TCP KeepAliveLWTRetain ReliableDeviceClient 12 00 8 dashboard Broker KeepAlive 3600 Broker 1.5 × 3600 = 5400 8 2 NB-IoT KeepAlive 60 60 PINGREQ 90% 48 30% 3 11 DISCONNECTTCP last_seenIsConn… [+19332 chars]
