In 2004 we tested several wireless LAN protocol analyzers and found two distinct characteristics: Those dedicated and built from the ground up for WLANs, and those that were modest add-ons to what were then labeled classic protocol analyzer products. Three years later, much has changed, but much has remained the same.
Three years later, much has changed, but much has remained the same. The products have grown, some more than others. After subjecting the latest products to several problem-identification tests, we found that AirMagnet Laptop is still the one to beat, as it excels at 802.11-specific analysis. Its rapid analysis and accuracy is clearly at the top of the list. But AirMagnet has considerable and highly evolved competition, so it's going to be difficult for the company to maintain its lead in this area.
We asked for tactical WLAN protocol analyzers, with an emphasis on portability as well as the ability to do spectrum analysis. Three of the four products tested (Fluke's OptiView III, WildPackets' OmniPeek Enterprise and AirMagnet Laptop) use the same card, running the WLAN/Wi-Fi spectrum analysis with largely the same application. None of the vendors that submitted this card (a great one from Cognio) did anything special to relate spectrum analysis to their application.
How we tested WLAN analyzers
It's like having a drill and a circular saw in the toolbox; they're important but unrelated to the core WLAN protocol-analysis applications tested. The fourth product tested, Sniffer Portable from Network General, did not provide spectrum analysis.
All of the products except Fluke's OptiView III used distributed sensor networks to feed data to a central engine. How the data is reviewed is treated differently among the applications. WildPackets and Network General offer a data view that is round-robin, meaning one sensor at a time, though alarms can be sent, received and reviewed via one console.
Otherwise, sensors are treated as separate objects. AirMagnet goes further, treating sensors as objects and offering more empirical object (meaning parental) management of sensors. Fluke's OptiView III is a stand-alone tool, and is not really designed for distributed sensor use, but rather as a tactical Swiss Army knife-like tool set.
Sensors (when used) come in two categories -- a notebook PC (desktops will work for branches and fixed locations as long as they have a wireless card) or a dedicated sensor device, similar to a wireless access point. We reviewed AirMagnet's and WildPackets' sensors. These sensors send information to a mothership engine that in turn serves as a viewing and manipulation/reporting point for captured data.
The differences in these approaches help define the use of the products with distributed sensor capabilities. Two categories emerge -- one in which a product serves as a 24/7 monitoring tool, much like an SNMP tool kit that monitors and watches a network; the second category works more like a tactical field-service tool kit.
The overlapping features for these categories are defined by the vendors -- all but Fluke take an overlapping approach.
Henderson is principal researcher and Dvorak is a researcher for ExtremeLabs in Indianapolis. They can be reached at email@example.com.
Henderson and Dvorak are also members of the Network World Lab Alliance, a cooperative of the premier reviewers in the network industry, each bringing to bear years of practical experience on every review. For more Lab Alliance information, including what it takes to become a member, go to www.networkworld.com/alliance.
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