1. A method for controlling, by a central control entity, a topology change in a network having a ring topology with a plurality of ring nodes via which data packets of various data transfers are transmitted to their corresponding destination nodes, the method comprising: for a data transfer to a destination node, configuring each ring node, using one or more switching instructions, with both a first output port for the data transfer to the corresponding destination node and an alternative output port for the data transfer to the destination node; receiving information about a topology change of the ring topology of the network; determining which of the data transfers are affected by the topology change, based upon the received information about the topology change; determining, for each of the affected data transfers, a new path through the network; determining new switching instructions for ring nodes that are affected by the new paths determined for the affected data transfers; and transmitting the new switching instructions to the affected ring nodes, wherein the determined new switching instructions contain information about a new first output port that is a preferred output port for said data transfer to said destination node, taking into account the topology change.