These notes are based on ethaniel's excellent guide. Please read that guide first and then consult these notes on some changes/tweeks I needed to do to get this running on the newest raspberyr pi OS (January 2023) with a Huawei E8372h-320 (2020 model).
Setup SMS forwarding with gammu on debian bullseye on a rasp pi B+ with the HUAWEI E8372h-320 (2020 model)
First and foremost we need to get the huawei into the correct mode. Unfortunately, usb modeswitch did not do this out-of-the-box for me.
Ensuring that the huawei stick does not switch into an incompatible mode automatically
cdc_ether by creating a file
/etc/modprobe.d/blacklist-huawei-cdc-usb-net.conf with the following contents: