You opened the ports properly. There is no doubt about that.
The problem is the NAS links (if you inpect the link, a href of what oyu are clicking) it will be 192.168.1.2 -- Why is it doing this. Because the NAS is not looking at the CLIENT (yourself at the office) but its own IP in the code.
People can argue that is how it should be for security reasons.. But I argue- the team who wrote the website did not think about this problem.(because if they did there would be an option to rewrite client IP links instead of local ones...)
With my NAS i wrote my own website because i wanted to see other things. Basically any ADMIN links i specifiaclly set to 192.168.1.1:port because i dont want anybody changing my stuff over the internet. But when I am at home it works fine.
Any links that i want to work over the internet i use a php function to find the CLIENTS IP address and write it into the a href so it will write
You can work around this problem by doing some simple things and NEVER expose your NAS webpage to the internet, ever.
- Use Putty to SSH into your NAS and use Tunneling - its like VPN but slighlty faster and does not requiere any other ports opening except SSH. I wrote about this over here