Most routers these days have uPnP(Universal Plug and Play) and for programs that support uPnP, the software can automatically open and close ports at will.
Open POL and you need to be at the Opening POL screen that shows the member list. Click on network settings and enable uPnP portmap. It will automatically map the ports it needs and the router will map the ports out until the program closes and the ports timeout and close.
You have to make sure that your router supports uPnP and if it doesnt its usually just a matter of a firmware update and the router should support uPnP.
Not all router configuration screens are the same. In fact, every company seems to use a different setup as to make it as hard as possible for the general user. If your router does not support uPnP then the website
http://www.portforward.com/ is the best resource for information on configuring your router.
Now its important that you use the triggering option for your router. When triggering is enabled, only a computer on the LAN can trigger a port by accessing it. After the port becomes inactive, there is a small delay before the port closes. this is much safer since it only allows the user on a LAN to open and will automatically close with no user interaction.