FTP – File Transfer Protocol
To get the general idea on the subject of FTP, it is important to be acquainted with the word protocol as a significant set of rules and conventions. The aim behind the protocols introduction intent was to make available communication (computer to computer) facilities. And well designed FTP is most suitable for this purpose and that’s why still in use. Though, it is on the screen since 1970s.
FTP is resided on the application layer of OSI standard model so particular tasks can be obtained with its use such as to uphold intercontinental communication and to produce standards relating online communication. File Transfer Protocol is well documented in the form of RFC 959. But all other related documents on the FTP technicality overviews are available at RFC sourcebook. The reliability of this protocol can be judged from that, it belongs to the oldest internet protocols family but can be implemented with the help of TCP protocol.
The uniqueness of this set of rules is hidden behind the usage of separate commands plus data links. But in order to known, how FTP works, it is necessary to put some light also on the functionality of it. The aim of its use is to generate a reliable standard files exchanging source over the TCP/IP network. FTP comes with the feature of flexibility, which is allowing it to put into practice over a non-TCP/IP network too. And another trait of it is its exchanging files ability with the different types of machines. But it offers an environment for interaction with lowest limitations between client and server machines. It uses communication channels via which packets can be transmitted directly to their destination.
Consistent end-to-end connection is possible with FTP, but a link is being used two types of connections, named as control connection initiated by user but to manage the data transfer, data connection is used. The common function of FTP is to shift files from a host side with TCP based internet help to a different host. Common purpose of being employed this protocol in a network is to upload documents and web pages from personal to an open web hosting machine (server). But both machines at two ends can use different control connections and data connections.
Well, authentication of FTP users is done through a signing in protocol clear text but it will be so if server is configured to permit this connection. User side can be consisted of FTP user interface, PI (protocol interpreter) and DTP (data transfer process). Anyhow, file system and DTP user both can form a client system. On the other hand, Server side is based on PI server and DTP server while both file system and DTP server can create server system. Data connection is established between DTP user and DTP server but control connection is established between FTP user interface and PI server. FTP server is listened with port 21 help but data connection can be made its first move from port 20 by server.
Following are some FTP commands which are named as: ABOR, ACCT, ALLO, AUTH, CCC and so on.