[21428] in bugtraq
Re: Small TCP packets == very large overhead == DoS?
daemon@ATHENA.MIT.EDU (Darren Reed)
Tue Jul 10 02:49:13 2001
From: Darren Reed <avalon@coombs.anu.edu.au>
Message-Id: <200107092228.IAA26460@caligula.anu.edu.au>
To: c3rb3r@hotmail.com (gregory duchemin)
Date: Tue, 10 Jul 2001 08:28:06 +1000 (Australia/ACT)
Cc: bugtraq@securityfocus.com
In-Reply-To: <F26660mqvgCBoE1pbzE00006a62@hotmail.com> from "gregory duchemin" at Jul 09, 2001 07:00:57 PM
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In some mail from gregory duchemin, sie said:
>
> hello,
>
> know if the TCP silly window syndrome might be used too ?
> Uploading/downloading files byte per byte to/from a remote ftp server with a
> stupid window size of one byte may generate a very high overhead.
Silly window sizes aren't so bad. If you have a window size of one then
you only ever have one outstanding piece of data sent at a time. So if
I have 16k of data, it might take 32k or more packets, but I can only send
one packet at a time.
In contrast, if I have a window of 16384 but the TCP MSS is only 1, I can
send all 16384 bytes now, each in their own packet, and more as I get ACKs
from the receiver.
Darren
