I have some EM7565 with SWI9X50C_01.07.02.00 or SWI9X50C_01.08.04.00 firmware, I am using ModemManager + libqmi + qmi_wwan/qcserial kernel driver on Linux to drive them. I found that with ATT SIM card, once I disconnect cellmodem (the wwan0 interface became down and there is no default route via wwan0 anymore), pinging the static IP address on the cellmodem allocated by ATT, still got echo reply packets.
# qmicli -p -d /dev/cdc-wdm0 --wds-get-packet-service-status [29 Nov 2020, 12:03:07] -Warning ** [/dev/cdc-wdm0] requested auto mode but no MBIM QMUX support available [/dev/cdc-wdm0] Connection status: 'disconnected' # # qmicli -p -d /dev/cdc-wdm0 --wds-get-autoconnect-settings [29 Nov 2020, 12:46:58] -Warning ** [/dev/cdc-wdm0] requested auto mode but no MBIM QMUX support available Autoconnect settings retrieved: Status: 'disabled' #
If I do “mmcli -m X -r”, pinging the cellmodem IP address from my dev PC stops receiving echo replies, but resumes receiving them once the reset is finished I guess.
However, if I use a Verizon Wireless sim card, after disconnecting cellmodem, pinging the cellmodem static IP address becomes completely unresponsive - this is what I have been exepcted.
So, how could I disconnect from ATT network properly?
Thanks a lot!