There's no card on the surveillance camera. Why?

There are several reasons to monitor the camera card:

The resolution and code stream of the camera are so high that the computer can't move.

The processing capacity of the switch is not enough, resulting in data loss (generally, one camera is not enough).

The network cable is too long (generally not more than 60 meters)

The quality of the network cable is too poor, it is not pure copper wire, and the core of the wire is very thin, generally only 20 meters can be transmitted.

The network cable follows the high voltage and is disturbed.