Once you are connected to Data API you have a capability to receive and send different messages: uplink messages from the device, debug messages, and so on...
All messages that are received or transmitted through Data API interface are JSON objects with the following format:
|type||string||Message type is used to divide messages by it's functionality: information messages, uplink messages, error messages and so on.|
|meta||object||Metadata is a common structure for all message types and contain such kind of information like: device identifier, message identifier and so on...|
|params||object||Contains specific parameters for the particular type of a message. For example, uplink messages cointain "payload" field, but it is missed in join requests.|
Each message contains a
type field that is included to divide messages by it's functionality: uplinks, downlinks, join, errors.
Each message type has a corresponding
For better understanding you could divide messages into two groups:
LoRaWAN - messages that are generated because of device actions or to perform any actions on the devices.
These messages have the following types:
Service messages that have types:
info. These messages are generated by NS in process of LoRaWAN message processing. This group has more informational/debug purpose that the first one.
Here is a list of message types:
|uplink||Uplink messages from devices. Contains payload, radio information, mac commands and so on...||from NS to AS|
|downlink_request||Request message generated by NS in case it has an opportunity to send downlink message to a device. In case of AS has any downlinks it will send it to the NS. More information could be found here.||From NS to AS|
|downlink_response||Response message generated by AS as a response to
||from AS to NS|
|downlink||Message generated by NS just after a downlink message was actually sent to a device. Note that it is not possible to use this type of message to actually send downlink to a device. Please use
||from NS to AS|
|join_request||Join request message is generated in case of device is using OTAA on the application side.||from NS to AS|
|join_response||Join accept message should be emitted by AS after a succesfull join procedure||from AS to NS|
|status_request||This message is generated by AS to request device status according to LoRaWAN specification. See DevStatusReq MAC command for details.||from AS to NS|
|status_response||Message with device status according to LoRaWAN specification.||fron NS to AS|
|downlink_claim||This type is used for Class C devices only and notifies the Network Server about a new, available uplink packet.||from AS to NS|
|error||These messages are generated by NS to inform AS about critical errors thathappened during LoRaWAN message processing and NS to AS interactions. For example: MIC is incorrect.||from NS to AS|
|warning||Message of these type are generated in case of error occurred during message processing, but NS was able to finish processing. For example: AS is not available.||from NS to AS|
|info||This is an auxiliary message type that could be used to understand all processing steps in details. For example: message was successfully delivered to AS.||from NS to AS|
Each message contains the following metadata structure (this structure is common for all message types):
|application||string||The application identifier (app_eui by LoraWAN specification)|
|device||string||The device identifier (dev_eui by LoraWAN specification)|
|device_addr||string||The device address (dev_addr by LoraWAN specification)|
|gateway||string||The gateway mac address|
|history||bool||This flag sets for saving the messages in Everynet Network Server History|
|network||string||The network of gateways identifier|
|packet_hash||string||Message hash. It is very important to understand messages hashes for bidirectional interaction. More information is available here.|
|packet_id||string||Message identifier. Each message has unique identifier. It is possible to use it to identify duplicates.|
|version||integer||Current version of everynet network server protocol, default: 1|
Data API supports bidirectional messaging using request-response model.
For example messages
downlink_response are used to get a downlink data from AS and send it to the device.
Here is a diagram that describes a message flow between NS and AS to send a downlink message to a device:
In other words the sequence is the following:
- NS sends AS
packet_hash= 1 and wait for the response
- AS process this message and send a response with
- NS match
downlink_responseand send message to the end device
params is specific for each type of message and described in corresponding section dedicated to the message type.