Method for data transmission in a redundantly operable communication network, in which - the communication network comprises at least a first and a second subnetwork (1, 2), each of which comprise communication devices (101-107, 201-206) that are connected to one another within a ring topology and each have at least one coupling element and also a first and a second ring connection, which are switchably connectable to one another by the coupling element, - the two subnetworks each comprise a communication device (101, 201) having an activated ring control unit (100, 200) that detects an interruption within the respective ring topology and also controls forwarding of payload data between the ring connections of the respective communication device on the basis of a detected interruption, - the two subnetworks are connected to one another by way of two coupling paths (10, 20) and each comprise two coupling communication devices (106-107, 205-206), connected to the coupling paths, that each additionally have a coupling connection and a coupling control unit, - one coupling communication device is selected, the coupling control unit of which is activated, while the coupling control units of the other coupling communication devices are deactivated, - the coupling path to which the selected coupling communication device is connected is operated as an inactive reserve coupling path until a fault occurs, while the other coupling path is operated as the active main coupling path for transmitting payload data, characterized in that - the coupling communication devices (106, 205) connected to the main coupling path detect the occurrence of a fault on the main coupling path and transmit status datagrams to the selected coupling communication device, the status datagrams additionally comprising configuration information regarding whether the respective coupling communication device connected to the main coupling path comprises an activable ring control unit, - in the event of a fault occurring on the main coupling path, which is signalled by a status datagram, the selected coupling communication device activates the reserve coupling path for transmitting payload data and transmits a topology change datagram to each of the two subnetworks, which topology change datagram prompts the communication devices to erase their respective local source address table (111, 121,..., 171, 211, 221,..., 271) after a predefined period of time has elapsed, - the predefined period of time is shortened compared to a reference value if no coupling communication device connected to the main coupling path comprises an activable ring control unit. - the communication network comprises at least a first and a second subnetwork (1, 2), each of which comprise communication devices (101-107, 201-206) that are connected to one another within a ring topology and each have at least one coupling element and also a first and a second ring connection, which are switchably connectable to one another by the coupling element, - the two subnetworks each comprise a communication device (101, 201) having an activated ring control unit (100, 200) that detects an interruption within the respective ring topology and also controls forwarding of payload data between the ring connections of the respective communication device on the basis of a detected interruption, - the two subnetworks are connected to one another by way of two coupling paths (10, 20) and each comprise two coupling communication devices (106-107, 205-206), connected to the coupling paths, that each additionally have a coupling connection and a coupling control unit, - one coupling communication device is selected, the coupling control unit of which is activated, while the coupling control units of the other coupling communication devices are deactivated, - the coupling path to which the selected coupling communication device is connected is operated as an inactive reserve coupling path until a fault occurs, while the other coupling path is operated as the active main coupling path for transmitting payload data, - the coupling communication devices (106, 205) connected to the main coupling path detect the occurrence of a fault on the main coupling path and transmit status datagrams to the selected coupling communication device, the status datagrams additionally comprising configuration information regarding whether the respective coupling communication device connected to the main coupling path comprises an activable ring control unit, - in the event of a fault occurring on the main coupling path, which is signalled by a status datagram, the selected coupling communication device activates the reserve coupling path for transmitting payload data and transmits a topology change datagram to each of the two subnetworks, which topology change datagram prompts the communication devices to erase their respective local source address table (111, 121,..., 171, 211, 221,..., 271) after a predefined period of time has elapsed, - the predefined period of time is shortened compared to a reference value if no coupling communication device connected to the main coupling path comprises an activable ring control unit.