A method of handling data traffic, the method comprising: a forwarding node receiving data packets; for each of the received data packets, the forwarding node extracting a first value from a delay requirement label of the data packets, the first value indicating a delay requirement of the data packets; for each of the received data packets, the forwarding node extracting a second value from an importance label of the data packets, the second value indicating a level of importance assigned to the data packet; depending on the first values and the second values, the forwarding node controlling forwarding of the received data packets; depending on the respective first value, the forwarding node assigning each received data packets to one of multiple delay classes; and in response to detecting that one of the delay classes is subject to congestion, the forwarding node discarding, depending on the respective second value, one or more of the data packets assigned to at least one other of the delay classes having a stricter delay requirement, wherein discarding one or more packets of the data packets comprises determining an importance level threshold by the forwarding node and discarding those packets for which the second value is below the determined importance level threshold; and, further, wherein detecting that the one or more delay classes is subject to congestion comprises the forwarding node estimating a delay associated with forwarding of one of the received data packets; the forwarding node comparing the estimated delay to the first value extracted from this data packets; and depending on the comparison, the forwarding node detecting that the delay class to which the data packets is assigned is subject to congestion. a forwarding node receiving data packets; for each of the received data packets, the forwarding node extracting a first value from a delay requirement label of the data packets, the first value indicating a delay requirement of the data packets; for each of the received data packets, the forwarding node extracting a second value from an importance label of the data packets, the second value indicating a level of importance assigned to the data packet; depending on the first values and the second values, the forwarding node controlling forwarding of the received data packets; depending on the respective first value, the forwarding node assigning each received data packets to one of multiple delay classes; and in response to detecting that one of the delay classes is subject to congestion, the forwarding node discarding, depending on the respective second value, one or more of the data packets assigned to at least one other of the delay classes having a stricter delay requirement, wherein discarding one or more packets of the data packets comprises determining an importance level threshold by the forwarding node and discarding those packets for which the second value is below the determined importance level threshold; and, further, wherein detecting that the one or more delay classes is subject to congestion comprises the forwarding node estimating a delay associated with forwarding of one of the received data packets; the forwarding node comparing the estimated delay to the first value extracted from this data packets; and depending on the comparison, the forwarding node detecting that the delay class to which the data packets is assigned is subject to congestion.