Observing the Evolution of Internet AS Topology

Data Sources Name Type #vantage points Historic RV+RIPE+Abilene+cernet BGP RIBS + updates ~500 Since 2004-1-1 Routeservers RIBS ~60 2004-11 Looking glasses Neighbor Ases+traceroute ~200 Skitter Traceroute ~20 2004-1-1 Dimes ~12k 2004-10 iPlane ~300 2006-7

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 Common 30,548

BGP data

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

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

Skitter data

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

Dimes Data Data available from Sept 23, 2004 to Nov 5, 2006

Verifying Dimes timestamps Compared 25,261 links with BGP Similar observations as Skitter data Disappearance period is off x=0 because I’m missing a month of Dimes data (Nov 2006), therefore last_seen timestamps of live links are off by some days when compared to BGP