Fixed Wireless Equipment

Simplified WLAN Analysis:
The AirMagnet Attraction Part 3 — continued

Peterson noted that many of the "missing" features he originally wanted have since been incorporated into new versions, including external antenna support, ongoing monitoring (now possible with AirMagnet Laptop), and support for other 802.11 standards (now possible with AirMagnet Duo). Still on Peterson's wish list: support for other 802.1X EAP types, use of additional wireless NICs, and the ability to use AirMagnet with a VPN client. In ISP-Planet tests, we had no trouble using AirMagnet and VPN client software like Certicom's movianVPN on the same Pocket PC, but were unable to do so simultaneously. This could inhibit end-to-end ping testing in WLANs protected by VPN tunneling.

Looking ahead
AirMagnet products have moved from handheld to laptop, from 802.11b to 802.11a. An obvious next step would be timely support for 802.11g. Kuan believes that hybrid networks are going to be around for awhile, and that concurrent dual-band support enables more efficient administration. "For example, you only need to do a site survey once with Duo; you don't have to survey 802.11b, then survey again for 802.11a," said Kuan. "Today, if 802.11g shows up, we will see it as 802.11b. In the future, we will have a patch to label these APs as 802.11g. We will treat at least high-speed 802.11g as a different media type."

Support for additional adapters and chipsets (e.g., Agere) can also be expected. "Initially, we felt that [card] binding was a better way to deal with differences in drivers and to provide a better product," said Au. "Long-term, we will move away from being tied to specific cards; we are now looking at models for doing this. For example, laptops and Pocket PCs will have built-in cards, and we want to be able to use these."

Plans to support additional EAP types are unclear. According to Kuan, "If you run EAP-TLS now, it can be configured outside of AirMagnet—AirMagnet controls 802.11 authentication options, but not higher layer authentication options." Nonetheless, we'd like to see AirMagnet analyze other EAP types as thoroughly as LEAP, and we'd like to be able to select from available EAP types when using tools to trouble-shoot connections.

We also expect to see AirWISE alarms expand over time. Several new alarms were added in the last release, recognizing new attacks that have heightened concerns but are not yet often encountered in the wild. Some other analyzers have the ability to define custom alarms, based on user-specified conditions. AirMagnet does not. Many built-in alarms have configurable thresholds (e.g., number of De-Authenticate frames that constitute a flood). But if you want an alarm not in the current list, you'll need to suggest an AirMagnet feature enhancement.

The bottom line
We agree with Peterson: most tasks we attempted with AirMagnet could be performed by anyone with basic understanding of the UI, but little or no RF expertise. Hotspot operators could easily send a field technician to a customer site to gather data, bringing home saved captures, exported objects, and logged survey records to be crunched by RF designers back at the home office. In our opinion, it is not that AirMagnet does more than a traditional network analyzer. (In some cases it does, but in many cases it does not.) The key difference is that AirMagnet feels more approachable, and that translates directly into improved staff productivity.

A few knobs could be clearer—for example, it is easy to confuse exporting data with exporting profiles. Help is good, but context-specific help would be even better. These are relatively minor nits in a product that is otherwise very intuitive. AirMagnet's drill-down, go-back approach keeps the user from getting lost or being overwhelmed at high levels, yet makes detail available as needed. Recording results for later offline analysis is essential; AirMagnet does this reasonably well in ad hoc mode, but automated export would make 24x7 monitoring much stronger—for example, forwarding high-priority alarms to the NOC.

We believe that most WLAN admins can benefit from having AirMagnet in their toolbox. Organizations on a tight budget will find AirMagnet more pricey that shareware, but then again, AirMagnet does much more than NetStumbler et al. Systems integrators and consultants that install and debug WLANs every day really need professional tools. When compared to commercial software, AirMagnet is competitively priced. Being able to use the same PDA for AirMagnet and other applications makes it more economical than dedicated analyzers. Those using AirMagnet on both platforms should purchase a Combo package to trim the pricetag. Requiring a specific PC card and yet another tool for higher-layer analysis are total cost of ownership disadvantages.

At the end of our evaluation, we asked ourselves: Would we use this product? Our answer is a resounding "Yes." We often fire up AirMagnet to quickly debug a glitch. It's not the only tool we use, but we'd definitely miss having it around. The essential question that hotspot operators (HSOs) must ask themselves: Is AirMagnet worth the price? HSOs operating on razor-thin margins hesitate to spend anything unless return-on-investment is clearly demonstrated. In the end, each HSO must make its own analysis. But in our opinion, HSOs (and other organizations) with multiple sites can probably justify purchasing at least one portable WLAN analyzer, and should take a good, hard look at AirMagnet.

—End

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