artificial latency for a network interface

From: David McWherter (
Date: Thu Jun 28 2001 - 20:18:36 EST

I once solved this problem using the QoS qdisc facilites:

It works on 2.2 kernels as well.


Andreas Schuldei writes:
> to simulate a sattelite link, I need to add a latency to a
> network connection.
> What is the easiest and best way to do that?
> I wanted to do that using two tun devices.
> I had hoped to have a routing like this:
> <-> eth0 <-> tun0 <-> userspace, waiting queue <-> tun1 <-> eth1
> I need to do it this way and not with iptables help, because it
> needs to work also on 2.2.x kernels.
> Now I started experimenting with the tun0 interfaces and got
> problems: till now I have not succeeded to get a tun0 interface
> up. the example code (br_select.c) in the package (as found for
> example on sourceforge) looks fishy and does not work too well.
> is it correct that only one /dev/tun file is necessary, but
> /dev/tun0 and tun1 are opend for reading and writing?

David T. McWherter

My religion consists of a humble admiration of the illimitable superior
spirit who reveals himself in the slight details we are able to perceive
with our frail and feeble mind.
                -- Albert Einstein
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