Today, for some reason, I was sufficiently motivated to diagnose (and workaround) the problem. To start with, I had to be able to measure the performance. I wanted something objective to keep myself honest. While potentially not the most accurate system in the world, I chose to go the quick and easy route and benchmark my cable Internet connection using http://speakeasy.net/speedtest. I'm in San Francisco, so I clicked on the San Francisco server and launched the speed test.
Before reporting the numbers, let me quickly describe my setup. I'm using a MacBook Pro which has an Apple AirPort Exterme 802.11n WiFi card. I was connected over WiFi to a Linksys WRT160N (802.11n) wireless router running firmware version 1.02.2. The wireless router is then connected to the cable modem.
So here were the results from my initial speed test:
- Download Speed: 1132 Kbps
- Upload Speed: 11288 Kbps
I decided to eliminate one variable from the equation. WiFi. I rummaged through my box of cables and dug up an Ethernet cable. I could have connected my laptop straight to the cable modem, but out of laziness, I connected it to one of the Ethernet ports on the back of the wireless router. I ran the speed test again.
- Download Speed: 20929 Kbps
- Upload Speed: 11278 Kbps
- Mixed
- BG Mixed
- Wireless-G Only
- Wireless-B Only
- Wireless-N Only
- Disabled
- Download Speed: 8865 Kbps
- Upload Speed: 8701 Kbps
Finally, out of curiousity, I tried Wireless-N Only. Here I get the same awful performance as when I started this whole exercise. In addition to these experiments, I tried doing the same thing from a Linux desktop that I have which only supports 802.11g. The machine is not too close to the wireless router and the signal strength isn't great. But the results from that machine follow the same trends as those collected from my MacBook Pro. So, it seems that the 802.11n mode on the WRT160N leads to bad performance.
I checked Linksys's website and it seems I have the latest firmware. A very cursory web search for this problem turns up nothing. I wonder if this is somehow unique to me or some other configuration option I have. Very odd... I'm just happy to have zippy Internet access again!