My site is behind a firewall. I can login to the design file ftp server, but when I try to send my file the transfer never starts. Your firewall may not allow incoming connections from outside the firewall. By default, when an ftp connection is opened to transfer data, the server initiates the connection and contacts the client at the port number provided by the client. From the server's point of view, this is an active transfer because the server initiates the connection to the client.
Most firewalls block incoming connections initiated from outside the firewall.
There is another data transfer mode called passive mode, which can be used to tell the server to permit the client to initiate the data connection. The client can request this mode via the PASV command if it supports passive transfers. Not all ftp clients support passive mode - in particular, the standard Solaris ftp client does not support it and other Unix ftp client programs may not either. If your ftp client supports passive mode, you should configure it to use this mode. This will cause our server to wait for the client to initiate the data connection.