i have a set-up of 1 NVR (124 Ch), 3 Switches (24 ports POE), and 72 cameras.. all switches are linked, and 1 patch cord from switch linked to NVR but the NVR supported of 4 ethernet i only use 1. My problem is some of the cameras are showing black screen and also the recording stop. I tried to power reset the NVR still not showing on screen. When i tried to power reset all the switches that's the time all the cameras are showing and all working fine. What would be the possible problem of Switches? some of the switches ports hanged or can't accomodate the load on every port? or does anyone knows any set-up to solvethis issue. Help please! thanks in advance!