asterCRM is an open Source call center software for asterisk based VoIP system, and has standard CRM functions. It provides a web-based user interface, both agents or managers could finish full call center funtion just using a browser. First asterCRM use a daemon script to catach all asterisk events from AMI(asterisk manager interface) and save the datas into a database, at the same time the browser use javascript to query useful events for the user from the database, (such as ring, dialing, hangup ...) and show them. When user want to control the call, he could use the browser to send a command to asterisk, same via AMI.