Just curious to how the Calls function knowns if a node is on or offline. Using SDR Truck I am feeding 2 different Calls nodes as well as to the standard Broadcastify relay servers. I lowered the offline time to 15 minutes, because i want to know right away when theres an issue. The problem I am seeing is just one of the Calls Node keeps reporting offline despite being online on the other node and stream. The question is, does calls use a heartbeat to know if a node is online or is it strictly looking at the last time a message was sent. In one of my nodes it could be several hours between calls on a quiet night.