finj - Terminology
[ L A S T U P D A T E : 2018-01-08 ]
What is this good for ?
A minimum of terminology is necessary to make sure that
we are all talking of the same things in the same way. This
page lists some of those terms with their definitions.
Part of this terminology comes from section 2.2 of
the rest is a collection of definitions found here and there.
The ASCII character set is 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
access privileges to the use of a system, and to the
in that system. Access controls are
necessary to prevent unauthorized or accidental use of
It is the prerogative of a
to invoke access controls.
> byte size
There are two byte sizes of interest in FTP: the logical byte
size of the
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 the data is to be
stored in a system, nor the logical byte size for interpretation of the
structure of the data.
> control connection
The communication path between the
user-PI and server-PI
for the exchange of commands and replies. This connection follows
the Telnet Protocol.
> data connection
A full duplex connection over which data is transferred, in a
specified mode and type
The data transferred may be a part of a
or a number of
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.
The data transfer process establishes and manages the
The DTP can be passive or active.
The end-of-line sequence defines the separation of printing
lines. The sequence is
Carriage Return, followed
The end-of-file condition that defines the end of a
The end-of-record condition that defines the end of a
> error recovery
A procedure that allows a
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 as a given checkpoint.
> FTP command
A set of commands that comprise the control information flowing from the
user-FTP to the server-FTP
> FTP reply
[NOT YET WRITTEN]
An ordered set of computer data (including programs), of
arbitrary length, uniquely identified by a
> file system
[NOT YET WRITTEN]
> java application
[NOT YET WRITTEN]
The mode in which data is to be transferred via a
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 (§3.4) of
The Network Virtual Terminal as defined in the Telnet Protocol.
The Network Virtual
A concept which defines a standard network
with standard commands and
may be structured as a set of independent parts called
pages. FTP supports the transmission of discontinuous
files as independent indexed pages.
Pathname is defined to be the character string which must be
input to a
in order to identify a
Pathname normally contains device and/or directory names,
and file name specification. FTP does not yet specify a standard
pathname convention. Each
must follow the
naming conventions of the
involved in the transfer.
The protocol interpreter. The user and server sides of the
protocol have distinct roles implemented in a
user-PI and a server-PI.
A sequential file may be structured as a number
of contiguous parts called records. Record structures are supported by
FTP but a file need not have record structure.
The data transfer process, in its normal "active" state,
with the "listening"
data port. It sets up parameters
> server-FTP process
A process or set of processes which perform the function of
file transfer in cooperation with a
and, possibly, another server. The functions consist of a
and a data transfer protocol
The server protocol interpreter "listens" on Port L for
a connection from a
and establishes a
control communication connection.
It receives standard
sends replies, and governs the
The data representation type used for data transfer and storage.
Type implies certain transformations between the time of data
storage and data transfer. The representation types defined in FTP
are described in the Section on Establishing Data Connections (§3.2) of
A person or a process on behalf of a person wishing to obtain a
file transfer service. The human user may interact
directly with a server-FTP process,
but use of a user-FTP process
is preferred since the protocol design is weighted towards automata.
The data transfer process "listens" on the
for a connection from a
If two servers are transferring data between them, the
> user-FTP process
A set of functions including a protocol interpreter, a data transfer
process and a user interface which together perform the function of
file transfer in cooperation with one or more
The user interface allows a local language to be used in the
command-reply dialogue with the
The user protocol interpreter initiates the
from its port U to the
and governs the
if that process is part of the file transfer.