iOS Simulator - testing over different connection types

I've been using trafic shaping for quite a long time to simulate slow or noisy connections, but finally made a script for that :)

#!/bin/sh


if [ "$#" -ne "3" ]

then

    echo "Usage:\n$0 <bandwidth in kpbs> <delay in ms> <packet loss ratio>";

    exit 1

fi  




BW=$1

DELAY=$2

PLR=$3



sudo ipfw pipe 1 config bw ${BW}Kbit/s delay $DELAY plr $PLR

sudo ipfw add 1 pipe 1 all from me to not me

sudo ipfw add 2 pipe 1 all from not me to me




echo "RETURN to stop connection noise"

read

sudo ipfw delete 1

sudo ipfw delete 2

exit 0

The script will simply add a pipe to your firewall with the bandwidth, delay and packet loss you specify and redirect all of your Mac's trafic over that pipe. It than waits for RETURN to delete the rule and get your trafic to normal.

Here is a table with some usefull parameters taken from :

http://blog.aptivate.org/2010/01/23/make-sure-your-apps-work-in-the-field/

Scenario	Bw (Kbit)	delay (ms)	pr (ratio)
2.5G mobile (GPRS)	50	200	0.2
3G mobile	1000	200	0.2
VSAT	5000	500	0.2
Busy LAN on VSAT	300	500	0.4

For more bandwidth info check:

http://en.wikipedia.org/wiki/List_of_device_bit_rates