The VCS software has the following primary functions

 
• Communicates with the Dialogic circuit boards and instructs the boards what action to take, such as playing prompts or listening for DTMF

• Parses, interprets, and executes the VoiceXML commands in the XML documents served by the web server

• Integrates with text-to-speech (TTS) and automatic speech recognition (ASR) software.

In an In-Front-of-the-Switch configuration, the VCS uses a Dialogic circuit board that connects to T1 or E1 line(s) that carry the voice calls. For a Behind-the-Switch configuration, the VCS has a Dialogic circuit board that connects to the premise-based switch.