A method includes transmitting packets of first and second traffic subflows via a first radio bearer to a second device; detecting that further packets of the second traffic subflow are to be transmitted via a second radio bearer to the second device; and transmitting a packet data unit via the first radio bearer to the second device, wherein the packet data unit includes an indication of a switch of the second traffic flow. Another method includes receiving from a first device packets of first and second traffic subflows via a first radio bearer; receiving from the first device a packet data unit including an indication that further packets of the second traffic subflow are to be received via a second radio bearer; establishing the second radio bearer between a second device and the first device; and receiving the further packets of the second traffic flow via the second radio bearer.