Web Services uses CometD version 3, an HTTP-based routing bus that uses an Ajax Push technology pattern known as Comet. Comet is a web application model that allows an HTTP request to push data to a browser, even if the browser has not requested it.
Web Services uses CometD to deliver unsolicited notifications to clients for real-time events, such as getting a new call or chat message. At runtime, CometD delivers messages, providing clients with a consistent approach while maintaining support for multiple browsers.
For details about CometD, see http://cometd.org/.
For details about how to configure CometD in Web Services, see cometDSettings.