Thursday, February 21, 2008

The Taste of Draft 802.11n

Lately, I found myself using only laptops at home, often accessing a Linux based file server. Both my and my wife's laptops are MacBooks with 802.11n built in. It kind of made sense to me to try to find 802.11n replacement for my good old proven Linksys WRT54G.

How it went. Well, so so. The standard is still not finalized, and there will probably be a lot of improvements in next few years while it gets more mature.

My first attempt was with Linksys WRT600N. It's an awesome device, with two radios. Meaning it can work on both 2.4GHz and 5GHz bands at the same time. However, there wasn't sufficient amount of love between my MacBooks and Linksys.

The first problem was very poor signal quality on 2.4GHz band. There was about 12 or so wireless network competing around. The WRT600N defaults to automatic selection for frequency and wide channels, and automatic settings made a really poor choice. They choose channel 1, which in my building is next to unusable for whatever reason. They also opted for wide channel, which simply wasn't going to fly in so crowded environment. Setting channel manually to 6 or 11, and turning off wide channel made things usable. However, 802.11n crippled into narrow channel on overcrowded 2.4GHz band gave me about the same transfer speeds as I was having with my good old WRT54G.

The 5GHz band looked much more promising. There were no other networks around me using that band. I got transfer speeds around 8 MB/s. Almost the speed of 100mbit Ethernet, and not exactly 2 times faster than theoretical maximum of 802.11g. Considering much lower transfer speeds I was getting on WRT54G, it was significant improvement.

However, the connection between my MacBooks and WRT600N when using 5GHz band simply wouldn't stay up. The devices would connect, work for a bit, than my MacBooks would loose connection to WRT600N for 5-10 minutes. Then they would reconnect, and work for some time, and drop connection again. An excessive amount of playing with manual settings did not improve a thing.

I also bought an WRC600N PCMCIA adapter and plugged it in an old Windows laptop. Needless to say, connection between WRT600N and WRC600N works perfectly. No drops.

Obviously, there was compatibility issue between MacBooks and WRT600N. I hope folks at Apple and Linksys will work things out in the months to follow. It would be interesting to try again once either of the companies makes firmware updates for their respective devices.

WRT600N is relatively expensive device, and it wasn't working for me. Waiting if an firmware update is going to be released (one day in the future) that would improve compatibility with Apple laptops, wasn't really an option. So I exchanged it for an Apple Airport Extreme wireless router.

Airport Extreme has only single radio, so you can choose between 2.4GHz or 5GHz bands, but can't have both at the same time. I decided to use Airport Extreme at 5GHz, and keep old WRT54G around to handle 2.4GHz band for older devices. Airport Extreme also has USB port, to connect both printers and hard drives (it shares them to both Windows and Mac OS X computers). However, don't expect much performance for disk sharing. I got about 1 MB/s accessing USB hard drive connected to it, which is *slow*. The new Time Capsule from Apple will probably correct this.

The network transfer speeds I was getting with Airport Extreme were about the same as with WRT600N, around 7-8 MB/s, peaking at 10 MB/s. Still about 3 times slower than theoretical maximum for 802.11n on 5GHz band. Still much faster then what I was getting with my old WRT54G. However this time, there were no problems with connection between MacBooks and base station dropping. It just worked. Love was in the air.

Interestingly, the WRC600N PCMCIA card in Windows laptop was showing slightly higher connection speeds when connected to Airport Extreme, than when connected to WRT600N. The Airport Extreme was definitely radiating more love into the air.

One nice surprise was that Airport Extreme have support for IPv6. I can't comment on how good it is, but it is there. WRT600N, just like some other Linksys routers I tried in the past talks only IPv4.

Here's the list of some pros and cons I've run into during short time I was playing with those two wireless routers.

Linksys WRT600N pros:
  • True dual-band, handles both 2.4 and 5GHz networks at the same time
  • Very configurable
  • Linksys routers were historically very robust
Linksys WRT600N cons:
  • Compatibility problems with Apple MacBooks
  • No IPv6
  • No printer sharing, Linksys sells separate print server for extra $$$
  • More expensive than Airport Extreme
Apple AirPort Extreme pros:
  • Well, works with Apple laptops, and seems it also works with Linksys clients
  • IPv6, if you want to play with it
  • Both disk and printer sharing (however, disk access relatively slow)
  • Cheaper than WRT600N
Apple AirPort Extreme cons:
  • Not as configurable as average Linksys router
  • No DDNS support
  • Can work at either 2.4 or 5 GHz bands, but not both simultaneously, if you choose 5 GHz band, you'll need second router to support single band 802.11n and older 802.11b and 802.11g devices
For an average Windows user, both devices would probably work about the same. The printer sharing of Airport Extreme is a nice bonus feature which could sway average users to choose it over WRT600N. For Apple MacBook users, there's probably not much choice. WRT600N will work with MacBooks on 2.4 band, but don't expect full 802.11n performance you'll get out of Airport Extreme. Advanced users of either platform will have to choose which features are important to them, and buy accordingly.

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