I’m happy to use AT commands, if that will not interfere with system software. To device ‘/dev/mhi_DUN’ I guess?

Here are the three uqmi commands that I think are most useful (on a GL-X750):

root@2HHG-4G:~# uqmi -d /dev/cdc-wdm0 --get-data-status
"connected"
root@2HHG-4G:~# uqmi -d /dev/cdc-wdm0 --get-signal-info
{
	"type": "lte",
	"rssi": -48,
	"rsrq": -10,
	"rsrp": -75,
	"snr": 114
}
root@2HHG-4G:~# uqmi -d /dev/cdc-wdm0 --get-current-settings
{
	"pdp-type": "ipv4",
	"ip-family": "ipv4",
	"mtu": 1500,
	"ipv4": {
		"ip": "10.34.236.123",
		"dns1": "10.205.64.1",
		"dns2": "10.205.64.1",
		"gateway": "10.34.236.124",
		"subnet": "255.255.255.248"
	},
	"ipv6": {
		
	},
	"domain-names": {
		
	}
}