A system includes: a packet processing function and a packet modification function. The packet processing function receives a packet generated by a sending application function and destined for a receiving application function. The packet includes first identifier information, and the packet processing function adds second identifier information thereto. The packet modification function: receives the packet; alters it in a way that prevents use of the first identifier information by a 3GPP conforming service data flow detection process to map the packet to a first service data flow for the sending application function; and provides the packet to a packet routing function with the second identifier information positioned in the packet to enable the packet routing function to use the second identifier information in the 3GPP conforming service data flow detection process to map the packet to the first service data flow and to a bearer for transporting the packet.