You’ve installed Zoneminder, but it doesn’t display video feed in the configured network camera window and the camera’s IP address in the Source field is red.
Most probably, Zoneminder doesn’t have enough memory to process the MPEG stream.
To increase the memory amount allocated for Zoneminder, edit the /etc/sysctl.conf file and add the following:
kernel.shmmax = 167782160
Restart the system. You should see the CCTV camera feed in the camera window now.