Communications method, apparatus, and system for recovering lost packets

A communications method, wherein the method comprises:

• recovering, by a first node when detecting that a first packet is lost, the first packet according to a local recovery mechanism, wherein the first packet is a packet obtained based on a packet sent by a first terminal to a second terminal, and the first node is a node on a network path between the first terminal and the second terminal communicating with the first terminal;
• adding, by the first node, first identification information related to local recovery to the first packet;
• and
• sending, by the first node, the first packet;
• wherein the first identification information identifies that the first packet is a packet recovered according to the local recovery mechanism, the first identification information identifies a quantity of times for which the first packet is recovered, or the first identification information identifies that a current network status indicates network congestion;
• wherein before the recovering, by a first node, the first packet according to a local recovery mechanism, the method further comprises:
• receiving, by the first node, the first packet;
• sending, by the first node, the first packet to a second node, wherein the second node is another node, other than the first node, on the network path between the first terminal and the second terminal communicating with the first terminal;
• and
• detecting, by the first node according to a packet acknowledgment mechanism, whether the first packet is lost in a process of transmitting the first packet to the second node.