Copter SITL uploading something to the internet

I installed SITL based on the newest ArduCopter code on my Raspberry Pi 3. It seems to work pretty well, but I’ve noticed as soon as I connect to the simulator with Mavlink Router, GCS, or anything else (locally), ~20kBps worth of data starts to be uploaded via my wlan0 interface. I`d like to know what exactly gets uploaded, and is there any way to stop it.

Hello,

That is probably the terrain database or the GCS imaging system that request some data

My guess is the same as khancyr’s.

tcpdump FTW.

Thank you for your input. “GCS imaging system that request some data” looks out of question, as the exact same thing happens just by connecting to Mavlink Router, but the terrain thing seems possible. I checked the parameters with Mission Planner, and it seems that both SIM_TERRAIN and TERRAIN_ENABLE are set to 0. Are there any parameters or any other way to disable that functionality?