Grading voice over IP: Can this technology pass the test?

The topic of testing may not scream excitement, but it does deserve a little more focus, especially when it comes to new territory such as voice over IP. Although any telecom carrier knows the significance of testing voice quality, echo or delay, several companies specializing in test solutions believe the industry may not be paying enough attention to it.

At the Voice on the Net show in Atlanta in September, Radcom introduced an advanced version of its voice-over-IP test solution product suite, the H.323 Call Generator. The product is geared toward the gateway developer and carrier markets and emulates the functionality of an H.323 terminal to generate more than 2000 calls. In addition, it adheres to Version 2 of the H.323 standard. It can generate 2016 simultaneous calls, according to sources at Radcom.

Another product offering is the AudioPro, which resides on the Ethernet line and monitors voice traffic, notably jitter, said Michael Winslow, director of products for the U.S. at Radcom. "Jitter is the area people like to measure the most. The AudioPro can pick up voice streams on any media that involves data," he said.

Although Radcom maintains that both products are simple to use, they can be complex. And though they are geared toward helping gateway developers before they pass on their products to the carrier, the Radcom equipment also is important for service providers because it can help them make the right product decision. Before carriers implement any device, they should know if the product is compatible with the rest of the network.

"Not being familiar with a technology can hurt a company," Winslow said. The industry "cannot live without testing tools if they expect to solve the problems that can occur in a network. There is not enough time in the year to do that; they need to have a machine to tell them what they are looking at within such a massive amount of data."

As voice quality improves, echo will become more apparent, said Graham Roussel, applications engineer for Tellabs' European applications development group. For now, testing may not be a focus, but that likely will change. As technology advances, so will the need to test it.

"The key now is to get basic quality of voice up on the network," Roussel said. Mobile providers "are looking more at getting voice transport up than at enhancing it. It is hard to enhance something that is of poor quality to start with."

However, when things in the IP world start moving fast, so will the world of testing, he said.

For now, "it is important that after carriers get the infrastructure up they look at the next stage, which is improving audio quality," Roussel added.

Not only is voice quality important to test, but interoperability between carriers also is critical if true IP communication is to be achieved. If interoperability testing is not fully completed, then the service cannot be delivered, said Jim Kwock, vice president of marketing for NetSpeak.

"Every carrier cares about interoperability between carriers. An open platform is the key to breaking through interoperability testing," he said.

IP telephony is still in its infancy, but the growth of the Voice on the Net and ISPCON shows is evidence that it is maturing.

"For it to be widespread, testing is of the utmost importance," said Patrick Pacifico, director of product management and product development for Wave Wireless Networking.