In a communication data stream transmitted within IP datagrams via a communication network, the timing of the transmission of the IP datagrams is oriented toward a timestamp which is transmitted to a transmitter of the IP datagrams. In this context, the transmitter reserves time intervals whose timing is geared to the received timestamp for the purpose of transmitting the IP datagrams. The IP datagrams are respectively assigned to one of the time intervals and are transmitted within the respectively associated time interval by the transmitter in line with the Internet protocol.