RFC 884 (rfc884) - Page 2 of 5


Telnet terminal type option



Alternative Format: Original Text Document





RFC 884                                                    December 1983


3. Default

   DON'T TERMINAL-TYPE

   WON'T TERMINAL-TYPE

   Terminal type information will not be exchanged.

4. Motivation for the Option

   This option allows a telnet server to determine the type of terminal
   connected to a user telnet program.  The transmission of such
   information does not immediately imply any change of processing.
   However, the information may be passed to a process, which may alter
   the data it sends to suit the particular characteristics of the
   terminal. For example, some operating systems have a terminal driver
   that accepts a code indicating the type of terminal being driven.
   Using the TERMINAL TYPE and BINARY options, a telnet server program
   on such a system could arrange to have terminals driven as if they
   were directly connected, including such special functions as cursor
   addressing, multiple colors, etc., not included in the Network
   Virtual Terminal specification.  This option fits into the normal
   structure of TELNET options by deferring the actual transfer of
   status information to the SB command.

5. Description of the Option

   WILL and DO are used only to obtain and grant permission for future
   discussion. The actual exchange of status information occurs within
   option subcommands (IAC SB TERMINAL-TYPE...).

   Once the two hosts have exchanged a WILL and a DO, the sender of the
   WILL TERMINAL-TYPE is free to transmit type information, spontan-
   eously or in response to a request from the sender of the DO.  At
   worst, this may lead to transmitting the information twice. Only the
   sender of the DO may send requests (IAC SB TERMINAL-TYPE SEND IAC SE)
   and only the sender of the WILL may transmit actual type information
   (within an IAC SB TERMINAL-TYPE IS ... IAC SE command).

   The terminal type information is an NVT ASCII string.  Within this
   string, upper and lower case are considered equivalent.  A few
   terminal type names useful in the context of IBM systems are listed
   below.  It is anticipated that additional names will be added in the
   future.  The complete list of valid terminal types will be found in
   the latest "Assigned Numbers" RFC.





Solomon & Wimmers