Re: [p2prg] New version of the mythbuster-ing draft

[Stevens.Le_Blond at sophia.inria.fr]

Enrico,

I have a few comments.

In Section 3.1:

You should distinguish between "local" cross-domain traffic (a single ISP
and a single torrent) and "global" cross-domain traffic (all ISPs and
214,443 torrents). This is very important because locality may allow to
save a lot of "local" cross-domain traffic in given scenarios without
being beneficial overall. In other words, if it's not possible to save
"global" cross-domain traffic, locality can be *mainly* useless.

"... Simulations and field tests have shown a reduction varying from 20%
to 80%."

If you consider local cross-domain traffic, our experiments with real
distributions of peers per AS actually show that you can save more than
99.5% of "local" Cross-domain traffic and 40% of "global" cross-domain
traffic ([LeBlond], Section 6.3).

"4.  Simulations of the localization approach proposed in [LeBlond]
     run on data collected from crawling of real BitTorrent swarms
     indicate a 40% reduction of cross-domain traffic."

We didn't run simulations but experiments with real BitTorrent clients.

The other works that you cite consider "local" cross-domain traffic so you
shouldn't compare those results with 40% which is for "global"
cross-domain traffic. I would suggest that you either create a subsection
for "global" cross-domain traffic or make this difference very clear. In
any case, you can't compare those numbers directly as they mean something
different.

In Section 3.2:

We have also shown that in the case of severe bottlenecks, BitTorrent with
locality can be more than 200% faster than regular BitTorrent ([LeBlond],
Section 5.3).

In case you didn't have a look at the second version of [LeBlond], here's
the refence:

Stevens Le Blond, Arnaud Legout, Walid Dabbous.
Pushing BitTorrent Locality to the Limit.
Technical Report (inria-00343822, version 2 - 12 May 2009), INRIA,
Sophia Antipolis, May 2009.
http://hal.inria.fr/inria-00343822/en/

Hope this helps.

All the best,
Stevens