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To: cs551@merlot.usc.edu
Subject: Re: End-game mode for BitTorrent 
Date: Fri, 27 Apr 2007 23:18:59 -0700
From: william@bourbon.usc.edu

Someone wrote:

  > On p. 29 of lecture 20, it reads that seeders will
  > unchoke peers "based on the uploading rate", then
  > "preferring peers which no one else happens to be
  > uploading to them at the moment".
  > 
  > Are the two statements counter to each other?

I don't think so...  I think the way to interpret the
last bullet is:

    as a result, this would prefer peers which no one else
    happens to be uploading to them at that moment

Does this make more sense now?

  > And is the second statement similar to "optimistic unchoking"
  > on the next page?

I don't think so either.  The word "optimistic" here is
probably not the best name for it.  In this case, it just
means "regardless of download rate".  So, it's giving all
other connections a chance by unchoking them in a round-robin
fashion.  (Is this really "optimistic"?  Can you find a
better word for it?)
--
Bill Cheng // bill.cheng@usc.edu <URL:http://merlot.usc.edu/william/usc/>