A gateway device detects whether a node corresponding to each node identifier in a node identifier chain gets on-line, the chain including node identifiers of a head node, service node via which the head node accesses tail node, and the tail node. When each node gets on-line, the gateway device distributes, as a gateway device accessed by the head node, a first stream classifying strategy associated with the chain to device hardware, and forwards a received data stream which is from the head node to the tail node according to the chain based on the first stream classifying strategy. The gateway device distributes, as a gateway device accessed by the service node, a second stream classifying strategy associated with the chain to the device hardware, and forwards a received data stream which is from the head node to the tail node according to the chain based on the second stream classifying strategy.