My video security started to work when I put the video security IP into the DMZ.
Sorry, I can't teach networking here. Please try this next as I found those systems do not document all the needed ports.
I have a Dlink DIR-628 router attached to a Comcrap cable modem. I've hooked up a video security system and can see it on the LAN, but can't get to it from outside. I've tested ports using CANYOUSEEME.ORG but the router is either not responding or connection refused. I've tried all the standard ports (25, 80, 110...) I've opened the port in Port Forwarding. Is there some reason either Comcrap is blocking the input or is it my router?