Bootstrapping process to connect a LwM2M client.

To use the 1NCE LwM2M Service, every time a client IoT device with a 1NCE SIM wants to connect or reattach, the bootstrap server needs to be contacted at first. A direct connection to the LwM2M server without prior communication towards the bootstrap service is not possible.

The task at hand for the bootstrap server is to accept the initial connection, handle the authorization of the SIM device using the SIM-as-an-Identity service and provide LwM2M server connectivity instructions with one-time specific security credentials. The following figure illustrates this process in details.

The shown steps are the following:

  1. The LwM2M client calls the bootstrap server at using plain CoAP.

  2. The bootstrap server responds with a data message containing all the necessary information for the client to connect to the actual LwM2M server.

  3. The LwM2M client device uses this information to trigger the registration on the LwM2M server using CoAPs. The DTLS Pre Shared Key (PSK) that is provided by the bootstrap server and used for the registration is regenerated on every bootstrap request.