Sniff Wi-Fi

Everybody likes high Wi-Fi speeds.  Because high Wi-Fi speeds mean that the channel is being used more efficiently ( often false ).  An efficient channel means that there's more available throughput ( only in sterile test environments ) and more available throughput means that more users can be supported concurrently ( completely wrong ). Unfortuantely, high Wi-Fi speeds sometimes  ( all the time )  come at a cost.  To get higher Wi-Fi speeds, wider channels must be used ( which makes the Wi-Fi suck ).  Using wider channels means that fewer channels will be available ( plus it ups minimum RSSI requirements, which just about guarantees a bad design ).  It is therefore essential that wireless professionals analyze the environment and carefully choose whether to use 40 MHz or 80 MHz wide channels ( or they could stop wasting everyone's time and just stick to 20 MHz channels ). But this blog post isn't about choosing the correct channel bandwidth ( although it should be, b

Two years ago tomorrow Apple introduced the iPhone 5.  It was a big deal.  It was a big deal for gadget folks who wanted a bigger iPhone.  It was a big deal for wireless LAN folks who wanted users to use smartphones with speedier WiFi.   Now the iPhone 6 has been announced and it appears to be more of the same.  Gadgeteers get their bigger iPhone.  Wireless folks get their faster speeds.  Problem is, the faster wireless speeds likely won't mean anything for high capacity wireless deployments. The big news about the iPhone 6 is 802.11ac.  Yippee!  Apple has finally adopted the latest and greatest WiFi standard in a mobile device. 802.11ac has data rates as high as 6.9 Gbps in the standard, but wireless LAN folks know that's not what happens in real life.  Real 802.11ac devices top out at a 1.3 Gbps data rate when multiple input-multiple output (MIMO) antenna systems are supported, while non-MIMO devices top out at 433 Mbps. The iPhone 6 and iPhone 6 Plus are non-MIMO 8

As long time readers of this blog might know, WildPackets OmniPeek has been my favorite WiFi sniffer for nearly a decade.  Then I found out about WildPackets' OmniWiFi 3-stream 802.11n USB adapter and I fell even more in love.  Now I learn that OmniPeek 7.5 has added wireless features to the Compass screen.  A good product has been made better (though time will tell if it lasts). First, OmniWiFi: The fact that different 802.11n devices have different capabilities is one of those things that sometimes flies under the radar.  The standard may say 600 Mbps, but just on the Apple website one can buy 802.11n devices with maximum rates of 65 Mbps (iPhone 4S), 150 Mbps (iPad Mini), 300 Mbps (Macbook Air 2012) and 450 Mbps (Macbook Pro 2012). 450 Mbps WiFi devices are the ones that give WiFi pros trouble because so many sniffing tools fail to capture 450 Mbps traffic.  The popular (at least with Wireshark devotees) AirPcap NX from Riverbed, the beloved (at least by yours truly) D-Lin