Re: TCP vs. UDP

"larytet" <[email protected]> Mon, 21 Mar 2005 22:17:27 -0000
Newsgroups gmane.network.bit-torrent.general
Message-ID <[email protected]>

20% of peers has connection with latency above 300ms
Another problem is geographical location of peers. Peers tend to
establish connections randomly creating unnecessary burden for ISPs.

from the article:"Our interest in latencies of the peers is due to the
well known feature of TCP congestion control which discriminates
against &#64258;ows with large round-trip times.
This, coupled with the fact that the average size of &#64257;les exchanged is
in the order of 2-4 MB, makes latency a
very important consideration when selecting amongst multiple peers
sharing the same &#64257;le."

Amazingly there are peers with 1s latency and more. Clearly these are
peers behind dial ups with large TCP packets in downstream queue
waiting for delivery.

The article contains lot of usefull statistics. I thought that there
are people who did not read it and would be interested in reading it.

--- In [email protected], Olaf van der Spek <OvdSpek@L...> wrote:
> larytet wrote:
> > 
> > this article is interesting
> 
> Where does it discuss TCP vs UDP?
> And how is the article relevent to BT?
> 
> > http://www.utsc.utoronto.ca/~rosselet/cscd58/ref05/p2p-measure.pdf
> > related to Napster/Gnutella, some measurements of connection latency
> > and available bandwidth. 
> > 
> > 
> > 
> > 
> > 
> >  
> > Yahoo! Groups Links
> > 
> > 
> > 
> >  
> > 
> > 
> 
> 
> -- 
> Olaf van der Spek
> http://xccu.sf.net/





 
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