Telnet terminal type option (RFC0884)
Original Publication Date: 1983-Dec-01
Included in the Prior Art Database: 2019-Feb-13
Internet Society Requests For Comment (RFCs)
M. Solomon: AUTHOR [+1]
This RFC specifies a standard for the ARPA Internet community. It specifies a method for exchanging terminal type information in the Telnet protocol.
Network Working Group Marvin Solomon Request for Comments: 884 Edward Wimmers University of Wisconsin - Madison December 1983
TELNET TERMINAL TYPE OPTION
This RFC specifies a standard for the ARPA Internet community. Hosts on the ARPA Internet that exchange terminal type information within the Telnet protocol are expected to adopt and implement this standard.
1. Command Name and Code
2. Command Meanings
IAC WILL TERMINAL-TYPE
Sender is willing to send terminal type information in a subsequent sub-negotiation
IAC DO TERMINAL-TYPE
Sender is willing to receive terminal type information in a subsequent sub-negotiation
IAC DON’T TERMINAL-TYPE
Sender refuses to accept terminal type information
IAC WON’T TERMINAL-TYPE
Sender refuses to send terminal type information
IAC SB TERMINAL-TYPE SEND IAC SE
Sender requests receiver to transmit his (the receiver’s) terminal type. The code for SEND is 1. (See below.)
IAC SB TERMINAL-TYPE IS ... IAC SE
Sender is stating the name of his terminal type. The code for IS is 0. (See below.)
Solomon & Wimmers [Page 1]
RFC 884 December 1983
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 be...