Internet Engineering Task Force Ran Atkinson, Editor
INTERNET DRAFT Sally Floyd, Editor
draft-iab-research-funding-01.txt Internet Architecture Board
29 June 2003
IAB Concerns & Recommendations Regarding Internet Research & Evolution
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
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."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
Abstract
This document discusses IAB concerns that ongoing research is needed
to further the evolution of the Internet infrastructure, and that
consistent, sufficient non-commercial funding is needed to enable
such research.
Feedback can be sent to the IAB mailing list at iab@ietf.org, or to
the editors at rja@extremenetworks.com and floyd@icir.org. Feedback
can also be sent to the mailing list set up for feedback at research-
funding@ietf.org. Requests to join can be sent to research-funding-
request@ietf.org, with "subscribe research-funding" in the body of
the request.
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Table of Contents
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1. Introduction
1.1. Document Organization
1.2. IAB Concerns
1.3. Contributions to this Document
2. History of Internet Research & Research Funding
2.1. Prior to 1980
2.2. 1980s and early 1990s
2.3. Mid-1990s to 2003
2.4. Current Status
3. Open Internet Research Topics
3.1. Scope & Limitations
3.2. Naming
3.2.1. Domain Name System (DNS)
3.2.2. New Namespaces
3.3. Routing
3.3.1. Inter-domain Routing
3.3.2. Routing Integrity
3.3.3. Routing Algorithms
3.3.4. Mobile & Ad-Hoc Routing
3.4. Security
3.4.1. Freely Distributable Prototypes
3.4.2. Formal Methods
3.4.3. Key Management
3.4.4 Cryptography
3.4.5 Security for Distributed Computing
3.4.6. Deployment Considerations in Security
3.4.7. Denial of Service Protection
3.5. Network Management
3.5.1. Configuration Management
3.5.1. Enhanced Monitoring Capabilities
3.5.2. Managing Networks, Not Devices
3.5.3. Improving the Scalability of Network Management
3.6. Quality of Service
3.6.1. Inter-Domain QoS Architecture
3.6.2. New Queuing Disciplines
3.7. Congestion control.
3.8. Studying the Evolution of the Internet Infrastructure
3.9. Middleboxes
3.10. Internet Measurement
3.11. Meeting the Needs of the Future
3.12. Additional topics
4. Conclusions
5. Acknowledgements
6. Security Considerations
7. IANA Considerations
9. AUTHORS' ADDRESSES
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1. Introduction
This document discusses the history of funding for Internet research,
expresses concern about the current state of such funding, and
outlines several specific areas that the IAB believes merit
additional research. Current funding levels for Internet research
are not generally adequate, and several important research areas are
significantly underfunded. This situation needs to be rectified for
the Internet to continue its evolution and development.
1.1. Document Organization
The first part of the document is a high-level discussion of the
history of funding for Internet research to provide some historical
context to this document. The early funding of Internet research was
largely from the U.S. government, followed by a period in the second
half of the 1990s of commercial funding and of funding from several
governments. [Add a citation.] However, the commercial funding for
Internet research has been reduced due to the recent economic
downturn.
The second part of the document provides an incomplete set of open
Internet research topics. These are only examples, intended to
illustrate the breadth of open research topics. This second section
supports the general thesis that ongoing research is needed to
further the evolution of the Internet infrastructure. This includes
research on the medium-time-scale evolution of the Internet
infrastructure as well as research on longer-time-scale grand
challenges. This also includes many research issues that are already
being actively investigated in the Internet research community.
Areas that are discussed in this section include the following:
naming, routing, security, network management, and transport. Issues
that require more research also include more general architectural
issues such as layering and communication between layers. In
addition, general topics discussed in this section include modeling,
measurement, simulation, test-beds, etc. We are focusing on topics
that are related to the IETF and IRTF (Internet Research Task Force)
agendas. (E.g., issues related to the global grid are not discussed
in this document because these issues are addressed through the
Global Grid Forum and other grid-specific organizations, not in the
IETF.)
Where at all possible, the examples in the paper point to separate
documents on these issues, and only give a high-level summary of the
issues raised in those documents.
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1.2. IAB Concerns
Recently, in the aftermath of September 11 2001, there seems to be a
renewed interest by governments in funding research for Internet-
related security issues. From [J02]: "It is generally agreed that
the security and reliability of the basic protocols underlying the
Internet have not received enough attention because no one has a
proprietary interest in them".
That quote brings out a key issue in funding for Internet research,
which is that because no single organization (e.g., no single
government, software company, equipment vendor, or network operator)
has a sense of ownership of the global Internet infrastructure,
research on the general issues of the Internet infrastructure are
often not adequately funded. In our current challenging economic
climate, it is not surprising that commercial funding sources are
more likely to fund that research that leads to a direct competitive
advantage.
The principal thesis of this document is that if commercial funding
is the main source of funding for future Internet research, the
future of the Internet infrastructure could be in trouble. In
addition to issues about which projects were funded, the funding
source can also affect the content of the research, for example,
towards or against the development of open standards, or taking
varying degrees of care about the effect of the developed protocols
on the other traffic on the Internet.
At the same time, many significant research contributions in
networking have come from commercial funding. However, for most of
the topics in this document, relying solely on commercially-funded
research would not be adequate. Much of today's commercial funding
is focused on technology transition, taking results from non-
commercial research and putting them into shipping commercial
products. We have not tried to delve into each of the research
issues below to discuss, for each issue, what are the potentials and
limitations of commercial funding for research in that area.
On a more practical note, if there was no commercial funding for
Internet research, then few research projects would be taken to
completion with implementations, deployment, and follow-up
evaluation.
While it is theoretically possible for there to be too much funding
for Internet research, that is far from the current problem. There
is also much that could be done within the network research community
to make Internet research more focused and productive, but that would
belong in a separate document.
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1.3. Contributions to this Document
A number of people have directly contributed text for this document,
even though, following current conventions, the official RFC author
list includes only the key editors of the document. The
Acknowledgements section at the end of the document thanks other
people who contributed to this document in some form.
2. History of Internet Research & Research Funding
2.1. Prior to 1980
Most of the early research into packet-switched networks was
sponsored by the U.S. Defense Advanced Research Projects Agency
(DARPA) [CSTB99]. This includes the initial design, implementation,
and deployment of the ARPAnet connecting several universities and
other DARPA contractors. The ARPAnet originally came online in the
late 1960s. It grew in size during the 1970s, still chiefly with
DARPA funding, and demonstrated the utility of packet-switched
networking.
2.2. 1980s and early 1990s
The ARPAnet converted to the Internet Protocol on January 1, 1983,
approximately 20 years before this document was written. Throughout
the 1980s, the U.S. Government continued strong research and
development funding for Internet technology. DARPA continued to be
the key funding source, but was supplemented by other DoD (US
Department of Defense) funding (e.g. via DCA's Defense Data Network
(DDN) program) and other U.S. Government funding (e.g. US Department
of Energy (DoE) funding for research networks at DoE national
laboratories, (US) National Science Foundation (NSF) funding for
academic institutions). This funding included basic research,
applied research (including freely distributable prototypes), the
purchase of IP-capable products, and operating support for the IP-
based government networks such as ARPAnet, ESnet, MILnet, and NSFnet.
In the late 1980s, the U.S. DoD desired to leave the business of
providing operational network services to academic institutions, so
funding for many academic activities moved over to the NSF. NSF
funding included research projects into networking, as well as
creating the NSFnet backbone and sponsoring the creation of several
NSF regional networks (e.g. SURAnet) and interconnections with
several international research networks.
Most research funding outside the U.S. during the 1980s and early
1990s was focused on the ISO OSI networking project or on then-new
forms of network media (e.g. wireless, broadband access). The
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European Union was a significant source of research funding for the
networking community in Europe during this period. Some of the best
early work in gigabit networking was undertaken in the UK and Sweden.
2.3. Mid-1990s to 2003
Starting in the middle 1990s, U.S. Government funding for Internet
research and development was significantly reduced. The premise for
this was that the growing Internet industry would pay for whatever
research and development that was needed. Some funding for Internet
research and development has continued in this period from European
and Asian organizations (e.g., the WIDE Project in Japan [WIDE]).
Reseaux IP Europeens [RIPE] is an example of market-funded networking
research in Europe during this period.
Experience during this period has been that commercial firms have
often focused on donating equipment to academic institutions and
promoting somewhat vocationally-focused educational projects. Many
of the commercially-funded research and development projects appear
to have been selected because they appeared likely to give the
funding source a specific short-term economic advantage over its
competitors. Higher risk, more innovative research proposals
generally have not been funded by industry. A common view in Silicon
Valley has been that established commercial firms are not very good
at transitioning cutting edge research into products, but were
instead good at buying small startup firms who had successfully
transitioned such cutting edge research into products.
Unfortunately, small startup companies are generally unable
financially to fund any research themselves.
2.4. Current Status
The result of reduced U.S. Government funding and profit-focused,
low-risk, short-term industry funding has been a decline in higher-
risk but more innovative research activities. Industry has also been
less interested in research to evolve the overall Internet
architecture, because such work does not translate into a competitive
advantage for the firm funding such work.
The IAB believes that it would be helpful for governments and other
non-commercial sponsors to increase their funding of both basic
research and applied research relating to the Internet. Furthermore,
those increased funding levels should be sustained and protected
against inflation going forward.
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3. Open Internet Research Topics
This section primarily discusses some specific topics that the IAB
believes merit additional research. Research, of course, includes
not just devising a theory, algorithm, or mechanism to accomplish a
goal, but also evaluating the general efficacy of the approach and
then the benefits vs. the costs of deploying that algorithm or
mechanism. Important cautionary notes about this discussion are
given in the next sub-section. This particular set of topics is not
intended to be comprehensive, but instead is intended to demonstrate
the breadth of open Internet research questions.
3.1. Scope & Limitations
This document is NOT intended as a guide for funding organizations as
to exactly which projects or proposals should or should not be
funded.
In particular, this document is NOT intended to be a comprehensive
list of *all* of the research questions that are important to further
the evolution of the Internet; that would be a daunting task, and
would presuppose a wider and more intensive effort than we have
undertaken in this document.
Similarly, this document is not intended to list the research
questions that are judged to be only of peripheral importance, or to
survey the current (global; governmental, commercial, and academic)
avenues for funding for Internet research, or to make specific
recommendations about which areas need additional funding. The
purpose of the document is to persuade the reader that ongoing
research is needed towards the continued evolution of the Internet
infrastructure; the purpose is not to make binding pronouncements
about which specific areas are and are not worthy of future funding.
For some research clearly relevant to the future evolution of the
Internet, there are grand controversies between competing proposals
or competing schools of thought; it is not the purpose of this
document to take positions in these controversies, or to take
positions on the nature of the solutions for areas needing further
research.
That all carefully noted, the remainder of this section discusses a
broad set of research areas, noting a subset of particular topics of
interest in each of those research areas. Again, this list is NOT
comprehensive, but rather is intended to suggest that a broad range
of ongoing research is needed, and to propose some candidate topics.
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3.2. Naming
The Internet currently has several different namespaces, including IP
addresses, sockets (specified by the IP address, upper-layer
protocol, and upper-layer port number), and the Fully-Qualified
Domain Name (FQDN). Many of the Internet's namespaces are supported
by the widely deployed Domain Name System [RFC refs] or by various
Internet applications [RFC-2407, Section 4.6.2.1]
3.2.1. Domain Name System (DNS)
The DNS system, while it works well given its current constraints,
has several stress points.
The current DNS system relies on UDP for transport, rather than SCTP
or TCP. Given the very large number of clients using a typical DNS
server, it is desirable to minimise the state on the DNS server side
of the connection. UDP does this well, so is a reasonable choice,
though this has other implications, for example a reliance on UDP
fragmentation. With IPv6, intermediate fragmentation is not allowed
and Path MTU Discovery is mandated. However, the amount of state
required to deploy Path MTU Discovery for IPv6 on a DNS server might
be a significant practical problem.
One implication of this is that research into alternative transport
protocols, designed more for DNS-like applications where there are
very many clients using each server, might be useful. Of particular
interest would be transport protocols with little burden for the DNS
server, even if that increased the burden somewhat for the DNS
client.
Additional study of DNS caching, both currently available caching
techniques and also of potential new caching techniques, might be
helpful in finding ways to reduce the offered load for a typical DNS
server. In particular, examination of DNS caching through typical
commercial firewalls might be interesting if it lead to alternative
firewall implementations that were less of an obstacle to DNS
caching.
The community lacks a widely agreed upon set of metrics for measuring
DNS server performance. It would be helpful if people would
seriously consider what characteristics of the DNS system should be
measured.
Some in the community would advocate replacing the current DNS system
with something better. Past attempts to devise a better approach
have not yielded results that persuaded the community to change.
Proposed work in this are could be very useful, but might require
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careful scrutiny to avoid falling into historic design pitfalls.
With regards to DNS security, major technical concerns include
finding practical methods for signing very large DNS zones (e.g.
.COM), practical methods for incremental deployment of DNS security,
and tools to make it easier to manage secure DNS infrastructure.
3.2.2. New Namespaces
Additionally, the Namespace Research Group (NSRG) of the Internet
Research Task Force (IRTF) studied adding one or more additional
namespaces to the Internet Architecture [LD2002]. Many participants
in the IRTF NSRG membership believe that there would be significant
architectural benefit to adding one or more additional namespaces to
the Internet Architecture. Because smooth consensus on that question
or on the properties of a new namespace was not obtained, the IRTF
NSRG did not make a formal recommendation to the IETF community
regarding namespaces. The IAB believes that this is an open research
question worth examining further.
Finally, we believe that future research into the evolution of
Internet-based distributed computing might well benefit from studying
adding additional namespaces as part of a new approach to distributed
computing.
3.3. Routing
The currently deployed unicast routing system works reasonably well
for most users. However, the current unicast routing architecture is
suboptimal in several areas, including the following: end-to-end
convergence times in global-scale catenets (a system of networks
interconnected via gateways); the ability of the existing inter-
domain path-vector algorithm to scale well beyond 200K prefixes; the
ability of both intra-domain and inter-domain routing to use multiple
metrics and multiple kinds of metrics concurrently; and the ability
of IPv4 and IPv6 to support widespread site multi-homing without
undue adverse impact on the inter-domain routing system. Integrating
policy into routing is also a general concern, both for intra-domain
and inter-domain routing. In many cases, routing policy is directly
tied to economic issues for the network operators, so applied
research into routing ideally would consider economic considerations
as well as technical considerations..
3.3.1. Inter-domain Routing
The current operational inter-domain routing system has between
150,000 and 200,000 routing prefixes in the default-free zone (DFZ)
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[RFC-3221]. ASIC technology obviates concerns about the ability to
forward packets at very high speeds. ASIC technology also obviates
concerns about the time required to perform longest-prefix-match
computations. However, some senior members of the Internet routing
community have concerns that the end-to-end convergence properties of
the global Internet might hit algorithmic limitations (i.e. not
hardware limitations) when the DFZ is somewhere between 200,000 and
300,000 prefixes. Research into whether this concern is well-founded
in scientific terms seems very timely.
The current approach to site multi-homing has the highly undesirable
side-effect of significantly increasing the growth rate of prefix
entries in the DFZ (by impairing the deployment of prefix
aggregation). Research is needed into new routing architectures that
can support large-scale site multi-homing without the undesirable
impacts on inter-domain routing of the current multi-homing
technique.
3.3.2. Routing Integrity
Recently there has been increased awareness of the longstanding issue
of deploying strong authentication into the Internet inter-domain
routing system. Currently deployed mechanisms (e.g. BGP TCP MD5
[RFC2385], OSPF MD5, RIP MD5 [RFC2082]) provide cryptographic
authentication of routing protocol messages, but no authentication of
the actual routing data. Current proposals (e.g. S-BGP [KLMS2000])
for improving this in inter-domain routing are unduly challenging to
deploy across the Internet because of their reliance on a single
trust hierarchy (e.g., a single PKI). Similar proposals (e.g. OSPF
with Digital Signatures, [RFC2154]) for intra-domain routing are
argued to be computationally infeasible to deploy in a large network.
Alternative approaches to authentication of data in the routing
system need to be developed. In particular, the ability to perform
partial authentication of routing data would facilitate incremental
deployment of routing authentication mechanisms. Also, the ability
to use non-hierarchical trust models (e.g. the web of trust used in
the PGP application) might facilitate incremental deployment and
might resolve existing concerns about centralized administration of
the routing system, hence merits additional study and consideration.
3.3.3. Routing Algorithms
The current Internet routing system relies primarily on only three
algorithms. Link-state routing uses the Dijkstra algorithm
[Dijkstra59]. The Distance-Vector and Path-Vector algorithms use the
Bellman-Ford algorithm [Bellman1957, FF1962]. Additional ongoing
basic research into graph theory as applied to routing is worthwhile
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and might yield algorithms that would enable a new routing
architecture or otherwise provide improvements to the routing system.
Currently deployed multicast routing relies on the Deering RPF
algorithm [Deering1988]. Ongoing research into alternative multicast
routing algorithms and protocols might help alleviate current
concerns with the scalability of multicast routing.
The deployed Internet routing system assumes that the shortest path
is always the best path. This is provably false, however it is a
reasonable compromise given the routing protocols currently
available. The Internet lacks deployable approaches for policy-based
routing or routing with alternative metrics (i.e. some metric other
than the number of hops to the destination). Examples of alternative
policies include: the path with lowest monetary cost; the path with
the lowest probability of packet loss; the path with minimized
jitter; and the path with minimized latency. Policy metrics also
need to take business relationships into account. Historic work on
QoS-based routing has tended to be unsuccessful in part because it
did not adequately consider economic/commercial considerations of the
routing system and in part because of inadequate consideration of
security implications.
3.3.4. Mobile & Ad-Hoc Routing
Mobile routing [IM1993] and mobile ad-hoc routing [RFC2501] are
relatively recent arrivals in the Internet, and are not yet widely
deployed. The current approaches are not the last word in either of
those arenas. We believe that additional research into routing
support for mobile hosts and mobile networks is needed. Additional
research for ad-hoc mobile hosts and mobile networks is also
worthwhile. Ideally, mobile routing and mobile ad-hoc routing
capabilities should be native inherent capabilities of the Internet
routing architecture. This probably will require a significant
evolution from the existing Internet routing architecture. (NB: The
term "mobility" as used here is not limited to mobile telephones, but
instead is very broadly defined, including laptops that people carry,
cars/trains/aircraft, and so forth.)
Included in this topic are a wide variety of issues. The more
distributed and dynamic nature of partially or completely self-
organizing routing systems (including the associated end nodes)
creates unique security challenges (especially relating to AAA and
key management). Scalability of wireless networks can be difficult
to measure or to achieve. Enforced hierarchy is one approach, but
can be very limiting. Alternative, less constraining approaches to
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wireless scalability are desired. Because wireless link-layer
protocols usually have some knowledge of current link characteristics
such as link quality, sublayer congestion conditions, or transient
channel behavior, it is desirable to find ways to let network-layer
routing use such data. This raises architectural questions of what
the proper layering should be, which functions should be in which
layer, and also practical considerations of how and when such
information sharing should occur in real implementations.
3.4. Security
The Internet has a reputation for not having sufficient security. In
fact, the Internet has a number of security mechanisms standardized,
some of which are widely deployed. However, there are a number of
open research questions relating to Internet security. In
particular, security mechanisms need to be incrementally deployable
and easy to use. "[Security] technology must be easy to use, or it
will not be configured correctly. If mis-configured, security will
be lost, but things will `work'" [S03].
3.4.1. Freely Distributable Prototypes
U.S.'s DARPA has historically funded development of freely
distributable implementations of various security technologies, such
as IP security, in a variety of operating systems. Experience has
shown that a good way to speed deployment of a new technology is to
provide an unencumbered, freely-distributable prototype. We believe
that applied research projects in Internet security will have an
increased probability of success if the research project teams make
their resulting software implementations freely available for both
commercial and non-commercial uses. Examples of successes here
include the DARPA funding of TCP/IPv4 integration into the 4.x BSD
operating system [MBKQ96] and DARPA/USN funding of ESP/AH design and
integration into 4.4 BSD [Atk96].
3.4.2. Formal Methods
There is an ongoing need for funding of basic research relating to
Internet security, including funding of formal methods research that
relates to security algorithms, protocols, and systems. For example,
while there has been significant work into hierarchical security
models (e.g. Bell-Lapadula) [BL1976], there has not been adequate
formal study of alternative security models (e.g. PGP's Web-of-Trust
model). Use of a hierarchical trust model creates significant
limitations in how one might approach securing components of the
Internet, for example the DNS, or the inter-domain routing system.
So research to develop new trust models or on the applicability of
existing non-hierarchical trust models to existing problems would be
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worthwhile.
While there has been some work on the application of formal methods
to cryptographic algorithms and cryptographic protocols, existing
techniques for formal evaluation of algorithms and protocols lack
sufficient automation. This lack of automation means that many
protocols aren't formally evaluated in a timely manner. This is
problematic for the Internet because formal evaluation has often
uncovered serious anomalies in cryptographic protocols. The creation
of automated tools for applying formal methods to cryptographic
algorithms and/or protocols would be very helpful.
3.4.3. Key Management
A recurring challenge to the Internet community is how to design,
implement, and deploy key management appropriate to the myriad
security contexts existing in the global Internet. Most current work
in unicast key management has focused on hierarchical trust models,
because much of the existing work has been driven by corporate or
military "top-down" operating models.
The absence of key management methods applicable to non-hierarchical
trust models (see above) is a significant constraint on the
approaches that might be taken to secure components of the Internet.
Research focused on removing those constraints by developing
practical key management methods applicable to non-hierarchical trust
models would be very helpful.
Topics worthy of additional research include key management
techniques, such as non-hierarchical key management architectures
(e.g. to support non-hierarchical trust models; see above), that are
useful by ad-hoc groups in mobile networks and/or distributed
computing.
Although some progress has been made in recent years, scalable
multicast key management is far from being a solved problem.
Existing approaches to scalable multicast key management add
significant constraints on the problem scope in order to come up with
a deployable technical solution. Having a more general approach to
scalable multicast key management (i.e. one having broader
applicability and fewer constraints) would enhance the Internet's
capabilities.
In many cases, attribute negotiation is an important capability of a
key management protocol. Experience with the Internet Key Exchange
(IKE) to date has been that it is unduly complex. Much of IKE's
complexity derives from its very general attribute negotiation
capabilities. A new key management approach that supported
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significant attribute negotiation without creating challenging levels
of deployment and operations complexity would be helpful.
3.4.4 Cryptography
There is an ongoing need to continue the open-world research funding
into both cryptography and cryptanalysis. Most governments focus
their cryptographic research in the military-sector. While this is
understandable, those efforts often have limited (or no) publications
in the open literature. Since the Internet engineering community
must work from the open literature, it is important that open-world
research continues in the future.
3.4.5 Security for Distributed Computing
MIT's Project Athena was an important and broadly successful research
project into distributed computing. Project Athena developed the
Kerberos [RFC-1510] security system, which has significant deployment
today in campus environments. However, inter-realm Kerberos is
neither as widely deployed nor perceived as widely successful as
single-realm Kerberos. The need for scalable inter-domain user
authentication is increasingly acute as ad-hoc computing and mobile
computing become more widely deployed. Thus, work on scalable
mechanisms for mobile, ad-hoc, and non-hierarchical inter-domain
authentication would be very helpful.
3.4.6. Deployment Considerations in Security
Lots of work has been done on theoretically perfect security that is
impossible to deploy. Unfortunately, Kent's S-BGP proposal is an
example of a good research product that has significant unresolved
deployment challenges. It is far from obvious how one could widely
deploy S-BGP without previously deploying a large-scale inter-domain
public-key infrastructure and also centralising route advertisement
policy enforcement in the Routing Information Registries or some
similiar body. Historically, public-key infrastructures have been
either very difficult or impossible to deploy at large scale. Some
have recently suggested that the PGP web-of-trust authentication
model should be applied to inter-domain advertisement of routing
prefixes [Schiller03]. Security mechanisms that need additional
infrastructure have not been deployed well. We desperately need
security that is general, easy to install, and easy to manage.
3.4.7. Denial of Service Protection
Historically, the Internet community has mostly ignored pure Denial
of Service (DoS) attacks. This was appropriate at one time since
such attacks were rare and are hard to defend against. However, one
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of the recent trends in malware (viruses, worms, etc.) has been the
incorporation of features that turn the infected host into a
"zombie". Such zombies can be remotely controlled to mount a
distributed denial of service attack on some victim machine. This
makes the design of anti-DoS measures of high importance to the
Internet. Some work has been done on this front [Sav00], [MBFIPS01],
but more is needed.
3.5. Network Management
The Internet had early success in network device monitoring with the
Simple Network Management Protocol (SNMP) and its associated
Management Information Base (MIB). There has been comparatively less
success in managing networks, in contrast to the hierarchical
monitoring of individual devices.
Unfortunately, network management research has historically been very
underfunded, because it is difficult to get funding bodies to
recognize this as legitimate networking research.
3.5.1. Configuration Management
Operators at the IAB Network Management Workshop [RFC-3535] held in
2002 reported that scalable distributed configuration management for
sets of network devices is a significant challenge today. An
enhanced network management architecture that more fully supports
real operational needs is desirable. Even individual improvements in
configuration management for sets of networked devices would be very
welcome. Such improvements would need to include an integrated
approach to security for the configuration data.
3.5.1. Enhanced Monitoring Capabilities
SNMP does not scale very well to monitoring large numbers of objects
in many devices in different parts of the network. An alternative
approach worth exploring is how to provide scalable and distributed
monitoring, not on individual devices, but instead on groups of
devices and networks-as-a-whole.
3.5.2. Managing Networks, Not Devices
In particular, at present there are few or no good tools for managing
a whole network of devices, though SNMP (Simple Network Management
Protocol) and CMIP (Common Management Information Protocol) are fine
for reading status of well-defined objects from individual boxes.
Applied research into methods of managing sets of networked devices
seems worthwhile. Ideally this configuration management approach
would support distributed management, rather than being strictly
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hierarchical.
As an example, the current set of network management tools for
managing multimedia (voice and video) IP networks is inadequate, and
research would be useful in this area. The lack of appropriate
network management tools has also been cited as one of the major
barriers to the deployment of IP multicast [D00, SP03].
3.5.3. Improving the Scalability of Network Management
An open issue related to network management is helping users and
others to identify and resolve problems in the network. If a user
can't access a web page, it would be useful if the user could find
out, easily, without having to run ping and traceroute, whether the
problem was that the web server was down, that the network was
partitioned due to a link failure, that there was heavy congestion
along the path, that the DNS name couldn't be resolved, that the
firewall prohibited the access, or something else. Current
approaches to network management do not scale sufficiently, so
network service providers and enterprises often have difficulty
operating their network(s) as successfully and economically as
desired. Hence, more work is needed to improve the scalability of
network management systems. This might involve application of
artificial intelligence, expert systems technology, or other
mechanisms, for example.
3.6. Quality of Service
There has been an intensive body of research and development work on
adding QoS to the Internet architecture for more than ten years now
[RFC-1633, RFC-2474, RFC-3260, RFC-2205, RFC-2210], yet we still
don't have end-to-end QoS in the Internet [RFC-2990]. The IETF is
good at defining individual QoS mechanisms, but poor at work on
deployable QoS architectures. Thus, while Differentiated Services
(DiffServ) mechanisms have been standardized as per-hop behaviors,
there is still much to be learned about the deployment of that or
other QoS mechanisms for end-to-end QoS. In addition to work on
purely technical issues, this includes close attention to the
economic models and deployment strategies that would enable an
increased deployment of QoS in the network.
In many cases, deployment of QoS mechanisms would significantly
increase operational security risks [RFC-2990], so any new research
on QoS mechanisms or architectures ought to specifically discuss the
potential security issues associated with the new proposal(s) and how
to mitigate those security issues.
One of the factors that has blunted the demand for QoS has been the
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transition of the Internet infrastructure from heavy congestion in
the early 1990s, to overprovisioning in backbones and in many
international links now. Thus, research in QoS mechanisms also has
to include some careful attention to the relative costs and benefits
of QoS in different places in the network. Applied research into QoS
should include explicit consideration of economic issues of deploying
and operating a QoS-enabled IP network [Clark02].
3.6.1. Inter-Domain QoS Architecture
Deploying existing Quality-of-Service (QoS) mechanisms, for example
Differentiated Services or Integrated Services, across an inter-
domain boundary creates a significant and easily exploited denial-of-
service vulnerability for any network that provides inter-domain QoS
support. This has caused network operators to refrain from
supporting inter-domain QoS. The Internet would benefit from
additional research into alternative approaches to QoS, approaches
that do not create such vulnerabilities and can be deployed end-to-
end [RFC-2990].
Also, current business models are not consistent with inter-domain
QoS, in large part because it is impractical or impossible to
authenticate the identity of the sender of would-be preferred traffic
while still forwarding traffic at line-rate. Absent such an ability,
it is unclear how a network operator could bill or otherwise recover
costs associated with providing that preferred service. So any new
work on inter-domain QoS mechanisms and architectures needs to
carefully consider the economic and security implications of such
proposals.
3.6.2. New Queuing Disciplines
The overall Quality-of-Service for traffic is in part determined by
the scheduling and queue management mechanisms at the routers. While
there are a number of existing mechanisms (e.g. RED) that work
reasonably well, it is possible that improved queuing strategies
might be devised. Mechanisms that lowered the implementation cost in
IP routers might help increase deployment of active queue management,
for example.
3.7. Congestion control.
TCP's congestion control mechanisms, from 1988 [J88], have been a key
factor in maintaining the stability of the Internet, and are used by
the bulk of the Internet's traffic. However, the congestion control
mechanisms of the Internet need to be expanded and modified to meet a
wide range of new stresses, from new applications such as streaming
media and multicast to new environments such as wireless networks or
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very high bandwidth paths, and new requirements for minimizing
queueing delay. While there are significant bodies of work in
several of these issues, considerably more needs to be done. (We
would note that research on TCP congestion control is also not yet
"done", with much still to be accomplished in high-speed TCP, or in
adding robust performance over paths with significant reordering,
intermittent connectivity, non-congestive packet loss, and the like.)
Several of these issues bring up difficult fundamental questions
about the potential costs and benefits of increased communication
between layers. Would it help transport to receive hints or other
information from routing, from link layers, or from other transport-
level connections? If so, what would be the cost to robust operation
across diverse environments?
For congestion control mechanisms in routers, active queue management
and Explicit Congestion Notification are generally not yet deployed,
and there are a range of proposals, in various states of maturity, in
this area. At the same time, there is a great deal that we still do
not understand about the interactions of queue management mechanisms
with other factors in the network. Router-based congestion control
mechanisms are also needed for detecting and responding to aggregate
congestion such as in Distributed Denial of Service attacks and flash
crowds.
As more applications have the need to transfer very large files over
high delay-bandwidth-product paths, the stresses on current
congestion control mechanisms raise the question of whether we need
more fine-grained feedback from routers. This includes the challenge
of allowing connections to avoid the delays of slow-start, and to
rapidly make use of newly-available bandwidth.
There is also a need for long-term research in congestion control
that is separate from specific functional requirements like the ones
listed above. We know very little about congestion control dynamics
or traffic dynamics a large, complex network like the global
Internet, with its heterogeneous and changing traffic mixes, link-
level technologies, network protocols and router mechanisms, patterns
of congestion, pricing models, and the like. Expanding our knowledge
in this area seems likely to require a rich mix of measurement,
analysis, simulations, and experimentation.
3.8. Studying the Evolution of the Internet Infrastructure
The evolution of the Internet infrastructure has been frustratingly
slow and difficult, with long stories about the difficulties in
adding IPv6, QoS, multicast, and other functionality to the Internet.
We need a more scientific understanding of the evolutionary
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potentials and evolutionary difficulties of the Internet
infrastructure.
This evolutionary potential is affected not only by the technical
issues of the layered IP architecture, but by other factors as well.
These factors include the changes in the environment over time (e.g.,
the recent overprovisioning of backbones, the deployment of
firewalls), and the role of standardization process. Economic and
public policy factors are also critical, including the central fact
of the Internet as a decentralized system, with key players being not
only individuals, but also ISPs, companies, and entire industries.
Deployment issues are also key factors in the evolution of the
Internet, including the continual chicken-and-egg problem of having
enough customers to merit rolling out a service whose utility depends
on the size of the customer base in the first place.
Overlay networks might serve as a transition technology for new
functionality, with an initial deployment in overlay networks, and
with the new functionality moving later into the core if it seems
warranted.
There are also increased obstacles to the evolution of the Internet
in the form of increased complexity [WD02], unanticipated feature
interactions [K00], interactions between layers [CWWS92],
interventions by middleboxes [RFC-3424], and the like. Because
increasing complexity appears inevitable, research is needed to
understand architectural mechanisms that can accommodate increased
complexity without decreasing robustness of performance in unknown
environments, and without closing off future possibilities for
evolution.
3.9. Middleboxes
Research is needed to address the challenges posed by middleboxes.
This includes issues of security, control, and data integrity, and on
the general impact of middleboxes on the architecture.
In many ways middleboxes are a direct outgrowth of commercial
interests, but there is a need to look beyond the near-term needs for
the technology, to research its broader implications and to explore
ways to improve how middleboxes are integrated into the architecture.
3.10. Internet Measurement
A recurring challenge is measuring the Internet; there have been many
discussions about the need for measurement studies as an integral
part of Internet research [Claffy03]. In this discussion, we define
measurement quite broadly. For example, there are numerous
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challenges in measuring performance along any substantial Internet
path, particularly when the path crosses administrative domain
boundaries. There are also challenges in measuring
protocol/application usage on any high speed Internet link. Many of
the problems discussed above would benefit from increased frequency
of measurement as well as improved quality of measurement on the
deployed Internet.
A key issue in network measurement is that most commercial Internet
Service Providers consider the particular characteristics of their
production IP network(s) to be trade secrets. Ways need to be found
for legitimate non-commercial researchers to be able to measure
relevant network parameters while also protecting the privacy rights
of the measured ISPs.
Absent measured data, there is possibly an over-reliance on network
simulations in some parts of the Internet research community and
probably insufficient validation that existing network simulation
models are reasonably good representations of the deployed Internet
(or of some plausible future Internet) [FK02].
Without solid measurement of the current Internet behaviour, it is
very difficult to know what otherwise unknown operational problems
exist that require attention, and it is equally difficult to fully
understand the impact of changes (past or future) upon the Internet's
actual behavioural characteristics.
3.11. Meeting the Needs of the Future
As network size, link bandwidth, CPU capacity, and the number of
users all increase, research will be needed to ensure that the
Internet of the future scales to meet these increasing demands. We
have discussed some of these scaling issues in specific sections
above.
However, for all of the research questions discussed in this
document, the goal of the research must be not only to meet the
challenges already experienced today, but also to meet the challenges
that can be expected to emerge in the future.
3.12. Additional topics
We have not included in this document discussions about the need for
additional research in providing tools for researchers (e.g.,
modeling, simulations, test-beds).
Any new sections in this document should be focused on the problems
that need to be addressed, rather than focused on the new approaches
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or technologies that might be promising answers to those problems.
4. Conclusions
This document has summarized the history of research funding for the
Internet and highlighted examples of open research questions. The
IAB believes that more research is required to further the evolution
of the Internet infrastructure, and that consistent, sufficient non-
commercial funding is needed to enable such research.
In case there is any confusion, we are not in this document
suggesting any direct or indirect role for the IAB, the IETF, or the
IRTF in handling any funding for Internet research.
5. Acknowledgements
The people who directly contributed to this document in some form
include the following: Ran Atkinson, Rob Austein, Jon Crowcroft,
Sally Floyd, James Kempf, Craig Partridge, Vern Paxson, and Mike St.
Johns. We are also grateful to Kim Claffy, Andrei Gurtov, Hilarie
Orman for feedback.
We have also drawn widely on the following sources: [CIPB02],
[IST02], [NV02], [NSF02], [NSF03], [NSF03a].
Upcoming workshops include the following: [COST-NSF03].
6. Security Considerations
This document does not itself create any new security issues for the
Internet community. Security issues within the Internet Architecture
primarily are discussed in Section 3.4 above.
7. IANA Considerations
There are no IANA considerations regarding this document.
Normative References
There are no Normative References because this is an Informational
document.
Informative References
[Atk96] R. Atkinson et alia, "Implementation of IPv6 in 4.4 BSD",
Proceedings of USENIX 1996 Annual Technical Conference, USENIX
Association, Berkeley, CA, January 1996.
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[Bellman1957] R.E. Bellman, "Dynamic Programming", Princeton
University Press, Princeton, NJ, 1957.
[BL1976] D. E. Bell & L. J. LaPadula, "Secure Computer Systems:
Unified Exposition and Multics Interpretation", MITRE Technical
Report NMTR-1997 (ESD-TR-75-306), The Mitre Corporation, March 1976.
[Claffy03] K. Claffy, "Priorities and Challenges in Internet
Measurement, Simulation, and Analysis", NSF PI meeting, January 2003.
URL "http://www.caida.org/outreach/presentations/2003/nsfpi0301/".
[Clark02] D. D. Clark, "Deploying the Internet - why does it take so
long and, can research help ?", Large-Scale Networking Distinguished
Lecture Series, (US) National Science Foundation, Arlington, VA, 8
January 2002. URL: http://www.ngi-supernet.org/conferences.html
[CSTB99] Computer Science & Telecommunications Board, (US) National
Research Council, "Funding a Revolution: Government Support for
Computing Research", National Academy Press, Washington, DC, 1999.
URL "http://www7.nationalacademies.org/cstb/pub_revolution.html".
[CIPB02] Critical Infrastructure Protection Board, "National Strategy
to Secure Cyberspace", The White House, Washington, DC, September
2002, URL "http://www.whitehouse.gov/pcipb".
[COST-NSF03] COST-IST(EU)--NSF(USA) Workshop on Networking, June,
2003. URL "http://cgi.di.uoa.gr/~istavrak/costnsf/".
[CWWS92] J. Crowcroft, I Wakeman, Z. Wang, & D. Sirovica, "Is
Layering Harmful ?", IEEE Networks, January 1992.
[Diot00] C. Diot, et alia, "Deployment Issues for the IP Multicast
Service and Architecture", IEEE Network, January/February 2000.
[Deering1988] S. Deering, "Multicast Routing in Internetworks and
LANs", ACM Computer Communications Review, Volume 18, Issue 4, August
1988.
[Dijkstra59] E. Dijkstra, "A note on two problems in connexion with
graphs", Numerishe Mathematik, 1, 1959, pp.269-271.
[FF1962] L.R. Ford Jr. & D.R. Fulkerson, "Flows in Networks",
Princeton University Press, Princeton, NJ, 1962.
[FK02] S. Floyd and E. Kohler, Internet Research Needs Better Models,
Hotnets-I. October 2002. URL
"http://www.icir.org/models/bettermodels.html".
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[Handley02] Mark Handley's viewgraphs to an NSF meeting, 2002.
[IM1993] J. Ioannidis & G. Maguire Jr., "The Design and
Implementation of a Mobile Internetworking Architecture", Proceedings
of the Winter USENIX Technical Conference, pages 489-500, January
1993.
[IST02] Research Networking in Europe - Striving for Global
Leadership, Information Society Technologies, 2002. URL
"http://www.cordis.lu/ist/rn/rn-brochure.htm".
[J88] Van Jacobson, Congestion Avoidance and Control, SIGCOMM, 1988.
URL "http://citeseer.nj.nec.com/jacobson88congestion.html".
[J02] William Jackson, "U.S. should fund R&D for secure Internet
protocols, Clarke says", 10/31/02, URL
"http://www.gcn.com/vol1_no1/security/20382-1.html".
[K00] Hans Kruse, The Pitfalls of Distributed Protocol Development:
Unintentional Interactions between Network Operations and
Applications Protocols, 8th International Conference on
Telecommunication Systems Design, Nashville, March 2000. URL
"http://www.csm.ohiou.edu/kruse/publications/TSYS2000.pdf".
[KLMS2000] S. Kent, C. Lynn, J. Mikkelson, & K. Seo, "Secure Border
Gateway Protocol (S-BGP)", Proceedings of ISoc Network & Distributed
Systems Security Symposium, Internet Society, Reston, VA, February
2000.
[LD2002] E. Lear & R. Droms, "What's in a Name: Thoughts from the
NSRG", Internet-Draft, December 2002.
[MBFIPS01] Ratul Mahajan, Steven M. Bellovin, Sally Floyd, John
Ioannidis, Vern Paxson, and Scott Shenker, Controlling High Bandwidth
Aggregates in the Network (Extended Version), July, 2001. URL
"http://www.icir.org/pushback/".
[MBKQ96] M. McKusick, K. Bostic, M. Karels, & J. Quarterman, "Design
and Implementation of the 4.4 BSD Operating System", Addison-Wesley,
Reading, MA, 1996.
[S03] J. I. Schiller, "Interception Technology: The Good, The Bad,
and The Ugly!", NANOG, June 2003. URL
"http://www.nanog.org/mtg-0306/schiller.html".
[Schiller03] J. I. Schiller, Private Communication, MIT, Cambridge,
MA. 2003.
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[NV02] NetVision 2012 Committee,"DARPA's Ten-Year Strategic Plan for
Networking Research", (US) Defence Advanced Research Projects Agency,
October 2002. Citation for acknowledgement purposes only.
[NSF02] NSF Workshop on Network Research Testbeds, October 2002. URL
"http://www-net.cs.umass.edu/testbed_workshop/".
[NSF03] NSF ANIR Principal Investigator meeting, January 9-10, 2003,
URL "http://www.ncne.org/training/nsf-pi/2003/nsfpimain.html".
[NSF03a] Revolutionizing Science and Engineering Through
Cyberinfrastructure, NSF Report, January 2003. URL
"http://www.cise.nsf.gov/evnt/reports/atkins_annc_020303.htm".
[ResearchQuestions] Web Page on "Papers about Research Questions for
the Internet", URL
"http://www.icir.org/floyd/research_questions.html".
[RFC-1510] J. Kohl & C. Neuman, "The Kerberos Network Authentication
Service (V5)", RFC 1510, September 1993.
[RFC-2082] F. Baker & R. Atkinson, "RIPv2 MD5 Authentication",
RFC-2082, January 1997.
[RFC-2154] S. Murphy, M. Badger, & B. Wellington, "OSPF with Digital
Signatures", RFC-2154, June 1997.
[RFC-2385] A. Heffernan, "Protection of BGP Sessions via the TCP MD5
Signature Option", RFC-2385, August 1998.
[RFC-2407] D. Piper, "The Internet IP Security Domain of
Interpretation for ISAKMP", RFC-2407, November 1998.
[RFC-2501] S. Corson & J. Macker, "Mobile Ad Hoc Networking (MANET):
Routing Protocol Performance Issues and Evaluation Considerations",
RFC-2501, January 1999.
[RFC-2990] G. Huston, "Next Steps for the IP QoS Architecture",
RFC-1990, November 2000.
[RFC-3221] G. Huston, "Commentary on Inter-Domain Routing in the
Internet", RFC-3221, December 2001.
[RFC-3424] L. Daigle (Ed.), "IAB Considerations for Unilateral Self-
Address Fixing (UNSAF) Across Network Address Translation", RFC-3424,
Internet Architecture Board, November 2002.
[RFC-3535] J. Schoenwalder, Editor, "Overfiew of the 2002 IAB Network
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Management Workshop", RFC-3535, May 2003.
[RIPE] RIPE (Reseaux IP Europeens), URL "http://www.ripe.net/ripe/".
[Sav00] Savage, S., Wetherall, D., Karlink, A. R., and Anderson, T.,
Practical Network Support for IP Traceback, SIGCOMM 2000.
[SP03] P. Sharma & R. Malpani, "IP Multicast Operational Network
Management: Design, Challenges, and Experiences", IEEE Network, March
2003.
[WD02] Walter Willinger and John Doyle, "Robustness and the Internet:
Design and Evolution", 2002, URL
"http://netlab.caltech.edu/internet/".
[WIDE] WIDE Project, URL "http://www.wide.ad.jp/".
9. AUTHORS' ADDRESSES
Internet Architecture Board
EMail: iab@iab.org
Internet Architecture Board Members
at the time this document was published were:
Bernard Aboba
Harald Alvestrand (IETF chair)
Rob Austein
Leslie Daigle (IAB chair)
Patrik Faltstrom
Sally Floyd
Jun-ichiro Itojun Hagino
Mark Handley
Geoff Huston (IAB Executive Director)
Charlie Kaufman
James Kempf
Eric Rescorla
Mike St. Johns
We note that Ran Atkinson, one of the editors of the document,
was an IAB member at the time that this document was created,
and that Vern Paxson, the IRTF chair, is an ex-officio member
of the IAB.
This draft was created in November 2002 and revised January 2003,
February 2003, and June 2003.
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