Method and apparatus for monitoring link state between nodes

A method for monitoring a link state between nodes, being applicable to a ring network system, wherein the ring network system comprises a first node, a second node and a third node which are sequentially connected, the method comprising:

• by the first node, monitoring whether message data transmitted by the second node is received for a first time duration to obtain a monitoring result, and determining whether to transmit a first diagnosis message to the second node based on the monitoring result comprises:
• in response to not monitoring the message data transmitted by the second node for M consecutive first time durations, transmitting, by the first node, the first diagnosis message to the second node, wherein M is a preset value;
• by the second node, after receiving the first diagnosis message, processing the first diagnosis message to obtain a second diagnosis message, and transmitting the second diagnosis message to the third node;
• by the third node, after receiving the second diagnosis message, processing the second diagnosis message to obtain a third diagnosis message, and transmitting the third diagnosis message to the second node;
• by the second node, after receiving the third diagnosis message, determining a validity of the third diagnosis message to obtain a determining result, and determining whether to transmit the third diagnosis message to the first node based on the determining result;
• and
• by the first node, monitoring whether the third diagnosis message transmitted by the second node is received for a second time duration to obtain a monitoring result, and determining a link state between the first node and the second node based on the monitoring result.