File transfer
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A protocol for file transfer or file transfer protocol is a convention or standard that controls or enables the transfer of files between two computing endpoints. Unlike with a general-purpose communication protocol, file transfer protocols are not designed to send arbitrary data or facilitate asynchronous communication such as Telnet sessions. They are meant solely to send the stream of bits stored as a single unit in a file system, plus any relevant metadata such as the filename, file size, and timestamp.
File transfer protocols usually operate on top of a lower-level protocol in a protocol stack. For example, the Internet FTP protocol operates as the topmost layer of the TCP/IP stack, whereas XMODEM, YMODEM, and ZMODEM typically operate across RS-232 serial connections to modems.
[edit] What Is File Transfer?
In computing, file transfer is a generic term for referring to the act of transmitting files over a computer network. While the term "file transfer" is often linked to the File Transfer Protocol (FTP), there are numerous ways to transfer files over a network. Servers which provide a file transfer service are often called file servers.
There are 2 Types of file transfers:
- "Pull-based" file transfers where the receiver initiates a file transmission request.
- "Push-based" file transfers where the sender initiates a file transmission request.
Some protocols for file transfer may provide both of these, and they are often referred to as "uploading" or "downloading", from the client's perspective.
File transfer can take place over a variety of levels:
- Transparent file transfers over network file systems.
- Explicit file transfers from dedicated file-transfer services like FTP or HTTP.
- Distributed file transfers over peer-to-peer networks.
- File transfers over instant messaging systems.
- File transfers between computers and peripheral devices.
- File transfers over direct modem or serial (null modem) links, such as XMODEM, YMODEM and ZMODEM.
