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P2P - Bandwidth - Upload:Download - Proportionate?

P2P transfers, such as those with BitTorrent, eMule, Limewire, etc., seem to have a very high UL:DL proportion. Specifically,  when I downloaded (in fact, I am still downloading) the CD Image for Dropline Gnome via BitTorrent, I found that my total traffic (Up + Down) exceeded 450 MB. Though I have downloaded only about 150 MB of the 300 odd MB file thus far.

Now, I agree that I have to share my bandwidth for other users in the system as well. It is only fair. But 1:3 against me? Is that the norm? Or is something wrong with the numbers I have given above?
KayJay Send private email
Monday, September 13, 2004

The "BitTorrent Economics" paper is particularly interesting.

"BitTorrent's choking algorithms attemt to achieve pareto efficiency using a more fleshed out version of tit-for-tat than that used to play prisoner's dilemma. Peers reciprocate uploading to peers which upload to them, with the goal of at any time of having several connections which are actively transferring in both directions. Unutilized connections are also uploaded to on a trial basis to see if better transfer rates could be found using them."

And from the FAQ:

I don't want you stealing my bandwidth! How can I stop it from uploading?

You could hack the source to not upload, but then your download rate would suck. BitTorrent downloaders engage in tit-for-tat with their peers, so leeches have very little success downloading.

etc. etc. Section 3.4 of the white paper "Anti-snubbing" might be of interest to you too. Send private email
Monday, September 13, 2004
What is "fair" when upload volume is around 7 times (that is the rate where I live, we do not have "unmetered") more expensive than "download" volume on a typical broadband connection.
Just me (Sir to you) Send private email
Monday, September 13, 2004
Did not quite understand you Sir, but nor is mine. I am on an aDSL link that comes with a cap of 1 GB, 5 GB or 10 GB per month. My package comes with a GB cap. And downloads are much faster than uploads, naturally.

Since what I get is essentially "free", I am not averse to "spending" on bandwidth for something I want. Just that, I find it a tad "expensive".

Thanks for those links Mark.
KayJay Send private email
Monday, September 13, 2004
We get caps on the upload/download percentage.
e.g. 10Gb of wich at most 15% is upload. To get the upload % upped (not nescessarily the total volume) you have to pay extra.
Just me (Sir to you) Send private email
Monday, September 13, 2004
Ah! Ok. Over here, it is the sum total. Overshooting used to result in a flat charge earlier (slabs of 250 MB), but of late they have brought it down to a pro-rata charge, calculated from a flat rate per GB.
KayJay Send private email
Monday, September 13, 2004
With Bittorrent, if you havent already done so and you are NAT'ed, forward 6881-6889 to your internal box specifically. This is usually the cause of really bad U/D ratio's on Bittorrent. Also, try getting a different client so you can see the connections etc.
Dan G Send private email
Monday, September 20, 2004
Most p2p programs will seek to maximize your download speed while also utilizing as much of your upload capacity as possible.  Bandwidth is like gold in p2p systems, so they basically take it where they can get it. 

That said, there's certainly a great deal of latent, unused bandwidth on all these systems.  You can see that from the frequent lack of uploads on any of the FastTrack or Gnutella apps, for example.  This bandwidth could and should be utilized to improve network efficiency.  Nodes could, for example, exchange more routing tables to index more content.

As another poster mentioned, you typically have more download capacity than upload capacity, so you'll usually download much more than you're uploading *at the moment when you have a download in progress*.  Anyway, it's only a concern if you pay by the bit.  BitTorrent's a little different and probably more aggressive at utilizing your upload capacity.
Adam Fisk Send private email
Wednesday, September 22, 2004

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