Make no mistake, using the new [VoiceXML 2.1 element](http://www.w3.org/TR/2005/CR-voicexml21-20050613/#sec-data) to fetch an XML document that can be utilized from within a VoiceXML script without a page transition is indeed handy. But there isn’t any asynchronous communication happening here "“ the external XML document is fetched only once, [typically at the begining](http://www.w3.org/TR/2004/REC-voicexml20-20040316/#dml6.1) of script execution. For asynchronous behavior, we need to look to one of VoiceXML’s sister technologies "“ the [Call Control eXtensible Markup Language](http://www.w3.org/TR/2005/WD-ccxml-20050111/) (CCXML).
The CCXML 1.0 specification (a last call working draft from the W3C) includes the [
The good folks at Voxeo (leaders in the effort to formalize the CCXML standard) have added functionality to their platform that allows the
When it comes to AJAX in VoiceXML, the same functionality is generally available but the needs of developers are somewhat different. Callers to a VoiceXML application probably don’t perceive page transitions in the same way that users of a visual web application do. VoiceXML has fetching and caching functionality built into it that can be used to manage the delay between page transitions. It’s probably a better use of developer time to understand fetching and caching more intimately than to try and replicate AJAX in voice applications.