SIP VoIP Phone
Linphone is an open source SIP Phone, available on the mobile and the desktop environment (iOS, Android, GNU/Linux, MAC OSX, Windows Desktop, Windows 10 UWP).
Linphone system makes a call to your mobile when the sensor device turned the exceptional status. It is also available to use as a nomal communication tool with other SIP users.
Make a call to the gateway directly from remote by your mobile and hang it up by yourself on the below interface, you can check the room sounds settled the gateway, or talk to someone in the room. Controlled Linphone on the below interface or by the IR remote controller.
Operation Display for Linphone