Well that kind of worked....
I set the ports to what you suggested and it will now display the 5 different cameras when im connected via WiFi but as soon as i switch to the 3G/4G network and try to connect using the DDNS service (dynDNS) it displays 5 cameras but its all the same camera? any ideas what could cause that?
I had to modify my router config to enable port forwarding of port 9000.
Also another thing i have found, as i have changed the HTTP port to port 90 i can no longer open the NVR in IE or Firefox, if i change it back to 80, i can open it again.
I think im getting somewhere, it just needs a little more work to be perfect