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

[Jon Crowcroft]

tcp is end to end

MANY end systems police the NUMBER of TCP conncetiosn you can make fro
ma given address - try downloading from redhat for example:-)
In message <200102011954.UAA56535 at info.iet.unipi.it>, Luigi Rizzo typed:

 >>> 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             .
 >>----------------------------------+-----------------------------------------

 cheers

   jon