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We used 20 geographically distributed hosts as the sources for our
traceroutes. 17 of these hosts were located in the U.S. (Figure
1) while 3 were located in Europe (at Stockholm
(Sweden), Bologna (Italy), and Budapest (Hungary)). The geographical
diversity in source locations enables us to study the variations in
routing properties as seen from different vantage points. For
logistical reasons, it was convenient for us to locate the traceroute
sources on university campuses. 18 out of the 20 traceroute sources
fell into this category. Furthermore, 9 of the 15 university locations
we considered in the U.S. were connected by the Internet2
backbone [19]. To add some diversity, we had one source in
Berkeley, CA connected to a home cable modem network (in addition to a
host at the University of California at Berkeley) and another in
Seattle, WA connected to the Microsoft Research network (in addition
to a host at the University of Washington at Seattle). These two pairs
of sources allow us to study (albeit to a limited extent2) what impact, if any, the nature of the
source's connectivity has.
The destination set for the traceroutes comprised several thousand hosts. These destinations hosts fell into 4 categories:
- UnivHosts: 265 Web servers and other hosts located on
university campuses in the U.S. The hosts were distributed across 44
of the 50 states in the U.S.
- LibWeb: 1,205 Web servers of public libraries [21]
distributed across 49 states in the U.S. We also ensured that the
distribution of the geographic locations of these libraries is not
skewed.
- TVHosts: 3,100 client hosts in the U.S. that connected to an
on-line TV program guide. A majority of these clients were located on
non-academic networks such as America Online (AOL).
- EuroWeb: 1,092 Web servers [23] distributed
across 25 countries in Europe.
For ease of exposition, we sometimes refer to UnivHosts, LibWeb, and
TVHosts as the U.S. hosts and EuroWeb as the European hosts.
This diverse set of destination hosts enables us to investigate the
properties of Internet routing in the context of a large set of
ISPs. In all, we traced approximately 84,000 end-to-end paths between
our traceroute sources and the destination hosts during
October-December 2000. Our data is available online at [27].
Next: Dataset from 1995
Up: Experimental methodology
Previous: Overview
Lakshminarayanan Subramanian
2002-04-14