RE: Azure IOT hub large Cloud 2 Device message

Charlie — Thu, 12 Dec 2024 13:04:11 GMT

Hi René,

No problem, let me kown if you need more help!

Best regards,

Charlie

RE: Azure IOT hub large Cloud 2 Device message

rene_pvh — Thu, 12 Dec 2024 12:23:39 GMT

Hi Charlie,

Thank you for the quick response.
We will try the posts you suggested.

Best regards,
René

RE: Azure IOT hub large Cloud 2 Device message

Charlie — Thu, 12 Dec 2024 11:43:53 GMT

Hi,

Thank you for reaching out to us.

The nRF9160 modem has a hardware resource constraint, as mentioned in the Modem Firmware 1.3.7 release notes:

2kB secure socket buffer size.

One potential solution is to use MbedTLS in the application core, as discussed here: RE: nRF9160 MQTT message payload over 2302 bytes results in Socket error: POLLERR and dropped connection

A better approach would be to split the message payload on the MQTT broker server side. This is supported by Azure IoT Hub MQTT 5 support by setting Maximum Packet Size. Unfortunately, the Zephyr MQTT client does not currently support MQTT 5. You can find more details here: Support for MQTT 5 · Issue #21633 · zephyrproject-rtos/zephyr.

If this feature is critical for your project, we recommend sharing your request on the feature request page. This could be a viable solution once Zephyr MQTT 5 support becomes available.

Best regards,
Charlie