[IP] Re: Comments on LARIAT and Comcast not same problem

[David Farber <dave@farber.net>]

________________________________________
From: Brett Glass [brett@lariat.net]
Sent: Sunday, February 17, 2008 2:36 PM
To: David Farber; ip
Cc: tlauck@madriver.com
Subject: Re: [IP] Re:    Comments on  LARIAT and Comcast not same problem

At 07:14 PM 2/16/2008, Tony Lauck wrote:


>It is a slight exaggeration to say that P2P relentlessly attempts to
>consume every shred of available bandwidth. This is not the case with
>properly set up bit torrent clients.

The default is for it to do so. And how many gamers, thirsting for
the latest World of Warcraft update, would change that default (if they
knew how)?

>In my case, I have configured my bit torrent client so that it uploads
>no more than 1.5x the volume of data that I choose to download, and it
>does so using no more than 50% of my peak DSL upload bandwidth. There is
>nothing relentless about this.

Alas, there is. Even if you throttle your BitTorrent client, your system
(and your ISP) will be beaten on relentlessly with requests for the
material. Day and night. Long after your own download is done. And unless
you "relent" by not doing P2P, you are still taking your ISP's bandwidth
for a third party. (See my comment to the FCC, mentioned earlier on this
list.)

>If I download at high speed for an hour,
>then my computer will upload at a reduced rate for perhaps ten times
>that period of time. If the network is overloaded then it will download
>at a lower rate for a longer period of time.

The entire point is that your software cares not whether any network
is "overloaded," and seeks to bypass all of the safeguards against
congestion which are part of the TCP/IP protocol suite. It is thus
abusive to the network.

>Proper network management, in my book, means building and managing a
>network so that cooperating users get good service, and so that non
>cooperating users can get better service by becoming more cooperative.

We attempt to do that. One of the most effective P2P mitigation tactics
we've tried is to slow down the user's connection to compensate for the
excessive duty cycle of P2P applications, keeping the net load (in
gigabits per month) imposed on the network by the user down to a
reasonable level. It's the equivalent of, say, limiting the number of
plates that a customer at a buffet can fill. Under this regime, users who
honor their contracts and are not abusive find that their browsing and
other legitimate activities are faster, because they can burst to higher
traffic levels. But ones with a 100% duty cycle can't, and so find
activities that need a burst of speed -- e.g. browsing -- to be more
sluggish. The flaw in this scheme is that it still lets abusers take
bandwidth from us for the benefit of third parties, such as Blizzard
and Vuze, without compensation.

>Some network operators seem to be better than others at achieving
>effective cooperation. Perhaps this is due to superior technology, more
>favorable business conditions, or superior management philosophy.
>
>I hope that the successful networks are succeeding due to their
>superior technology, because I have more faith in progress in the
>technical dimension than in the management dimension -- not to mention
>the political dimension, where progress seems to be retrograde more
>often than not.

I believe that the form of behavior modification mentioned above is,
indeed, superior technology, as it uses a firm but gentle hand to
motivate users to do what they have agreed to do and not abuse the
network or use abusive technologies such as P2P. This, is of course,
one man's opinion, but it reflects the views of many in the industry.

--Brett Glass, LARIAT.NET


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