Dialogue Session Management Using VoiceXML

A spoken dialogue system capable of maintaining a human-machine conversation over a telephone must simultaneously maintain many dialogue sessions with different callers and third-party servers running applications over the Internet. There are three main issues to be addressed. First, the caller's identity has to be passed between each dialogue turn. Secondly, the dialogue state and connections to third party servers have to be continuously maintained. Thirdly, the system interfaces have to follow some standards, especially Internet protocols. We use session tickets and session object hashes to address these issues. Each dialogue turn is encoded in a session data object and VXML page. The session tickets contain the session ID and security-related information passed between the Voice XML interpreter and document server. The session object hash stores the third party connection handle, which is retrieved for subsequent dialogue turns.