Using ipfw pipes for bandwidth management - can it allow for "bursting"?

From: Adam Nealis (
Date: 09/26/01

Date: Wed, 26 Sep 2001 14:14:49 +0100 (BST)
From: Adam Nealis <>

Hi all,

I have perused the list archives and RTFM on ipfw
(which I use on this machine at home). I am interested
in investigating some free bandwidth management tools
and as a FreeBSD fan I'd like to use something that was
part of the core OS.

What I want to do is to restrict connections by IP
address to having a nominal bandwidth, but allow for
occasional bursts.

In going through the ipfw man page, I came across

pipe number config [bw bandwidth | device] [delay ms-delay]
[queue {slots | size}] [plr loss-probability]
[mask mask-specifier] [buckets hash-table-size]
[red | gred w_q/min_th/max_th/max_p]

and it looks like red/gred are important in traffic shaping
and maybe bursting. However, I have been unable to find a
description of what exactly the w_q/min_th/max_th/max_p
parameters mean.

Which brings me here ;)

Am I going along the right lines with this or am I already
tangential? Are there better, (preferably free) tools out
there that I can use for this?

Adam Nealis.

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