Network Working Group J. Arkko
Internet-Draft Ericsson
Intended status: Informational T. Hardie
Expires: May 7, 2020 Google
November 04, 2019
Report from the IAB workshop on Design Expectations vs. Deployment
Reality in Protocol Development
draft-arkko-arch-dedr-report-00
Abstract
The Design Expectations vs. Deployment Reality in Protocol
Development Workshop was convened by the Internet Architecture Board
(IAB) in June 2019. This report summarizes its significant points of
discussion and identifies topics that may warrant further
consideration.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Workshop Agenda . . . . . . . . . . . . . . . . . . . . . . . 4
3. Position Papers . . . . . . . . . . . . . . . . . . . . . . . 4
4. Discussions . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1. Past experiences . . . . . . . . . . . . . . . . . . . . 6
4.2. Principles . . . . . . . . . . . . . . . . . . . . . . . 6
4.3. Centralised deployment models . . . . . . . . . . . . . . 7
4.4. Security . . . . . . . . . . . . . . . . . . . . . . . . 8
4.5. Future . . . . . . . . . . . . . . . . . . . . . . . . . 8
5. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1. Summary of discussions . . . . . . . . . . . . . . . . . 9
5.2. Actions . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.2.1. Potential architecture actions and outputs . . . . . 11
5.2.2. Potential other actions . . . . . . . . . . . . . . . 11
5.3. Other publications . . . . . . . . . . . . . . . . . . . 11
5.4. Feedback . . . . . . . . . . . . . . . . . . . . . . . . 11
6. Informative References . . . . . . . . . . . . . . . . . . . 11
Appendix A. Particant List . . . . . . . . . . . . . . . . . . . 14
Appendix B. Acknowledgements . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction
The Design Expectations vs. Deployment Reality in Protocol
Development Workshop was convened by the Internet Architecture Board
(IAB) in June 2019. This report summarizes its significant points of
discussion and identifies topics that may warrant further
consideration.
Note: While late in being submitted, this report is still an early
version. Comments and contributions are appreciated. We expect to
call for review of the -01 version.
The background for the workshop was that a number of protocols have
presumed specific deployment models during the development or early
elaboration of the protocol. Actual deployments have, however, often
run contrary to these early expectations when economies of scale,
DDoS resilience, market consolidation, or other factors have come
into play. These factors can result in the deployed reality being
highly concentrated.
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This is a serious issue for the Internet, as concentrated,
centralized deployment models present risks to user choice, privacy,
and future protocol evolution.
On occasion, the differences to expectations were almost immediate,
but they also occur after a significant time has passed from the
protocol's initial development.
Examples include:
Email standards, which presumed many providers running in a largely
uncoordinated fashion, but which has seen both significant market
consolidation and a need for coordination to defend against spam and
other attacks. The coordination and centralized defense mechanisms
scale better for large entities, which has fueled additional
consolidation.
The DNS, which presumed deep hierarchies but has often been deployed
in large, flat zones, leading to the nameservers for those zones
becoming critical infrastructure. Future developments in DNS may see
concentration through the use of globally available common resolver
services, which evolve rapidly and can offer better security.
Paradoxically, concentration of these queries into few services
creates new security and privacy concerns.
The Web, which is built on a fundamentally decentralized design, but
which is now often delivered with the aid of Content Delivery
Networks. Their services provide scaling, distribution, and Denial
of Service prevention in ways that new entrants and smaller systems
operators would find difficult to replicate. While truly small
services and truly large ones may operate using only their own
infrastructure, many others are left with the only practical choice
being the use of a globally available commercial service.
Similar developments may happen with future technologies and
services. For instance, the growing use of Machine Learning
technology presents challenges for distributing effective
implementation of a service throughout a pool of many different
providers.
In [RFC5218] the IAB tackled what made for a successful protocol. In
[RFC8170], the IAB described how to handle protocol transitions.
This purpose of the workshop was to explore cases where the initial
system design assumptions turned out to be wrong, looking for
patterns in what caused those assumptions to fail (e.g.,
concentration due to DDoS resilience) and in how those failures
impact the security, privacy, and manageability of the resulting
deployments.
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While the eventual goals might include proposing common remediations
for specific cases of confounded protocol expectations.
The workshop call for papers invited the submission of position
papers which would:
o Describe specific cases where systems assumptions during protocol
development were confounded by later deployment conditions.
o Survey a set of cases to identify common factors in these
confounded expectations.
o Explore remediations which foster user privacy, security and
provider diversity in the face of these changes.
A total of 21 position papers were received, listed in Section 3. On
site or remote were 30 participants, listed in Appendix A.
2. Workshop Agenda
After opening and discussion of goals for the workshop, the
discussion focused on five main topics:
o Past experiences. What have we learned?
o Principles. What forces apply to deployment? What principles to
take into account in design?
o Centralised deployment models. The good and the bad of
centralisation. Can centralisation be avoided? How?
o Security. Are we addressing the right threats? What should we
prepare ourselves for?
o Future. What can we do? Should we get better at predicting, or
should we do different things?
3. Position Papers
The following position papers were submitted to the workshop:
o Jari Arkko. "Changes in the Internet Threat Model" [Arkko2019]
o Vittorio Bertola. "How the Internet Was Won and Where It Got Us"
[Bertola2019]
o Carsten Bormann. "WiFi authentication: Some deployment
observations from eduroam" [Bormann2019]
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o Stephane Bortzmeyer. "Encouraging better deployments"
[Bortzmeyer2019]
o Brian Carpenter and Bing Liu. "Limited Domains and Internet
Protocols" [Carpenter2019]
o Alissa Cooper. "Don't Forget the Access Network" [Cooper2019]
o Stephen Farrell. "We're gonna need a bigger threat model"
[Farrell2019]
o Phillip Hallam-Baker. "The Devil is in the Deployment"
[HallamBaker2019]
o Ted Hardie. "Instant Messaging and Presence: A Cautionary Tale"
[Hardie2019]
o Paul Hoffman. "Realities in DNSSEC Depployment" [Hoffman2019]
o Christian Huitema. "Concentration is a business model"
[Huitema2019]
o Geoff Huston. "The Border Gateway Protocol, 25 years on"
[Huston2019]
o Dirk Kutscher. "Great Expectations: Protocol Design and
Socioeconomic Realities" [Kutscher2019]
o Julien Maisonneuve. "DNS, side effects and concentration"
[Maisonneuve2019]
o John Mattsson. "Privacy, Jurisdiction, and the Health of the
Internet" [Mattsson2019]
o Moritz Muller. "Rolling Forward: An Outlook on Future Root
Rollovers" [Muller2019]
o Joerg Ott. "Protocol Design Assumptions and PEPs" [Ott2019]
o Lucas Pardue. "Some challenges with IP multicast deployment"
[Pardue2019]
o Jim Reid. "Where/Why has DNS gone wrong?" [Reid2019]
o Mohit Sethi and Tuomas Aura. "IoT Security and the role of
Manufacturers: A Story of Unrealistic Design Expectations"
[Sethi2019]
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o Andrew Sullivan. "Three kinds of concentration in open protocols"
[Sullivan2019]
These papers are available from the IAB website [CFP] [POS].
4. Discussions
4.1. Past experiences
The workshop investigated deployment cases from WebPKI to DNSSEC,
from BGP to NATs, from DNS resolvers to CDNs, and from IOT to instant
messaging and social media applications.
4.2. Principles
Several underlying principles can be observed in the example cases
that were discussed. Deployment failures tend to be associated with
cases where interdependencies make progress difficult and there's no
major advantage for early deployment. Despite persistent problems in
the currently used technology, it becomes difficult for the ecosystem
to switch to better technology. For instance, there are a number of
areas where the Internet routing protocol, BGP, is lacking, but
success in deploying significant improvements has been lacking, for
instance in the area of security.
Another principle appears to be first mover advantage. Several
equally interesting technologies have fared in very different ways,
depending whether there was an earlier system that provided most of
the benefits of the new system. Again, despite potential problems in
an already deployed technology, it becomes difficult to deploy
improvements due to lack of immediate incentives and due to the
competing and already deployed alternative that is proceeding forward
in the ecosystem. For instance, WebPKI is very widely deployed and
used, but DNSSEC is not. Is this because the earlier commercial
adoption of WebPKI, and the initially more complex interdependencies
between systems that wished to deploy DNSSEC.
The workshop also discussed different types of deployment patterns on
the Internet:
o Delivering functionality over Internet as a web service. The
Internet is an open and standardised system, but the service on
top may be closed, essentially running two components of the
service provider's software against each other over the browser
and Internet infrastructure. Several large application systems
have grown in the Internet in this manner, encompassing large
amounts of functionality and a large fraction of Internet users.
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o Delivering concentrated network services that offer the standard
capabilities of the Internet. Examples in this category include
the provisioning of DNS resolution, some mail services, and so on.
The second case is more interesting for an Internet architecture
discussion. There can, however, be different underlying situations
in that case. The service may be simply a concentrated way to
provide a commodity service. The market should find a natural
equilibrium for such situations. This may be fine, particularly,
where the service does not provide any new underlying advantage to
whoever is providing it (in the form of user data that can be
commercialized, for instance, or as training data for an important
machine learning service).
Secondly, the service may be an extension beyond standard protocols,
leading to some questions about how well standards and user
expectations match. But those questions could be addressed by better
or newer standards. But the third situation is more troubling: the
service are provided in this concentrated manner due to business
patterns that make it easier for particular entities to deploy such
services.
4.3. Centralised deployment models
Many of the participants have struggled with these trends and their
effect on desirable characteristics of Internet systems, such as
distributed, end-to-end architecture or privacy. Yet, there are many
business and technical drivers causing the Internet architecture to
become further and further centralised.
The hopeful side of this issue is that there are some potential
answers:
o DDOS defenses do not have to come through large entities, as
layered defenses and federation also helps similarly.
o Surveillance state data capture can be fought with data object
encryption, and not storing all of the datal in one place.
o Open interface help guard against the bundling of services in one
large entity; as long as there are open, well-defined interface to
specific functions these functions can also be performed by other
parties.
o Commercial surveillance does not seem to curbed by current means.
But there are still possibilities, such as stronger regulation,
data minimisation, or browsers acting on behalf of users. There
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are hopeful signs that at least some browsers are becoming more
aggressive in this regard. But more is needed.
One comment made in the workshop that the Internet community needs to
move back from regulation to trying to curb the architectural trend
of centralization instead. Another comment was that discussing this
in the abstract is not as useful as more concrete, practical actions.
For instance, one might imagine DOH deployments with larger number of
trusted resolvers.
4.4. Security
This part of the discussed focused on whether in the current state of
the Internet we actually need a new threat model.
Many of the communications security concerns have been addressed in
the past few years, with increasing encryption. However, issues with
trusting endpoints on the other side of the communication have not
been addressed, and are becoming more urgent with the advent or
centralised service architectures.
The participants in the workshop agreed that a new threat model is
needed, and that non-communications-security issues need to be
treated.
Other security discussions were focused on IOT systems, algorithm
agility issues, and experiences from difficult security upgrades such
as the DNSSEC key rollover.
The participants cautioned against relying too much on device
manufacturers for security, and being clear on security models and
assumptions. Security is often poorly understood, and the
assumptions about who the system defends against and not are not
clear.
4.5. Future
The workshop turned into a discussion of what actions we can take:
o Documenting our experiences?
o Providing advice (to IETF, to others)
o Waiting for the catastrophe that will make people agree to
changes? (hopefully not this)
o Work at the IETF?
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o Technical solutions/choices?
The best way for ietf to do things is through standards; convinging
people through other requests is difficult. The IETF needs to:
o pick pieces that it is responsible for
o being reactive for the rest, be available as an expert in other
discussions, provide Internet technology clue where needed, etc.
One key question is what other parties need to be involved in any
discussions. Platform developers (mobile platforms, cloud systems,
etc) is one such group. Specific technology or business groups (such
as email provider or certificate authority forums) are another.
The workshop also discussed specific technology issues, for instance
around IOT systems. One observation in those systems is that there
is no single model for applications, they vary. There are a lot of
different constraints in different systems and different control
points. What is needed perhaps most today is user control and
transparency (for instance, via MUD descriptions). Another issue is
management, particularly for devices that could be operational for
decades. Given the diversity of IOT systems, it may also make more
sense to build support systems for the broader solutions that
specific solutions or specific protocols.
There are also many security issues. While some of them are trivial
(such as default passwords), one should also look forward and be
prepared to have solutions for, say, trust management for long time
scales, or be able to provide data minimization to cut down on
potential for leakages. And the difficulty of establishing peer-to-
peer security strengthens the need for a central point, which may
also be harmful from a long-term privacy perspective.
5. Conclusions
5.1. Summary of discussions
The workshop met in sunny Finnish countryside and made the non-
suprising observation that technologies sometimes get deployed in
surprising ways. But the consequences of deployment choices can have
an impact on security, privacy, centralised vs. distributed models,
competition, surveillance, and the IETF community cares deeply about
these aspects, so it is worthwhile to spend time in analysis of these
choices.
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The prime factor driving deployments is perceived needs; expecting
people to recognise obvious virtues and therefore deploy is not
likely to work.
And the ecosystem is complex, including for instance many parties:
different business roles, users, regulators, and so on, and
perceptions of needs and ability to act depends highly on what party
one talks to.
While the workshop discussed actions and advice, there is a critical
question of who these are targeted towards. There is need to
construct a map of what parties need to perform what actions.
The workshop also made some technical observations. One recent trend
is that technology is moving up the stack, e.g., in the areas of
services, transport protocol functionality, security, naming, and so
on. This impacts how easy or hard changes are, and who is able to
perform them.
It was also noted that interoperability continues to be important,
and we need to explore what new interfaces need standardisation --
this will enable different deployment models & competition. Prime
factor driving deployments is actual needs; we cannot force anything
to others but can provide solutions for those that need them. Needs
and actions may fall on different parties.
The workshop also considered the balancing of user non-involvement
and transparency and choice, relevant threats such as communicating
with malicious endpoints, the role and willigness of browsers in
increasing the ability to defending the users' privacy, and concerns
around centralised control or data storage points
The workshop also discussed specific issues around routing, denial-
of-service attacks, IOT systems, role of device manufacturers, the
DNS, and regulatory reactions and their possible consequences.
5.2. Actions
The prime conclusion from the workshop was that the topic is not
completed in the workshop. Much more work is needed. The best way
for ietf to do things is through standards. The IETF should focus on
the parts that it is responsible for, and be available as an expert
on other discussions.
The documents/outputs and actions described in the following were
deemed relevant by the participants.
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5.2.1. Potential architecture actions and outputs
o Develop and document a modern threat model
o Continue discussion of consolidation/centralisation issues
o Document architectural principles, e.g., (re-)application of the
end-to-end principle
The first receiver of these thoughts is the IETF and protocol
community, but combined with some evangelising & validation elsewhere
5.2.2. Potential other actions
o Pursue specific IETF topics, e.g., work on taking into account
reputation systems in IETF work, working to ensuring certificate
scoping can be appropriately limited, building end-to-end
encryption tools for applications, etc.
o General deployment experiences/advice, and documenting deployment
assumptions possibly already in WG charters
o A report, and a short summary article will be produced from the
workshop.
5.3. Other publications
The workshop results have also been reported at [ISPColumn] by Geoff
Huston.
5.4. Feedback
Feedback regarding the workshop is appreciated, and can be sent to
the program committee, the IAB, or the architecture-discuss list.
6. Informative References
[Arkko2019]
Arkko, J., "Changes in the Internet Threat Model",
Position paper submitted for the IAB DEDR workshop , June
2019.
[Bertola2019]
Bertola, V., "How the Internet Was Won and Where It Got
Us", Position paper submitted for the IAB DEDR workshop ,
June 2019.
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[Bormann2019]
Bormann, C., "WiFi authentication: Some deployment
observations from eduroam", Position paper submitted for
the IAB DEDR workshop , June 2019.
[Bortzmeyer2019]
Bortzmeyer, S., "Encouraging better deployments", Position
paper submitted for the IAB DEDR workshop , June 2019.
[Carpenter2019]
Carpenter, B. and B. Liu, "Limited Domains and Internet
Protocols", Position paper submitted for the IAB DEDR
workshop , June 2019.
[CFP] IAB, ., "Design Expectations vs. Deployment Reality in
Protocol Development Workshop 2019",
https://www.iab.org/activities/workshops/dedr-workshop/ ,
April 2019.
[Cooper2019]
Cooper, A., "Don't Forget the Access Network", Position
paper submitted for the IAB DEDR workshop , June 2019.
[Farrell2019]
Farrell, S., "We're gonna need a bigger threat model",
Position paper submitted for the IAB DEDR workshop , June
2019.
[HallamBaker2019]
Hallam-Baker, P., "The Devil is in the Deployment",
Position paper submitted for the IAB DEDR workshop , June
2019.
[Hardie2019]
Hardie, T., "Instant Messaging and Presence: A Cautionary
Tale", Position paper submitted for the IAB DEDR
workshop , June 2019.
[Hoffman2019]
Hoffman, P., "Realities in DNSSEC Depployment", Position
paper submitted for the IAB DEDR workshop , June 2019.
[Huitema2019]
Huitema, C., "Concentration is a business model", Position
paper submitted for the IAB DEDR workshop , June 2019.
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[Huston2019]
Huston, G., "The Border Gateway Protocol, 25 years on",
Position paper submitted for the IAB DEDR workshop , June
2019.
[ISPColumn]
Huston, G., "Network Protocols and their Use",
https://www.potaroo.net/ispcol/2019-06/dedr.html , June
2019.
[Kutscher2019]
Kutscher, D., "Great Expectations: Protocol Design and
Socioeconomic Realities", Position paper submitted for the
IAB DEDR workshop , June 2019.
[Maisonneuve2019]
Maisonneuve, J., "DNS, side effects and concentration",
Position paper submitted for the IAB DEDR workshop , June
2019.
[Mattsson2019]
Mattsson, J., "Privacy, Jurisdiction, and the Health of
the Internet", Position paper submitted for the IAB DEDR
workshop , June 2019.
[Muller2019]
Muller, M., "Rolling Forward: An Outlook on Future Root
Rollovers", Position paper submitted for the IAB DEDR
workshop , June 2019.
[Ott2019] Ott, J., "Protocol Design Assumptions and PEPs", Position
paper submitted for the IAB DEDR workshop , June 2019.
[Pardue2019]
Pardue, L., "Some challenges with IP multicast
deployment", Position paper submitted for the IAB DEDR
workshop , June 2019.
[POS] IAB, ., "Position Papers: DEDR Workshop",
https://www.iab.org/activities/workshops/dedr-workshop/
position-papers/ , June 2019.
[Reid2019]
Reid, J., "Where/Why has DNS gone wrong?", Position paper
submitted for the IAB DEDR workshop , June 2019.
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[RFC5218] Thaler, D. and B. Aboba, "What Makes for a Successful
Protocol?", RFC 5218, DOI 10.17487/RFC5218, July 2008,
<https://www.rfc-editor.org/info/rfc5218>.
[RFC8170] Thaler, D., Ed., "Planning for Protocol Adoption and
Subsequent Transitions", RFC 8170, DOI 10.17487/RFC8170,
May 2017, <https://www.rfc-editor.org/info/rfc8170>.
[Sethi2019]
Sethi, M. and T. Aura, "IoT Security and the role of
Manufacturers: A Story of Unrealistic Design
Expectations", Position paper submitted for the IAB DEDR
workshop , June 2019.
[Sullivan2019]
Sullivan, A., "Three kinds of concentration in open
protocols", Position paper submitted for the IAB DEDR
workshop , June 2019.
Appendix A. Particant List
The following is a list of participants on site and over a remote
connection:
o Arkko, Jari
o Aura, Tuomas
o Bertola, Vittorio
o Bormann, Carsten
o Bortzmeyer, Stephane
o Cooper, Alissa
o Farrell, Stephen
o Flinck, Hannu
o Gahnberg, Carl
o Hallam-Baker, Phillip
o Hardie, Ted
o Hoffman, Paul
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o Huitema, Christian (remote)
o Huston, Geoff
o Komaitis, Konstantinos
o Kuhlewind, Mirja
o Kutscher, Dirk
o Li, Zhenbin
o Maisonneuve, Julien
o Mattson, John
o Muller, Moritz
o Ott, Joerg
o Pardue, Lucas
o Reid, Jim
o Rieckers, Jan-Frederik
o Sethi, Mohit
o Shore, Melinda (remote)
o Soininen, Jonne
o Sullivan, Andrew
o Trammell, Brian
Appendix B. Acknowledgements
The authors would like to thank the workshop participants, the
members of the IAB, and the participants in the architecture
discussion list for interesting discussions. The workshop organizers
would also like to thank Nokia for hosting the workshop in excellent
facilities in Kirkkonummi, Finland.
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Authors' Addresses
Jari Arkko
Ericsson
Email: jari.arkko@piuha.net
Ted Hardie
Google
Email: ted.ietf@gmail.com
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