Paper Review:
End-to-End Routing Behavior in the Internet

Reviewer: Robert Dugas


This paper deals with the problem of measuring real-world behavior of routing protocols on the internet.


Various statistics are presented that likelyhood and possible causality of such issues as 'fluttering', loops and too many hops.

Main Ideas

  • Routing protocols are effective at eliminating loops at the AS level but less so at finer granularities.
  • Measuring real world behavior of routing protocols is an important evaluative step.
  • Route alternation should be examinined as an issue to prevent in future protocol incarnations.


    Many papers have been writing describing routing statics and the like. Perhaps for its time it was more revolutionary than it now appears to be.

    The method employed to meaure routing statistics was to run traceroute at various time intervals on a "representative" sample of webservers then examine the changes or lack thereof.

    Regardless of statistics, it is difficult to argue that 37 hosts can accurately approximate behaviour of the entire internet. Further, tricky assumptions were made (such as if routing was identical at 2 arbitrarily spaced sampling points it had not changed in between) to lessen the validity of some claims. Futhermore, many outage statics are wildly inaccurate due to the fact that they were not able to be recorded.

    Highlighted findings were that assymetry is increasing and should be dealt with. In addition, the presence of loops was greater than anticipated and longer in duration.