Rockin’ Fast Network


Normally at work, we have two networks, an unprotected and a protected wifi network, here’s a cool way to implement this. We are going to try this at our Seattle office.

h2. Internally

If you are lucky, you have all new machines from Apple (yeah!) that are 802.11n. These are all the late model MacBook, MacBook Pro and MacBook Air. So now you can have a fast and much safer network. Here is what you need to do:

“Set”:, your AirPort Utility>Airport>Wireless to 802.11n (5GHz) and “use wide channels”. What this does is to push all those MacBooks into the fresh air of 5GHz out of all those 2.4GHz standard cards. That means you have clean radio frequencies and if you aren’t pushing range (2.4GHz propagates better than 5GHz) like an open office, you are going to go from 130Mbps to 270Mbps because wide channel uses twice the channel width so you get double the data. It is also safer in that most laptops only have 2.4GHz radios and should have less interference.

I’ve tried this with an Time Capsule and the results are a little surprising. Copying a 350MB file, here are the speeds I got:

| | | Upload to TC | Download to Mac |
| 802.11n wide channel 5GHz | Macbook Air | 22MBps | 78MBps |
| 802.11n (b/g compatibility 2.4GHz | Macbook Air | 6MBps | 6MBps |

So the loading seems asymmetric as if the MacBook Air has some other issues. The 78MBps is pretty impressive for real world through compared with the 300Mbps theoretical maximum (or 30MBps). The 22MBps seems closer to what is real, so maybe there is some buffering or something going on. Both are impressive though compared with the 802.11n/b/g performance. As an aside, this is with a single computer no the network, so all this bandwidth has to be shared, that is why switched wired Ethernet is still better, each port-to-port connection gets the full 100Mbps or 1Gbps (in Gigabit case).

The conventional 802.11n with a theoretic capacity of 108Mbps seems about right. It is symmetric with a true over the air throughput of 6MBps (about 60Mbps) and on the disk, I get 5.5MBps of disk transfer.

h2. External

Then you can setup another Airport Base Station Extreme or even an el cheapo Airport to 802.11b/g at 2.4GHz and leave this open. This lets devices that are presumably not from your company in. I would put this on the open Internet so folks can have basic access and such.