Device Connectivity & Protocol

- MQTT broker (EMQX / Mosquitto) with cluster and shared subscriptions - CoAP for constrained devices (UDP, low power) - HTTP long-poll / WebSocket for non-MQTT devices - LwM2M device management protocol integration - Connection authentication: X.509 mTLS or username/password with per-device credentials - Topic structure design: /tenant/{tenant_id}/device/{device_id}/telemetry/{metric}