'Back in the day' this was done by using a serial cable attached to a Nokia 3810 or similar handset and speaking AT commands.
Gnokii was the tool... https://en.wikipedia.org/wiki/Gnokii
It was great for out-of-band network monitoring.
Gnokii was the tool... https://en.wikipedia.org/wiki/Gnokii
It was great for out-of-band network monitoring.