EC25 internet traffic deactivating linux driver (usb ethernet) connection

we use the EC25 modem in an embedded (yocto) linux system. We disable the internet connection commanding linux network manager. We expect that no data has been sent by the modem on that connection. However our customer says that going on switzerland from Italy the modem SIM made some traffic (some bytes every 15 minutes).
Do the modem itself request data to phone provider in case of roaming…also if network connection is off?
To stop the dpd context I can send to the modem a “AT+CGACT=0,1” command…however I would like to understand more on modem behaviour and what kind of data the modem is exchanging

Thanks in advance.
Best regards,

If module is not dialed, no traffic will be generated.

Hi Isaac,
please define “dialed”, because customer says that the module did DATA (no sms,no voice call) traffic.

Before the module performs data traffic, it must fist dial to establish a network data connection.

" it must fist dial to establish a network data connection."

Of course, at the modem initializazion (system start) I send AT+CGDCONT=1,“IPV4V6”,“myAPN” and AT+CGACT=1,1 so the module is ready to exchange data over the internet. After that, if required (as in the case described…going to another country) I disable the network connection, at linux level.

The problem is that the modem exchange data also if linux network manager has disabled the card connection (usbEthernet).

I see that the EC25 modem has a command to manage the roaming service…
…maybe this is the solution that ensure no data on roaming.