A method includes receiving, by an ingress network element, a data packet, wherein an ingress flow entry is stored in the ingress network element. The ingress flow entry comprises flow description information and a processing network element indication, where the flow description information matches the data packet, and the processing network element indication is used to indicate a processing network element that processes the data packet after the ingress network element. The method further includes sending, by the ingress network element, the data packet to the processing network element according to the ingress flow entry, so that the processing network element performs context processing on the data packet.