February 2009 – ANT Research News

We just posted a tech report “Understanding Address Usage in the Visible Internet” at <ftp://ftp.isi.edu/isi-pubs/tr-656.pdf>.

The abstract summarizes the tech report:

Although the Internet is widely used today, there are few sound estimates of network demographics. Decentralized network management means questions about Internet use cannot be answered by a central authority, and ﬁrewalls and sensitivity to probing means that active measurements must be done carefully and validated against known data. Building on frequent ICMP probing of 1% of the Internet address space, we develop a clustering algorithm to estimate how Internet addresses are used. We show that adjacent addresses often have similar characteristics and are used for similar purposes (61% of addresses we probe are consistent blocks of 64 neighbors or more). We then apply this block-level clustering to provide data to explore several open questions in how networks are managed. First, the nearing full allocation of IPv4 addresses makes it increasingly important to estimate the costs of better management of the IPv4 space as a component of an IPv6 transition. We provide about how effectively network addresses blocks appear to be used, ﬁnding that a signiﬁcant number of blocks are only lightly used (about one-ﬁfth of /24 blocks ha
ve most addresses in use less than 10% of the time). Second, we provide new measurements about dynamically managed address space, showing nearly 40% of /24 blocks appear to be dynamically allocated, and dynamic addressing is most widely used in countries more recently to the Internet (more than 80% in China, while less then 30% in the U.S.).

Xue Cai and John Heidemann. Understanding Address Usage in the Visible Internet. Technical Report N. ISI-TR-2009-656, USC/Information Sciences Institute, February, 2009. http://www.isi.edu/~johnh/PAPERS/Cai09b.html

We just posted a pre-print of the paper “Uses and Challenges for Network Datasets”, to appear at IEEE CATCH in March. The pre-print is at <http://www.isi.edu/~johnh/PAPERS/Heidemann09a.html>.

The abstract summarizes the paper:

Network datasets are necessary for many types of network research. While there has been significant discussion about specific datasets, there has been less about the overall state of network data collection. The goal of this paper is to explore the research questions facing the Internet today, the datasets needed to answer those questions, and the challenges to using those datasets. We suggest several practices that have proven important in use of current data sets, and open challenges to improve use of network data.

More specifically, the paper tries to answer the question Jody Westby put to PREDICT PIs, which is “why take data, what is it good for”? While a simple question, it’s not easy to answer (at least, my attempt to dash of a quick answer in e-mail failed). The paper is an attempt at a more thoughtful answer.

The paper tries to summarize and point to a lot of ongoing work, but I know that our coverage was insufficient. We welcome feedback about what we’re missing.

John Heidemann and Christos Papadopoulos. Uses and Challenges for Network Datasets. In Proceedings of the IEEE Cybersecurity Applications and Technologies Conference for Homeland Security (CATCH), pp. 73-82. Washington, DC, USA, IEEE. March, 2009. http://www.isi.edu/~johnh/PAPERS/Heidemann09a.html