This is a way of communicating on the half-duplex communication line, includes receiving and transmitting devices (walkie-talkie) by the way of pressing the button for switching to the voice mode or transition to the listening mode. It works as a radio speaker; one can talk by pressing the button and can listen to a voice message by releasing the button.
From mobiSIP Android or iPhone: SIP Client iPhone is uniquely designed and developed to add the power of making voice over internet transfer protocol calls directly through the Android or iPhone. It’s developed by mobisnow.