Telnet Protocol is a method of providing a standard way of communication
between computer terminals. Through Telnet Protocol, computers are able to
communicate in a bi-directional and eight-bit oriented method. It is
generally used to allow standard terminal interfacing as well as standard
The original purpose of a Telnet Protocol is to allow a user login to a
remote terminal and have communication access to other terminals through a
telnet server program. This telnet server program handles and processes
all data passed by every connected terminals.
Connection of terminals in a telnet protocol is established using the
Transmission Control Protocol (TCP), the transmitter of data. Basically,
there are three concepts that make telnet protocol an important
• Network Virtual Terminal
Network Virtual Terminal or NVT is an imaginary device that
facilitates communication between terminals without the need for
terminals to remember each other's characteristics. This is done
through mapping of each terminal's characteristics and conventions
that make it seem like the there is a virtual terminal that provides
similar mapping for all connected terminals.
NVT defines the data sent between terminals. An NVT has a printer
incoming data, and a keyboard that produces outgoing data. It uses
character sets known as the NVT ASCII. All incoming NVT codes are
converted into actual codes by a client's telnet program. Such codes
include those needed to operate the user's devices such as the display
and keyboard. Examples of which are LF or decimal 10 for Line Feed,
CR or decimal 13 for Carriage Return, BS or decimal 8 for Backspace,
• Concept of Negotiations
Terminals in a Telnet connection are different from each other. Aside
from the NVT conventions that they comply with during...