File Transfer Protocol
File Transfer Protocol or FTP is an Application layer protocol that helps to move files from local to remote file systems using control connection and data connection.
What is a control connection?
It helps send control information such as user identification, password, commands to change remote directory, etc. It is initiated on port number 21.
What is a data connection?
Data connection is used to send the actual file. It is initiated on port number 20.
What is an FTP session?
As FTP session is started, the client establishes a control TCP connection with the server. The client sends control information, and the receiver initiates a data connection.
The control remains active throughout the session.
What are the data structures allowed?
FTP allows three data structures:
- File structure
- Record structure
- Page structure
What are FTP commands?
Some of the FTP commands are as follows:
| Command | Meaning |
| USER | It sends user identification to the server. |
| PASS | It sends the user password to the server. |
| CWD | It allows the user to work with different directories. |
| PWD | It returns the name of the current working directory. |
| RMD | It removes a directory specified in the pathname. |
| MKD | It creates a directory specified in the pathname. |
| ABOR | It asks the server to abort the previous FTP service command. |
| QUIT | It terminates the user. |
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