  Many organizations have the mission of assessing the quality of broadband
access services offered by Internet Service Providers (ISPs). They deploy
network probes that periodically perform network measures towards selected
Internet services. By analyzing the data collected by the probes it is often
possible to gain a reasonable estimate of the bandwidth made available by the
ISP. However, it is much more difficult to use such data to explain who is
responsible of the fluctuations of other network qualities. This is especially
true for latency, that is fundamental for several nowadays network services. On
the other hand, there are many publicly accessible BGP routers that collect the
history of routing changes and that are good candidates to be used for
understanding if latency fluctuations depend on interdomain routing.
  In this paper we provide a methodology that, given a probe that is located
inside the network of an ISP and that executes latency measures and given a set
of publicly accessible BGP routers located inside the same ISP, decides which
routers are best candidates (if any) for studying the relationship between
variations of network performance recorded by the probe and interdomain routing
changes. We validate the methodology with experimental studies based on data
gathered by the RIPE NCC, an organization that is well-known to be independent
and that publishes both BGP data within the Routing Information Service (RIS)
and probe measurement data within the Atlas project.
