This is the device ID. The bearer key reference. We have several ways to identify the device. E.g. for inmarsatc, we use fleetID and vesselID (and mobile number, if available). For D+, we use the vesselID. Daily Report uses the IMO number. The callsign. For instance, Globewireless uses this. The Globalstar device id. Example: 0-545312 The vesselID contains a unique GUID identifying the device. We use this e.g. for the API. IMEI - International Mobile Equipment Identity (e.g. BGAN) The inmarsat C mobile number. This is the DNID for INMARSATC. This is the terminal, member number, GUID, MMSI, etc. This is the IMO number.