Siera 340U

• Vid/Pid - 1199:68A2 (may change for production units)

The Sierra 340U uses the cdc-wdm and qmi-wwan drivers and presents a /dev/cdc-wdmX control device and a wwanX wan interface. There are several alternative libraries for interacting with the modem.

• libqmi (original implementation, used in ModemManager)
• uqmi (used in openWRT)
• qmimodem (oFono)

libqmi ships with a userspace utility, qmicli, which can be used to get registration status, signal strength, network technology, and to connect and disconnect. After connecting, you can acquire an addressing information using DHCP.

The 340U has been tested with qmicli and everything works as expected. It does not work with uqmi, but this is the only modem I've tried with uqmi, so I may be using it wrong.