Arnaud's Blog

Opinions on open source, standards, and other things

The cost of wifi and wifi security

I break a long silence to write about something I just found out about wifi and wifi security. Admittedly it may not be an earthshaking discovery but having searched for info on the subject it doesn’t seem like it is covered much so it seems worth a blog post (plus, for once, I can give this higher priority than everything else.)

There is a lot of info out there on how to set up your home wifi and set it up to be secured. However, little is said about what this will cost you. I mean in loss of speed.

I did some tests over the weekend and here is what I found, using, with a cable internet connection:

Directly connected to the cable modem (no router, no wifi): ~23Mbps download

Connected via cable through my router (“Belkin Wireless G Plus Router”), no wifi: ~17Mbps download. Gasp, that’s a 25% loss right there. I’m no network expert so I don’t know if that’s normal but I sure didn’t expect to lose that much just going through the router. But that’s actually nothing. Read on.

Connected via wifi through my router, with an open connection, no security: ~14Mbps download. Ouch. Here goes another 18%. Unfortunately that’s not even close to be the end of it.

Connected via wifi through my router, with security set to WPA-PSK TKIP: ~8Mbps download. Wow! That’s yet another 42% loss just for turning the security on, which every website out there says you MUST do.

The loss due to the security setting motivated me to run tests against the various security options my router supports. It turns out that all WPA options and WEP 128bits basically lead to the same poor results.

Setting security to WEP 64bits is the only security option that doesn’t severely impact performance: ~13Mbps.

Sad state of affair!

WEP is known to be very weak and easy to break in minutes by a knowledgeable hacker. 64bits is that much faster to break than 128bits obviously.

So here you have it. The choice is between fast and unsecured or secured and slow. Stuck between a rock and a hard place.

Obviously results will vary depending on the router you use but, here is the rub: when shopping for routers I find very little/no info on the impact of turning security on. Most products claims are typically in optimal circumstances, as in “up to xxx”. and relative, as in “10x faster than xxx). This is of no help determining what performance you will actually get.

One thing that plays a role in the performance you get is the CPU your router is equipped with. Yet, from what I’ve seen, this is not a piece of information that is readily available.

To make matters worse, from what I’ve seen, websites such as CNET don’t highlight that aspect either. So, you’re pretty much on your own to figure it out.

Beware. Run some tests and see for yourself what you get.


November 28, 2010 Posted by | standards | , , , , | 9 Comments