File Transfer Protocol specification (RFC0765)
Original Publication Date: 1980-Jun-01
Included in the Prior Art Database: 2000-Sep-13
Publishing Venue
Internet Society Requests For Comment (RFCs)
Related People
Abstract
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.
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
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