VoIP call quality getting worse - study

A new study suggests the quality of voice over IP is getting worse.

Brix Networks, a company that develops monitoring tools for service providers, analysed data it gathered from a free website it created two years ago called TestYourVoip.com, which allows consumers to test the quality of their VoIP services.

While it's no secret net phone services don't offer the same call quality as traditional phones, in its study - published on Monday - Brix discovered VoIP call quality has declined by about five per cent in the past 18 months.

With almost one million VoIP connections tested through its website, Brix said about 20 per cent of all calls had unacceptable quality. This is up from about 15 per cent of calls made about a year ago.

Kaynam Hedayat, chief technology officer for Brix, said the decline in voice quality is happening because voice services are increasingly competing for resources on the same IP network as other services such as video, music downloads and interactive gaming.

IP telephony calls ride over the same network that is also delivering internet access and in some cases IP-based video. While the speed of broadband networks has increased, consumers are doing more on the net, which affects call quality, he said.

He added: "The network is ready for VoIP. But now that there are more services running over the same pipe, carriers need to differentiate packets and prioritise service."

Many internet companies offering voice services, such as EarthLink, Google, Vonage and Yahoo!, are opposed to allowing phone companies or cable operators, which own the underlying broadband networks, to prioritise traffic in order to improve call quality. They fear network operators will abuse their power by charging unreasonably high fees and eventually squeeze out competing traffic. These companies have been calling for Congress to pass laws restricting such practices.

But some analysts say the time is quickly approaching when network operators will have to prioritise delay-sensitive traffic such as voice or video.

Zeus Kerravala, an analyst at the Yankee Group, said: "Prioritising traffic is going to have to happen. The vision for many service providers is to offer video, internet access and voice on one pipe. And the addition of video is going to be a huge hit on the network.

"I think consumers will be less tolerant with jittery TV than they have been with voice, so service providers better get the prioritisation mechanisms in place today before they try to sell the public on internet-based video."

Marguerite Reardon writes for CNET News.com