WifiNigel

I've been read lots recently about BYOD and how many users in an organisation may well have 2, 3, 4 or more devices that they wish to use on a WiFi network. The will often have a laptop, possibly a tablet and almost certainly some type of smartphone. The characteristics of these different types of device vary enormously, depending on the device capabilities and their RF characteristics. I thought it might be interesting to just fire up 4 random devices I have in my home and compare the signal levels I could see from the same SSID on my home ADSL router. Each device had some type of software installed that could (allegedly) report the signal level that the AP is observed at from the client device point of view. I know this isn't a particularly definitive approach, as the software used probably has varying levels of accuracy, so I wouldn't treat these results as being too accurate. But, they may give an indication of different device performance. The devices I tested

Here's an interesting little gotcha I wasted a few hours on recently... I have been looking at QOS on a Cisco WLC and was looking at DSCP markings in CAPWAP packets between a Cisco WLC and access point. I did this by spanning the switch port that the AP is connected to and then using a copy of Wireshark on another switch port to capture the traffic so that I could have a look through it. However, when I looked at the CAPWAP frames, Wireshark was reporting most of the CAPWAP packets as being "Association Requests" and that they were "[Malformed Packets]". After testing this in quite a number of versions of Wireshark (assuming a Wireshark decode bug), I finally gave up and reported a bug to the guys at Wireshark. They were incredibly quick to respond and diagnosed the issue very quickly! It turns out that Cisco have not implemented the final draft of CAPWAP (according the guys at Wireshark), and that there is an option in Wireshark for Cisco CAPWAP support

There are many configuration settings on a piece of networking kit that are just 'there'. They sit there year after year just minding their own business being a quiet little chunk of configuration sitting in their default state not doing anyone any particular harm. Then, occaisionally, you come across some obscure case that causes you to actually pay attention to what exactly that particular setting is 'bringing to the party'. One particular instance I came across recently is the 'Fast SSID Change' setting on a Cisco WLC. From memory, it's been sat there for quite a while on many of the controllers I've installed, sitting dutifully in its default state of 'Disabled'. I've never really paid it much attention as it doesn't (on the face of it) seem to cause anyone any particular problems. However, I recently ran in to a situation where a customer had some Apple iPads that he wanted to connect to an SSID that was mapped to an internal