Re: Three states for a binary bit (was Re: TCP (and SCTP) sucks on high speed networks)

[Panos GEVROS <P.Gevros@cs.ucl.ac.uk>]

"David P. Reed" :

 |By focusing design effort on a particular implementation, one implicitly 
 |adopts its assumptions.  In this case (trying to overload ECN with fairness 
 |and reliable detection of congestion), you tend to bind the architectural 
 |accidents of today's Internet (single path routing, no traffic engineering, 
 |no  market making, no load shifting to other times, no adaptive coding) as 
 |a permanent solution.  And worse, that solution is limited.
 |So before you call for "more complexity in the net", try thinking about 
 |"more intelligence at the endpoints".  Only if you have given that serious 
 |consideration, AND tried to deploy end-to-end solutions (which take several 
 |years), should you dare to try to impose centralized and 
 |application-ignorant solutions.

one of the arguments for the shift of focus from the end-points to the router 
was that end-points are no longer trusted to be well behaved (kind and 
adaptive) like they used to be in the past,
one way to deal with this would be to _enforce_ certain (control) behaviors on 
the end-points,
that could be the triumph of the end-to-end argument, scalability, even 
differentiated services could come for free

 |It's lazy and arrogant to presume that the network designer knows what the 
 |users need in a resource allocation algorithm, such as managing "congestion".
 |At most, the network can detect congestion.

it would be desirable for the network to provide information which the (well 
behaved) end-points can use to optimise their strategies,  -there will be a 
tradeoff here between the complexity and marginal benefit from it though, ECN 
is such a thing,

regards,
Panos