A method for determining the association of sub-signals transmitted in inverse multiplexing, in particular by way of an optical transport network OTN, with the transmission sections guiding the sub-signals, having the following method steps: (a) a digital transmit signal that is to be transmitted is divided into a certain number M of a plurality of sub-signals, wherein each sub-signal of a transmit side of a transmission section associated with this sub-signal is transmitted to a receive side of the associated transmission section; (b) at the receive sides of the transmission sections the sub-signals are reassembled to form a digital receive signal, characterised by the following further method steps: (c) after synchronization has been effected on the receive side for the correct assembly of the sub-signals to form the digital receive signal the signal-transmission by way of at least one predetermined transmission section is interrupted for a detection process to determine the association of the sub-signals with the transmission sections; (d) on the receive side during the detection process to determine the association of the sub-signals with the transmission sections in the digital receive signal with the aid of one or a plurality of expected features of the sub-signals it is detected which sub-signal or which sub-signals is/are still contained in the digital receive signal or which sub-signal or which sub-signals is/are no longer contained in the digital receive signal; and (e) the steps (c) and (d) are carried out as many times as required for certain different individual transmission sections or for certain different combinations of a plurality of transmission sections until sufficient information is available in order to determine for one predetermined, a plurality of predetermined or all the transmission sections which sub-signal is transmitted by way of the relevant predetermined transmission section. (a) a digital transmit signal that is to be transmitted is divided into a certain number M of a plurality of sub-signals, wherein each sub-signal of a transmit side of a transmission section associated with this sub-signal is transmitted to a receive side of the associated transmission section; (b) at the receive sides of the transmission sections the sub-signals are reassembled to form a digital receive signal, characterised by the following further method steps: (c) after synchronization has been effected on the receive side for the correct assembly of the sub-signals to form the digital receive signal the signal-transmission by way of at least one predetermined transmission section is interrupted for a detection process to determine the association of the sub-signals with the transmission sections; (d) on the receive side during the detection process to determine the association of the sub-signals with the transmission sections in the digital receive signal with the aid of one or a plurality of expected features of the sub-signals it is detected which sub-signal or which sub-signals is/are still contained in the digital receive signal or which sub-signal or which sub-signals is/are no longer contained in the digital receive signal; and (e) the steps (c) and (d) are carried out as many times as required for certain different individual transmission sections or for certain different combinations of a plurality of transmission sections until sufficient information is available in order to determine for one predetermined, a plurality of predetermined or all the transmission sections which sub-signal is transmitted by way of the relevant predetermined transmission section.