AVISO Provides Sound Reporting

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A successful voice-over-IP implementation on what was once a data-only network requires extensive network checks. Last month, Alcatel Internetworking Inc. debuted Alcatel Assessment for VOIP Solution, a reasonably good network remediation system for this purpose.

Interestingly, Alcatels AVISO makes a competitor of NetIQ Corp.s Vivinet Assessor. Until now, Alcatel has used Vivinet Assessor to perform network assessments.

In eWEEK Labs tests, we got good information from the $3,330 AVISO software package, but Vivinet Assessor provides much greater detail about Cisco Systems Inc.s network devices, which is crucial for making detailed remediation plans.

AVISO does provide information about the configuration of Alcatel network equipment, and because AVISO uses telephone handsets as end points, it can take longer to install and use. However, it will likely prove to be less costly than competing products.

AVISO software requires Alcatel telephone handsets (sold separately), instead of end points installed on computers, which is how NetIQs Vivinet Assessor works. The advantage of using telephone handsets is that testers can hear the quality of the call.

This agentless approach to testing also means that there is significantly less cleanup work after the tests are completed. It also made AVISO among the easiest network test products that weve ever used. The drawback is that the handsets have to be physically handled, which could add significant time and labor costs to the testing.

One key advantage of AVISO is that we were able to make voice calls between the test phones and hear the quality of the call. Because “hearing is believing” when getting executive support for a VOIP conversion, we found this feature quite useful. Demonstration voice calls placed between the test handsets and supported by AVISO also made it easy for us to hear network problems that caused excessive jitter.

IT managers are likely to see VOIP contractors show up with the AVISO tool to perform network audits in preparation for a voice convergence project. Our tests showed that reports generated from AVISO should provide reliable measures of network performance but give little in the way of remediation advice. As products such as AVISO evolve, we expect to see reports augmented with quality-of-service and configuration suggestions to make voice work smoothly in the enterprise.

In our tests, we used two Alcatel E-reflex model 4010 IP phones and a PowerDsine 6012 midspan power unit to add AC power to our data network. Importantly, although AVISO uses real IP handsets, no other telephone switch equipment is required to run tests, thus significantly reducing the time and expense that might otherwise be associated with testing using actual IP handsets.

We mention the PowerDsine unit, which adds AC power to existing Category 5 Ethernet cable systems, because this is one area of data network remediation that will likely come to the fore as IT managers progress with a network assessment.

Now that the 802.3af power-over-Ethernet standard is in place, adding these kinds of devices will be required to make VOIP a reality. (IP phones can use midspan power devices to circumvent being plugged in to a wall outlet.)

Testing in large networks will likely be arduous. For example, AVISO required us to assign static IP addresses to the test phones. And in large networks, it will likely make sense to test with at least four to seven pairs of phones, moving phones from network segment to network segment to collect measurements.

In the test network, we used Ixia Communications Inc.s Ixia 1600 Traffic Generator and performance analyzer to add loads. Then we used AVISO to run a series of tests that we scheduled for various start times and durations. This is an important ability because it let us check voice quality during peak calling times, which is the real measure of any phone system.

AVISO measured round-trip delay, jitter and bad frame interpolations, while allowing us to select various codecs (coding schemes that govern conversion of the analog voice signal) to see which was the most appropriate for our network infrastructure.

We collected data and used the statistical analysis reporting tool provided as a module in AVISO to generate reports that predicted VOIP performance on our data network. These reports should prove useful as the first step in putting together a network remediation plan.

Senior Analyst Cameron Sturdevant can be contacted at cameron_ [email protected].