Patent ID: 7251690

Claim:
A method of reporting a status from a first node over a communications link to a second node, comprising the steps of: maintaining at the first node a first value and a second value, the first value representing the status at the first node and the second value representing a status at the second node as perceived by the first node; updating said first value in accordance with an updated status; responsive to updating said first value, sending a transmission indicating said updated first value over said communications link from the first node to the second node; receiving at the first node over said communications link a confirmation of said transmission from the second node; and responsive to receipt of said confirmation, updating said second value in accordance with the updated status; setting a timer at the first node to count down a first period; resetting the timer if a transmission indicating an updated first value being sent from the first node to the second node occurs prior to said first period expiring; and transmitting a heartbeat message from the first node to the second node if said first period expires prior to a transmission indicating an updated first value being sent from the first node to the second node.