Delay, echo and static are big no-nos when it comes to voice quality over a network. And although testing for these problems has been a traditionally time-consuming and costly task, one company has developed a tool that it says requires little operator intervention.
According to Agilent Technologies Inc., , its theme since day one has been to reduce the time it takes to troubleshoot network problems and restore service with the quality that customers demand. In keeping up with this promise, the company recently released the Voice Quality Tester Responder, which allows network operators to lower test costs when deploying large voice-over-IP networks.
The VQT Responder works in conjunction with Agilent’s Voice Quality Tester, which tests clarity, echo, delay and voice quality over any network, and in addition correlates that information with other Agilent network-testing gear, including the Agilent’s Network Analyzer and Network Advisor offerings.
According to Steve Witt, vice-president and general manager of the network systems test division for Agilent in Colorado Springs, Colo., the VQT responder provides VoIP testing and troubleshooting to distributed network sites.
“What we are doing to lower costs is allow these products to be distributed and left in the network environment and enable troubleshooting remotely so that it doesn’t require someone driving across the city in rush hour or walking across a campus with a handheld product to be able to solve a problem,” Witt explained. “They can solve it directly from their own desktop and really reduce the time it takes to identify and solve a problem.”
Although designed to work with VoIP networks, Witt assured that the VQT Responder is appropriate for any voice network and is equipped with standard telephony interfaces as well as VoIP interfaces.
In terms of speech quality, the VQT Responder relies on industry standard Perceptual Speech Quality Measurement (PSQM+), Perceptual Analysis Measurement System (PAMS) and the ITU-approved standard Perceptual Evaluation of Speech Quality. Agilent explained that these algorithms measure speech quality and produce chords that a human being would produce, as opposed to the traditional method of testing that uses electrical signals.
For Bell Canada’s iTechCentre in Ottawa, voice quality standards are high and the division recently opted for the Agilent VQT to keep it that way. According to Jean-Marc Goulet, lab infrastructure support manager, the iTechCentre is currently using the VQT to analyze clarity, delay and signal loss on a variety of call scenarios and VoIP solutions. Although a relatively new implementation, Goulet said the iTechCentre is pleased with the support and functionality the product offers.
“We believe this is a unique product and the most efficient to meet our current requirements,” Goulet said. “Our testers were particularly impressed by the ability to test voice quality up to the actual PSTN or IP phone. Other solutions did not offer this functionality. The VQT…provided us with end-to-end voice quality measurements as experienced by a user.”
John Anderson, IP telephony product manager with Agilent’s Network Systems Test division also in Colorado Springs, Colo., said the demand for the VQT Responder has been high and since its release, has been well-received by the enterprise and carrier space.
“Testing networks using the techniques that the VQT provides is very popular and very much needed,” Anderson said. “However, it requires specialized hardware to support the telephony interfaces. Typically it has been a relatively expensive solution to deploy on a large scale. That is what the VQT Responder is directed toward. It significantly reduces the cost of deploying a VQT solution to hundreds of different sites.”
Existing VQT customers may purchase the VQT VoIP Ethernet interface licence priced at $7,850. Non-VQT customers can purchase the VQT Responder, available now, for $7,693. Agilent’s Canadian headquarters are in Mississauga, Ont. For more information, visit the company on the Web at http://www.agilent.com.