The present invention is drawn to a call trace system and method that is simple to establish in a short amount of time. The call trace is implemented through a Web browser page which remotely programs central offices to trace calls to particular number. When a trace is established a message is sent back...http://www.google.com.tw/patents/US7796746?utm_source=gb-gplus-share專利 US7796746 - Method and system for call tracing
