(Strength1): It is possible to see multiple groupings at the same
(Strength2): Collected data is available for analysis over time.
(Issue1): Graph shows IP path connectivity only, not actual
traffic on physical links.
(Issue2): Graph reflects only outgoing packet paths. The incoming
path is often different, as ISP interconnect agreements often divert traffic
through different connections.
(Issue3): Graph doesn't include networks announced in the core
routing tables but not contained in the routing arbiter database. Preliminary
analysis suggests that these omissions may account for 20% of IP networks.