AirPort Extreme Base Station 802.11n (2nd gen.): Slower speeds with WPA2 encryption enabled

On numerous occasions, and in our wireless troubleshooting tutorial, we've noted that turning off wireless security (encryption) or switching security protocols (from WPA2 to WEP or vice versa, etc.) can eliminate a number of connectivity issues with AirPort Base stations and third-party wireless routers; these include slowness in throughput, problems establishing connections and more.

This scenario manifested in MacFixIt's testing of Apple's new 802.11n-capable AirPort Extreme Base station, conducted by Ted Landau and published in a column yesterday. Ted found that Internet download speeds were relatively dismal when WPA2 encryption was enabled on an 802.11n connection. Interestingly, the same performance hit did not occur when an 802.11g connection was established on similar hardware. In other words, 802.11n connections with WPA2 encryption appear (at least in some cases) to deliver slower throughput than 802.11g connections with WPA2 encryption.

Note that this finding does not imply faster Internet throughput from 802.11n connections -- the Internet connection tested was not fast enough to saturate either 802.11g or 802.11n connections. Instead, there appears to be some sort of bottleneck introduced by the combination of 802.11n connections and WPA2 security.

Unfortunately, as pointed out by Ted, there is no option to use the alternative WEP security protocol on the new AirPort Extreme 802.11n (WEP is not supported by the 802.11n spec), meaning users seeking to eliminate the bottleneck may need to turn off wireless security altogether, or seek alternative solutions as listed in our wireless tutorial.

Toggling or turning off wireless security can be accomplished using the AirPort Admin Utility (located in Applications/Utilities) for older Base stations, or the AirPort Utility (also located in Applications/Utilities) for the newer AirPort Extreme 802.11n Base Station. For the latter, with the AirPort Utility open, click on the AirPort button at the top of the window, then select the "Wireless" tab and pick your desired option from the "Wireless Security:" drop-down menu.

Feedback? Late-breakers@macfixit.com.

Resources