Voice eXtensible Markup Language, or VoiceXML , is a markup language similar to HTML, that is used for developing IVR services and leverages the power of web development and content delivery. VoiceXML was designed for creating audio dialogs that feature synthesized speech, digitized audio, recognition of speech or dual-tone multifrequency (DTMF) key input, and recording of spoken input. It is a common language for content providers, tool providers, and platform providers, and it promotes service portability across implementation platforms.
VoiceXML separates service logic from user interaction and presentation logic in VoiceXML voice web pages. It also shields application authors from low-level, platform-specific IVR and call control details. VoiceXML is easy to use for simple interactions, yet it provides language features to support complex IVR dialogs.
VoiceXML programs are rendered (or executed) by a VoiceXML browser, much like an HTML program is rendered using an internet browser (such as Internet Explorer). A Cisco Voice Gateway (or router) can provide the VoiceXML browser function. For small deployments, the Ingress Voice Gateway and VoiceXML Gateway are typically deployed in the same router. The Cisco IOS VoiceXML Gateway provides both gateway and VoiceXML browser functions.
In the most simple call processing scenario, a new call arrives and the voice gateway dial peer matches the call to an available VoiceXML gateway port. The VoiceXML gateway port represents a Voice over IP (VoIP) endpoint and can be logically thought of as a voice response unit (VRU) port. Upon arrival of the new call, the VoiceXML gateway (that is, the VRU) sends an HTTP request to a Cisco Unified CVP VXML Server for instruction. The URL contained in the HTTP request correlates to a specific VoiceXML doc.
In response to the HTTP request, the Unified CVP VXML Server sends the requested, dynamically generated VoiceXML doc to the VoiceXML gateway (that is, the voice browser) to be rendered. A typical VoiceXML doc is short and prompt the caller for some input, then includes the results in a new HTTP request that redirects the caller to another URL and VoiceXML doc. Because a typical call requires numerous prompts and caller inputs, there are numerous VoiceXML documents that need to be rendered and a large number of possible paths through these VoiceXML documents.
To logically link the many different VoiceXML documents that may need to be rendered and to greatly simplify the task of creating VoiceXML documents, a graphical scripting tool is often used to allow the IVR service developer to easily develop complete IVR services with conditional logic and customer relationship management (CRM) database integration. Cisco Unified Call Studio is one such scripting tool. The Cisco Unified CVP VXML Server is capable of executing scripts developed with Cisco Unified Call Studio, and both were designed to work with Cisco Unified CVP Server, Cisco Voice Gateways, Cisco VoiceXML Gateways, Cisco Unified Communications Manager, Cisco Unified Contact Center, and Cisco's VoIP-enabled LAN/WAN.