MESSAGE TRANSCEIVING METHOD, INFORMATION ACQUISITION AND TRANSCEIVING METHOD, AND RELATED DEVICE

A message receiving and sending method, an information obtaining, receiving, and sending method, and a related device are provided, and belong to the field of broadband network technologies. The method includes: A first user plane network element obtains keepalive information of a terminal device; receives a migration begin request message sent by a control plane network element; and in response to receiving the migration begin request message, after receiving a first keepalive request packet sent by the terminal device, sends a first keepalive response packet for the first keepalive request packet to the terminal device based on the keepalive information. When a communication fault occurs between the terminal device and a second user plane network element, the terminal device is migrated from the second user plane network element to the first user plane network element. If the terminal device sends the first keepalive request packet to the first user plane network element in this case, even if the first user plane network element has not obtained forwarding control entry information, the first user plane network element can send the first keepalive response packet based on the keepalive information, to avoid a case in which the terminal device goes offline due to a keepalive detection failure.