About Using FTP

When you use FTP you log in to an FTP server where you have access to your account which contains directories where you can send and receive files. You upload (put) files to be sent to your Sponsor into your File Transfer Service account and you download (get) files from your Sterling File Transfer Service account that your Sponsor has sent to you.

Sterling File Transfer Service has the ability to initiate an FTP session to retrieve (get) your data. This is done on a scheduled basis. The scheduled times can be set up for your convenience determined by your business needs. For IBM? to do this you must provide an IP address logon and password and your Sponsor must have requested this arrangement.

Using FTP to access your Sterling File Transfer Service account is similar to using a remote Telnet session where subdirectories and files are viewed using a list or directory command. You access or move between directories using a change directory command. These commands are supported on Sterling File Transfer Service and are used to access upload files to and download files from each directory in your account.

Active and Passive Modes

The FTP protocol is unusual in that two TCP/IP connections between the client and server are required to transmit files. Commands and responses between the client and server are exchanged across the control connection. Data transfers including directory listings are conducted on one or more distinct data connections. On Sterling File Transfer Service a new data connection is opened each time a transfer is necessary.

The Sterling File Transfer Service supports both active and passive FTP modes. No prior setup is necessary to change from one mode to the other. However contact Customer Support to determine if your account supports both active and passive modes.

In active FTP mode which is the default for most FTP clients the client initiates the control connection and the server initiates all data connections. However some firewalls reject connection attempts from Sterling File Transfer Service which prevents data connections from being built. When this happens FTP sessions time out after several minutes of inactivity and you receive no information as to why the session failed.

Customers who consistently experience FTP time-outs when performing ls dir get mget put or mput commands can often correct the problem by switching to passive FTP mode. In this mode the FTP client initiates all the data connections. Because firewalls usually allow all outbound connections the problem with establishing data connections is corrected.

If passive FTP mode might be useful for your connection to Sterling File Transfer Service see your FTP client documentation to determine whether it is supported and how it can be enabled. Passive FTP can also be used with Event-driven FTP. Contact Customer Support to have passive FTP mode enabled on an Event-driven directory.

ASCII Transfer Mode

ASCII data transfer mode (see RFC 959) is intended for transferring text files.

Binary Transfer Mode

Binary data transfer mode (see RFC 959) is the default mode that Sterling File Transfer Service uses to transfer files and does not allow any changes to the contents of the file. Binary file transfer mode is also sometimes referred to as IMAGE mode.