title: WebRTC Android video chat app, can't make one device ring another
body: <p>This might sound silly, but I have been searching for a very long time on how to do that, and all what I get is only being more confused :/ 
  I have made a webRTC video chat application and it is working just fine, what I need now is how to ring one android-device from another when that other wants to call first one, I mean until now I must enter the same room name on both devices to be able to make a video call and that's not practical cuz in real life how will the other peer or device user know that someone wants to call him, I have read about SIP, but it seems not what I am looking for, please help.</p>