[e2e] TCP un-friendly congestion control

[Saverio Mascolo]

Richard,

do you think that e2e bandwidth estimation a la Westwood could improve TCP
over high speed paths?

At   http://www-ictserv.poliba.it/mascolo/tcp%20westwood/Results24.htm

we report some tests obtained using an implementation of Westwood in Linux
2.4. We have executed ftp  from Bari (South of Italy) to Uppsala, Sweden,
and Ucla, California. Some interesting improvements have been found. A
complete report along with the Linux code will be available soon.

Saverio
-----------
Saverio Mascolo, Ph.D
Associate Professor
Dipartimento di Elettrotecnica ed Elettronica, Politecnico di Bari
Via Orabona 4, 70125 Bari,  Italy
email: mascolo at poliba.it
http://www-dee.poliba.it/dee-web/Personale/mascolo.html


----- Original Message -----
From: "Richard Carlson" <RACarlson at anl.gov>
To: <end2end-interest at postel.org>
Sent: Monday, June 09, 2003 5:04 PM
Subject: Re: [e2e] TCP un-friendly congestion control


> As chair of the Internet 2 Land Speed Record judging committee, I can
> confirm that TCP over long fat networks is not hopeless.  The last 2
> records, using IPv4 and IPv6, show that hosts can push the network to the
> limit.  For the latest IPv4 record a team from the US and Europe ran Iperf
> for 3700 seconds (yes just over 1 hour) between 2 PC's with 10 Gigabit
> Ethernet NICs.  They achieved a throughput rate of 2.3 Gbps, with the
> connection being limited by a transatlantic OC-48 link.  The latest IPv6
> record is being processed now, but it is equally impressive.  See the
> I2-LSR web page http://lsr.internet2.net for details.
>
> Another thing to consider, Les Cottrell from SLAC ran some tests with
these
> 10 Gig NICs and tested the standard Linux 2.4 TCP, FAST TCP, HPTCP, and
one
> other high performance implementation.  These tests showed no difference
> between any of the TCP implementations over 1 particular network path.  If
> Les is on this list maybe he can provide a pointer to these results.
>
> Rich
>
> At 05:26 PM 6/6/03 -0400, Craig Partridge wrote:
>
> >In message <20030606140028.A59651 at xorpc.icir.org>, Luigi Rizzo writes:
> >
> > >exactly -- that's the whole point, the packet rate is so high that
> > >there are many chances to have occasional losses anywhere in the
> > >system, not just due to the channel but even because of operating
> > >system issues on some of the intermediate boxes or end nodes.
> >
> >OK, let me get on my high horse here for a moment.
> >
> >The original poster asserted that in an environment where the network
> >went at 1 Gbps and had 50ms of delay, TCP was hopeless.
> >
> >The point I was trying to drive home is that it is not hopeless.  That
> >you have to define the environment far more carefully before you assert
> >that TCP can or cannot do the job.  One of my frustrations these days is
> >people who fail to be careful.  I was trying to encourage care in the
> >problem statement.
> >
> >Thanks!
> >
> >Craig
>
> ------------------------------------
>
> Richard A. Carlson                              e-mail: RACarlson at anl.gov
> Network Research Section                        phone:  (630) 252-7289
> Argonne National Laboratory                     fax:    (630) 252-4021
> 9700 Cass Ave. S.
> Argonne,  IL 60439
>