VoIP improving in quality and reliability

According to new research by Keynote Systems, the quality and reliability of VoIP is continuing to improve and the technology is catching up with traditional public telephony networks.

Technology testing firm, Keynote, made more than 125,000 calls between New York and San Francisco over a month, as part of the study.

Although the firm recorded some delay and call completion problems, two of the VoIP companies tested achieved a completion rate of over 99.5 per cent.

Keynote looked at a number of indicators, including service availability, call completion percentage and audio delay.

It tested 12 different VOIP and PacketCable phone services for their reliability, responsiveness and clarity and then compared the results with PSTN services from AT&T and Verizon.

The study only looked at VoIP over telephones, and not ’soft phone service’ through computers.

The research found that there was still a problem with audio delay in calls, with VoIP’s performance still lagging behind PSTN and PacketCable in this area.

VOIP providers had a one-way audio delay of between 150 to 250 ms, while both PSTN and PacketCable had a mean average audio delay of below 150 milliseconds.

The most common audio problems for VOIP calls were audio holdover, front clipping, other kinds of clipping, and hum.

PacketCable performed the best in terms of audio problems in nearly all indicators.

Overall, the findings show that VoIP is improving but there is still room for improvement in terms of quality of calls.