On Mar 24, 2011, at 4:27 PM, Ravi Ramaswamy wrote:
> Hi All - I am new to this mailer. Hopefully my question is posed to the
> correct list.
Welcome.
> I am using 2.5 Tbps as the peak volume of peering traffic over all peering
> points for a Tier 1 ISP, for some modeling purposes. Is that a reasonable
> estimate?
That's actually a very difficult research question for the academic community,
and one that they've been struggling with since they lost their overview of the
NSFNET backbone in ~1992.
Ironically, it's quite easy for any one ISP to answer internally, but these
numbers are closely held as trade-secrets.
One thing you can do is look at the total volume of publicly-reported traffic
across IXP switch fabrics:
https://prefix.pch.net/applications/ixpdir/summary/growth-region/?sort1=bandwidth&sort2=_current&order=desc
https://prefix.pch.net/applications/ixpdir/?show_active_only=0&sort=traffic&order=desc
…where you see about 8.3Tbps of overall reported traffic. Then you could do
various analyses comparing IXPs where crossconnects are prevalent (Equinix
Ashburn, say) to ones where they are not, and looking at which ISPs peer at
each. You could also try to find out from ISPs which IXPs they use
crossconnects at, and which they don't. That may be easier information for you
to get than how much traffic they're doing individually.
It might also be interesting to look at some of the IXPs that publish
per-participant traffic figures, to see if you can develop characteristic
statistical distributions for amount-each-participant-contributes-to-the-IXP,
though you should be cautioned that the curve might be much heavier-tailed for
a large exchange than a small one.
Ultimately, if you're considering this as an academic research question, you
may want to think about the utility of examining a "black box" question like
this, when the answer is plainly known to other people, just not known to, or
verifiable by, you. The chances of getting the answer "right" are low, and if
you do get it "right" neither you nor your thesis advisor would ever find that
out. There are many other classes of problem that are potentially much more
rewarding, because they would contribute to our overall knowledge of how the
network works: BGP route convergence and stability properties in chaotic (i.e.
real-world) networks; documenting the performance and economic effects (and the
tradeoff with stability) of denser peering meshes; study of the uptake of
DNSSEC; study of the prevalence of different IPv4/IPv6 transition
technologies...
-Bill
