Re: [ledbat] "Oh Noes, the Internetz will Melt Down..."

On 2008-12-1, at 17:56, Nicholas Weaver wrote:
> The typical Fear Mongering "UDP Death Uhz Da Internetz":
> http://www.theregister.co.uk/2008/12/01/richard_bennett_utorrent_udp/

Wow. Talk about jumping to conclusions. That is quite an "article".

> However, the question is, does anyone have insight into the "uTP"
> congestion control protocol and what it is actually doing?

See http://forum.utorrent.com/viewtopic.php?id=49813

"What is in 1.9:
uTP, the micro transport protocol. This UDP-based reliable transport  
is designed to minimize latency, but still maximize bandwidth when the  
latency is not excessive. We use this for communication between peers  
instead of TCP, if both sides support it. In addition, we use  
information from this transport, if active, to control the transfer  
rate of TCP connections. This means uTorrent, when using uTP, should  
not kill your net connection - even if you do not set any rate limits.

What was in 1.8.1:
uTP, but connection attempts were not initiated by default, and there  
was no control over TCP as described above. You can enable it, but  
likely you will see the uTP connections not transfering much data,  
because they are pushed out of the way by TCP."

This last bit sounds a lot like if uTP is is using some sort of less- 
than-best-effort CC. (I believe someone mentioned in Minneapolis that  
utorrent would implement BitTorrent's DNA - maybe this is it?

Lars

Re: [ledbat] "Oh Noes, the Internetz will Melt Down..."

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