Run it like
throttle -p 3000 -d 1000ms -s 256Kbit/s start
d - network delay you want
s - speed
I used to use the ipfw commands directly. I didn't want the client to remember the syntax and also starting and stopping the throttling involved a couple of commands which can go wrong. So I wrote this and also had some default values so that he can just do throttle start and throttle stop
It's called the "network conditioner" and it does lag, packet loss, latency, bandwidth limiting, and more. And it's free.
I can't recall the names of any dev shops for the OSX products I have purchased, much less the ones I use for free.
I have no problem with people selling simple tools that make built-in features more accessible.
I would need to test my virtual-connection-over-UDP code with packet loss, latency and incorrect packet order delivery and I really wouldn't want to write code inside my app to test.
Lets you set up a linux box to act as a configurable router that does network emulation. Useful if you want to test devices that don't have their own emulation options.
Are there good examples of using tc to emulate a crappy connection?
At least this guy has the decency to point out that it's already built into OS X right there on the landing page ;)
If you need to do this stuff to a saturated gigabit pipe in both directions, then may I suggest the superbly named 1U Network Nightmare, yours for only $9999.
Available on Windows / OS X / Linux
One the downside it needs Java!
Does the same thing and is free!