On Aug 15, 2015, at 1:41 PM, Job Snijders <j...@instituut.net> wrote: > On Sat, Aug 15, 2015 at 11:01:56PM +0530, Glen Kent wrote:
>> Is there a paper or a presentation that discusses the drops in the core? >> >> If i were to break the total path into three legs -- the first, middle >> and the last, then are you saying that the probability of packet loss >> is perhaps 1/3 in each leg (because the packet passes through >> different IXes). > > It is unlikely packets pass through an IXP more then once. “Unlikely”? That’s putting it mildly. Unless someone is selling transit over an IX, I do not see how it can happen. And I would characterize transit over IXes far more pessimistically than “unlikely”. [Combining responses] On Aug 15, 2015, at 1:21 PM, Owen DeLong <o...@delong.com> wrote: > > I would say that the probability of a packet drop at any particular peering > point is less than the probability at one of the two edges. > > However, given that most packets are likely to traverse multiple peering > points between the two edges, the probability of a packet drop along > the way at one of the several peering points overall is roughly equal > to the probability of a drop at one of the two edges. I’m a little confused why most packets are “likely to traverse multiple peering points”? Most packets these days are sourced from one of three companies. (Which Owen should know well. :) At least one of those companies published stats saying the vast majority of packets are “zero or one” AS hop from the destination. I cannot imagine Google or Netflix being 50% behind Akamai on that stat. Which clearly implies most packets traverse “zero or one” AS hop - i.e. one or zero peering points. Finally, I would love to see data backing up the statement that packets are more likely to drop at one edge (assuming the destination?) than at a peering point. -- TTFN, patrick
