A method in which the propagation times of a target network are simulated in an actual network, wherein the topology of the target network includes a number of senders and a number of receivers, and wherein the topology of the actual network includes one or more of the senders and receivers. A path between a first sender and a first receiver in the topology of the actual network differs from the path between the first sender and the first receiver in the topology of the target network, wherein in the actual network at least one first message of the first sender is received through a first network interface by a gateway having at least two network interfaces, is delayed by a delay, and is sent through a second network interface on a path to the first receiver.