Speech on a Network
The whole idea behind VoiceXML is portability and a truly open Web-based architecture that allows businesses to build applications once and run them almost anywhere. It’s a goal shared by SOA, which by definition is a framework that lets companies build, deploy, and integrate services independent of applications and the computing platforms on which they are built.
In many leading technology companies today, VoiceXML is a fundamental piece of their overall Web or SOA strategy. "The platform market once was fragmented," Cramoysan admits. "[Now] there has been a high level of VoiceXML adoption in terms of new systems coming out and very wide acceptance of VoiceXML as the standard language. What we’ve seen over the last five to seven years is a shift from legacy, proprietary applications to more open source using VoiceXML, opening the doors for interoperability from one application to another."
Cawn says he has also started to see a more rapid conversion to VoiceXML. "And as we see more people move from proprietary to VoiceXML, SOA will happen," he maintains.
In fact, Daniel Hong, senior analyst at Datamonitor, has repeatedly pointed to a dramatic rise in the number of VoiceXML-based applications in the last few years alone. Whereas slightly more than 30 percent of the 600,000 IVR ports shipped in 2005 were based on VoiceXML, he predicts that this year more than half of the ports shipped will be VoiceXML-based, and by 2010, those numbers will climb to more than 70 percent. Speech technology vendors like IBM, Nortel, Avaya, Genesys Telecommunications Laboratories, and Cisco Systems have led the way with applications that are VoiceXML-compliant and SOA-ready, according to a number of analysts.
Still, one can’t deny the existence of competing standards, including Speech Application Language Tags (SALT). Koloski notes that VoiceXML and SALT are two very different standards, "which creates inherent interoperability challenges. You still can’t take a Microsoft product and just plop it in with [just any vendor’s] product."
"You could apply SOA principles without VoiceXML, but I’m not sure why you would," Cramoysan says.
Rehor, one of the authors of VoiceXML, agrees, noting that SOA and VoiceXML leverage the same underlying technologies and share the same goals. "VoiceXML is a natural fit for an SOA," he adds.
And while some companies have opted instead to layer their SOA around proprietary, legacy systems and applications with a basic Web interface, Rehor says such a deployment fails to take into account long-term goals. "It’s like putting a shiny paint job on an old 1972 Chevy Vega. In the end, you still have an old 1972 Vega," he states.
Still, some have argued against VoiceXML by claiming that current versions of the programming language do not fully cover all the things that people might do with speech. Rehor notes, however, that future versions of VoiceXML will address any lingering inconsistencies with an SOA. Version 3.0 (which is due for release later this year) will contain added support for speaker verification, video, and multimodal applications, he explains.
SOA: A Picture Is Worth 1,000 WordsWhether or not speech applications are included, many industry experts argue that businesses have been slow to convert their systems to an SOA because they are still confused about what an SOA looks like. They have mistakenly been led to look at it as a puzzle with interlocking pieces. "In a puzzle, one piece only interacts with the other pieces around it. In an SOA, each piece can interact with any other piece anywhere in the puzzle," states Steve Cramoysan, research director for enterprise communications applications at Gartner.
Steve Cawn, sales team leader for speech solutions at IBM, agrees. "It’s not a puzzle. It’s more like a bicycle wheel," he says. "The hub is the server at the center and each spoke represents one of the [applications] tied into it and one another."