The results come from Brix Networks' TestYourVoIP.com site, a free VoIP quality-testing portal. Brix claims that nearly one million VoIP phone tests have been conducted at the site since its March, 2004 launch.
Brix claims that from late 2004 through mid-2006, the tests done at the site have shown a consistent decrease in overall voice quality as calculated via the Mean Opinion Score (MOS). MOS is an a measurement of conversational voice quality that rates calls on a scale from one (bad) to five (excellent). Test calls with a MOS of 3.6 or better are usually regarded as being satisfactory, and those below it as unsatisfactory. Only 81 percent of VoIP calls tested on the site were rated at 3.6 or better, the company says.
How accurate are the results? Without a third party to analyze them, it's difficult to know. Brix, though, sells IP and VoIP testing solutions, and the company does have a vested interest in touting any results that show poor VoIP quality. On the other hand, anyone who has made a VoIP call knows only too well the sometimes erratic nature of call quality.