Study Shows VoIP Quality Leaves Room for Improvement

While the argument for adopting Voice over Internet Protocol (VoIP) in the contact center may be won, the push for better service quality for consumers remains an issue, according to a recent study by Keynote Competitive Research, the industry analysis group of Keynote Systems.

The study evaluated the quality of 125,000 calls placed in San Francisco and New York from June 1 through June 30. It found that calls placed over cable and VoIP still lag behind traditional phone service. The good news, according to the report, is that the services are proving to be highly competitive in the growing telecommunications market.

The study measured and compared the call quality of AT&T’s CallVantage and traditional phone service, Comcast’s Digital Voice, Primus Lingo, Packet 8, Sun Rocket, TimeWarner Cable’s Digital Phone, EarthLink’s trueVoice, Verizon’s VoiceWing and traditional phone service, Vonage, and Vonics Digital. Testing was done using both male and female voices. Evaluations were conducted by 16 panelists who heard the voice samples and assigned each call a score from one to five. Calls were then run through Keynote’s own Voice Perspective application, an automated end-to-end call quality measuring tool. Keynote did not release individual company scores, but did make them available to participants.

The study, the results of whice were released in mid-September, found that VoIP and cable phone service providers need to continue developing products; only two of those evaluated offered 100 percent availability to users.

"As VoIP continues to make inroads into business and residential users, customers expect no less than a toll-quality voice call," says Rajeev Kutty, VoIP product manager at Keynote. "In order to achieve that, service providers will have to continuously monitor the quality of the calls and examine and isolate bottlenecks before they affect customers."

Though the study revealed conclusively that VoIP call quality needs improvement, Kutty notes that the calls’ overall mean opinion score (MOS) has improved since Keynote conducted its first survey in 2005. The study’s worst performer this year started out in the first test with a MOS of 2.96, but has now reached 3.06.

But other factors, such as external microphones and speakers, Internet connection speeds, and operating systems, also can affect call quality and should be taken into account before writing off a service provider’s performance as poor, warns Chris Thompson, senior director for unified communications solutions marketing at Cisco Systems. "It doesn’t tend to be as much of a service problem as it is an access or device problem for the consumer," he says.

In fact, call quality and availability are expected to vary between services, Thompson explains. "Consumers make trade-offs based on price, accessibility, and mobility, and it’s important to understand that mix," he says. "If you were using a home telephony product from your cable company, they would offer a different grade of service than a free service like Skype. [Consumers] put up with a little call quality degradation for cheapness."