System and method for implementing call waiting functions over a network architecture which includes a public switched telephone network (PSTN) and the Internet. The call waiting system allows a user to receive incoming call information from a third party without interrupting an active connection with...http://www.google.com.hk/patents/US6144644?utm_source=gb-gplus-share專利 US6144644 - System and method for implementing call waiting functions over a network
