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Re: [Mldonkey-users] feature suggestion: forward error correction
From: |
Christian Brandt |
Subject: |
Re: [Mldonkey-users] feature suggestion: forward error correction |
Date: |
Thu, 5 Sep 2002 09:14:32 +0200 |
User-agent: |
Mutt/1.3.22.1i |
On Thu, Sep 05, 2002 at 05:19:06AM +0200, Goswin Brederlow wrote:
> C and D are still online and together they have 4 different chunks:
>
> 25 D-----C 36 ===> 2356 D------C 2356
>
> Using FEC both can now restore the original file.
Ok, this may work out. But you also increase traffic: A FEC which is only able
to reconstruct one part out of five or 2 out of 15 increases Bandwidth by
15-20%, make this 2 out of 7 or something like that and you quickly need 40 or
50% more bandwidth. Those numbers are educated guesses, hamming code & Co have
faded out of my view after a decade or so.
My 2cent: Bandwidth is too expensive to be wasted this way as incomplete files
are an rare exception, not the general case. But still its an ugly exception
;-) Also this would make the Donkeyprotocol too complex for Joe Average to
understand. Hey, most even do not understand "for 1-3kb/s I get 3-9kB, for
4-9kb/s I get 12-45kb/s and for 10kb/s I get limitless bandwidth". Most would
start to think of donkey beeing an user-annoying-tool and not a p2p-software.
--
Christian Brandt
life is short and in most cases it ends with death
but my tombstone will carry the hiscore