Azure C2D Feedback Status and Retry Recommendations

• Expired

  Description: Device did not receive the outbound message within the expiry duration

  Retry Recommendation: Implement a retry mechanism with exponential backoff to resend the message. Ensure that the device is online and operational.

• DeviceMaximumQueueDepthExceeded

  Description: Outbound message failed because the device queue limit was reached.

  Retry Recommendation: Retry after the device comes online, so that the messages in the queue get cleared.

• Failed

  Description: Failed to initiate outbound message.

  Retry Recommendation: This can happen due to any outage or service disruption. Implement a retry mechanism with exponential backoff to resend the message.

Note

Messages in the Pending state will be processed and moved to Sent status almost immediately (within a few seconds). While designing outbound applications and device firmware, please consider the following behaviors:

• During unexpected Azure outages, a message will move to the Failed state within approximately a minute (this time frame is approximate and not guaranteed). The outbound message should be retried by the calling application with a new API request/message ID. Devices should be capable of handling duplicate messages.

• During unexpected Trimble Cloud IoT service outages, messages may remain in the Pending status for an extended period, which is expected behavior. Upon service restoration, Pending messages will be processed. If the ExpiryInSecs set by the application when sending the outbound messages elapses before processing, the message will be dropped and marked as Failed. For critical messages where the application needs to know the delivery status immediately, the direct_methods feature is recommended.