# apt install --no-install-recommends libqmi-utils ifmetric
# cp -v ./qmi-network@.service /etc/systemd/system/
# systemctl daemon-reload
# systemctl enable --now qmi-network@0

# This will NOT work without a .network for your wwan device.
[Unit]
Description=qmi-network for cdc-wdm%i device

Before=freepbx.service
Before=asterisk.service

Requires=sys-subsystem-net-devices-wwan%i.device

[Service]
Type=simple
Restart=always
RestartSec=60s
TimeoutSec=90s

# Make sure the state is cleared before starting.
ExecStartPre=-rm /tmp/qmi-network-state-cdc-wdm%i

# Stop wwan so it can be reconfigured.
ExecStartPre=networkctl down wwan%i

# Raw IP must be enabled.
ExecStartPre=sh -c "echo 'Y' | tee /sys/class/net/wwan%i/qmi/raw_ip"

# Bring up the network.
ExecStartPre=networkctl up wwan%i

# Start the network via qmi-network scripts.
# As some networks and/or devices take a long time to connect we should
# give it some time to be ready before starting the connection process.
ExecStartPre=-sh -e -c "sleep 5; qmi-network /dev/cdc-wdm%i start && sleep 5;"

# Main loop with **very basic** failover.
ExecStart=sh -e -c "while true; do ping -w 10 -c 3 one.one.one.one || (ping -w 10 -I wwan%i -c 3 one.one.one.one && ifmetric wwan%i 128); sleep 30; done;"

# Stop.. DOWN TIME!
ExecStop=networkctl down wwan%i
ExecStop=qmi-network /dev/cdc-wdm%i stop
# Be sure the network state is cleared on stop too.
ExecStop=-rm /tmp/qmi-network-state-cdc-wdm%i

[Install]
WantedBy=sys-subsystem-net-devices-wwan%i.device