The invention relates to a method for reducing the header size of data packets by removing inner headers from the data packets, wherein at least an outer header remains for routing purposes. When removing the inner headers from a data packet, a newly configured address of the receiving and/or the transmitting entity is inserted in the remaining outer header of the data packet. Context information is provided in the receiving entities for reconstructing the removed inner headers, wherein the context information is referred to by the newly configured address that is in the source and/or destination address of the outer header. The reduced data packet is transmitted with only one header, thereby significantly reducing the size of each data packet. The original packet is completely reconstructed at the receiving entity thereby allowing to proceed with the usual processing of each data packet.