cisco sg-300

I use Cisco SG300-52MP in a system with 48 LTS 4MP cameras (a little overkill because all cameras use average 160W and this $switch$ can deliver over 700W). Works OK but I noticed that once per 2-3 weeks it's causing all cameras to disappear from iVMS (failed to get a stream) and the only way...

What kind of camera system is good to use with this NAS? I intend to use and possibly set up the NAS as an NVR if possible,, the switch that I have is a Cisco SG-300 10mmp. Any help would be great,, this is my alpha stage on research, I intend on purchasing a minimum of 4 cameras by the end...