The File Transfer Protocol (FTP) is a part of the Internet protocol suite that is able to transfer computer files between machines with widely different operating systems.
It is an 8-bit protocol, capable of handling any type of file without further processing such as MIME or UUEncode. However, FTP has extremely high latency; that is, the time between beginning the request and starting to receive the required data can be quite long, and a sometimes-lengthy login procedure is required.
Application layer | FTP | SMTP | HTTP | ... |
Transport layer | TCP | UDP | ||
Network layer | IP ICMP | ARP | ||
data link layer | Ethernet | Token Ring | FDDI | ... |
FTP is standardized in RFC 0959 by the IETF as:
- RFC 0959 File Transfer Protocol (FTP). J. Postel, J. Reynolds. Oct-1985. (Format: TXT=147316 bytes) http://www.ietf.org/rfc/rfc959.txt
The objectives of FTP are:
- To promote sharing of files (computer programs and/or data).
- To encourage indirect or implicit (via programs) use of remote computers
- To shield a user from variations in file storage systems among hosts
- To transfer data reliably and efficiently.
- Passwords and file contents are sent in plaintext
- It is hard to filter FTP traffic using a firewall, since the data connection is made to an apparently arbitrary port
- It is possible to tell a server to send to an arbitrary port of a third computer
Many sites that run FTP servers enable so-called "anonymous ftp". Users do not need an account on the server. They are asked to send their email addresses as their passwords, but there is no verification.
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2 See also 3 External Links |
Nowadays, web browsers can manage the FTP protocol, via a URL in the form ftp://<ftpserveraddress> (e.g., [1]).
A username and password may also be added: ftp://<login>:<password>@<ftpserveraddress>.
In GUIs such as MS Windows, one can create a so-called desktop shortcut for more easy access to FTP servers.FTP and web browsers