3G dongle Huawei E1550 is able to make voice calls using Huawei app in Windows. With search I found the same app for Linux (called Mobile Partner), seems it's working and makes calls, but without sound (tested on several machines). Is there any other software for making voice calls with this modem?
Making voice calls using Huawei E1550
linux;modem;3g;telephony;huawei