LwM2M Client Connection Monitor Shows Disconnected

In this tutorial, you'll learn about LwM2M Client Connection Monitor Shows Disconnected. We cover key concepts, practical examples, and best practices.

The Problem

LwM2M client connection monitor shows disconnected even when the network is up.

Quick Fix

Wrong

// No connection monitoring implemented```

Client cannot detect server disconnection or network changes.

### Right

```cpp
#include <anjay/anjay.h>
#include <anjay/core.h>

static void conn_status_handler(anjay_t *anjay,
    anjay_ssid_t ssid, bool connected) {
  if (connected) {
    Serial.print("Server ");
    Serial.print(ssid);
    Serial.println(" connected");
  } else {
    Serial.print("Server ");
    Serial.print(ssid);
    Serial.println(" disconnected");

    // Attempt reconnection
    anjay_retry_connection(anjay, ssid);
  }
}

int main(void) {
  anjay_t *anjay = anjay_new(&config);

  // Register connection status callback
  anjay_connection_monitor_register(anjay, conn_status_handler);

  anjay_start(anjay);

  // Monitor loop
  while (true) {
    anjay_sched_run(anjay);

    static uint32_t last_check = 0;
    if (millis() - last_check > 60000) {
      // Force a registration update to verify connectivity
      anjay_update_registration(anjay);
      last_check = millis();
    }
  }
}```

Server 1 connected\nServer 1 disconnected\nRetrying connection...\nServer 1 connected\n```

Prevention

LwM2M connection monitoring detects server and transport layer status. Register a callback with anjay_connection_monitor_register(). The callback fires on connect/disconnect events. On disconnect, implement retry logic with exponential backoff. Periodically force registration updates to verify connectivity. Monitor CoAP ping/pong for UDP keepalive.

DodaTech engineers apply these same patterns across Doda Browser, DodaZIP, and Durga Antivirus Pro for production IoT reliability.

FAQ