NetIQs Assessor Gauges VOIP Impact

Determining whether an existing IP network can support satisfactory voice traffic just got easier with NetIQ Corp.'s first release of Chariot VoIP Assessor.

Determining whether an existing IP network can support satisfactory voice traffic just got easier with NetIQ Corp.s first release of Chariot VoIP Assessor.

In eWeek Labs tests, we easily developed and ran tests that showed us where planned voice implementations were likely to succeed or fail. When VoIP Assessor found problems, it generated reports that diagnosed bandwidth, jitter or the voice codec as the likely culprit.

Enterprises that are considering using VOIP (voice over IP) should use VoIP Assessor to verify IP telephone vendor network tests and to estimate the networks capability to handle increasing call loads in the future. Because VoIP Assessor is based on NetIQs Chariot network performance measurement tool, this first-version product has a proven track record of providing reasonably correct predictions about network performance.

Those who are kicking the tires can lease the software, which shipped in October, starting at $4,000 for a month. Enterprise IT managers who are planning to deploy VOIP in stages will likely find the $14,000 fee for a perpetual license a good investment.

The biggest drawback of the product is its lack of testing variability. We could only set up test runs that emulated users making a 2-minute phone call every 5 minutes between 8:30 a.m. and 4 p.m. Although call centers often operate with this kind of static traffic load, very few offices operate this way. We would like to add bursts and lulls in traffic to emulate a more typical workload.

Finisar Corp.s $5,595 Surveyor 4.1 network monitoring software is an able competitor with most of the same capabilities. VoIP Assessors major edge is that it generates better reports. VoIP Assessor uses the MOS (mean opinion score) method to rate voice connections between test sites, and the results are a comprehensive series of measurements summed up in useful reports at the end of the test run.

For an initial pilot program and for senior executives, the summary report is ready for presentation without further modification. The report summarizes likely VOIP performance in the network with thoughtful explanations at each step of the way. VoIP Assessor breaks down calls based on codec algorithms, jitter, delay and data loss. The report provides an overall MOS number with a chart that shows what (if anything) is causing the biggest problem for the test voice traffic.

VoIP Assessor is designed with simplicity and ease of use in mind. Even so, setup can be a laborious task. After installing end points (software agents) on computers where IP phones would be placed, we then had to define test runs, including the codec, call frequency and call duration.

We ran tests over several days using traffic generators to periodically increase the traffic on the network. In tests, VoIP Assessor imposed significant amounts of traffic on the production network during working hours. This enabled VoIP Assessors tests to accurately predict actual performance, but network managers should monitor tests closely to ensure that they dont disrupt or prevent real work.

The long report—in our tests, more than 50 pages—provides detailed analysis of call performance. This information will be particularly useful for network designers who must change infrastructure to accommodate a voice implementation. As with the summary report, the long report was carefully laid out and supplied useful information without much sifting.

Senior Analyst Cameron Sturdevant can be contacted at