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Keynote Study Shows VoIP Performance Lags PSTN
[July 11, 2005]

Keynote Study Shows VoIP Performance Lags PSTN

TMCnet Wireless and Technology Columnist

Despite the promises of cost-savings, consumers aren't likely to buy into the Voice over IP (VoIP) value proposition unless service providers address key performance issues. That's because, compared to public switched telephone network (PSTN), VoIP reliability and audio clarity still falls short, according to a new study.

VoIP service providers as measured by a sampling of six of the leading U.S. companies falls short in every metric compared with PSTN, concluded an independent survey examining end-user perceptions of service quality conducted by Keynote Systems, the San Mateo, Calif.-based performance measurement specialists.

“When you average it out, the industry on a whole has a lot to catch up on,” said Dharmesh Thakker, Senior Product Manager for Service Level Management Solutions at Keynote.

The study, entitled the “Keynote VoIP Competitive Intelligence Study,” is the subject of a free webinar hosted by TMCnet. The webinar will be held Tuesday, July 12, at 1 pm ET/10P.

While the findings aren’t particularly surprising given the infancy of the burgeoning VoIP industry, analysts agree the quantitative data is significant because it provides validation. “What I get out of it is the third-party verification,” said Will Stofega, analyst at IDC’s VoIP Services practice.

To be sure, no one believes the results are likely to hinder VoIP acceptance in the consumer market. As such, analysts like Stofega haven’t revised downward their growth forecast for VoIP consumer deployments. The IDC analyst still projects a compound annual growth rate of 94 percent with the consumer VoIP market reaching 27 million by 2009.

Still, the valuable insight provided by the Keynote study could be a valuable benchmarking tool for service providers. “It's a reasonable first start,” agreed Eric H. Siegel, senior analyst at Burton Group. “The actual way they are doing the measurement seems to be quite good. And the data seems quite reasonable.”

The five-week study examined the service offerings of Vonage, AT&T CallVantage, Lingo, Packet 8, Verizon and Skype. To sample the voice packet transmissions, Keynote also examined Comcast, Time Warner Cable, AT&T, Sprint and UUNET as network carriers. Only VoIP-to-PSTN and PSTN-to-PSTN (as a baseline) calls were tested; no VoIP-to-VoIP calls were made during the data collection period. Here’s what Keynote found:

No one VoIP service provider or network carrier dominated in every key performance metric. Vonage led its peers in reliability while AT&T CallVantage won for Best Audio Clarity. Keynote noted there was a noticeable gap between the leading companies and the laggards in both reliability and audio clarity but declined to disclose the complete league tables generated by the study. As for the network carriers, Time Warner Cable was the Most Reliable while UUNET and Time Warner Cable were tied for Best Audio Clarity.

“Everyone needs to catch up compared with PSTN,” Thakker concluded. “The average VoIP performance is still not up to the standards of PSTN based on reliability and quality.”


Robert Liu is executive editor at TMCnet.  Previously, he was executive editor at Jupitermedia and has also written for CNN, A&E, Dow Jones and Bloomberg.  For more articles by Robert Liu, please click here.

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