Although standard email allows the transfer of files (attachments), sending a large file via email has a number of drawbacks. The email may never arrive at its destination, or it may take a long time to do so. This is not uncommon behavior and is due to the nature of how email works. For these reasons CokerExpo has another method of receiving files, - FTP.

The list below outlines the steps to follow in order to send a file to CokerExpo via FTP. If at any stage you get stuck refer to the troubleshooting section below:

1. From Windows or Mac, start Internet Explorer (or ‘Start’ then ‘Run’) and type into the address bar, ‘ftp.cokerexpo.co.uk’.
2. You should be prompted with a login box. Enter your login username and password as agreed with CokerExpo staff.
3. Once logged in you should have a window displaying the contents of your shared folder. Simply place a file (drag and drop) into this window to transfer it to CokerExpo. Similarly, you can drag and drop a file from this window to your local machine.

Troubleshooting

Q: Some users are not able to access CokerExpo FTP Server from Internet Explorer. The hourglass will appear for a short time, and then nothing will appear.
A: This usually happens when IE has not been configured to run in Passive Mode. IE should be configured to use "Passive FTP" which can be set on the advanced tab of your IE Internet Options dialog

Q: Does CokerExpo support restarting/resuming broken transfers?
A: Yes. CokerExpo FTP Server supports the REST command which will allow FTP clients to restart/resume a broken transfer.

Q: How does CokerExpo FTP Server transfer files, and what ports does it use?
A: When a user generates a directory listing or uploads/downloads a file from CokerExpo, CokerExpo FTP server will use a port. Once the file transfer has completed, the port goes back into the ‘available’ list to be used again. The available Port Range values are 10,000 to 10,500. Port 21 should remain open as this is the control channel for any FTP access.

Users can enter ‘ftp.cokerexpo.co.uk’ and will be able to access the CokerExpo FTP server, provided that they have a username/password.

A few comments about passive (PASV) vs. active (PORT) mode:

When the FTP client connects to the FTP server on port 21, the client and server open what is referred to as the control connection or control channel. This connection is used to send and receive commands between the client and server. For instance, once the command channel has been established, the FTP client will send over the USER or PASS command and the FTP server will respond over that same channel. When the FTP client wants to generate a directory listing or upload/download a file, it needs to open a second connection to the server. This second connection will be used to perform the actual data transfer. If the FTP client is running in active (PORT) mode, then the FTP client will issue a PORT command to the CokerExpo FTP Server. This PORT command contains the IP address and port # on which the FTP client is waiting. CokerExpo FTP Server must open a connection back to the FTP client on that address/port and send the data to the client. If the FTP client is running in passive (PASV) mode, then the FTP client will issue a PASV command to the CokerExpo FTP Server. CokerExpo will respond (over the command channel) with an IP address and port # on which CokerExpo FTP Server is waiting. The FTP client is then responsible for opening the data channel to the CokerExpo FTP Server. Once the data channel has been established, the two sides can transfer the data. Why is this distinction important? It’s important because there are many times when the FTP client is behind a firewall/router/cablemodem. These firewalls sometimes prohibit computers from the outside world from opening a connection to a computer on the inside LAN. If the FTP client is on the internal LAN and uses the PORT command to tell CokerExpo FTP Server to ‘call me back’ on address/port x.x.x.x.y.y, CokerExpo FTP Server will try to open that connection, but will get refused by the firewall. The result from the FTP client’s point of view will be that you can connect to the CokerExpo FTP Server, but no files show up. When this happens, the FTP client needs to use PASV mode. If you have FTP clients that can connect to the CokerExpo FTP server, but they cannot see any files, nor can they upload/download files, it is usually because they need to be in PASV mode.