FTP (File Transfer Protocol) is a standard application layer network protocol designed for file transfer between computers in TCP/IP networks. Developed in the early 1970s, FTP remains one of the most effective methods of file exchange on the internet, providing reliable upload and download of data between client and server.
Architecture and Operating Principle
FTP operates on client-server model, where FTP client establishes connection with FTP server to perform file operations. The protocol uses two separate communication channels: control connection for command and response transmission (usually port 21) and data channel for open file transmission. Such management ensures effective session management and optimization of large data volume transmission.
FTP supports two main working connection modes for data transmission. Active mode assumes that server initiates connection to client for file transfer, which may cause problems when working through firewalls. Passive mode allows client to independently maintain both connections, making the protocol more compatible with modern network forms and permanent security.
Authentication Methods
The protocol provides several user authentication options. Anonymous access allows connecting to public FTP servers without registration, using standard credentials. Username and password authentication provides access to protected resources, credential transmission occurs openly without encryption.
Application Area
FTP is widely used for website publishing, software distribution, data backup creation, file exchange between organizations and public file archive support. Many hosting providers offer FTP access for website content management, while corporate environments use the protocol for operational data exchange between themselves.
The main disadvantage of classic FTP is the absence of data and account control, making the protocol vulnerable to information interception. To solve security problems, protected variants have been developed: FTPS (FTP over SSL/TLS) adds encryption to standard FTP, while SFTP (SSH File Transfer Protocol) uses SSH infrastructure to ensure security.
Modern Alternatives
In modern conditions, FTP is often replaced by more secure file transfer protocols, cloud data storage services or HTTP-based solutions for file upload. Nevertheless, FTP maintains relevance in legacy systems, automated processes and protocols where implementation simplicity and broader compatibility with various platforms is required.