On second thought, I've gotten a little ahead of myself. After visiting a few other sites (this one in particular), I not sure the link I gave above would be of any help anyway. And the hacks from the petri.co.il site may be too advanced for you.

Based on what you said, you either have this or most likely this. You may want to read more about gateways here. This FAQ may also be of use.

If you don't have a user guide on hand, you may want to use this pdf file. It helps if you already know how to access the web interface.

I could've arranged what I wrote above into something more straightforward, but it would be better if I knew what you knew first.