[e2e] Is a control theoretic approach sound?

John T. Wen wen at cat.rpi.edu
Mon Aug 4 08:43:41 PDT 2003


Alfredo:

What I mean is the self-clocking and gain scaling are the same thing (i.e.,
self clocking is modeled as delay dependent gain in flow control).

John

----- Original Message -----
From: "Sig." <agrieco at poliba.it>
To: "John T. Wen" <wen at cat.rpi.edu>
Cc: "Alfredo Grieco" <a.grieco at poliba.it>; <end2end-interest at postel.org>;
"Saverio Mascolo" <mascolo at poliba.it>; <shivkuma at ecse.rpi.edu>;
<wen at ecse.rpi.edu>; <arcak at ecse.rpi.edu>
Sent: Saturday, August 02, 2003 3:45 PM
Subject: Re: [e2e] Is a control theoretic approach sound?


> Hi John,
>
> I think that without the self-clocking you need to scale the gain of the
> controller to achieve stability. On the other hand, if you exploit
> the self-clocking, the stability of the system is no more dependent on the
> value of the gain.
>
> Alfredo
>
>
>
> Scrive "John T. Wen" <wen at cat.rpi.edu>:
>
> > Hi Alfredo:
> >
> > Self clocking is modeled as scaling the source controller gain to be
> > inversely proportional to the delay.  This was done in the linear
context by
> > Low, Paganini, and Doyle in their various papers on scalable congestion
> > control.   We have also done this in the nonlinear context to achieve
global
> > asymptotic stability.
> >
> > John
> >   ----- Original Message -----
> >   From: Alfredo Grieco
> >   To: end2end-interest at postel.org
> >   Cc: Saverio Mascolo ; shivkuma at ecse.rpi.edu ; wen at ecse.rpi.edu ;
> > arcak at ecse.rpi.edu
> >   Sent: Saturday, August 02, 2003 7:04 AM
> >   Subject: Re: [e2e] Is a control theoretic approach sound?
> >
> >
> >   Hi all,
> >
> >   I would like to add one more point to this discussion,
> >
> >   in particular, I noticed that in many papers on TCP modeling, the
> > self-clocking principle, which is at the core of the Internet stability,
is
> > not explicitly taken into account.
> >
> >
> >
> >   My question is :
> >
> >   can we effectively model the Internet without taking into account one
of
> > the major key points of TCP congestion control ?
> >
> >
> >   Alfredo Grieco
> >
> >
> >   ---------------------------------------------------
> >   Luigi Alfredo Grieco
> >   DEE Politecnico di Bari,
> >   Via Orabona 4 - 70125 Bari, Italy
> >   Tel. +39-080-5963301
> >   Fax +39-080-5963410
> >   http://www-ictserv.poliba.it/grieco
> >
>
>
>





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