 11
4.2. Routing Research Questions to be Addressed . . . . . . . 12
5. Security Considerations . . . . . . . . . . . . . . . . . . . 15
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 15
9. Informative References . . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction
Historically, the meaning of an IP address has been to identify an
interface on a network device. Network routing protocols were
initially designed to determine paths through the network toward
destination addresses so that IP packets with a common destination
address converged on that destination. Anycast and multicast
addresses were also defined and these new address semantics
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necessitated variations to the routing protocols and the development
of new protocols.
Over time, routing decisions were enhanced to route packets according
to additional information carried within the packets and dependent on
policy coded in, configured at, or signaled to the routers. Perhaps
the most obvious example is Equal-Cost Multipath (ECMP) where a
router makes a consistent choice for forwarding packets over a number
of parallel links or paths based on the values of a set of fields in
the packet header.
Many proposals have been made to add semantics to IP addresses. The
intent is usually to facilitate routing decisions based solely on the
address and without the need to find and process information carried
in other fields within the packets. We call this approach "Semantic
Addressing".
There are many approaches to Semantic Addressing. These range from
assigning a prefix to have a special purpose and meaning (such as is
done for multicast addressing) through allowing the owner of a prefix
to use the low-order bits of an address for their own purposes. Some
Semantic Addressing proposals suggest variable address lengths,
others offer hierarchical addresses, and some introduce a structure
to addresses so that they can carry additional information in a
common way.
A survey of ways in which routing decisions have been made based on
additional information carried in packets, and a catalogue of
proposals for Semantic Addressing can be found in
[I-D.king-irtf-semantic-routing-survey].
Some Semantic Addressing proposals are intended to be deployed in
limited domains [RFC8799] (networks) that are IP-based, while other
proposals are intended for use across the Internet. The impact the
proposals have on routing systems may require clean-slate solutions,
hybrid solutions, extensions to existing routing protocols, or
potentially no changes at all.
This document describes some of the key challenges to routing that
are present in today's IP networks. It then defines the concept of
"Semantic Routing" and presents some of the challenges to the
existing routing system that Semantic Addressing may present.
Finally, this document presents a list of related research questions
that offer opportunities for future research into new or modified
routing protocols that make use of Semantic Addressing.
In this document, the focus is on routing and forwarding at the IP
layer. It is possible that a variety of overlay mechanisms exist to
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perform service or path routing at higher layers, and that those
approaches may be based on Semantic Addresses, but that is out of
scope for this document. Similarly, it is possible that Semantic
Addresses can be applied in a number of underlay network
technologies, and that, too, is out of scope for this document.
This document draws on surveys and analysis performed in "Survey of
Semantic Internet Routing Techniques"
[I-D.king-irtf-semantic-routing-survey].
2. Current Challenges to IP Routing
Today's IP routing faces several significant challenges which are a
consequence of the architectural design decisions and exponential
growth. These challenges include mobility, multihoming, programmable
paths, scalability and security, and were not the focus of the
original design of the Internet. Nevertheless, IP-based networks
have, in general, coped well in an incremental manner as each new
challenge has evolved. This list is presented to give context to the
continuing requirements that routing protocols must meet as new
semantics are applied to IP addresses.
Mobility - Mobility introduces several challenges, including
maintaining a relationship between a sender and a receiver in
cases where sender and/or receiver changes their point of network
attachment. The original network must always be informed about
the mobile node's current location, to allow continuity of
services. Mobility users may also consume resources, while
physical moving. The mobile user service instances and
attachments will also change due to varying load or latency, e.g.,
in Multi-access Edge Computing (MEC) scenarios.
Multihoming - Multihomed stations or multihomed networks are
connected to the Internet via more than one access network and
therefore, may be assigned multiple IP addresses from different
pools of addresses. There are challenges concerning how traffic
is routed back to the source if the source has originated its
traffic using the wrong address for a particular connection, or if
one of the connections to the Internet is degraded.
Multi-path - The Internet was initially designed to find the
single, "best" path to a destination using a distributed routing
algorithm. Current, IP-based networks topologies facilitate
multiple paths each with different characteristics and with
different failure likelihoods. It may be beneficial to send
traffic over multiple paths to achieve reliability and enhance
throughput, and it may be desirable to select one path or another
in order to provide delivery qualities or to avoid transiting
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specific areas of an IP-based network. However, the way in which
packets are routed using the best or shortest path means that
distinguishing these alternate paths and directing traffic to them
can be hard. Further, problems concerning scalability, commercial
agreements among Service Providers, and the design of BGP make the
utilization of multi-path techniques difficult for inter-domain
routing. (Note that this discussion is distinct from Equal Cost
Multi-path (ECMP) where packets are directed onto two "parallel"
paths of identical least cost using a hash algorithm operated on
some of the packets' header fields.)
Multicast - Delivering the same packet to multiple destinations
can place considerable load on a network. Solutions that
replicate the packet at the source or at the network edge may
obviously see multiple copies of the packet flowing along the same
network links. A number of solutions have been tried over the
years to move replication into the network to make more optimal
use of the network resources, but these approaches are complex to
set up and manage requiring sophisticated protocols that can
determine the best multicast delivery topologies, as well as
hardware that can replicate packets. In order that packets can be
addressed to a group of destinations and not be routed using the
normal unicast approaches, parts of the addressing space (that is,
address prefixes) have been reserved to indicate multicast.
Programmable Paths - The ability to decouple IP-based network
paths from routing protocols and agreements between Service
Providers, would allow users and applications to configure and
select network paths themselves, based on required path (that is,
traffic-delivery) characteristics. Currently, user and
application packets follow the path selected by routing protocols
and the way traffic is routed through a network is under the
exclusive control of the Service Provider that owns the network.
End-Point Selection - As compute resources and content storage
moves closer to the edge of the network, there are often multiple
points in the network that can satisfy user requests. In order to
make best use of these distributed services and so to not overload
parts of the network, user traffic needs to be steered to
appropriate servers or data centres. In many cases, this function
may be achieved in the application layer (such as through DNS) or
in the transport layer (such as using ALTO). The challenge is to
balance higher-layer decisions about which application layer
resources to use with information from the lower layers about the
availability and load of network resources.
Scalability - There are many scaling concerns that pose critical
challenges to the Internet. Not least among these challenges is
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the size of the routing tables that routers in an IP-based network
must maintain and exchange with their peers. As the number of
devices attached to the network grows, so the number of addresses
in use also grows, and because of the address allocation schemes,
the mobility of devices, and the various connectivity options
between networks, the routing table sizes also grow and are not
amenable to aggregation. This problem exists even in limited
domains (such as IoT), where the size of the routing table - as
more devices are added to the network - may be a gating factor in
there applicability of certain routing protocols. It may be noted
that scaling issues are exacerbated by multihoming practices if a
host that is multihomed is allocated a different address for each
point of attachment.
Security - Issues of security and privacy have been largely
overlooked within the routing systems. However, there is
increasing concern that attacks on routing systems can not only be
disruptive (for example, causing traffic to be dropped), but may
cause traffic to be routed via inspection points that can breach
the security or privacy of the payloads.
Some of the challenges outlined here were previously considered
within the IETF by the IABs "Routing and Addressing Workshop" held in
Amsterdam, The Netherlands on October 18-19, 2006 [RFC4984]. Several
architectures and protocols have since been developed and worked on
within and outside the IETF, and these are examined in
[I-D.king-irtf-semantic-routing-survey].
3. What is Semantic Routing?
Typically, in an IP-based network packets are forwarded using the
least cost path to the destination IP address. Service Providers may
also use techniques to modify the default forwarding behavior based
on other information present in the packet and configured or
programmed into the routers. These mechanisms, sometimes called
semantic routing techniques include "Preferential Routing", "Policy-
based Routing", and "Flow steering".
Examples of semantic routing usage for IP-based networks include the
following:
o Using addresses to identify different device types so that their
traffic may be handled differently [SEMANTICRTG].
o Expressing how a packet should be handled, prioritized, or
allocated network resources as it is forwarded through the network
[TERASTREAMref].
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o Deriving IP addresses from the lower layer identifiers and using
addresses depending on the underlying connectivity (for example,
[RFC6282].
o Indicating the application or network function on a destination
device or at a specific location; or enable Service Function
Chaining (SFC).
o Providing semantics specific to mobile networks so that a user or
device may move through the network without disruption to their
service [CONTENT-RTG-MOBILEref].
o Enabling optimized multicast traffic distribution by encoding
multicast tree and replication instructions within addresses
[MULTICAST-SRref].
o Content-based routing (CBR), forwarding of the packet based on
message content rather than the destination addresses
[OPENSRNref].
o Identifying hierarchical connectivity so that routing can be
simplified [EIBPref].
o Providing geographic location information within addresses
[GEO-IPref].
o Using cryptographic algorithms to mask the identity of the source
or destination, masking routing tables within the domain, while
still enabling packet forwarding across the network
[BLIND-FORWARDINGref].
A detailed description of IP-based semantic routing, and a survey of
semantic routing proposals research projects can be found in
[I-D.king-irtf-semantic-routing-survey].
Several technical challenges exist for semantic routing in IP-based
network. These include:
o Address consumption caused by lower address utility rate. The
wastage mainly comes from aligning finite allocation for semantic
address blocks.
o Encoding too many semantics into prefixes will require evaluation
of which to prioritize.
o Risk of privacy/information leakage.
o Burdening the user, application, or prefix assignment node.
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o Source address spoofing preventing mechanisms may be required.
o Overloading of routing protocols causing stability and scaling
problems.
o Depending on encoding mechanisms, there may be challenges for data
planes to scale the processes of finding, reading, and looking up
semantic data in order to forward packets at line speed.
o Backwards compatibility with existing IP-based networking.
3.1. Architectural Considerations
Semantic data may be applied in a number of ways to integrate with
existing routing architectures. The most obvious is to build an
overlay such that IP is used only to route packets between network
nodes that utilize the semantics at a higher layer. There are a
number of existing uses of this approach including Service Function
Chaining (SFC) [RFC7665] and Information Centric Networking (ICN)
[RFC8763]. An overlay may be achieved in a higher protocol layer, or
may be performed using tunneling techniques (such as IP-in-IP) to
traverse the areas of the IP network that cannot parse additional
semantics thereby joining together those nodes that use the semantic
data.
The application of semantics may also be constrained to within a
limited domain. In some cases, such a domain will use IP, but be
disconnected from Internet (see Section 3.1.1). In other cases,
traffic from within the domain is exchanged with other domains that
are connected together across an IP-based network using tunnels or
via application gateways (see Section 3.1.2). And in still another
case traffic from the domain is routed across the Internet to other
nodes and this requires backward-compatible routing approaches (see
Section 3.1.3).
3.1.1. Isolated Domains
Some IP network domains are entirely isolated from the Internet and
other IP-based networks. In these cases, there is no risk to
external networks from any semantic addressing or routing schemes
carried out within the domain. Thus, the challenges are limited to
enabling the desired function within the domain.
All of the challenges could exist even in a limited domain, but the
impact may be significantly reduced both because of the limited size
of the domain, and because there is no need to interact with native
IP routers.
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Many approaches in isolated domains will utilize environment-specific
routing protocols. For example, those suited to constrained
environments (for IoT) or mobile environments (for smart vehicles).
Such routing protocols can be optimized for the exchange of
information specific to semantic routing.
3.1.2. Bridged Domains
In some deployments, it will be desirable to connect together a
number of isolated domains to build a larger network. These domains
may be connected (or bridged) over an IP network or even over the
Internet.
Ideally, the function of the bridged domains should not be impeded by
how they are connected, and the operation of the IP network providing
the connectivity should not be compromised by the act of carrying
traffic between the domains. This can generally be achieved by
tunneling the packets between domains using any tunneling technique,
and this will not require the IP network to know about the semantic
routing used by the domains. The challenges in this scenario are
very similar to those for Section 3.1.1 except that the network
created from the set of domains may be larger, and some routing
mechanism must be applied to know in which remote domain a
destination is situated.
An alternative to tunneling is achieved using gateway functionality
where packets from a domain are mapped at the domain boundary to
produce regular IP packets that are sent across the IP network to the
boundary of the destination domain where they are mapped back into
packets for use within that domain. Such an approach presents
additional challenges especially at the boundary of the destination
domain where some mechanism must enable the mapping back into
semantic-enabled packets.
3.1.3. Semantic Prefix Domains
A semantic prefix domain [I-D.jiang-semantic-prefix] is a portion of
the Internet over which a consistent set of semantic-based policies
are administered in a coordinated fashion. This is achieved by
assigning a routable address prefix (or a set of prefixes) for use
with semantic addressing and routing so that packets may be routed
through the regular IP network (or the Internet) using the prefix and
without encountering or having to use any semantic addressing. Once
delivered to the semantic prefix domain, a packet can be subjected to
whatever semantic routing is enabled in the domain.
Examples of semantic prefix domains include:
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o Administrative domains
o Applications
o Autonomous systems
o Hosts
o Network types
o Routers
o Trust regions
o User groups
A semantic prefix domain has a set of pre-established semantic
definitions which are only meaningful locally. Without an efficient
mechanism for notification, exchange, or configuration of semantics,
the definitions of semantics are only meaningful within the local
semantic prefix domain, and the addresses on a packet from within a
domain risk being misinterpreted by hosts and routers outside the
domain. While, sharing semantic definitions among semantic prefix
domains would enable wider semantic-based network function, such
approaches run the risk of complexity caused by overlapping
semantics, and require a significant trust model between network
operators. More successful approaches to multi-domain semantics
might be to rely either on backwards-compatible techniques or on
standardized semantics.
A semantic prefix domain may also span several physical networks and
traverse multiple service provider networks. However, when an
interim network is traversed (such as when an intermediary network is
used for interconnectivity) the relevance of the semantics is limited
to network domains that share a common semantic policy, and tunneling
may be needed to traverse transit domains.
Examples of prefix-partitioned semantic addressing that already exist
include:
o Documentation addresses
o Loopback addresses
o Multicast address space
o Private use addresses
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o IPv4-IPv6 encoding
o Routers
o Trust regions
o User groups
4. Challenges for Internet Routing Research
It may not be possible to embrace all emerging scenarios outlined in
this document with a single approach or solution. Requirements such
as 5G mobility, near-space-networking, and networking for outer-
space, may need to be handled using separate network technologies.
Therefore, developing a new Internet architecture that is both
economically feasible and which has the support of the networking
equipment vendors, is a significant challenge in the immediate future
of the Internet.
Improving IP-based network capabilities and capacity to scale, and
address a set of growing requirements presents significant research
challenges, and will require contributions from the networking
research community.
4.1. Research Principles
Research into semantic addressing should be founded on regular
scientific research principles [royalsoc]. Given the importance of
the Internet today, it is critical that research is targeted,
rigorous, and reproducible.
The most valuable research will go beyond an initial hypothesis, a
report of the work done, and the results observed. Although that is
a required foundation, networking research needs to be independently
reproducible so that claims can be verified or falsified. Further,
the networks on which the research is carried out need to both
reflect the characteristics that are being explicitly tested, and
reproduce the variety of real networks that constitute the Internet.
Thus, when conducting experiments and research to address the
questions in the next section, attention should be given to how the
work is documented and how meaningful the test environment is, with a
strong emphasis on making it possible for others to reproduce and
validate the work.
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4.2. Routing Research Questions to be Addressed
As research into the scenarios and possible uses of semantic
addressing progresses, a number of questions need to be addressed in
the scope of routing. These questions go beyond "Why do we need this
function?" and "What could we achieve by carrying this additional
semantic in an IP address?" The questions are also distinct from
issues of how the additional semantics can be encoded within an IP
address. All of those issues are, of course, important
considerations in the debate about semantic addressing, but they form
part of the essential groundwork of research into semantic addressing
itself.
This section sets out some of the concerns about how the routing
system might be impacted by the use of semantic addressing. These
questions need to be addressed in separate research work or folded
into the discussion of each semantic addressing proposal.
1. What is the scope of the semantic address proposal? This
question may be answered as:
* Global: It is intended to apply to all uses of IP addresses.
* Backbone: It is intended to apply to IP-based network
connectivity.
* Overlay: It is to be used as an overlay network over previous
uses of IP or other underlay technologies using tunneling.
* Gateway: The semantic addressing will be used within a limited
domain, and communications with the wider Internet will be
handled by a protocol or application gateway.
* Domain: The use of the semantic addressing is entirely limited
to within a domain or private network.
Underlying this issue is a broader question about the boundaries
of the use of IP, and the limit of "the Internet". If a limited
domain is used, is it a semantic prefix domain [RFC8799] where a
part of the IP address space identifies the domain so that an
address is routable to the domain but the additional semantics
are used only within the domain, or is the address used
exclusively within the domain so that the external impact of the
routability of the address that carries additional semantics is
not important?
2. What will be the impact on existing routing systems? What would
happen if an address with additional semantics was released
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according to normal operations, accidentally, or maliciously?
How would the existing routing systems react? For example: how
are cryptographically generated addresses made routable; how are
the semantic parts of an address distinguished from the routable
parts; is there an impact on the size and maintenance of routing
tables due to the addition of semantics to addresses?
3. What path characteristics are needed for the routed paths? Since
one of the purposes of adding semantics to IP addresses is to
cause special processing by routers, it is important to
understand what behaviors are wanted. Such path characteristics
include (but are not limited to):
* Quality: expressed in terms of throughput, latency, jitter,
drop precedence, etc.
* Resilience: expressed in terms of survival of network failures
and delivery guarantees;
* Destination: How is a destination address to be interpreted if
it encodes a choice of actual destinations?
In these cases, how do the routing protocols utilize the address
semantics to determine the desired characteristics? What
additional information about the network does the protocol need
to gather? What changes to the routing algorithm is needed to
deliver packets according to the desired characteristics?
4. Can we solve these routing challenges with existing routing tools
and methods? We can break this question into more detailed
questions.
* Is new hardware needed? Existing deployed hardware has
certain assumptions about how forwarding is carried out based
on IP addresses and routing tables.
* Do we need new routing protocols? We might ask some
subsidiary questions:
+ Can we make do with existing protocols, possibly by tuning
configuration parameters or using them out of the box?
+ Can we make simple backward-compatible modifications to
existing protocols such that they work for today's IP
addresses as well as enhanced-semantic addresses?
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+ Do we need entirely new protocols or radically evolutions
of existing protocols in order to deliver the functions
that we need?
+ Should we focus on the benefits of optimized routing
solutions, or should we attempt to generalize to enable
wider applicability?
Do we need new management tools and techniques? Management of
the routing system (especially diagnostic management) is a
crucial and often neglected part of the problem space.
5. What is the scalability impact for routing systems? Scalability
can be measured as:
* Routing table size. How many entries need to be maintained in
the routing table? Some approaches to semantic addressing may
be explicitly intended to address this problem.
* Routing performance. Routing performance may be considered in
terms of the volume of data that has to be exchanged both to
establish and to maintain the routing tables at the
participating routers. It may also be measured in terms of
how much processing is required to derive new routes when
there is a change in the network routing information.
* Routing convergence is the time that it takes for a routing
protocol to discover changes (especially faults) in the
network, to distribute the information about any changes to
the network, and to reach a stable state across the network
such that packets are routed consistently.
For all questions of routing scalability, research that presents
real numbers based on credible example networks is highly
desirable.
6. To what extent can multicast be developed:
* To support programmable SDN systems such as P4 [BIER-P4]?
* To satisfy end-to-end applications?
* To apply per-packet multicasting to develop new services?
* As a separate network layer distinct from IP or by encoding
group destinations into IP addresses?
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7. What aspects need to be standardized? It is really important to
understand the necessity of standardization within this research.
What degree of interoperability is expected between devices and
networks? Is the limited domain so constrained (for example, to
a single equipment vendor) that standardization would be
meaningless? Is the application so narrow (for example, in niche
hardware environments) such that interoperability is best handled
by agreements among small groups of vendors such as in industry
consortia?
5. Security Considerations
Research into semantic addressing and routing must give full
consideration to the security and privacy issues that are introduced
by these mechanisms. Placing additional information into address
fields might reveal details of what the packet is for, what function
the user is performing, who the user is, etc. Furthermore, in-flight
modification of the additional information might not directly change
the destination of the packet, but might change how the packet is
handled within the network and at the destination.
6. IANA Considerations
This document makes no requests for IANA action.
7. Acknowledgements
Thanks to Stewart Bryant for useful conversations. Luigi Iannone,
Robert Raszuk, Dirk Trossen, Ron Bonica, Marie-Jose Montpetit, Yizhou
Li, Toerless Eckert, Tony Li, Joel Halpern, Stephen Farrell, and
Carsten Bormann made helpful suggestions.
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).
8. Contributors
Joanna Dang
Email: dangjuanna@huawei.com
9. Informative References
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[BIER-P4] Merling, D., Lindner, S., and M. Menth, "Hardware Based
Evaluation of Scalable and Resilient Multicast with BIER
in P4", Presentation IETF-108 BIER Working Group Online
Meeting, 2020,
<https://datatracker.ietf.org/meeting/108/materials/
slides-108-bier-05-bier-in-p4-00>.
[BLIND-FORWARDINGref]
Simsek, I., "On-Demand Blind Packet Forwarding",
Paper 30th International Telecommunication Networks and
Applications Conference (ITNAC), 2020, 2020,
<https://www.computer.org/csdl/proceedings-article/
itnac/2020/09315187/1qmfFPPggrC>.
[CONTENT-RTG-MOBILEref]
Liu, H. and W. He, "Rich Semantic Content-oriented Routing
for mobile Ad Hoc Networks", Paper The International
Conference on Information Networking (ICOIN2014), 2014,
2014, <https://ieeexplore.ieee.org/document/6799682>.
[EIBPref] Shenoy, N., "Can We Improve Internet Performance? An
Expedited Internet Bypass Protocol", Presentation 28th
IEEE International Conference on Network Protocols, 2020,
<https://icnp20.cs.ucr.edu/Slides/NIPAA/D-3_invited.pptx>.
[GEO-IPref]
Dasu, T., Kanza, Y., and D. Srivastava, "Geotagging IP
Packets for Location-Aware Software-Defined Networking in
the Presence of Virtual Network Functions", Paper 25th ACM
SIGSPATIAL International Conference on Advances in
Geographic Information Systems (ACM SIGSPATIAL 2017),
2017, <https://about.att.com/ecms/dam/sites/labs_research/
content/publications/
AI_Geotagging_IP_Packets_for_Location.pdf>.
[I-D.jiang-semantic-prefix]
Jiang, S., Sun, Q., Farrer, I., Bo, Y., and T. Yang,
"Analysis of Semantic Embedded IPv6 Address Schemas",
draft-jiang-semantic-prefix-06 (work in progress), July
2013.
[I-D.king-irtf-semantic-routing-survey]
King, D., Farrel, A., and J. Dang, "A Survey of Semantic
Internet Routing Techniques", draft-king-irtf-semantic-
routing-survey-00 (work in progress), May 2021.
King & Farrel Expires December 16, 2021 [Page 16]
Internet-Draft Routing Challenges June 2021
[MULTICAST-SRref]
Jia, W. and W. He, "A Scalable Multicast Source Routing
Architecture for Data Center Networks", Paper IEEE
Journal on Selected Areas in Communications, vol. 32, no.
1, pp. 116-123, January 2014, 2014,
<https://ieeexplore.ieee.org/document/6799682>.
[OPENSRNref]
Ren, P., Wang, X., Zhao, B., Wu, C., and H. Sun, "OpenSRN:
A Software-defined Semantic Routing Network Architecture",
Paper IEEE Conference on Computer Communications Workshops
(INFOCOM WKSHPS), Hong Kong, 2015, 2015,
<https://www.researchgate.net/
publication/308827498_OpenSRN_A_software-
defined_semantic_routing_network_architecture>.
[RFC4984] Meyer, D., Ed., Zhang, L., Ed., and K. Fall, Ed., "Report
from the IAB Workshop on Routing and Addressing",
RFC 4984, DOI 10.17487/RFC4984, September 2007,
<https://www.rfc-editor.org/info/rfc4984>.
[RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6
Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
DOI 10.17487/RFC6282, September 2011,
<https://www.rfc-editor.org/info/rfc6282>.
[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>.
[RFC8763] Rahman, A., Trossen, D., Kutscher, D., and R. Ravindran,
"Deployment Considerations for Information-Centric
Networking (ICN)", RFC 8763, DOI 10.17487/RFC8763, April
2020, <https://www.rfc-editor.org/info/rfc8763>.
[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>.
[royalsoc]
The Royal Society, "Evidence synthesis : Principles", Web
page Principles for good evidence synthesis, September
2018, <https://royalsociety.org/topics-policy/projects/
evidence-synthesis/principles/>.
King & Farrel Expires December 16, 2021 [Page 17]
Internet-Draft Routing Challenges June 2021
[SEMANTICRTG]
Strassner, J., Sung-Su, K., and J. Won-Ki, "Semantic
Routing for Improved Network Management in the Future
Internet", Book Chapter Springer, Recent Trends in
Wireless and Mobile Networks, 2010, 2010,
<https://link.springer.com/
chapter/10.1007/978-3-642-14171-3_14>.
[TERASTREAMref]
Zaluski, B., Rajtar, B., Habjani, H., Baranek, M., Slibar,
N., Petracic, R., and T. Sukser, "Terastream
implementation of all IP new architecture", Paper 36th
International Convention on Information and Communication
Technology, Electronics and Microelectronics (MIPRO),
2013, 2013,
<https://ieeexplore.ieee.org/document/6596297>.
Authors' Addresses
Daniel King
Lancaster University
UK
Email: d.king@lancaster.ac.uk
Adrian Farrel
Old Dog Consulting
UK
Email: adrian@olddog.co.uk
King & Farrel Expires December 16, 2021 [Page 18]