Identifiers
The LWM2M Enabler defines specific identifiers for entities used within the LWM2M Protocol. These identifiers are defined in Table 15.
| Identifier | Semantics | Description |
|---|---|---|
| Endpoint Client Name | URN | Identifies the LWM2M Client on one LWM2M Server (including LWM2M Bootstrap Server). |
| LWM2M Bootstrap Server URI | URI | Uniquely identifies the LWM2M Bootstrap Server. Provided to the LWM2M Client during the Bootstrap procedure |
| LWM2M Server URI | URI | Uniquely identifies the LWM2M Server. Provided to the Client during Bootstrap procedure. |
| Short Server ID | 16-bit unsigned integer | Uniquely identifies each LWM2M Server configured for the LWM2M Client. The identifier is assigned during the Bootstrap procedure. |
| Human Readable Object URN | URN for the OMA Management Object | Assigned by the Object specification. |
| Object ID | 16-bit unsigned integer | Uniquely identifies the Object in the LWM2M Client. This identifier is assigned by OMA. |
| Object Instance ID | 16-bit unsigned integer | Uniquely identifies the Object Instance of the Object within the LWM2M Client. This identifier is assigned by LWM2M Client or LWM2M Server.MAX_ID 65535 is a reserved value and MUST NOT be used for identifying the Object Instance. |
| Resource ID | 16-bit unsigned integer | Uniquely identifies the Resource within the Object. Short integer ID, with a range assigned by the Object specification and unique to that Object, and a Reusable Resource ID range assigned by OMA and re-usable between Objects. |
| Resource Instance ID | 16-bit unsigned integer | Uniquely identifies the Resource Instance in the Resource. This identifier is assigned by LWM2M Client or LWM2M Server. |
Table 15: LWM2M Identifiers
Endpoint Client Name
Following formats are RECOMMENDED for this identifier to guarantee uniqueness:
| Format |
|---|
| UUID URN: Identify a device using a Universally Unique IDentifier (UUID). The UUID specifies a valid, hex digit character string as defined in [RFC4122]. The format of the URN is urn:uuid:########-####-####-############ |
Other URN formats MAY be used. In particular, URN formats defined in [DMREPPRO] Section 5.5 can be used.
Reusable Resources
When Objects are designed for a similar purpose, for example Objects for use in network management, or Objects for use in embedded device automation, similar Resources are useful in more than one Object. For example in embedded device automation, Objects for different purposes may contain common Resource types such as digital input, digital output, analogue input, analogue output, dimmer value, unit, min measurement, max measurement, value range etc.
If a Resource can feasibly be re-used with the same meaning in multiple Object definitions, it can be defined as a Reusable Resource ID and registered with OMNA. Other Objects may then make use of this Reusable Resource ID in another Object definition. The definition of the Resource MUST be the same with the exception of the Multiple Resource, Mandatory and Description fields.