From the little information you've provided I presume that this is not a serious question and you just want to complain.
Actually its a serious question with a bit of complaining as it is a very frustrating situation. I will try to provide more info but as it seems to be random, I'm not sure what else I can add. It seems that if I am not actively using the application for an hour or so it quits responding and I have to restart. This happens independently from how many overall apps I have open or what else I am working in.
Additional note: In the time that I took to write this (so indd is open but not active, it has become unresponsive and I will have to restart.
In the realm of more info it would be good to know the version of ID, the OS, and if you have any third-party plugins or background utilities that could be causing this.
ID does seem to lose network connections on the Mac...