LWM2M registration and de-registration events

This relates to the internal function of IMPACT. This is for data collection which is for supporting applications predominantly for sensor data. The application is informed of the lifecycle of the device to ensure a consistent experience.

The IMPACT LWM2M plug-in sends the following events to trigger internal policies:

  • When an LWM2M device is registered, an ATTACH event is sent. Here, ATTACH is the generic alert type issued by the LWM2M Client to the LWM2M Server when the Client detects a new device.
  • When an LWM2M device sends registered updates, an UPDATE event is sent. Here, UPDATE is the generic alert type issued by the LWM2M Client to the LWM2M Server when an existing device is updated successfully.
  • When an LWM2M device sends de-register updates, a DETACH event is sent. Here, DETACH is the generic alert type issued by the LWM2M Client to the LWM2M Server when an existing device is detached from the LWM2M Client.

When an LWM2M device is deregistered, a generic alert notification with type LWM2M_DEREGISTER is sent. A deregistered device is not reachable, so the alert does not trigger any policy. You get a notification of the alert event if the nbi.send.genericalert.event system setting is set to true. See nbi.send.genericalert.event in the IMPACT Configuration Guide.

Device lifetime expiry

In the LWM2M values.yaml file, if the parameter REJECT_EXPIRED_ENDPOINTS is set to true, then the operations at the endpoint is rejected once the expiry time is reached. If set to false, the operations at the endpoint are allowed even beyond the expiry time.

By default, this parameter is set to false.

For more information, see Sample values.yaml file for LWM2M deployment section.

Optional Apache Camel notification

The following Apache Camel notification may be raised by LWM2M devices and sent to third-party products, such as the Nokia Service Management Platform:

deviceNotFound: If a device is not found during bootstrap and LWM2M registration, this notification is sent as long as one of the following conditions are met:

  • The bootstrap interface has the auto create flag set to false.

  • The registration interface is on a clear channel with DLTS disabled. If DTLS is enabled, the DTLS handshake will fail because the PSK is not found.