TCP vs. UDP

[larytet]

this article is interesting
http://www.utsc.utoronto.ca/~rosselet/cscd58/ref05/p2p-measure.pdf
related to Napster/Gnutella, some measurements of connection latency
and available bandwidth.






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[Olaf van der Spek]

Post by larytet
this article is interesting

Where does it discuss TCP vs UDP?
And how is the article relevent to BT?

Post by larytet
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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[larytet]

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.

Post by Olaf van der Spek

Post by larytet
this article is interesting

Where does it discuss TCP vs UDP?
And how is the article relevent to BT?

Post by larytet
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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[Olaf van der Spek]

Post by larytet
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.

That's certainly true, but I couldn't find the TCP vs UDP bit.

Post by larytet

Post by Olaf van der Spek

Post by larytet
this article is interesting

Where does it discuss TCP vs UDP?
And how is the article relevent to BT?

Post by larytet
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/

Yahoo! Groups Links

--
Olaf van der Spek
http://xccu.sf.net/



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[larytet]

indirectly some of the facts support idea of using UDP.

In real network average performance of TCP can not be exceeded by
proprietary UDP transport, but it can be argued that in some cases
such proprietary protocol can be made efficient "enough" and for some
networks - specifically for fat connections with high latency and
uniformly distributed low packet loss, can beat TCP performance.

Post by Olaf van der Spek

Post by larytet
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.

That's certainly true, but I couldn't find the TCP vs UDP bit.

Post by larytet

Post by Olaf van der Spek

Post by larytet
this article is interesting

Where does it discuss TCP vs UDP?
And how is the article relevent to BT?

Post by larytet
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/

Yahoo! Groups Links

--
Olaf van der Spek
http://xccu.sf.net/

Yahoo! Groups Links

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