[43211] in North American Network Operators' Group
Re: Traffic Shape or Rate Limit
daemon@ATHENA.MIT.EDU (Joe Abley)
Tue Oct 2 12:59:40 2001
Date: Tue, 2 Oct 2001 12:58:54 -0400
From: Joe Abley <jabley@automagic.org>
To: Deepak Jain <deepak@ai.net>
Cc: "Christopher J. Wolff" <chris@bblabs.com>, nanog@merit.edu
Message-ID: <20011002125854.E36532@buffoon.automagic.org>
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On Tue, Oct 02, 2001 at 12:51:39PM -0400, Deepak Jain wrote:
> Everything drops packets if you fill the buffers...
>
> Rate limiting vs Traffic Shaping is about intent and QoS in my experience.
There are some devices that attempt to control traffic without
filling buffers, such as the PacketShaper range of products by
Packeteer. The PacketShapers control performance of individual
TCP sessions by modifying the window size advertisements in flight
to simulate reactions to congestion conditions.
I have used PacketShapers before. They can be very capable and
useful boxes if matched to appropriate traffic/flow volumes (and
if the applications responsible for the traffic being shaped are
tolerant of the layering violations that the boxes engage in).
Joe
