@onioneer You can try using AT commands to query the modem's status, check the signal strength, and debug the connection. The /dev/ttyUSB2 interface is reserved for AT command communication with the modem. And the AT command reference for the modem can be found here: https://itbrainpower.net/downloadables/Quectel_EC25_EC21_AT_Commands_Manual_V1.0.pdf Start with the AT commands listed under section 6 - Network Service Commands