802.11 Quick Review
Sometimes when I teach folks to use Protocol Analyzing tools, they don’t know where to start. So I have them go through the following table as a quick review of 802.11 behaviors. If you know how 802.11 is supposed to work, really understand the protocol, then with very little information you can make judgments about how your wireless network is working.
Here are the ‘basics’ that every Wireless LAN Professional needs to understand intrinsically. This should be fairly second nature to you.
So if you see a network with lots and lots of Management frames, and hardly any Data or Control frames, you can deduce you have an ‘Idle’ network. Learning to recognize these ‘ratios’ will help in your troubleshooting efforts.
802.11 Quick Review
| Size | Speed | Distance | |
|---|---|---|---|
| Control | Tiny | 1Mb | Far |
| Management | Small | 1Mb | Far |
| Data | Huge | Fast | Near |
| Control | Management | Data | |
| Idle Network | Small | Huge (Beacons, Probes) | Small |
| Good Network | 1:1 Ctrl to Data Ratio | Is What It Is | 1:1 Ctrl to Data Ratio |
| Bad Network | 1:3 Ctrl to Data Ratio (ACK only on Success) | Is What It Is | More data than Ctrl (Retries) |
| Hidden Node | 3:1 Ctrl to Data Ratio RTS-CTS-ACK | Is What It Is | More Ctrl than Data |
If you have any small tables or ‘tricks’ on how use troubleshoot your wireless networks, please send them along to feedback@wlanpros.com
WLW 012 – University Wireless / Financial Ruts
University Wireless / Financial Ruts Audio clip: Adobe Flash Player (version 9 or above) is required to play this audio clip. Download the latest version here. You also need to have JavaScript enabled in your browser.
First a discussion with Max Lopez of the University of Colorado about issues with running a Wireless Network in a University environment. Max comes with lots of experience, not only at the University, but years in working with a variety of corporations.
The second segment is with Derek Sisterhen, lead financial coach with Lukas Coaching, as well as host of a weekly show called Past Due Radio. He’ll share with us some ways to get out of the financial ruts we might find ourselves in.
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Apple iPad Wi-Fi Detailed Analysis
After the ‘first look’ post earlier, I thought it might be worth the trouble to setup a couple small experiments to see about the differences quantitatively between Apple’s MacBookPro, iPhone and iPad.
First about the iPad’s internal wireless setup. (photos come from iFixit.com) The system is using a Broadcom BCM4329XKUBG 802.11n WiFi + Bluetooth 2.1 + EDR and FM w/2 antenna leads – this small chip allows for multiple RF functions in one package. It is connected to an antenna mounted on the back of the iPad underneath the Apple logo (made of plastic, so easier to get RF signals through)
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