[lug] Bittorrent getting lots of bits, but the file fills up slowly

[Michael Hirsch]

On 4/30/05, Nate Duehr <nate at natetech.com> wrote:
> On Fri, Apr 29, 2005 at 06:27:33PM -0500, John Karns wrote:
> > On Thu, 28 Apr 2005, Michael Hirsch wrote:
> >
> > >I'm having a very strange problem.  I'm using bittorrent
> > >(btdownloadxxx.py) to get the latest mandriva distribution.  I have
> > >comcast so I'm getting over 300 KB/s.  Great huh?  Nooooo.
> > >
> > >The rate at which the file is growing is no where close to that.  It
> > >is at least 10 times slower.  Although btdownload said it would take
> > >about an hour and a half, it has taken over 10 hours so far.  It says
> > >that there is only 6 minutes left, but an hour ago it said 15 minutes.
> > >This is crazy.
> >
> > IIRC, DL bw is also dependent on your UL bw.  Also, check your router / fw
> > for port forwarding settings.  You should have a number of ports open
> > starting at 6881.  E.g., 6881 - 6889.
> 
> Since BT creates traffic both directions (when things are set up
> correctly) and since most residential connections are asymmetrical [sp],
> make sure your upload rate is limited to something below what you really
> see in the real world for a reasonable upload speed on your Internet
> pipe of choice.
> 
> If you don't, your upstream pipe becomes congested with uploads and your
> ACK packets telling others that you've received their packets have to be
> retransmitted with resulting slowdowns in your true download speed.

That has definitely happened to me.  That's why I always limit
uploading to 20 KB/s.

Michael