MQTT data limit

[dave]

Hi,

Using ncs v2.7 on the nrf9160, is there a data limit using MQTT to communicate with Azure IoT Hub per message?  I'm trying to determine if I will need to chunk my telemetry data into multiple messages or if I can fit it all into one message.

[Hakon]

Hello,

Using ncs v2.7 on the nrf9160, is there a data limit using MQTT to communicate with Azure IoT Hub per message?

I'm assuming you are using MQTT with TLS, and in that case there is a TLS buffer limit of 2 KB. This can be avoided by using the mbedtls stack instead of the modem lib TLS stack.

[dave]

Thanks. You are correct we're using MQTT with TLS

I'm not familiar with the difference between the stacks and will do some research, but

Does the mbedTLS  stack have a data limit? 

Aside from the data limit are there any advantages / disadvantages to using one over the other? 

I have a low power system and need an average current of 300 uA max if that makes a difference. In general we will be transmitting data about 10 times a day and may run over 2kB per message ( maybe not for every message, hard to know). We can chunk the data if necessary

Thanks!