On Wed, Jun 13, 2007 at 06:47:30PM +0200, Daniele Arena wrote: [snip]
Traffic matrices (at least up to now and AFAIK) have only been built by traffic measurements by IXPs whose switches all support sFlow. Not all switches do, so not many IXPs have that feature.
Several IXPs have traffic matrices built on data entered manually. That is usually not too reliable as people forget to update the peering data after having updated their peerings on the routers.
Not to mention that even at member-driven IXes, you will find members who believe they can keep their AS-level adjacencies secret and opt-out. IMO, a major reason you don't see much traction for this data in larger/non-co-op IXes (most of the US, sadly). Cheers, Joe -- RSUC / GweepNet / Spunk / FnB / Usenix / SAGE