up to my knowledge GSM modem | Projects › Projects › GSM Module port configuration problem › up to my knowledge GSM modem November 13, 2015 at 5:50 pm #13481 Ashutosh BhattParticipant up to my knowledge GSM modem works on some specific COM ports only like COM1 or COM2 likewise. if in your system by default GSM modem is connected to some other port like COM11, COM21 then it wont work
