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

Laird Popkin laird at pando.com
Wed Apr 23 19:50:25 UTC 2008

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. :-)

Laird Popkin
CTO, Pando Networks
520 Broadway, 10th floor
New York, NY 10012

laird at pando.com
c) 646/465-0570

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