Introduction to the functions of the FTP protocol

With more and more functions of the network, our daily life is inseparable from the use of the network. Then, to complete so many complex tasks, the protocols supporting and regulating it will inevitably be varied. Now we will describe the FTP protocol.

In TCP/IP, the FTP service generally runs on ports 20 and 21. The TCP Port number of the FTP standard command is 21, and the Port data Port is 20. Port 20 is used to transmit data streams between the client and the server, while port 21 is used to transmit the control flow and the command is imported to the ftp server. When data is transmitted through a data stream, the control flow is idle. When the control flow is idle for a long time, the firewall of the client sets the session to time out, which may cause some problems when a large amount of data passes through the firewall. At this time, although the file can be successfully transmitted, because the control session will be disconnected by the firewall, transmission will produce some errors.

An FTP task transfers files from one computer to another, regardless of the location, connection method, or even whether the two computers use the same operating system. Assume that the two computers communicate over the ftp protocol and can access the Internet. You can use ftp commands to transmit files. There are some nuances in the use of each operating system, but the basic command structure of each protocol is the same.

Functions of FTP

As shown in its name

The main function of FTP is to allow users to connect to a remote computer and run FTP server programs on these computers) to check what files are available on the remote computer, then copy the files from the remote computer to the local computer, or send the files from the local computer to the remote computer.

The FTP protocol can achieve the following goals:

1. Facilitate file sharing of computer programs or data)

2. Encourage indirect or implicit use of remote computers

3. shield users from the details of various file storage systems (filesystems) on different hosts.

4. reliable and efficient data transmission