[e2e] TCP ex Machina

[Detlef Bosau]

Am 22.07.2013 08:35, schrieb Fred Baker (fred):
> I'm not sure folks are really concerned about operating boundaries as much as outcomes. In general, and in specific in the words of Nandita Dukkipati and folks like her, I think folks would like to maximize throughput and minimize the

And I'm not sure, that we are maximizing or minimizing anything. The 
more complex the formulae will be, the more difficult it will be to make 
reality obey them.

Sometimes the belief in an optimum window in TCP resembles the belief in 
an optimum amount of money by the monetarism guys.

- We have to share ressources: No problem! Use the optimum window!
- We want to maximize throughput? " " "
- We want to minimze latency? " " "

Perhaps it's a personal attitude of mine at the moment, perhaps I'm 
simply tired, but it doesn't matter how complex the question is: The 
simple answer is: Use the correct CWND.

(When I was a student I was acquainted to some guys of Campus Crusade 
for Christ. They shared the "Four Spiritual Laws" as the only effective 
solution for each and anything. Unfortunately, although this has been 
more then twenty years ago, I'm still looking for the problem fitting 
this solution.)

However, it may be my mood in the moment.

E.g., VJ told us in his famous talk from 2006, that TCP does not work 
well in wireless environments when we're moving around.

O.k., this is only seven years ago and my Linux now include an 
experimental BIC (I don't know for sure, I never looked particularly for 
this), and this doesn't help in wireless environments when I'm moving 
around.

Did anything else change? Or do we, to a certain degree, repeat the same 
things we repeat for 20 years now?

In the talk from 2006, VJ was afraid that we are stuck in some kind of 
deadlock.
This is basically a similar view to that taken by Ford and Iyengar in 2009.

Is there some truth in it?

Detlef


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