Communication system, has conference control unit to which call-control-protocol message is transmitted, where message specifies whether terminal is to be added or conference is to be created or conference is to be terminated

摘要

The system has a conference server and a conference control unit to which a call-control-protocol message is transmitted. The message specifies whether a communication terminal of a conference is to be added or a conference is to be created. The message further specifies whether the conference is to be terminated or information is to be transmitted to the terminal over a conference provided by the server. Independent claims are also included for the following: (A) a method for controlling a communication system (B) a method for controlling a communication terminal (C) a method for controlling a conference unit.