A study by Keynote gives those two firms top marks in reliability and audio clarity, respectively.
Keynote rated AT&T CallVantage Packet 8, Primus Lingo, SkypeOut, Verizon Voicewing and Vonage in its study of overall VoIP service quality. Vonage rated first overall, with a significant gap between it and the other five services.
On the topic of audio clarity, Keynote finds that AT&T rated well above the rest of the competition. The study cites the audio delay factor as a space for improvement. Overlapping conversations lead to frustrations for callers. In the event of a 911 emergency, that kind of overlap could be disastrous.
“A key take-way from the study is that Internet telephone service is not yet up to the standards to which users are accustomed when using standard plain old telephone service’,” Keynote says in a statement.
Keynote collected ten factors into the overall quality indicators of reliability and audio clarity:
• Service Availability – indicating the reliability of the service
• Outage Hours – how many minutes the service was unavailable during the study collection period and on a daily basis
• Average number of call attempts – how many times, on average, a user must call to establish a connection
• Dropped Calls – the number of times a call is dropped in the midst of a conversation
• Audio Delay – once the call is established, the average lag between utterances. High audio delay leads to overlapping and unpleasant conversations in real-life.
• Listening quality (or Mean Opinion Score – MOS) measured using the Perceptual Evaluation of Speech Quality scale (PESQ) – the internationally recognized ITU-T P.862 standard
• Audio delay consistency over time
• Audio delay geographic uniformity between New York and San Francisco
• MOS consistency over time
• MOS geographic uniformity between New York and San Francisco
David Utter is a staff writer for Murdok covering technology and business. Email him here.
