Chanalyzer is marketed for larger campuses, while the InSSIDer Office and Personal is targeted to smaller environments. I think that both have great value, but in this post I will focus on Chanalyzer.
Chanalyzer + Wi-Spy DBx will give you a view of the “invisible” spectrum that is in a particular area. This licensed product works with a specially created USB spectrum analyzer to help troubleshoot WiFi.
The Wi-Spy DBx USB dongle is a spectrum analyzer that samples the air and gathers the raw RF data to assemble a live view of both the 2.4 and 5GHz bands.
To use Chanalyzer (+ Wi-Spy DBx), you will need to have the software on your device, the supported USB spectrum analyzer dongle and the proper licensing to use the software.
Connect the Wi-Spy DBx to the USB port on your machine.
Open Chanalyzer and the spectrum analyzer RF scan begins immediately… Given there are no issues with licensing, the USB or software.
As you can see in the screenshot above, we are presented with an inviting GUI. In this screenshot I have been running the spectrum analyzer for a while to display a longer time span sample.
Across the top of the GUI are several drop downs that allow you to customize the view, select scanning options, using report builder, tools, help, etc… There is also an option to use a CleanAir AP, which will be covered near the end of this post.
Along the bottom pane is radio details. In the bottom left pane is the radio that is collecting wireless network information (Wi-Fi drop down) and the right side displays the radio(s) that are conducting the spectrum analysis.
On the left is the Time Span navigation window. This allows you to adjust and review snapshots from different segments during the session. Notice that there are 2 time span windows in my screenshot with an arrow over the left column — This is because I am sampling the RF with 2 cards and the arrow allows me to switch between bands in the time span column as well as the main overview window.
The main window on the right side is the RF spectrum density overview in real time. There are a few display options on top of this window that allow you to review the spectrum analysis data with different display options selected.
The bottom large window has all of the wireless network information, being reported by the radio that you chose to do so. My image shows the Networks Table option — This window allows you to see an overview of the WLANs, select different WLANs for inspection and you are also able to filter using the FILTERS options.
Now that you have an brief overview of the GUI, I really want to talk about the data that you see in the time span and main overview window.
The spectrum analysis data is presented in a waterfall format and has color coded data entry points that plot along the waterfall display. The color represents the amplitude level of the incoming signal. The scale swings from light blue to dark red (red being the strongest).
Luckily I wanted some popcorn, so I fired up the microwave. As you can see below the microwave created an increase in data points in the waterfall which reflects the increase in amplitude — Very useful view for troubleshooting.
The main spectrum overview viewing options are also helpful for troubleshooting, especially when used in conjunction with the WLAN information window.
Ex: Select the NETWORKS tab and then select the WLANs from the network table on the bottom of the GUI to show the networks in an overlay in the main overview window.
Ex: Select the INSPECTOR tab to mouse over the main display window for real time frequency information about the particular mouse over data point.
You are also able to use your mouse to sweep a selection of the band for a Frequency Zoom to take a deeper inspection at a particular spread in the spectrum. Doing this will open up a new window and restart the ‘capture’.
This data all looks great with the DBx USB card, but wait ’til you get a load of this…
CleanAir, the Cognio chipset and Chanalyzer… The spectrum analyzer
ménage à trois love affair… And who doesn’t like to be able to remote T-shoot?
We will need to configure an AP to work with the CleanAir functionality built in to Chanalyzer, but first open the CleanAir tab on Chanalyzer.
After selecting ‘Connect to a CleanAir AP’ a box will appear. The information for these fields will be provided by the next step.
For this example, I am using a Cisco Lightweight Access Point on my 2504 WLC with a 3602e AP (no WSSI module).
The access point (AP) should be flipped to SE-Connect mode — This will impact clients. You can do the CleanAir setup in local mode, but you will only see data for the channels that the AP is currently on. In SE-Connect mode the AP will scan all available/supported channels.
All of the information you need for the Chanalyzer CleanAir prompt seen above and also the functionality to change the AP mode is on one page of the WLC. This is found under WIRELESS > All APs > Your AP
Note the highlighted areas correspond with the Connect to CleanAir AP form from above
Change the AP mode to SE-Connect and apply the changes… The AP will reboot. Once the AP has joined the controller after the reboot, navigate back to WIRELESS > All APs > Your. Copy and Paste the AP’s IP address and Network Spectrum Interface Key (NSI Key) to the corresponding box in Chanalyzer. Next enter a friendly name, so that you can easily move between CleanAir APs.
WLC CLI Resource:
config ap mode se-connect LAB-AP-1
- Changing the AP’s mode or submode will cause the AP to reboot.
Are you sure you want to continue? (y/n)
show ap config 802.11(variable) LAB-AP-1
show ap config general LAB-AP-1
The Chanalyzer GUI does have a few changes in this mode, but what is most noticeable is that the data that is presented is much better looking – This is thanks to the built in chipset that the AP is using for spectrum analysis.
Behold – The cliffs of Meta!
Not only is the overview box data much better to look at, but by having this option to change a lightweight AP mode, I am now able to view spectrum analysis remotely. Yeah — That is pretty cool!
I have not covered all of what these products are capable of, but this should give you a good overview and help you to start exploring and learning the interface.