accessing Citrix from the Web

I just installed Citrix winframe XP on a W2K server box. I can access Citrix from the LAN, I'm having problems accessing it from the Internet. I opened port 1494 for Citrix and to test if i opened the ports correctly I set up a FTP server which I can access from the web. Is there any trick on how to access Citrix from the Web?

We are connected to DSL through Verizon and are accessing the DSL using a Linksys router.

 

Do you need a client app to connect to a Citrix server?

 

I have the ICA client running from home, So there is a client to connect. I connected the client from home the same way I connected in the office.