[Nanog] P2P traffic optimization Was: Lies, Damned Lies, and Statistics [Was: Re: ATT VP: Internet to hit capacity by 2010]

Christopher Morrow morrowc.lists at gmail.com
Wed Apr 23 16:14:12 CDT 2008


On Wed, Apr 23, 2008 at 3:50 PM, Laird Popkin <laird at pando.com> wrote:
>
>  On Apr 23, 2008, at 2:17 PM, Christopher Morrow wrote:
>
> > On Wed, Apr 23, 2008 at 11:39 AM, Alexander Harrowell
> > <a.harrowell at gmail.com> wrote:
> >
> > >
> > >
> > >
> > > On Wed, Apr 23, 2008 at 3:47 PM, Christopher Morrow
> > > <christopher.morrow at gmail.com> wrote:
> > >
> > > >
> > > > It strikes me that often just doing a reverse lookup on the peer
> > > > address would be 'good enough' to keep things more 'local' in a
> > > > network sense. Something like:
> > > >
> > > > 1) prefer peers with PTR's like mine (perhaps get address from a
> > > > public-ish server - myipaddress.com/ipchicken.com/dshield.org)
> > > > 2) prefer peers within my /24->/16 ?
> > > >
> > > > This does depend on what you define as 'local' as well, 'stay off my
> > > > transit links' or 'stay off my last-mile' or 'stay off that godawful
> > > > expensive VZ link from CHI to NYC in my backhaul network...
> > > >
> > >
> > > Well. here's your problem; depending on the architecture, the IP
> addressing
> > > structure doesn't necessarily map to the network's cost structure. This
> is
> > > why I prefer the P4P/DillTorrent announcement model.
> > >
> > >
> >
> > sure 80/20 rule... less complexity in the clients and some benefit(s).
> > perhaps short term something like the above with longer term more
> > realtime info about locality.
> >
>
>  For the applications, it's a lot less work to use a clean network map from
> ISP's than it is to in effect derive one from lookups to ASN, /24, /16,
> pings, traceroutes, etc. The main reason to spend the effort to implement
> those tactics is that it's better than not doing anything. :-)
>

so.. 'not doing anything' may or may not be a good plan.. bittorrent
works fine today(tm). On the other hand, asking network folks to turn
over 'state secrets' (yes some folks, including doug's company)
believe that their network diagrams/designs/paths are  in some way
'secret' or a 'competitive advantage', so that will be a blocking
factor. While, doing simple/easy things initially (most bittorrent
things I've seen have <50 peers certainly there are more in some
cases, but average? > or < than 100? so dns lookups or bit-wise
comparisons seem cheap and easy) that get the progress going seems
like a grand plan.

Being blocked for the 100% solution and not making
progress/showing-benefit seems bad :(

-Chris




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