A method and apparatus for monitoring the operability status of nodes of a communication network determines first node status data at a first node by causing it to diagnose its own status and the status of at least one second node, and to send the first node status data to at least one second node. The first node receives second node status data from at least one second node, and determines node status evaluation data at the first node based on the determined first node status data and the received second node status data.