Comcast Best in VoIP Quality, AT&T Best in VoIP Reliability

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Comcast Best in VoIP Quality, AT&T Best in VoIP Reliability

keynote-systems-logo.gifKeynote Systems released their latest VoIP quality report with some interesting findings. For one, Comcast, a cable company dominated the voice quality rankings beating the closest competitor by nearly 300 points. As for reliability, to no surprise AT&T won this category, no doubt to their decades of experience in building reliable voice and data networks.

Keynote Systems measures VoIP quality (MOS scores), call completion, etc. by automatically placing calls from corporate apartments using residential VoIP services and network services just like a typical residential customer would.  Service Reliability scores are based on the key performance metrics of Service Availability, Average Answer Time and Number of Dropped Calls. Additionally,  Audio Quality is an aggregate of Audio Clarity and Audio Delay (latency, jitter) performance factors. The study compares the relative performance of PSTN (regular analog) service, Broadband VoIP providers (e.g. Vonage, Verizon VoiceWing, EarthLink trueVoice, AT&T CallVantage etc), and cable voice services (e.g. Time Warner Digital Phone, Comcast Digital Voice). Test calls were placed from residential locations in New York and San Francisco.

Keynote ranked VoIP Service Providers in two categories: Reliability and Audio Quality. The Service Availability, Call Completion, Average Answer Time, and Dropped Audio performance factors all contribute to the Reliability ranking.

In the summary report they only list the top 3 VoIP provider names and then have Provider D - I as anonymous. You have to purchase the full report to see the names. I'm guessing Packet8 and Vonage are somewhere in this anonymous list.

Provider                   Reliability Points    Rank 
AT&T Landline                    996                1
Time Warner Digital Phone        925                2
Verizon VoiceWing                872                3
Provider D                       859                4
Provider E                       793                5
Provider F                       687                6
Provider G                       643                7
Provider H                       408                8
Provider I                       374                9

Audio Quality
Provider                   Reliability Points     Rank 
Comcast Digital Voice            901                1
Verizon VoiceWing                609                2
AT&T Landline                    506                3
Provider D                       500                4
Provider E                       487                5
Provider F                       480                6
Provider G                       462                7
Provider H                       252                8
Provider I                       0                  9

General Observations
• The best providers always deliver dial tine and connect the call to the number dialed in a timely fashion.
• Only one of the providers in the study failed to provide dial tone 99.9% of the time or better.
• All providers had very small percentages of calls with dropped audio, but only two providers had zero calls with dropped audio.
• One VoIP provider required two seconds more than any other voice provider to connect calls after dialing.
• Most providers had slightly more audio delay and slightly lower MOS in Wave 6 as compared to Wave 5.
• Eight of the nine providers in the study had a better call completion rate in Wave 6 than was evidenced in the Wave 5 results.

What's amazing is that Comcast has been adding a ton of new VoIP customers each quarter. In fact, Comcast has become the nation's fourth largest phone company. The cable company has signed up four million VoIP customers in just the last two years. Relatedly, Forrester Research analysts have projected that Cable VoIP providers will claim up to 80% of the 28.4 million residential VoIP users by 2013. This forecast includes an expected growth from the approximately 19 million installed lines in 2008.

Check out the summary report.

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