Abstract: A method for generating a plurality of messages for inviting communication devices to a communication conference. The method includes establishing a first communication conference with a plurality of first communication devices, receiving a plurality of communication device identifiers from a communication device participating in the first communication conference, which communication device identifiers identify communication devices to be invited to at least a second communication conference, determining communication devices from the plurality of the communication devices, which are already involved in the first communication conference, and generating messages for inviting communication devices to the second communication conference only for those communication devices which are not involved in another the first communication conference.