Method for transmitting real-time messages in a computer network, in particular real-time computer network, - wherein said computer network comprises two or more computing nodes (21, 22, 23, 24, 25, 26) and one or more star couplers (1, 2, 3, 4), wherein said computing nodes (21, 22, 23, 24, 25, 26) are interconnected via at least one star coupler (1, 2, 3, 4), wherein each computing node (21, 22, 23, 24, 25, 26) is connected to the at least one star coupler (1, 2, 3, 4) via at least one of the communication links, and wherein the computing nodes exchange messages (M1, M2) with one another and with the at least one star coupler, wherein a global time base is provided, and wherein the messages comprise at least a first non-empty set (SSET) of real-time messages; and - wherein star couplers, which are synchronized to the global time base, transmit said first non-empty set (SSET) of real-time messages according to a synchronized communication paradigm in which real-time messages are transmitted according to a communication schedule, and - wherein computing nodes (21, 22, 23, 24, 25, 26), which are synchronized to the global time base, transmit said first non-empty set of real-time (SSET) messages according to the synchronized communication paradigm, characterised in that the at least one star coupler (1, 2, 3, 4), which has lost synchronization to the global time base, and a computing node (21, 22, 23, 24, 25, 26) of the two or more computing nodes, which has lost synchronization to the global time base, - transmits a second non-empty subset (CSET) of said first non-empty subset (SSET) of real-time messages according to an unsynchronized communication paradigm and stops the transmission of said second non-empty subset (CSET) of real-time messages according to the synchronized communication paradigm, wherein said second non-empty subset (CSET) comprises real-time messages defined as critical. - wherein said computer network comprises two or more computing nodes (21, 22, 23, 24, 25, 26) and one or more star couplers (1, 2, 3, 4), wherein said computing nodes (21, 22, 23, 24, 25, 26) are interconnected via at least one star coupler (1, 2, 3, 4), wherein each computing node (21, 22, 23, 24, 25, 26) is connected to the at least one star coupler (1, 2, 3, 4) via at least one of the communication links, and wherein the computing nodes exchange messages (M1, M2) with one another and with the at least one star coupler, wherein a global time base is provided, and wherein the messages comprise at least a first non-empty set (SSET) of real-time messages; and - wherein star couplers, which are synchronized to the global time base, transmit said first non-empty set (SSET) of real-time messages according to a synchronized communication paradigm in which real-time messages are transmitted according to a communication schedule, and - wherein computing nodes (21, 22, 23, 24, 25, 26), which are synchronized to the global time base, transmit said first non-empty set of real-time (SSET) messages according to the synchronized communication paradigm, characterised in that the at least one star coupler (1, 2, 3, 4), which has lost synchronization to the global time base, and a computing node (21, 22, 23, 24, 25, 26) of the two or more computing nodes, which has lost synchronization to the global time base, - transmits a second non-empty subset (CSET) of said first non-empty subset (SSET) of real-time messages according to an unsynchronized communication paradigm and stops the transmission of said second non-empty subset (CSET) of real-time messages according to the synchronized communication paradigm, wherein said second non-empty subset (CSET) comprises real-time messages defined as critical.