File Transfer Protocol specification
RFC 765
Document | Type |
RFC - Unknown
(June 1980; No errata)
Obsoleted by RFC 959
Obsoletes RFC 542
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Authors | |||
Last updated | 2013-03-02 | ||
Stream | Legacy stream | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Stream | Legacy state | (None) | |
Consensus Boilerplate | Unknown | ||
RFC Editor Note | (None) | ||
IESG | IESG state | RFC 765 (Unknown) | |
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
IEN 149 J. Postel RFC 765 ISI June 1980 FILE TRANSFER PROTOCOL INTRODUCTION The objectives of FTP are 1) to promote sharing of files (computer programs and/or data), 2) to encourage indirect or implicit (via programs) use of remote computers, 3) to shield a user from variations in file storage systems among Hosts, and 4) to transfer data reliably and efficiently. FTP, though usable directly by a user at a terminal, is designed mainly for use by programs. The attempt in this specification is to satisfy the diverse needs of users of maxi-Hosts, mini-Hosts, and TIPs, with a simple, and easily implemented protocol design. This paper assumes knowledge of the following protocols described in the ARPA Internet Protocol Handbook. The Transmission Control Protocol The TELNET Protocol DISCUSSION In this section, the terminology and the FTP model are discussed. The terms defined in this section are only those that have special significance in FTP. Some of the terminology is very specific to the FTP model; some readers may wish to turn to the section on the FTP model while reviewing the terminology. TERMINOLOGY ASCII The ASCII character set as defined in the ARPA Internet Protocol Handbook. In FTP, ASCII characters are defined to be the lower half of an eight-bit code set (i.e., the most significant bit is zero). access controls Access controls define users' access privileges to the use of a system, and to the files in that system. Access controls are necessary to prevent unauthorized or accidental use of files. It is the prerogative of a server-FTP process to invoke access controls. 1 June 1980 IEN 149 File Transfer Protocol RFC 765 byte size There are two byte sizes of interest in FTP: the logical byte size of the file, and the transfer byte size used for the transmission of the data. The transfer byte size is always 8 bits. The transfer byte size is not necessarily the byte size in which data is to be stored in a system, nor the logical byte size for interpretation of the structure of the data. data connection A simplex connection over which data is transferred, in a specified mode and type. The data transferred may be a part of a file, an entire file or a number of files. The path may be between a server-DTP and a user-DTP, or between two server-DTPs. data port The passive data transfer process "listens" on the data port for a connection from the active transfer process in order to open the data connection. EOF The end-of-file condition that defines the end of a file being transferred. EOR The end-of-record condition that defines the end of a record being transferred. error recovery A procedure that allows a user to recover from certain errors such as failure of either Host system or transfer process. In FTP, error recovery may involve restarting a file transfer at a given checkpoint. FTP commands A set of commands that comprise the control information flowing from the user-FTP to the server-FTP process. 2 IEN 149 June 1980 RFC 765 File Transfer Protocol file An ordered set of computer data (including programs), of arbitrary length, uniquely identified by a pathname. mode The mode in which data is to be transferred via the data connection. The mode defines the data format during transfer including EOR and EOF. The transfer modes defined in FTP are described in the Section on Transmission Modes. NVT The Network Virtual Terminal as defined in the TELNET Protocol. NVFS The Network Virtual File System. A concept which defines a standard network file system with standard commands and pathname conventions. FTP only partially implements the NVFS concept at this time. page A file may be structured as a set of independent parts called pages. FTP supports the transmission of discontinuous files asShow full document text