Velaro has a feature that "pings" the visitor to check and see if they are still active and connected during a chat session.
If a chat session is in progress and the visitor closes their chat window or leaves the page on which Velaro chat is installed, Velaro detects this action. Likewise, if the visitor loses internet connectivity, Velaro also detects this.
For both cases, Velaro notifies the agent with a system message "The visitor is inactive and may have left the page or lost their internet connection".
The reason for this notice is to that the agent will be aware that if they send a message but do not hear from the visitor for awhile, they may have navigated away from the chat window or lost their connection.