A method comprising: generating at a DSL transmitter time-marker information for a data unit based on a sequence numbering of a multicarrier symbol and/or a sequence numbering of a FEC codeword, wherein the time-marker information indicates a current point of time when the data unit crosses the gamma interface arranged hierarchically directly underneath a bonding sublayer; storing the time-marker information at the DSL transmitter; transmitting the data unit from the DSL transmitter to a DSL receiver; transmitting a request for retransmission from the DSL receiver to the DSL transmitter; and based on the request, retransmitting the data unit including the time-marker information from the DSL transmitter to the DSL receiver, receiving at the bonding sublayer second data to be transmitted, the bonding sublayer being provided for bonding of a first link and a second link; distributing the data unit to a first processing path associated with the first link and a further data unit from the second data to a second processing path associated with the second link; providing a first time-marker information for the data unit distributed to the first processing path and providing a second time-marker information for the further data unit distributed to the second processing path; transmitting the data unit and the further data unit over the first and second link, respectively; based on a request for retransmission on the first link, retransmitting the data unit including the first time-marker information and based on a request for retransmission on the second link, retransmitting the further data unit including the second time-marker information. generating at a DSL transmitter time-marker information for a data unit based on a sequence numbering of a multicarrier symbol and/or a sequence numbering of a FEC codeword, wherein the time-marker information indicates a current point of time when the data unit crosses the gamma interface arranged hierarchically directly underneath a bonding sublayer; storing the time-marker information at the DSL transmitter; transmitting the data unit from the DSL transmitter to a DSL receiver; transmitting a request for retransmission from the DSL receiver to the DSL transmitter; and based on the request, retransmitting the data unit including the time-marker information from the DSL transmitter to the DSL receiver, receiving at the bonding sublayer second data to be transmitted, the bonding sublayer being provided for bonding of a first link and a second link; distributing the data unit to a first processing path associated with the first link and a further data unit from the second data to a second processing path associated with the second link; providing a first time-marker information for the data unit distributed to the first processing path and providing a second time-marker information for the further data unit distributed to the second processing path; transmitting the data unit and the further data unit over the first and second link, respectively; based on a request for retransmission on the first link, retransmitting the data unit including the first time-marker information and based on a request for retransmission on the second link, retransmitting the further data unit including the second time-marker information.