Hello,
We are trying to determine the actually sent packet data from a nrf9160 device through zephyr over NB-IOT. Since we cannot capture the packet on the network, we want to see what the size is that gets sent and what we are billed for. We are trying to optimize for fitting as much data as possible into the 1kb blocks we are billed at.
Sending the same fixed with data every minute, looking at the portal of our provider it shows a changing data sent size. It varies by 100-400 bytes, and is almost 2x the sent data size. We are sending data over http without encryption, so we expect some amount of TCP/IP header data, some cell connection header, and TCP retries but the readings from the provider feel too variable.
Is there a MTU set that causes the packets to be split up, along with a large header? Or is a config flag in `prj.conf` similar to `CONFIG_LTE_LINK_CONTROL_LOG_LEVEL_DBG=y` that provides debug level info about all the packets sent. This post seems relevant but does not explain the variable packet size we receive.
Regards,
Sawaiz
