NO LINK" appears on monitor

[tony01]

This place has an (ENS NVR SN3216/16P-K.)

The problem is that once in a while on the monitor, I see “no link” for the cameras

(10 ENS cameras, SIP34T3/28-C) (2 switches, UNV NSW2010-10T-POE-IN)

To switch A are like 4 cameras and a link to switch B, on switch B are the rest of the cameras and the link from switch A, the ethernet cable, computer cable, and one cable from NVR LAN.



Question what can be the problem?

Do I need internet to see the cameras? Or only I need internet to view remotely?

 

[TonyR]

You only need Internet for remote viewing.

Since all the cameras go to 2 POE switches and then to the NVR LAN (NVR POE ports not being used) any poor connection between a switch and the NVR can produce that "no connection".

I would check all connections between switches and NVR, possibly a weak latch or poor crimp on a RJ-45, cut cable jacket, maybe even some oxidation or corrosion on the contacts of the RJ-45. I'd check the NVR <-> switch <-> switch connnections first.

If this is NOT a recent error but has done this from the start it may be a bandwidth limitation of the NVR; the specs here say "Up to 2-ch@12 MP or 3-ch@8 MP or 6-ch@4 MP or 12-ch@1080p decoding capacity" and you say 10 each 4MP cameras are connected.....if configured at their highest resolution it could be that IF this has been displaying that "no connection" from the very start.

If not, I'm thinking its an intermitant connection in one of the cables or a failing port on a switch. Again, I'd check the NVR <-> switch <-> switch connnections first.