Usually yes, with an AT command: http://www.messagestick.net/modem/Hayes_Ch1-1.html
Knowledge of AT commands is still useful today, but the modems are cellular: https://www.twilio.com/docs/iot/supersim/introduction-at-com...
Knowledge of AT commands is still useful today, but the modems are cellular: https://www.twilio.com/docs/iot/supersim/introduction-at-com...