How much data consumed on MQTT connection

Question

I wonder how much data will be consumed (approximately) over say one month if I just connected to an MQTT server.(without sending or receiving any messages).

I need to calculate it to measure what data plan should I recharge for my sim card used in IoT application.

Thanks

Answer 1

Edit: fix broken link as suggested by @Jacob

I hope that you can find your answers here:

MQTT data usage

By the way... The client sets the keep alive value when it sends a CONNECT request to the server (aka the broker). Potentially, if the client choose 0 as keep alive value, no data is consumed except for setup connection.

Answer 2

Last time I had to do something similar I simulated the traffic of a month.

Because computers are much faster than IoT devices, just use any kind of high-level library to send the traffic the IoT devices would be sent in a month and then measure the TCP traffic.