(Data1): 220,533 IP addresses (nodes)
(220,533 nodes, 374,013 links, and 154,104 target
destination IP addresses.)
(Data2): BGP Routing Table of 16 Jan 2000, from the
Oregon Route Views Project
containing 75,643 total prefixes.
(Aggregate1): IP addresses in 32,798 BGP prefixes
were mapped to their best-match origin AS
in the BGP Routing Tables, yielding 5,107 AS nodes.
Each of these AS nodes approximately maps to an ISP.
(Aggregate2): Outdegree and indegree are calculated by breaking down the directional paths that skitter collects into their corresponding links. Then, counting the number of links that start in a given AS and end in another represents its outdegree. Likewise, the number of links starting
elsewhere that end up in a given AS represent its indegree.
(Filter1): Remove leaf nodes.
(Filter2): Remove nodes with an out-degree of zero.
(Filter3): Remove 2-loops (two nodes with outgoing edges
connected only to each other.)