How to configure port forwarding on the VoxSun router installed in our office?

You can create a port forwarding rule on your VoxSun router by following these steps:
1. Log in to your VoxSun router. Your router's IP and administrator username and password are provided on a piece of paper that was included in your router's box.
2. From the menu on the side, click on "IP" to expand this submenu and then click on "Firewall".
3. Once in the "Firewall" page, click on the tab named "NAT" at the top.
4. Click on the "Add New" button.
5. Follow these guidelines for the different fields:
Chain: dstnat
Protocol: Select either UDP or TCP, depending on the type of port you want to open.
Dst. Port: Write in the port number that you wish to redirect.
In. Interface: Select the Internet interface. Usually this will be "ether1,” but if your router is authenticated to PPPoE, you will need to select "pppoe-out1".
Action: dst-nat
To Addresses: Write in the IP address of the server/computer to which the router will redirect the port.
6. Click on the "OK" button to save.
Once your forward is complete, you should be able to access the forwarded port remotely. You can also modify an existing rule by clicking anywhere on the line from within of the NAT rules.
Important: Never disable/delete/modify the built-in srcnat rule and any other of the firewall rules, as those may disable your Internet connection.