A method and corresponding equipment for setting up a conference call via a communication network that uses session initiation protocol (SIP) signalling for call setup, the method including steps (E1a E2a E3a E4a) of providing during the call setup signalling to a subscriber invited to participate in...http://www.google.com.au/patents/US20040202303?utm_source=gb-gplus-sharePatent US20040202303 - Method and apparatus for providing conference call announcement using SIP signalling in a communication system
