Review: Telera DeVXchange (Part II)
Telera Extensions
To enable development of better call-control features (over and above the basic functionality that is supported by VoiceXML platform), the Telera Voice platform has created a number of extensions. The table below lists the various extensions and their functionality.
| Call Control Elements | Description |
| ALERT_LEG | Alerting a call-leg and direct it to a specified URL |
| BRIDGE_CALL | Bridges the current call with another call |
| CREATE_LEG_AND_DIAL | Enables a voice application to make outbound calls. This provides enhanced functionality over VoiceXML's <transfer> element |
| END_SESSION | Destroys all legs of the session |
| HANGUP_AND_DESTROY_LEG | Terminates the call |
| LEG_WAIT | Puts the executing VoiceXML interpreter in the wait stage |
| QUEUE_CALL | Puts the call on hold |
| REXFER | Transfers the call from one call-center agent to another |
| SCRIPT_RESULT | Returns the results of a script execution |
| SET | Provides a state management mechanism to otherwise stateless voice applications |
| UBRIDGE_CALL | Breaks the bridge between the specified legs of the call |
Let's look at the functionality of one of extensions by taking a look at an example. The example below shows an interactive voice application that is allowing the user to say "Customer Service" in order to be connected to a customer service representative. The CREATE_LEG_AND_DIAL element connects the caller with the agent specified in the TELNUM attribute. The IVRURL specifies the document to execute for the second leg once the call has been connected. Using these extensions it is actually possible for the application to "whisper" information about the caller to the agent before bridging the call.


Conclusion
Overall, I believe CodeCenter has the necessary toolsets for a useful VoiceXML development platform, with the key being support for the VoiceXML 2.0, call tracer, grammar verifier/manager and outbound notification. The extensions are definitely interesting and provide a lot of added functionality on-top of VoiceXML, but should probably evolve through support of a standard such as CCXML. AppBuilder has a lot of potential for being a server-side dynamic VoiceXML application tool, however, it does need to be upgraded to support VoiceXML 2.0 and CCXML.
Resources
About Hitesh Seth
A freelance author and known speaker, Hitesh is a
columnist on VoiceXML technology and regularly writes for
technology publications including Java Developer's Journal, Web Services
Journal, XML Journal and The Computer Bulletin on emerging technology topics such as J2EE, Microsoft .NET, XML, Wireless
Computing, Speech Applications, Web Services & Enterprise/B2B Integration. He is the
conference chair for VoiceXML
Planet Conference & Expo. Hitesh received his
Bachelors Degree from the Indian Institute of Technology Kanpur (IITK), India.
Feel free to email any comments or suggestions about the articles featured in
this column at hks@hiteshseth.com.



Solid state disks (SSDs) made a splash in consumer technology, and now the technology has its eyes on the enterprise storage market. Download this eBook to see what SSDs can do for your infrastructure and review the pros and cons of this potentially game-changing storage technology.