Making the World Safe for Vo-Fi

If there’s one thing the world “knows” about VoIP, it’s the multitude of ways that the quality of packet-based phone calls can be degraded—or shot down entirely.

It’s no secret that running IP-based phone calls over a wired network is fraught with pitfalls. Then imagine how problematic the undertaking is when you add in the complexities and uncertainties associated with wireless networks.

In theory, the mobility provided by a Wi-Fi-equipped phone is a boon to business people, but there’s a price to pay. From the problem of limited bandwidth to the hazards of radio frequency interference, and the insecure nature of the air connection, Vo-Fi (our favorite shorthand for “voice over wireless LAN”) faces many challenges.

Enterprise has reported on a number of companies that track and monitor the performance of voice over wired IP networks—Qovia, SyncVoice, Brix, and Network Instruments, to name a few—but California-based AirMagnet Inc. is the only company we’re aware of that has created a product specifically designed to monitor and manage telephony over wireless IP networks—and hybrid networks that include wireless subnets.

Today, AirMagnet announced the release of version 3.0 of its VoFi Analyzer PRO, and it’s got some noteworthy new features. We spoke with Wade Williamson, the company’s director of product management and got the low-down.

“The idea of voice over wireless LAN is based on efficiency,” Williamson told us. “If you have a system that’s really hard to troubleshoot, it’s going to be hard for that system to be efficient. Having a tool that lets you keep these things up and running the way they’re expected to helps people get what what they were expecting out of these voice deployments.” In a nutshell, that’s what VoFi Analyzer does.

It finds and clarifies troubles that occur on the network, but focuses on voice-related problems. “We’re specifically looking for those types of things that are troublesome to voice applications that might be tolerated just fine in a data application that voice can be a little more sensitive to,” he explained.

“What we want to do is pinpoint what’s going wrong in a call, and give you correlated statistics for those calls,” Williamson said. “What I mean by correlate is if you see a drop in call quality, we want to be able to tell you what happened at the same time. Was there a bunch of guys joining the network at the same time? Was there a spike of data traffic? Something that would give you a good clue to what’s going wrong.”

Analyzer PRO 3.0 brings some innovative ideas to this quest. For the first time, a monitoring tool is sampling three sources of information: air, phone, and wire.

Williamson elaborates: “We’re starting to build an analysis that integrates not only just the stuff that we can hear from the air—which is what AirMagnet has always done—but in this case we’re getting data directly from the phones, and, through integration with Cisco’s Call Manager and Vocera servers, we’re getting some wired-side information. When you can correlate what you can see in the air with both endpoints of a call you get a really interesting diagnostic into what’s going on out there.”

In fact, the integration with Cisco and Vocera isn’t brand new to this version, but it is deepened. The phone data-stream analysis uses Syslog messages—Syslog being the proprietary management system devised by Vo-Fi pioneer SpectraLink to help manage its IP phone deployments—and currently works only with SpectraLink phones.

Another innovation is Analayzer’s ability to read traffic even on fully encrypted networks. “We’re able to do the analysis without decrypting,” Williamson explained. ” Even without looking at the payload, by looking at the traffic patterns and things like that, we can tell what is voice and what’s not; what codec are they using on the voice side, so we can get some really strong analysis even on fully encrypted traffic.”

This allows Analyzer to provide MOS scores (def.) and R-values (another subjective call quality experience rating) without decoding the full protocol stack. “Picture yourself as hospital network manager having problems with VoIP. It really just is not an option to decrypt your network for an afternoon so that you can capture packets and do some troubleshooting,” Williamson said.

If awards are a valid indication, the networking industry thinks Analyzer PRO 3.0 is a big deal. It won a Best of Show Award at the recent Interop in May, and Communication Solutions Product of the Year award. “It’s certainly being very well received out there,” Williamson commented.

The product, which is a software package designed to run on a laptop (for mobility) is available now, at a cost of $12,000. VoFi Analyzer 3.0, identical except for the Syslog and Cisco/Vocera integrations, is $10,000.

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