For years, I have used NetStumbler as my primary Wi-Fi network discovery tool. No longer, Nuts about Nets, LLC has stolen my allegiance with a program called NetSurveyor. Before discussing the tool, I would like to share some information about the company. Founder Steve Leytus describes Nuts about Nets, LLC as:
“A leading innovator of low-cost, PC-based, Wi-Fi diagnostic tools used for installing, optimizing, and troubleshooting 802.11 (Wi-Fi) networks. We continually strive to develop new and easy-to-use tools that professionals and non-professionals alike apply in the real world situations to gain optimal performance from their wireless networks.”
I believe it. The company has developed PC-based RF spectrum analyzers, Wi-Fi channel analyzers, 2.4x and 5.x GHz channel/signal generators, and 802.11 packet injectors. NetSurveyor and NetStress are the two I write about and are free. I also tried several of the for-pay applications, besides being inexpensive, they perform well and have features of devices costing a great deal more.
While checking out the Web site I came across a comment that hit home. Telling me that Nuts about Nets was using a different approach:
“Unless one has intimate knowledge of the 802.11 standard and its inner workings, it is not possible to predict how an 802.11 network will behave when you are armed solely with RF measurements. This is why we focus on performance metrics. They more accurately predict how your wireless network will actually perform.”
Wanting to know more about the performance metrics, I phoned Steve Leytus and asked all sorts of questions. Mr. Leytus was patient, yet enthusiastic with his answers. One would expect no less, from the owner of a company called Nuts about Nets. Here is what he had to say:
TechRepublic: Nuts about Nets, LLC is certainly a unique name. How did the company get its start?
Leytus: Two unemployed friends-a software engineer and Boeing assembly line mechanic-decided to combine their experience, skills, and interests to start a computer network install and consulting business. Early on, it became apparent that inexpensive tools for troubleshooting Wi-Fi networks did not exist. We saw this as an opportunity and changed our focus. That shift led to our first product, AirSleuth, an inexpensive 2.4 GHz spectrum analyzer.
Choosing a name for a company is tough. We wanted a name that conveyed what we do (the ‘Nets’ part) and also that we enjoy it (the ‘Nuts about’ part). The world is full of serious issues. Troubleshooting Wi-Fi networks is not one of them. We wanted to keep things light, conveying to others that we are passionate about our work. Yet, we also understand the world will not come to an end if people do not use our tools.
TechRepublic: You have a wide array of products. Could you describe the different product classifications?
Leytus: When one is faced with troubleshooting Wi-Fi problems, the task may seem daunting. Not because Wi-Fi is so conceptually difficult to understand, but because you can’t see or touch the medium.
One approach to solving problems is to break them down, performing measurements on each component. The “data points” you accumulate are used to fill in the puzzle of what is working and what’s not. We have the following four basic product classes that mirror well-tested troubleshooting strategies:
- Network Discovery: The process of detecting beacon packets transmitted by 802.11 access points.
- RF Spectrum Analysis: The process of detecting all RF transmissions within a frequency band. Mainly used to identify interference sources.
- WiFi Channel Analysis: The process of measuring RF interference using an 802.11 network adapter. This approach better predicts how a Wi-Fi network will actually perform in the current environment.
- Connection Analysis: The process of measuring throughput performance of 802.11 devices when connected to a Wi-Fi network. The ultimate metric when it comes to troubleshooting a network.
TechRepublic: Your approach for determining which channel to use is different. Does it involve Indirect Measurement of Microwave Interference (IMMI) technology? Could you explain how IMMI works?
Leytus: When it comes to troubleshooting Wi-Fi networks, 802.11 devices make better diagnostic tools than spectrum analyzers. That’s because a spectrum analyzer knows nothing about the 802.11 standard, its internal protocols, or the methods used to mitigate interference from other wireless devices.
As to how IMMI works, I can only speak in generalities, because the patent process is not finalized. I can say, the IMMI software uses a standard 802.11 device to query each channel for its “potential” or “available” throughput performance.
It turns out, most Wi-Fi problems are solved by changing to a better channel. This is because:
- The interfering device may belong to someone else and you have no control over it.
- The interfering device may be different wireless technology (e.g. a wireless security system).
- It’s not easy to track down the source of interference.
Here’s an example: Suppose you are tasked with installing a new Wi-Fi network. But, you are limited to using either channel one or two. Also, the company next door is using channel one. So, which channel do you use for your new network? Channel two, right? Wrong.
Inherent in the 802.11 standard is the ability to “arbitrate” channel usage. That is, two APs using the same channel will share the medium. That allows the APs to sense each other and coordinate their use of the channel.
It’s not optimal, but at least they are sharing.
If the two APs are on adjacent channels, they see one another as interference. They can’t share and end up blocking one another. Unlike non-802.11 devices such as a spectrum analyzer, IMMI understands that adjacent channels are being used and promotes using the same channel.
Our latest product, WifiEagle employs IMMI technology to quantify throughput performance of each channel. Not only does this allow you to determine the best channel. You can predict (in a quantitative way) the increase or decrease expected by reconfiguring an access point to use a different channel.
Two Nuts about Nets tools
Now I’d like to focus on my two favorite applications, NetSurveyor and NetStress. And it’s not because they are free, but that helps. Both tools will give the person responsible for the health of a Wi-Fi network a good idea as to what’s happening in the physical space as well as actual RF links. First, let’s look at NetSurveyor.
NetSurveyor is an 802.11 network discovery tool similar to NetStumbler. Both gather information about local Wi-Fi access points in real time and display it. NetSurveyor includes these additional features:
- The data is displayed using a variety of different diagnostic views and charts.
- The data can be recorded for extended periods and played-back at a later date/time.
While testing NetSurveyor, I found that I did not quite understand the terminology used on the diagnostic charts. So, I asked Steve Leytus if he would explain them:
“The tabs show the same data but from different graphical perspective. Often, when data is charted a feature jumps out in one chart that was not apparent in another.”
The following are his description of diagnostic charts:
AP Timecourse: This chart displays the beacon strength of each access point as a function of time. The Y-axis reports the signal strength as a signal quality (0 - 100%). Where a maximum signal is assumed to be -20 dBm and the dissociation signal is -85 dBm.
AP Differential: This chart displays the current beacon strength of each access point compared with a snapshot taken at an earlier point in time. This way, you get immediate feedback as to whether anything changed and if it was for the better or not.
Channel Usage: This chart combines access points by channel and displays a summary of channel usage. The Y-axis reports the signal strength of beacons as a signal quality (0 - 100%). This chart is helpful, as it shows how active a particular channel is.
Channel Timecourse: This chart also combines access points by channel. However, the channel usage is displayed as a function of time.
Heatmap: This chart combines the access points by channel, with the summary of channel usage being displayed as a waterfall graph. Each horizontal line represents beacon signal strengths by channel measured during one scan. The color legend to the right indicates signal strength, with red being the strongest.
Spectrogram: This chart is a 3D view of channel usage as a function of time. Each channel is represented by its own set of bar graphs. Essentially it combines the Channel Usage and Channel Timecourse views into a single 3D chart.
That certainly is a lot of useful information from a free app. Let’s move on to NetStress.
The main purpose of any IT network is to move data. Optimizing throughput would then be considered an important metric and that’s what NetStress is all about. The tool generates network traffic and analyzes the network’s throughput performance. Steve Leytus mentioned that:
- Using NetStress to create a reference benchmark will facilitate troubleshooting when something happens to the network’s performance.
- NetStress can also be used to get real-time feedback about any modifications made to the network.
I have used similar products, but none this feature rich and easy to use. That said, I read how NetStress is being revised for the better. I asked Steve Leytus about that:
“We’ve received lots of good suggestions for new features. The next version of NetStress will include the following:
- Ability to use TCP packets, UDP packets, or both
- Control packet size
- Choice of uplink and/or downlink flow
- Create multiple data streams”
It became obvious that Steve and Nuts about Nets know a lot about 802.11-diagnostic equipment. I had one last question for him. For the uninitiated, what tools would you suggest?
“First, NetSurveyorand NetStress are obvious choices. They provide useful information about the Wi-Fi landscape. The next tools I would recommend are WifiEagle and AirHORN.
WifiEagle uses IMMI technology to help determine which Wi-Fi channel will provide the best performance-and that’s what it boils down to most of the time.
AirHORN is the only RF source on the market that transmits on the channels you select. Using WifiEagle to view RF activity, it’s interesting to fire-up AirHORN and see the RF activity. It helps breakdown the mystery surrounding wireless communications.”
I’ve put both NetSurveyor and NetStress to good use already, significantly increasing a client’s Wi-Fi network throughput. Have to admit, I like tools that make my job easier.
Lest I forget, thanks to Steve Leytus for creating these tools and his insight in answering my questions.