I use Screen Cast to give presentations of mobile apps. I have done a lot of presentations and I noticed that once in a while Screen Cast stops broadcasting. I want the application to run continuously so that I can explain without any interruption. What should I do to prevent this? Please help.

I am using IP Phone Camera to monitor my office connected on a Wi-Fi network. I want to prevent unintended people from viewing the camera. Is there any setting to do this?