Re: [nsp] Introducing artificial delay?

From: Blaz Zupan (blaz@amis.net)
Date: Wed May 01 2002 - 11:36:39 EDT


> We're sending some of our staff to Korea next month for the World Cup in
> soccer.
> Based on our experiences from the Olympics in Sydney two years ago we'd like
> to test how their applications perform
> when running from Korea to Denmark.
>
> Any ideas on how we might introduce an artificial delay in our test setup?
> We'll be using Frame Relay or leased line access in Korea, so introducing
> delay between the serial interfaces of two routers could be an option.

You can take a spare PC with two ethernet cards and put FreeBSD on it, then
use dummynet and configure something like this:

        ipfw add pipe 1 ip from A to B
        ipfw pipe 1 config bw 1Mbit/s delay 400ms

This would simulate a 1Mbps link with a 400ms delay. dummynet can also
simulate packet loss. For more information on dummynet you can take a look at:

        http://info.iet.unipi.it/~luigi/ip_dummynet/



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