Traffic Shaping/Simulating slower network connections

While scanning my RSS feeds this afternoon, I caught the headline Traffic Shaping in Mac OS X. Very cool. I knew Dummynet support couldn’t be super far away from the Mac, but frankly I’d never looked.

When I wanted to drive a network connection down the 28.8k modem speeds, I found a POS intel box and slapped FreeBSD on it. This was all for testing purposes – it’s a lot easier to “make” a 56k modem connection than to purchase a landline these days. In fact, I wrote a fair bit about it back in June.

One of the things that came to me when I was reading Clark’s article was that making a little shell script for your Mac could make for a really quick and easy test setup if you’re developing or testing websites. You can slim down your own network connections and either host the site from your laptop, or you can do the reverse and see how your site looks from Safari or Firefox. Just remember to make a script to underdo the traffic bandwidth restrictions, or you’ll be hollering in no time.

At my last job, there were several times when I was doing some crazy network connection testing in the field and needed a backchannel. Fortunately, an iBook with a bluetooth telephone nearby made it all work when we couldn’t get the satellite link to establish.

Published by heckj

Developer, author, and life-long student. Writes online at

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