In Part I and Part II of my look at the Keynote Systems VoIP call quality test, I reviewed the methodologies Keynote Systems used to study and then rate VoIP carriers and providers.
In this section, I will name the winners, as determined by Keynote:
Most Reliable VoIP Service Provider- Vonage.
Best Audio Clarity- AT&T CallVantage.
Most Reliable Network Carrier- Time Warner Cable.
(Network Carrier with) Best Audio Quality-a tie between UUNET (now known as MCI Wholesale Network Services and Time Warner Cable.
Keynote has also released breakdowns for three individual call quality characteristics of VoIP provider calls:
Service Availability (percentage of calls that were successful): Vonage Soft Phone was first, followed by the standard Vonage service.
Average MOS (Average Mean Score of voice audio quality)- The standard Vonage service finished first, followed by AT&T CallVantage.
Average Audio Delay (the average amount of time it takes audio to travel from caller to recipient)- AT&T CallVantage led, followed by Vonage Soft Phone.
Parsing these results, it appears that for the best VoIP call audio quality, you couldn't do any better than placing an AT&T CallVantage VoIP call over a high-speed Time Warner Cable connection. But if that call absolutely, positively has to get through, then a Vonage call over Time Warner Cable would be the way2go.