Sniff Wi-Fi

In my last (real) post, I detailed how I used WildPackets OmniPeek to solve an iPhone 5 QoS problem.  But what about AirMagnet WiFi Analyzer?  I am a fan of both of those fine WiFi sniffers, so I figure it's a good idea to show you how QoS can be analyzed with Fluke Networks' signature WiFi protocol analyzer. WildPackets OmniPeek is more of a hardcore protocol analyzer than AirMagnet WiFi Analyzer is.  If you're going to be doing the type of sniffing I detailed in the last blog post , you will have an easier go of it with WildPackets' product.  But AirMagnet is popular and both tools are expensive.  So if you happen to be a gal (or guy) who needs to troubleshoot WiFi voice or video and you have AirMagnet, this brief tutorial should help. To begin analyzing QoS, one must first capture on the VoFi devices channel.  In my case I associated my iPhone 5 to a network with the SSID of "R&T".  Then I looked at the Start screen in AirMagnet: The "...

My love for WildPackets OmniPeek may be one of the few things in technology that exceeds my love for the iPhone... Now that I've run off 20% of my audience, let's talk about how the former can be used to figure out if the latter is causing a problem. I have a lot of enemies in life, and I'm proud of that.  In my opinion, part of being an adult is recognizing who your enemies are.  UCLA football players are my enemy when they play college football.  Drivers who text while stopped at green lights are my enemy when I am running late.  (No comments from the peanut gallery on that one, GT Hill .)  And deductive reasoning is often my enemy when troubleshooting. Deductive reasoning is oh so tantalizing.  It's simple math; A + B = C.  The WLAN works (C) when VoFi handsets (B) connect to my APs (A).  If I switch out the VoFi handsets for SIP-based iPhones (thus changing the value of B) and the WLAN ...

I am working on an online video project, so I want to test out some videos.  Here's a two minute video on capturing WiFi in Mac OS X.

I am going to try a Reddit AMA. http://www.reddit.com/r/IAmA/comments/1oguh2/im_a_wifi_expert_ask_me_anything/

It's Columbus Day!  A holiday that many of us heard of, a few of us object to and some of us don't get the day off for.  Let's call it a half-holiday. Yours truly is going to celebrate the day by celebrating one of my favorite sniffers, Fluke AirMagnet WiFi Analyzer.  Due to it being half-holiday, this will be a half-efforted blog post.  So no links and no graphics.  Just a little talk about my favorite part of that fine sniffer. AirMagnet WiFi Analyzer from Fluke Networks has been around for a long, long time (at least in WiFi years) and it continues to be one of the top WiFi sniffing options available.  I probably like WildPackets OmniPeek a little bit more because of its ease in manipulating frame traces, but AirMagnet (as I'll call Fluke AirMagnet WiFi Analyzer from here on out) has long been the best option for solving the vast majority of in-the-field WiFi problems. Last week I got to introduce AirMagnet to a few folks and it struck me that eve...

It's a rough world out there, folks.  The economy stinks (or, is great if you live in western North Dakota), finding love is harder than ever (or, easier than ever if you use online dating) and WiFi bandwidth is scarce (or, plentiful if you use the 5 GHz band).  Into this quagmire wades the Google Chromecast.  A cheap ($35 USD), little (about the size of an e-cigarette case) gadget that allows you to mirror your smartphone/tablet/computer screen to your television.  If you want to feel like a member of the 1% (at least, the top 1% of WiFi spectrum consumers), this is the gadget for you. Reviews, tutorials and takes on Google's Chromecast are plentiful, so let's skip that.  On this blog we don't care whether people like the gadget.  We care about what the gadget does to the WiFi.  Does it suck up bandwidth?  Is it chatty during down times?  Does it interfere with existing networks? Let's take the first question last ( Charles Van Doren v...

The iPhone 5 is a chatty device.  How chatty?  I checked, and it is chattier than I thought. Yours truly has done more WiFi sniffing of iPhones than yours truly cares to recount.  What has always stood out about these captures is the amount of chatter than an iPhone seems to engage in. I did a little test of my unlocked iPhone 5 to see exactly how chatty it was.  The test involved me turning on the phone's screen, spending a second looking at iMessage (which happened to be the last app I was on when the screen was turned off), pressing the Home button, opening the Twitter app (because, after all, if you're not on Twitter these days then you're not wasting your time properly) and refreshing my Twitter feed. The test took about fifteen seconds.  My capture saw WiFi frames going to or from my phone for about 17.64 seconds (rounded up to 18 for the purposes of a catchier blog post title).  Here is what it looked like: The good news is that my phone...