The invention relates to a method in an arrangement of a communication network, controlling a chain of functions for processing data packets of a flow associated with a device. The method comprises obtaining (610) an indication indicating that information associated with a context of at least one of the functions has been altered. The context is related to the flow and at least one of the communication network, the device, a route of the flow, and a source instance of each of the at least one function. The method further comprises determining (620) to relocate the at least one function for processing the data packets from the respective source instance to a respective target instance based on the obtained indication. The method also comprises relocating (630) the at least one function for processing the data packets to the respective target instance.