Port Forwarding problem

[#1]

Thank you everyone for your advice.
Taking your comments on board ...I have reset the ports to default on the CCTV DVR to HTTP port 80 and server port to 8000.
I have even set the netgear router to allow remote access on port 8080 and in theory using Internet Explorer and typing in the IP address and colon and 8080 I should be able to access the router remotely but the browser cannot find the address.
I am at a loss to know what to do next.
Any suggestions gratefully received.

[#2]

You may be aware of this already,  but just in case.
Are you trying to access your system using the IP address or the domain name?
If you're using you plusnet (f9, etc) domain name,  that might be the cause, as the DNS information contains all 4 addresses you're allocated,  and the system is free to chose which one it wants to use;  unfortunately,  only one of them is actually valid.
You have to use the address that the router is assigned.
Also,  have you tried accessing the system from inside your home network, but using the external address of the router?