We have cameras hard wired to a DVR which runs through our router. My ISP blocks Port 80, which is the default setting on the DVR, but the tech support from the company we got the camera system from says that we can use any port from 81-89 to avoid having to upgrade our ISP service, so I am not sure that is the problem either. As of now it is on Port 89 and I can access it through my LAN at work but I can't see it from home.
The manual says to open a DNS account at DynDns.com (The purpose of the DNS is so you type in a host name rather than the IP address to access it). From my LAN, when I type in the host name, it works and the camera views come up, when outside of my LAN (home, etc.), we don't get anything.
The ports on the DVR match the ports forwarded on the router. The DNS is tied into the router, as well as the DVR. I'm kind of at a loss here for over a week. The computer guy I called in to help cancelled on me twice. We have been going crazy for over a week now with this!