kc claffy

Border gateway protocol (BGP) and traceroute data workshop report

By: 
kc claffy
Appears in: 
CCR July 2012

On Monday, 22 August 2011, CAIDA hosted a one-day workshop to discuss scalable measurement and analysis of BGP and traceroute topology data, and practical applications of such data analysis including tracking of macroscopic censorship and filtering activities on the Internet.

Workshop on internet economics (WIE2011) report

By: 
kc claffy
Appears in: 
CCR April 2012

The second Workshop on Internet Economics [2], hosted by CAIDA and Georgia Institute of Technology on December 1-2, 2011, brought together network technology and policy researchers with providers of commercial Internet facilities and services (network operators) to further explore the common objective of framing an agenda for the emerging but empirically stunted field of Internet infrastructure economics. This report describes the workshop discussions and presents relevant open research questions identified by its participants.

"Network Neutrality": the meme, its cost, its future

By: 
kc claffy
Appears in: 
CCR October 2011

In June 2011 I participated on a panel on network neutrality hosted at the June cybersecurity meeting of the DHS/SRI Infosec Technology Transition Council (ITTC), where "experts and leaders from the government, private, financial, IT, venture capitalist,and academia and science sectors came together to address the problem of identity theft and related criminal activity on the Internet." I recently wrote up some of my thoughts on that panel, including what network neutrality has to do with cybersecurity.

The 3rd Workshop on Active Internet Measurements (AIMS-3) Report

By: 
kc claffy
Appears in: 
CCR July 2011

On February 10-12, 2011, CAIDA hosted the third Work- shop on Active Internet Measurements (AIMS-3) as part of our series of Internet Statistics and Metrics Analysis (ISMA) workshops. As with the previous two AIMS workshops, the goals were to further our understanding of the potential and limitations of active measurement research and infrastructure in the wide-area Internet, and to promote cooperative solutions and coordinated strategies to address future data needs of the network and security research communities.

Tracking IPv6 Evolution: Data We Have and Data We Need

By: 
kc claffy
Appears in: 
CCR July 2011

Exhaustion of the Internet addressing authority’s (IANA) available IPv4 address space, which occurred in February 2011, is finally exerting exogenous pressure on network operators to begin to deploy IPv6. There are two possible outcomes from this transition. IPv6 may be widely adopted and embraced, causing many existing methods to measure and monitor the Internet to be ineffective. A second possibility is that IPv6 languishes, transition mechanisms fail, or performance suffers. Either scenario requires data, measurement, and analysis to inform technical, business, and policy decisions.

Measured Impact of Crooked Traceroute

By: 
Matthew Luckie, Amogh Dhamdhere, kc claffy, and David Murrell
Appears in: 
CCR January 2011

Data collected using traceroute-based algorithms underpins research into the Internet’s router-level topology, though it is possible to infer false links from this data. One source of false inference is the combination of per-flow load-balancing, in which more than one path is active from a given source to destination, and classic traceroute, which varies the UDP destination port number or ICMP checksum of successive probe packets, which can cause per-flow load-balancers to treat successive packets as distinct flows and forward them along different paths.

Public Review By: 
R. Teixeira

The research community has applied traceroute-style probing to measure Internet topologies for more than a decade with systems such as Skitter/Ark, Dimes, or Rocketfuel. These topologies are the basis of many other research efforts. Unfortunately, recent studies showed that classic traceroute can report false links when a router in the path performs load balancing. Although new probing techniques correct measurement artifacts under per-flow load balancing, we cannot correct topologies that have already been collected using classic traceroute and no prior work has studied how these errors affect inferred topologies. A natural question is then: how accurate are the topologies that we have all been using in our research?
This paper gives us a mixed answer. Measurement artifacts due to per-flow load balancing introduce only few errors when traceroute is used to discover a macroscopic topology (i.e., an Internet-wide topology), but they introduce significant errors when discovering the topology of an ISP. Such a sharp difference in the fraction of false links between the macroscopic topology and the ISP topology suggests that the error really depends on the set of vantage points and the networks traversed. This paper studies only one source of errors in inferred Internet topologies. As the authors point out: "the state of the art in Internet topology measurement is essentially and necessarily a set of hacks, which introduce many sources of possible errors". Hopefully, new studies will follow to understand the caveats of measured Internet topologies and to measure more accurate topologies. In the mean time, this paper confirms that we should be cautions when using inferred Internet topologies.

The 2nd Workshop on Active Internet Measurements (AIMS-2) Report

By: 
kc claffy, Emile Aben, Jordan Auge, Robert Beverly, Fabian Bustamante, Benoit Donnet, Timur Friedman, Marina Fomenkov, Peter Haga, Matthew Luckie, and Yuval Shavitt
Appears in: 
CCR October 2010

On February 8-10, 2010, CAIDA hosted the second Workshop on Active Internet Measurements (AIMS-2) as part of our series of Internet Statistics and Metrics Analysis (ISMA) workshops. The goals of this workshop were to further our understanding of the potential and limitations of active measurement research and infrastructure in the wide-area Internet, and to promote cooperative solutions and coordinated strategies to addressing future data needs of the network and security research communities.

The Workshop on Internet Topology (WIT) Report

By: 
Dmitri Krioukov, kc claffy, Marina Fomenkov, Fan Chung, Alessandro Vespignani, and Walter Willinger
Appears in: 
CCR January 2007

Internet topology analysis has recently experienced a surge of interest in computer science, physics, and the mathematical sciences. However, researchers from these different disciplines tend to approach the same problem from different angles. As a result, the field of Internet topology analysis and modeling must untangle sets of inconsistent findings, conflicting claims, and contradicting statements.

AS Relationships: Inference and Validation

By: 
Xenofontas Dimitropoulos, Dmitri Krioukov, Marina Fomenkov, Bradley Huffaker, Young Hyun, kc claffy, and George Riley
Appears in: 
CCR January 2007

Research on performance, robustness, and evolution of the global Internet is fundamentally handicapped without accurate and thorough knowledge of the nature and structure of the contractual relationships between Autonomous Systems (ASs). In this work we introduce novel heuristics for inferring AS relationships. Our heuristics improve upon previous works in several technical aspects, which we outline in detail and demonstrate with several examples. Seeking to increase the value and reliability of our inference results, we then focus on validation of inferred AS relationships.

Public Review By: 
Ernst Biersack

Inferring AS relationships using publicly available data is a difficult task for which various heuristics have been proposed. This paper revisits the problem, points out shortcomings of existing heuristics, and proposes improvements. The reviewers liked the paper for several reasons:

  • The paper does a nice job in reviewing the state of the art and improves on the existing heuristics.
  • The authors try to asses the quality of their inferences by contacting a small group ASs whom they asked for an explicit validation of the results. However, the sample size may be too small to allow any definite conclusions.
  • The heuristics proposed are implemented and the results of the AS inference made publicly available on a weekly basis. This should provide a basis on which further research can build on
    and compare its results against.

In summary, this paper combines existing and new heuristics for AS inference into a tool, the results of which are made available to the community.

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