The second network node 30 is suitable for congestion control, a.k.a. flow control, in a transport network. As can be seen in FIG. 9, the second network node 30 comprises means 31 adapted to receive, from a first network node, a congestion notification message 300. As described earlier, the congestion notification message 300 includes a combination of: (1) a flow identifier 310 identifying a flow that contributes to congestion and (2) back-off information 320 indicating a suitable back-off to compensate for the congestion caused by the flow associated with said flow identifier. Furthermore, the second network node 30 comprises means 32 adapted to adjust one or more parameters on the basis of said back-off information.

FIG. 10 illustrates an example implementation of the second network node 30 illustrated in FIG. 9. In this example implementation, the second network node 30 comprises a processor 33 and a memory 34. Also, a communications interface 35 may be provided in order to allow the first network node to communicate with other apparatuses (e.g., a first network node), etc. To this end, the communications interface 35 may comprise a transmitter (Tx) and a receiver (Rx). Alternatively, the communications interface 35 may comprise a transceiver (Tx/Rx) combining both transmission and reception capabilities. The communications interface 35 may include a RF interface allowing the first network node to communicate with apparatuses etc through a radio frequency band through the use of different radio frequency technologies e.g. standardized by the 3rd Generation Partnership Project (3GPP), or any other wireless technology such as Wi-Fi, Bluetooth?, etcetera.