[100375] in North American Network Operators' Group

home help back first fref pref prev next nref lref last post

Re: The next broadband killer: advanced operating systems?

daemon@ATHENA.MIT.EDU (Leo Bicknell)
Mon Oct 22 14:36:25 2007

Date: Mon, 22 Oct 2007 14:06:38 -0400
From: Leo Bicknell <bicknell@ufp.org>
To: nanog@merit.edu
Mail-Followup-To: nanog@merit.edu
In-Reply-To: <Pine.LNX.4.64.0710221838550.15766@uplift.swm.pp.se>
Errors-To: owner-nanog@merit.edu



--AhhlLboLdkugWU4S
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

In a message written on Mon, Oct 22, 2007 at 06:42:48PM +0200, Mikael Abrah=
amsson wrote:
> You can achieve the same thing by running a utility such as TCP Optimizer.
>=20
> http://www.speedguide.net/downloads.php
>=20
> Turn on window scaling and increase the TCP window size to 1 meg or so,=
=20
> and you should be good to go.

A bit of a warning, this is not exactly the same thing.  When using
the method listed above the system may buffer up to 1 Meg for each
active TCP connection.  Have 50 people connect to your web server
via dialup and the kernel may eat up 50 Meg of memory trying to
serve them.  That's why the OS defaults have been so low for so
long.

The auto-tuning method I referenced dynamically changes the size
of the window based on the free memory and the speed of the client
allowing an individual client to get as big as it needs while
insuring fairness.

On a single user system with a single TCP connection they both do the
same thing.  On a very busy web server the first may make it fall over,
the second should not.

YMMV.

--=20
       Leo Bicknell - bicknell@ufp.org - CCIE 3440
        PGP keys at http://www.ufp.org/~bicknell/
Read TMBG List - tmbg-list-request@tmbg.org, www.tmbg.org

--AhhlLboLdkugWU4S
Content-Type: application/pgp-signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (FreeBSD)

iD8DBQFHHOatNh6mMG5yMTYRAkxeAKCBiekjTGXAFPUt7V+Uu3/UFgxvtQCcDc36
ATycrUClew0cqajCoP/m8QE=
=7dww
-----END PGP SIGNATURE-----

--AhhlLboLdkugWU4S--


home help back first fref pref prev next nref lref last post