A data unit processing entity 4 is described, which has a decision part 41 for setting a forwarding address FA on the basis of an identifying address in a received data unit, by referring to decision data stored in a decision data memory 42. A management part 43 is provided, which is arranged to provide a network control function 51 with access to the decision data in the decision data memory 42, in order to change said decision data, independently of any access given to mobile nodes.