Viola’s NetAlly Lifecycle Manager aims to address VoIP quality concerns

* A look at Viola’s NetAlly Lifecycle Manager 5.1

VoIP is on the rise with companies anxious to take advantage of the cost savings. Still, questions remain about its reliability and overall quality. Viola Networks recently took steps to help improve the situation when it introduced NetAlly Lifecycle Manager 5.1. The latest release includes a new algorithm for aggregating voice quality measurements among groups of VoIP network calls, referred to as the Service Level Index (SLI).

NetAlly uses a combination of active and passive monitoring to collect data for VoIP service level analysis. In performing active monitoring, NetAlly uses agents to simulate VoIP calls and examine the range of factors that can cause voice quality problems, such as packet loss, jitter, delay, and echo. NetAlly then converts the collected data to a Mean Opinion Score (MOS). A widely accepted measurement for assessing VoIP service quality, MOS is not without challenges. As a pure measurement, MOS lacks insight to the actual causes behind quality issues, and as a mean score, doesn’t account for discrepancies between divergent assessments of the same data point.

MOS is a subjective measurement, aggregating and averaging performance; in the process, the calls that fail to meet service level agreements may drop off the radar. Despite its imperfections, MOS is useful as a generic measurement of call quality. Viola’s SLI incorporates MOS, and similar subjective quality assessment methodologies, but rather than settle on an average assessment that minimizes poor performance, SLI weights the group experience by examining the distribution of MOS calls.

Although a degree of extrapolation is still involved in the SLI metric, NetAlly dashboards highlight the weighted score provided by the SLI, helping companies see at a glance their group call performance, and even predict network degradation. Since companies can define their VoIP networks’ own level of acceptability — according to SLAs, user groups, geography, or however they choose to segment their networks — the SLI metric is significant in identifying call quality events related to entities that are important to the organization.

Viola faces considerable competition from players such as NetIQ, Brix Networks, Apparent Networks, Fluke Networks, and many others. Both Viola and NetIQ integrate with IP PBX vendors (Cisco, Avaya, and Mitel), giving them a competitive edge in the managed service provider market. Lacking partnerships with most equipment manufacturers, Brix and Apparent tend to compete with Viola in pre-deployment assessments. Like Viola NetAlly, Fluke OptiView addresses the VoIP lifecycle, from pre-deployment assessment through optimization. Fluke’s strength is in passive monitoring, whereas Viola shines in active testing. As both vendors round out their products, Fluke will become a key competitor for Viola.

Viola’s NetAlly has also been compared with ClearSight’s Analyzer, but Viola points out that the two products are more complementary than competitive. ClearSight Analyzer is a protocol analyzer, which NetAlly is not. Instead, NetAlly would be more likely to incorporate ClearSight data as part of its own VoIP quality analysis.

Quality of service within VoIP networks is a critical issue, particularly among companies whose SLAs assure a certain standard of quality 99.9% of the time. Viola’s new metric helps companies ensure they’re not overlooking quality issues obscured by averaged data points. Although the SLI won’t pinpoint network problems, it will help companies identify call quality events within defined segments — such as SLAs, groups of users, or physical location — and provide the data needed to drill down on specific events.

Along with strengths in monitoring and troubleshooting comes the challenge of managing very large databases, potentially terabytes in size. Customers need to be prepared to manage highly scalable databases, either through carrier service providers, clustered environments with dedicated database administrators, or for smaller applications, deploying automated routines — such as data aggregation and purges — that are designed to self-manage the database. Ultimately customers must decide the tradeoff between maintaining terabytes of troubleshooting and trending data, and producing SLA reports for customers.

The SLI enhances the enterprise’s ability to monitor VoIP performance by minimizing the averaging bias introduced by standard quality measurements — a significant improvement for VoIP performance management. This announcement supports Viola’s intent to play a role of leadership in VoIP management. The trick for Viola will be to stay ahead of the curve in a very appealing market space.

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Copyright © 2006 IDG Communications, Inc.

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