Re: TCP (and SCTP) sucks on high speed networks

[Kaleelazhicathu R R Kumar <kaleelaz@comp.nus.edu.sg>]

hi,
 On same lines we have proposed a change in the existing TCP stack by
adding an additional option which will help TCP distinguish corruption
from congestion and act accordingly. The paper has been accepted in
INFOCOM 2001.We have found that this approach helps in improving the
performance of TCP in higher corruption prone networks like the wireless
to a greater extent.
  Thanks.
  Renjish. 


It's not important to be the best, but the first.

On Thu, 30 Nov 2000, Matt Wakeley wrote:

> TCP's "congestion avoidance" algorithms are not compatible with high speed,
> long distance networks.  The "cut transmit rate in half on packet loss and
> increase the rate additively" algorithm will simply not work.
> 
> Consider a 10Gbs link to a destination half way around the world.  A packet
> drop due to link errors (not congestion or infrastructure products) can be
> expected about every 20 seconds.  However, with a RTT of 100ms (not even
> across the continent), if a TCP connection is operating at 10Gbs, the packet
> drop (due to link error) will drop the rate to 5Gbs.  It will take 4 *MINUTES*
> for TCP to ramp back up to 10Gbps.
> 
> Therefore, there needs to be a change to TCP's congestion avoidance algorithm
> for future high speed networks.  Since SCTP is based on the same algorithms,
> it is doomed to the same fate.
> 
> -Matt
>