LwM2M/CoAP Access

Introduction

Lightweight Machine to Machine (LwM2M), proposed by the Open Mobile Alliance (OMA), is a lightweight, standard, and universal IoT device management protocol that can be used to quickly deploy IoT services in client/server mode. LwM2M establishes a set of standards for IoT device management and application. It provides lightweight, compact, and secure communication interfaces and efficient data models for M2M device management and service support.

LwM2M/CoAP authentication supports both encrypted and non-encrypted access modes. Non-encrypted mode: Devices connect to IoTDA carrying the node ID through port 5683. Encrypted mode: Devices connect to IoTDA carrying node ID and secret through port 5684 by the DTLS/DTLS+ channel.

You are advised to use the encrypted access mode for security purposes.

For details about LwM2M syntax and APIs, see specifications.

IoTDA supports the plain text, opaque, Core Link, TLV, and JSON encoding formats specified in the protocol. In the multi-field operation (for example, writing multiple resources), the TLV format is used by default.

Constraints

Endpoints

For details about the platform endpoint, see Platform Connection Information.

Use the endpoint corresponding to CoAP (5683) or CoAPS (5684) and port 5683 (non-encrypted) or 5684 (encrypted) for device access.

Authentication Process

Figure 1 LwM2M/CoAP access authentication process

1. An application calls the API for registering a device. Alternatively, a user uses the IoTDA console to register a device.
2. The platform allocates a secret to the device and returns timeout.
   

   • The secret can be defined during device registration. If no secret is defined, the platform allocates one.
   • If the device is not connected to the platform within the duration specified by timeout, the platform deletes the device registration information.
3. During login, the device sends a connection authentication request carrying the node ID (such as the IMEI) and secret if it is a security device, or carrying the node ID if it is a non-security device.
4. If the authentication is successful, the platform returns a success message, and the device is connected to the platform.

Development Process

1. Development on the platform: Create products, develop product models and codecs on the platform, and register devices. For details, see Creating a Product, Developing a Product Model, Developing a Codec, and Registering a Device.
2. Development on the device: Use modules and Tiny SDKs on the device side for access. For details, see IoT Device SDK Tiny (C) User Guide.

Best Practices

Developing a Smart Street Light Using NB-IoT BearPi

FAQ

LwM2M/CoAP access FAQ: