that is separate from specific functional requirements like the ones
listed above. We know very little about congestion control dynamics
or traffic dynamics of 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
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 the 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 some 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 [Kruse00], 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. More concretely, research is needed on how to evolve the
Internet will still maintaining its core strengths, such as the
current degree of global addressability of hosts, end-to-end
transparency of packet forwarding, and good performance for best-
effort traffic.
3.9. Middleboxes
Research is needed to address the challenges posed by the wide range
of middleboxes [RFC-3234]. This includes issues of security,
control, 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
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 cooperative measurement studies, e.g., to allow 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 behavior, 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 behavioral characteristics.
3.11. Applications
Research is needed on a wide range of issues related to Internet
applications.
Taking email as one example application, research is needed on
understanding the spam problem, and on investigating tools and
techniques to mitigate the effects of spam, including tools and
techniques that aid the implementation of legal and other non-
technical anti-spam measures [ASRG]. "Spam" is a generic term for a
range of significantly different types of unwanted bulk email, with
many types of senders, content and traffic-generating techniques. As
one part of controlling spam, we need to develop a much better
understanding of its many, different characteristics and their
interactions with each other.
3.12. 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.
3.13. Freely Distributable Prototypes
U.S.’s DARPA has historically funded development of freely
distributable implementations of various Internet technologies (e.g.,
TCP/IPv4, RSVP, IPv6, and IP security) in a variety of operating
systems (e.g., 4.2 BSD, 4.3 BSD, 4.4 BSD, Tenex). Experience has
shown that a good way to speed deployment of a new technology is to
provide an unencumbered, freely-distributable prototype that can be
incorporated into commercial products as well as non-commercial
prototypes. Japan’s WIDE Project has also funded some such work,
primarily focused on IPv6 implementation for 4.4 BSD and Linux.
[WIDE] We believe that applied research projects in networking 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], DARPA/USN funding of ESP/AH design and
integration into 4.4 BSD [Atk96], as well as separate DARPA/USN and
WIDE funding of freely distributable IPv6 prototypes [Atk96, WIDE].
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, in this document we are not
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, Guy Almes, Rob Austein, Vint
Cerf, Jon Crowcroft, Sally Floyd, James Kempf, Joe Macker, Craig
Partridge, Vern Paxson, Juergen Schoenwaelder, and Mike St. Johns.
We are also grateful to Kim Claffy, Dave Crocker, Michael Eder, Eric
Fleischman, Andrei Gurtov, Stephen Kent, J.P. Martin-Flatin, and
Hilarie Orman for feedback on earlier drafts of this document.
We have also drawn from the following reports:
[CIPB02,IST02,NV02,NSF02,NSF03,NSF03a].
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. Informative References
[ASRG] Anti-Spam Research Group (ASRG) of the IRTF. URL
"http://asrg.sp.am/".
[Atk96] R. Atkinson et al., "Implementation of IPv6 in 4.4
BSD", Proceedings of USENIX 1996 Annual Technical
Conference, USENIX Association, Berkeley, CA, USA.
January 1996. URL
http://www.chacs.itd.nrl.navy.mil/publications/CHACS/
1996/1996atkinson-USENIX.pdf
[Bellman1957] R.E. Bellman, "Dynamic Programming", Princeton
University Press, Princeton, NJ, 1957.
[Claffy03] K. Claffy, "Priorities and Challenges in Internet
Measurement, Simulation, and Analysis", Large Scale
Network meeting, (US) National Science Foundation,
Arlington, VA, USA. 10 June 2003. URL
"http://www.caida.org/outreach/
presentations/2003/lsn20030610/".
[Claffy03a] K. Claffy, "Top Problems of the Internet and What
Sysadmins and Researchers Can Do To Help", plenary talk
at LISA’03, October 2003. URL
"http://www.caida.org/outreach/presentations/
2003/netproblems_lisa03/".
[Clark02] D. D. Clark, "Deploying the Internet - why does it take
so long and, can research help?", Large-Scale
Networking Distinguished Lecture Series, (U.S.)
National Science Foundation, Arlington, VA, 8 January
2002. URL: http://www.ngi-
supernet.org/conferences.html
[CSTB99] Computer Science and Telecommunications Board, (U.S.)
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, USA. September 2002, URL
"http://www.whitehouse.gov/pcipb".
[CWWS92] J. Crowcroft, I. Wakeman, Z. Wang, and D. Sirovica, "Is
Layering Harmful?", IEEE Networks, Vol. 6, Issue 1, pp
20-24, January 1992.
[Diot00] C. Diot, et al., "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", Numerische Mathematik, 1, 1959, pp.269-271.
[FF1962] L. R. Ford Jr. and D.R. Fulkerson, "Flows in Networks",
Princeton University Press, Princeton, NJ, 1962.
[FK02] S. Floyd and E. Kohler, "Internet Research Needs Better
Models", Proceedings of 1st Workshop on Hot Topics in
Networks (Hotnets-I), Princeton, NJ, USA. October
2002. URL
"http://www.icir.org/models/bettermodels.html".
[IM1993] J. Ioannidis and G. Maguire Jr., "The Design and
Implementation of a Mobile Internetworking
Architecture", Proceedings of the Winter USENIX
Technical Conference, pages 489-500, Berkeley, CA, USA,
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".
[Jacobson88] Van Jacobson, "Congestion Avoidance and Control",
Proceedings of ACM SIGCOMM 1988 Symposium, ACM SIGCOMM,
Stanford, CA, August 1988. URL
"http://citeseer.nj.nec.com/jacobson88congestion.html".
[Jackson02] William Jackson, "U.S. should fund R&D for secure
Internet protocols, Clarke says", Government Computer
News, 31 October 2002. URL
"http://www.gcn.com/vol1_no1/security/20382-1.html".
[Kruse00] Hans Kruse, "The Pitfalls of Distributed Protocol
Development: Unintentional Interactions between Network
Operations and Applications Protocols", Proceedings of
the 8th International Conference on Telecommunication
Systems Design, Nashville, TN, USA, March 2000. URL
"http://www.csm.ohiou.edu/kruse/publications/
TSYS2000.pdf".
[KLMS2000] S. Kent, C. Lynn, J. Mikkelson, and K. Seo, "Secure
Border Gateway Protocol (S-BGP)", Proceedings of ISOC
Network and Distributed Systems Security Symposium,
Internet Society, Reston, VA, February 2000.
[LD2002] E. Lear and R. Droms, "What’s in a Name: Thoughts from
the NSRG", expired 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", ACM Computer
Communications Review, Vol. 32, No. 3, July 2002. URL
"http://www.icir.org/pushback/".
[MBKQ96] M. McKusick, K. Bostic, M. Karels, and J. Quarterman,
"Design and Implementation of the 4.4 BSD Operating
System", Addison-Wesley, Reading, MA, 1996.
[MGVK02] Z. Mao, R. Govindan, G. Varghese, & R. Katz, "Route
Flap Dampening Exacerbates Internet Routing
Convergence", Proceedings of ACM SIGCOMM 2002, ACM,
Pittsburgh, PA, USA, August 2002.
[NV02] NetVision 2012 Committee,"DARPA’s Ten-Year Strategic
Plan for Networking Research", (U.S.) Defense Advanced
Research Projects Agency, October 2002. Citation for
acknowledgement purposes only.
[NSF02] NSF Workshop on Network Research Testbeds, National
Science Foundation, Directorate for Computer and
Information Science & Engineering, Advanced Networking
Infrastructure & Research Division, Arlington, VA, USA,
October 2002. URL "http://www-
net.cs.umass.edu/testbed_workshop/".
[NSF03] NSF ANIR Principal Investigator meeting, National
Science Foundation, Arlington, VA, USA. January 9-10,
2003, URL "http://www.ncne.org/training/nsf-
pi/2003/nsfpimain.html".
[NSF03a] D. E. Atkins, et al., "Revolutionizing Science and
Engineering Through Cyberinfrastructure", Report of NSF
Advisory Panel on Cyberinfrastructure, January 2003.
URL "http://www.cise.nsf.gov/evnt/reports/
atkins_annc_020303.htm".
[NSF03b] Report of the National Science Foundation Workshop on
Fundamental Research in Networking. April 24-25, 2003.
URL "http://www.cs.virginia.edu/~jorg/workshop1/NSF-
NetWorkshop-2003.pdf".
[Floyd] S. Floyd, "Papers about Research Questions for the
Internet", web page, ICSI Center for Internet Research
(ICIR), Berkeley, CA, 2003 URL
"http://www.icir.org/floyd/research_questions.html".
[RFC-1510] Kohl, J. and C. Neuman, "The Kerberos Network
Authentication Service (V5)", RFC 1510, September 1993.
[RFC-1633] Braden, R., Clark, D., and S. Shenker, "Integrated
Services in the Internet Architecture: an Overview",
RFC 1633, June 1994.
[RFC-2082] Baker, F. and R. Atkinson, "RIP-2 MD5 Authentication",
RFC 2082, January 1997.
[RFC-2210] Wroclawski, J., "The Use of RSVP with IETF Integrated
Services", RFC 2210, September 1997.
[RFC-2154] Murphy, S., Badger, M., and B. Wellington, "OSPF with
Digital Signatures", RFC 2154, June 1997.
[RFC-2385] Heffernan, A., "Protection of BGP Sessions via the TCP
MD5 Signature Option", RFC 2385, August 1998.
[RFC-2407] Piper, D., "The Internet IP Security Domain of
Interpretation for ISAKMP", RFC 2407, November 1998.
[RFC-2501] Corson, S. and J. Macker, "Mobile Ad hoc Networking
(MANET): Routing Protocol Performance Issues and
Evaluation Considerations", RFC 2501, January 1999.
[RFC-2990] Huston, G., "Next Steps for the IP QoS Architecture",
RFC 2990, November 2000.
[RFC-3221] Huston, G., "Commentary on Inter-Domain Routing in the
Internet", RFC 3221, December 2001.
[RFC-3234] Carpenter, B. and S. Brim, "Middleboxes: Taxonomy and
Issues", RFC 3234, February 2002.
[RFC-3424] Daigle, L. and IAB, "IAB Considerations for UNilateral
Self-Address Fixing (UNSAF) Across Network Address
Translation", RFC 3424, November 2002.
[RFC-3467] Klensin, J., "Role of the Domain Name System (DNS)",
RFC 3467, February 2003.
[RFC-3535] Schoenwaelder, J., "Overview of the 2002 IAB Network
Management Workshop", RFC 3535, May 2003.
[RFC-3387] Eder, M., Chaskar, H., and S. Nag, "Considerations from
the Service Management Research Group (SMRG) on Quality
of Service (QoS) in the IP Network", RFC 3387,
September 2002.
[RIPE] RIPE (Reseaux IP Europeens), Amsterdam, NL. URL
"http://www.ripe.net/ripe/".
[Savage00] Savage, S., Wetherall, D., Karlink, A. R., and
Anderson, T., "Practical Network Support for IP
Traceback", Proceedings of 2000 ACM SIGCOMM Conference,
ACM SIGCOMM, Stockholm, SE, pp. 295-306. August 2000.
[Schiller03] J. I. Schiller, "Interception Technology: The Good, The
Bad, and The Ugly!", Presentation at 28th NANOG
Meeting, North American Network Operators Group
(NANOG), Ann Arbor, MI, USA, June 2003. URL
"http://www.nanog.org/mtg-0306/schiller.html".
[SM03] P. Sharma and R. Malpani, "IP Multicast Operational
Network Management: Design, Challenges, and
Experiences", IEEE Network, Vol. 17, No. 2, March
2003.
[SMA03] N. Spring, R. Mahajan, & T. Anderson, "Quantifying the
Causes of Path Inflation", Proceedings of ACM SIGCOMM
2003, ACM, Karlsruhe, Germany, August 2003.
[WD02] Walter Willinger and John Doyle, "Robustness and the
Internet: Design and Evolution", Unpublished/Preprint,
1 March 2002, URL
"http://netlab.caltech.edu/internet/".
[WIDE] WIDE Project, Japan. URL "http://www.wide.ad.jp/".
8. 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
Mark Handley
Bob Hinden
Geoff Huston (IAB Executive Director)
Jun-ichiro Itojun Hagino
Eric Rescorla
Pete Resnick
Jonathan Rosenberg
We note that Ran Atkinson, one of the editors of the document, was an
IAB member at the time that this document was first created, in
November 2002, and that Vern Paxson, the IRTF chair, is an ex-officio
member of the IAB.
Full Copyright Statement
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except as set forth therein, the authors retain all their rights.
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