Connecting to a remote server with AT&T mobileBrodaband card

I have a medical transcription service and connect via the internet using Ipswitch FTP Pro which provides a FTP to SSL connection and have no problem connecting on any source of internet connection DSL,Wi-FI using our wireless card on the laptop. I just purchased a AT&T Sierra Wireless broadband usb card and can connect to the internet fine but when I start Ipswitch it will not connect. AT&T tech support has been a joke.