FTP connection to a ReadtNAS Ultra

I am having a problem setting up a FTP connection to my ReADYnas uLTRA 4 THRU MY vERIZON fios rOUTER. iT SEEMS TO ESTABLISH A CONNECTION BUT TIMES OUT WHEN REQUESTIONG A DIRESTORY LIST. iF i AM INSIDE MY ROUTER THE FTP CLIENT WORKS. iI CHECKED AND THE PORTS I AM USING ARE OPENED. I AM OUT OF IDEAS. HELP!