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

[Luigi Rizzo]

> My specific suggestion would be to start using linear increase (increase
> the window by a constant x for each Ack) instead of the sublinear
> increase we have now (increase by 1/W), for the high speed connections

the terminology is confusing... a constant-increase-per-ack means
multiplicative increase over time.

	cheers
	luigi

> (e.g. when W > 40). We can tune the constant "x" so that the increase at
> the threshold point (W=40?) is equal on both sides of the threshold
> (e.g., x=1/40). The behavior would remain exactly the same in the case
> of high error rates, but we would gain better control in the case of low
> error rates. Then, the application designers would not be forced into
> "optimisations."
> 
> -- Christian Huitema
> 
> > -----Original Message-----
> > From: Bob Braden [mailto:braden at ISI.EDU] 
> > Sent: Thursday, February 01, 2001 11:18 AM
> > To: J.Crowcroft at cs.ucl.ac.uk; Christian Huitema
> > Cc: end2end-interest at postel.org
> > Subject: RE: [e2e] [Fwd: RED-->ECN]
> > 
> > 
> >   *> 
> >   *> Jon,
> >   *> 
> >   *> Yes, we could indeed decide that penalizing long 
> > sessions is a good
> >   *> thing. But, guess what, the guys writing the download 
> > applications are
> >   *> no dummies. If they observe that 
> >   *> 	loop until EOF
> >   *> 		open connection
> >   *> 		go to current file location
> >   *> 		get an additional 5 megabytes, or the rest of the file
> >   *> if less
> >   *> ... gets then better performance than just "open a 
> > connection and get
> >   *> the file," guess what they will do? Indeed, you could 
> > call that an
> >   *> intelligence test -- smart elephants morph into mice, 
> > the other ones go
> >   *> the way of the dinosaurs. But then, why are we bothering 
> > writing complex
> >   *> requirements for TCP?
> > 
> > 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?
> > 
> > Bob Braden
> >  
> > 
>