A method includes receiving, by a network device, notification packets separately sent by a plurality of forwarding nodes, where each notification packet includes interface forwarding delay information of the forwarding node that sends the notification packet, device forwarding delay information of the forwarding node, and a transmission delay of a link connected to the forwarding node; obtaining the interface forwarding delay information and the device forwarding delay information of each of the plurality of forwarding nodes, and obtaining a transmission delay of a link between the plurality of forwarding nodes; and computing a forwarding path between a first forwarding node and a second forwarding node, where a forwarding delay of the forwarding path meets a delay requirement of a service.