Even with remote management disabled port 80 on the router will not be free as then you wouldn't be able to connect to it from your LAN. You must change either the router or the cameras to something else such as 8080. I'd try it without any firewall rules at first just to make sure you can establish a connection. Drayteks support NAT loopback so you should be able to access a device on your WAN IP address from inside your LAN, provided there are no port clashes.

edit - cross posted with hornby

Hello,
I do this to our security:
- Create a separate lan
- change the default ports
- change admin password, and create limited users
- open ports, and restringe to the public ip of the company who will acess to the system. probably they have an fixed public ip.
Regards,

AcerTravel wrote: Hello,
I do this to our security:
- Create a separate lan
- change the default ports
- change admin password, and create limited users
- open ports, and restringe to the public ip of the company who will acess to the system. probably they have an fixed public ip.
Regards,

Right I got it working now.

It turns out that everything that I was doing was correct, I just had to login to my cctv system and change the default gateway on there as it was still set up as my old one.

Many thanks to everyone for helping out.