[e2e] [Fwd: RED-->ECN]

[Luigi Rizzo]

> Christian,
> 
> Unhh, maybe because the Internet is heterogeneous, and some parts of it
> will always have 4% loss rates rather than .01%?
> 
> It is unclear whether your interesting observation is a bug, as you
> suggest, or rather a feature that results from the basic packet physics.
> Why is it a bad thing if users can optimize their service by opening
> multiple TCP connections?

because depending on the number of connections the dynamics of the
set of tcp connections change from AIMD to MIMD to no-congestion-control
as below:
 
  HTTP head request to get file_size # 2 RTT
  n = file_size / initial_window ;
  for i = 0 to n-1 do
    # all this in parallel, 2RTT + n*fork delay
    get a chunk of size initial_window at offset i*initial_window & 
  done

and voila. total 4RTT, no cong.control, fully compliant TCP.
(i don't remember if christian's model assumed that the loss
changes with the number of connections, but probably not. )

	cheers
	luigi
----------------------------------+-----------------------------------------
 Luigi RIZZO, luigi at iet.unipi.it  . ACIRI/ICSI (on leave from Univ. di Pisa)
 http://www.iet.unipi.it/~luigi/  . 1947 Center St, Berkeley CA 94704
 Phone (510) 666 2927             .
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