Apparatus, wherein the apparatus is applied to a communications system comprising at least three nodes, a second node in the at least three nodes is configured to communicate with a third node by using a first node, and the apparatus comprises: a processing module, configured to determine a link between the first node and the second node is abnormal; and a transceiver module, configured to send first notification information to the third node, wherein the first notification information is used to indicate that the link between first node and the second node is abnormal, wherein the transceiver module is specifically configured to: recover the link between the first node and the second node; and send the first notification information to the third node if the link fails to be recovered, wherein the processing module is further configured to set a first preset time threshold; and the transceiver module is further configured to send the first notification information to the second node when the link fails to be recovered and the first preset time threshold is reached; wherein the transceiver module is further configured to send second notification information to the third node if the link is successfully recovered within a second preset time threshold, wherein the second notification information is used to indicate that the link is recovered. a processing module, configured to determine a link between the first node and the second node is abnormal; and a transceiver module, configured to send first notification information to the third node, wherein the first notification information is used to indicate that the link between first node and the second node is abnormal, wherein the transceiver module is specifically configured to: recover the link between the first node and the second node; and send the first notification information to the third node if the link fails to be recovered, wherein the processing module is further configured to set a first preset time threshold; and the transceiver module is further configured to send the first notification information to the second node when the link fails to be recovered and the first preset time threshold is reached; wherein the transceiver module is further configured to send second notification information to the third node if the link is successfully recovered within a second preset time threshold, wherein the second notification information is used to indicate that the link is recovered. recover the link between the first node and the second node; and send the first notification information to the third node if the link fails to be recovered, wherein the processing module is further configured to set a first preset time threshold; and the transceiver module is further configured to send the first notification information to the second node when the link fails to be recovered and the first preset time threshold is reached; wherein the transceiver module is further configured to send second notification information to the third node if the link is successfully recovered within a second preset time threshold, wherein the second notification information is used to indicate that the link is recovered.