Creating and Deploying VoiceXML Applications with the
voxBuilder Online Development Environment

By Dave Burke

(Continued from Part 1)

Different projects have different VoiceXML, grammar, audio, and script files associated with them, which may be edited or uploaded. Projects may be local, that is with all files hosted statically on voxBuilder, or remote, by pointing at an external web server under control of the developer. A combination of the two project types is possible as well e.g. host dynamic VoiceXML remotely to the platform but store static audio locally.

Phone Number Management

The voxBuilder environment supports the concept of phone number management and assignment. Phone numbers of different types (e.g. premium rate, national, international etc) can be quickly procured by Voxpilot for any European market and attached to a voxBuilder account. The phone number may then be attached to a specific project at the discretion of the developer/administrator so that direct execution of the application is possible.

Call Scheduling

Call scheduling is the ability to accept a request (over the Internet) to place an outbound call at a specific time, to a specific number, executing a specified voxBuilder project. The voxBuilder environment exports this functionality as an XML-over-HTTP service that enables scheduling, and querying status of calls. For example, to schedule a call one might submit the following XML (e.g. to run the HelloWorld application illustrated in Figure 3).

Log Access

The voxBuilder ODE allows the developer to search for VoiceXML and ASR logs over a time period for a specific project as illustrated in Figure 4.

Log files may be viewed or downloaded individually or in bulk ZIP archives. VoiceXML log files may be viewed in real-time also for fast debugging. The ODE uses a novel streaming mechanism for high performance access to log information even over slower Internet connections. Figure 5 illustrates a typical VoiceXML log.

VoiceXML and Grammar Validation

The voxBuilder ODE allows the developer to validate a VoiceXML file against the XML DTD or schema. This allows early trapping of simple syntactic errors as illustrated in Figure 6.

It is also possible to validate grammar files (Nuance GSL) for syntactic correctness and also test for vocabulary coverage either by supplying a specific phrase or by generating all possible phrase combinations. Figure 7 illustrates an example of the possible phrases accepted by a grammar.

"Behind the Scenes"

The voxBuilder ODE executes on a J2EE cluster, which facilitates robustness and scalability. While the environment could have been implemented using other technologies, Java is somewhat complimentary to VoiceXML, - being an object-oriented language (XML itself may be regarded as object-oriented) with strong XML processing support. Of course, not all components of a VoiceXML VSP are suited to implementation in Java e.g. the core components such as the VoiceXML interpreter and SSML processor are implemented natively for performance and scalability.

Since all VoiceXML applications are routed through the voxBuilder environment, it is a natural place to put management functionality. The voxBuilder system actually doubles as an administration system for Voxpilot personnel and allows complete control of all VoiceXML applications running on the VSP. For example, phone numbers can be configured and mapped to accounts, user privileges can be controlled (e.g. the ability to place outbound calls), statistical usage information is gathered, and contact information and mail alerting is supported.

Conclusion

The voxBuilder environment is a powerful tool for developing, deploying, and maintaining VoiceXML applications. It continues to evolve and improve based on feedback from the ever-growing VoiceXML community of developers wishing to deploy cutting edge applications without the upfront costs of hosting telephony and speech services. Many new features are planned for the ODE in the near future including runtime debugging, speech recognition tuning tools, statistical information generation, multimodal functionality, and VoIP access. Finally, the interested reader can sign up for a free trial of voxBuilder at http://ode.voxpilot.com and get developing VoiceXML straight away!

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