Example data transmission methods and apparatus are disclosed. One example method includes receiving a first data packet. When a first ring node detects that a link between the first ring node and a second ring node on a first ring port is faulty, it is determined whether the received first data packet is a wrapped data packet. If the first data packet is a non-wrapped data packet, a second ring port is determined based on the first ring port, the first data packet is wrapped into a wrapped data packet to generate a second data packet, and the second data packet is forwarded through the second ring port.