Restreamer eating bandwidth when started in the network

[cecchisandrone]

Subject of the issue I have a restreamer instance running in a network structured like this (RPI is connected via ethernet cable):

Everything runs smoothly in Restreamer but I have a problem with the WAN bandwidth that I really can't understand. Basically when I start restreamer, if I do a speedtest, bandwidth is reduced, more than 50%. This is really strange as the camera streams are only 300kbps and no clients are connected to Restreamer of course. I attach iftop executed on the RPI:

I also attach the status screen on the TP-Link CPE 210 antenna to demonstrate there is no traffic from other clients at the same time:

Those are the speedtest executed with running/not running Restreamer

Do you have any insight on how to do further troubleshooting? Your environment Restreamer running in Docker on RPI3, 2.12.0