Patent ID: 11968082
Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 6:
7. A non-transitory machine-readable medium having computer code stored therein, which when executed by a set of one or more processors of a network device configured to function as a first controller in a software defined networking (SDN) network, causes the first controller to perform operations for monitoring a second controller, the first controller and the second controller being part of a cluster of controllers, controllers in the cluster communicating with each other over an out-of-band network dedicated for controller-to-controller communications, and controllers in the cluster communicating with switches in the SDN network over an in-band network that is separate from the out-of-band network, the operations comprising:
determining that the second controller cannot be reached over the out-of-band network;
sending a first control message to a switch over the in-band network in response to a determination that the second controller cannot be reached over the out-of-band network, the first control message including a health check request message and an instruction for the switch to send the health check request message to the second controller, and the switch being a designated switch that has a control channel connection to the first controller and the second controller over the in-band network, and the monitoring component, when executed by the set of one or more processors, further causes the first controller to determine that the out-of-band network has a failure in response to a determination that the health check acknowledgement message has been received from the second controller over the in-band network, the health check acknowledgement message being included in a second control message sent by the switch to the first controller over the in-band network;
configuring the switch to establish a control channel connection to all controllers in the cluster;
receiving a third control message from the switch over the in-band network, the third control message including a health check request message generated by a third controller in the cluster, the switch having a control channel connection to the third controller; and
sending a fourth control message to the switch over the in-band network in response to receiving the third control message, the fourth control message including a health check acknowledgement message and an instruction for the switch to send the health check acknowledgement message to the third controller; and
determining that the second controller has a failure in response to a determination that the health check acknowledgement message has not been received from the second controller over the in-band network.