<i>Older</i> modems are &#x2F;dev&#x2F;ttyUSBx or &#x2F;dev&#x2F;ttyACM but newer modems might be using the MBIM [1] standard and don&#x27;t really expose AT interfaces to the user.<p>1: <a href="https:&#x2F;&#x2F;www.kernel.org&#x2F;doc&#x2F;Documentation&#x2F;networking&#x2F;cdc_mbim.txt" rel="nofollow">https:&#x2F;&#x2F;www.kernel.org&#x2F;doc&#x2F;Documentation&#x2F;networking&#x2F;cdc_mbim...</a>