Optical/IP Networks

VOIP Testers Tested in ITU Battle

Two specialist test-and-measurement companies will be put through their paces in March in an International Telecommunication Union (ITU) bake-off designed to pick a standard for measuring voice quality on VOIP networks.

Psytechnics Ltd. and Telchemy Inc. make test-and-measurement software that can be embedded into both network monitoring devices and endpoint devices for analyzing packet loss problems on IP networks. Their software has been in trials with France Telecom SA (NYSE: FTE) and ECtel Ltd. (Nasdaq: ECTX) for the past 18 months, and the results will be heard at the ITU meeting in March.

The standoff between these two companies comes at a time when carriers are beginning to move voice-over-IP services out the lab and into production networks (see Carriers Put VOIP to the Test).

”Congestion is the biggest offender,” says Alan Clark, CEO of Telchemy. “It leads to jitter, which is the most significant parameter when it comes to measuring voice quality.” He says "bad" jitter reveals itself in jitter buffer discards. These occur when packets that don't arrive soon enough are dropped.

Today, telecom equipment companies use a method known as PESQ (perception evaluation of speech quality), which compares the signal of a VOIP call at both ends of the network to determine if there’s any degradation.

This approach doesn’t make much sense, according to Iain Woods, marketing director at Psytechnics, as it doesn’t measure the signal in a live network. He says the network administrator has to make a test call to perform any kind of analysis, which fuzzes the results. “The new standard will do it on the basis of a live call,” he says.

ITU spokesman Vincent Barriac says the purpose of the future standard, known as P.VTQ, is to estimate speech quality based on protocol parameters mainly taken from the IP packet headers, which should give a more accurate assessment of call quality. It will also have the ability to feed back diagnostic data, making it more applicable to network management, than just straight testing, he says.

But does anyone really care about a little piece of VOIP testing software under the microscope for yonks at the ITU?

Jeremy Duke, VOIP analyst at Synergy Research, notes that the VOIP test equipment market is an “extremely lucrative business that is transparent to a lot of people.” And it’s growing fast; last year the market was worth $133 million, but it's projected to hit $606.9 million by 2010, according to Frost & Sullivan.

The bake-off winner may get a big slice of a growing market, but the vendors themselves haven't yet polished their acceptance speeches. “It’s a young market; there’s not much VOIP deployed yet,” says Telchemy's Clark. "We still have a long way to go to completely understand how IP behaves."

— Jo Maitland, Senior Editor, Light Reading

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