Problems getting smart FTP to connect router problem?

Hi, can someone please help.

I try to access an ftp site through smart ftp and the connection always times out.

I have an idea why this might be. I think it may be because im behind a firewall (although i have enabled smartFTP to be alowed) or it is because my router isnt set up to allow smartFTP through.

Now i have a vauge idea how to do this through port forwarding ? but i dont know what ip address to use.

Im guessing the port should be port 21 right? but what is the server ip. In my router menu option it says

ip: 192 . 168 . 1 . x

Does any one know what the x should be?

many thanks