UPF Heartbeat
Once the registration is complete, Nrfmgr checks if the "nr hb-enable" option is configured. If "nr hb-enable" is configured already, Nrfmgr builds or sends the Heartbeat Request message. Nrfmgr then starts the timer using the heartbeat timer-value received from peer NRF. If no heartbeat response is received until the heartbeat timer-value, Nrfmgr picks the endpoint with the next lowest priority-number. This process continues with all the endpoints in a round-robin fashion endlessly. To stop this process, you must delete the configuration.