Observing the Evolution of Internet AS Topology

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Observing the Evolution of Internet AS Topology
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Data Sources
Name Type vantage points Historic
RVRIPEAbilenecernet BGP RIBS updates 500 Since 2004-1-1
Routeservers RIBS 60 2004-11
Looking glasses Neighbor Asestraceroute 200 2004-11
Skitter Traceroute 20 2004-1-1
Dimes Traceroute 12k 2004-10
iPlane Traceroute 300 2006-7
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Comparision between data sources
Period since 2004-10 BGP Skitter Dimes
Total 111,122 74,741 111,372
Unique 45,386 28,170 35,521
Union 187,882 187,882 187,882
Common 30,548 30,548 30,548
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BGP data
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Accuracy of BGP timestamps

• Picked 54 routers (37 ASes) with consistent data
  during the 3 yrs splitted these routers in two
  sets, such that each ASN belonged to just one
  set
• Set0 29 routers, 18 Ases, w/ 95,939 links
• Set1 25 routers, 19 Ases, w/ 99,122
• Common links to Set0 and Set1 91,804

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Accuracy of BGP timestamps

• Only about 10 of links timestamps are off, an
  effect of revelation process
• Generally, BGP timestamps can be used as
  calibration points to evaluate accuracy of
  traceroute timestamps

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Skitter data
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Verifying Skitter timestamps
40,041 out of 97,216 skitter links appear in BGP
monitors

• About 10 of links appear first / disappear last
  in Skitter an effect of revelation process in
  BGP
• About 40 of links have same timestamp as in BGP
• 50 of links timestamps are off in Skitter

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Dimes Data
Data available from Sept 23, 2004 to Nov 5, 2006
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Verifying Dimes timestamps
Compared 25,261 links with BGP

• Similar observations as Skitter data
• Disappearance period is off x0 because Im
  missing a month of Dimes data (Nov 2006),
  therefore last_seen timestamps of live links are
  off by some days when compared to BGP