home *** CD-ROM | disk | FTP | other *** search
-
-
-
-
-
-
-
-
- Network Working Group C. Hedrick
- Request for Comments: 1079 Rutgers University
- December 1988
-
-
- Telnet Terminal Speed Option
-
- Status of This Memo
-
- This RFC specifies a standard for the Internet community. Hosts on
- the Internet that exchange terminal speed information within the
- Telnet protocol are expected to adopt and implement this standard.
- Distribution of this memo is unlimited.
-
- This standard is modelled on RFC 930 [1], the telnet terminal type
- option. Much of the text of this document is copied from that RFC.
-
- Motivation
-
- Most operating systems have provisions to keep track of the speed
- (bit rate) of directly attached terminals and modems. This
- information is used to control various timing-dependent display
- processes, e.g., the number of padding characters used for delay.
- Some software also has user interfaces that are tuned differently for
- fast and slow terminals. The purpose of this option is to provide
- similar information for telnet connections.
-
- 1. Command Name and Code
-
- TERMINAL-SPEED
-
- Code = 32
-
- 2. Command Meanings
-
- IAC WILL TERMINAL-SPEED
-
- Sender is willing to send terminal speed information in a
- subsequent sub-negotiation.
-
- IAC WON'T TERMINAL-SPEED
-
- Sender refuses to send terminal speed information.
-
-
-
-
-
-
- Hedrick [Page 1]
-
- RFC 1079 Telnet Terminal Speed Option December 1988
-
-
- IAC DO TERMINAL-SPEED
-
- Sender is willing to receive terminal speed information in a
- subsequent sub-negotiation.
-
- IAC DON'T TERMINAL-SPEED
-
- Sender refuses to accept terminal speed information.
-
- IAC SB TERMINAL-SPEED SEND IAC SE
-
- Sender requests receiver to transmit his (the receiver's)
- terminal speed. The code for SEND is 1. (See below.)
-
- IAC SB TERMINAL-SPEED IS ... IAC SE
-
- Sender is stating his terminal speed. The code for IS is 0.
- (See below.)
-
- 3. Default
-
- WON'T TERMINAL-SPEED
-
- Terminal speed information will not be exchanged.
-
- DON'T TERMINAL-SPEED
-
- Terminal speed information will not be exchanged.
-
- 4. 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-SPEED...).
-
- Once the two hosts have exchanged a WILL and a DO, the sender of the
- DO TERMINAL-SPEED is free to request speed information. Only the
- sender of the DO may send requests (IAC SB TERMINAL-SPEED SEND IAC
- SE) and only the sender of the WILL may transmit actual speed
- information (within an IAC SB TERMINAL-SPEED IS ... IAC SE command).
- Terminal speed information may not be sent spontaneously, but only in
- response to a request.
-
- The terminal speed information is an NVT ASCII string. This string
- contains the decimal representation of the transmit and receive
- speeds of the terminal, separated by a comma, e.g.,
-
- 9600,100
-
-
-
- Hedrick [Page 2]
-
- RFC 1079 Telnet Terminal Speed Option December 1988
-
-
- No leading zeros may be included. No extraneous characters such as
- spaces may be included.
-
- The following is an example of use of the option:
-
- Host1: IAC DO TERMINAL-SPEED
-
- Host2: IAC WILL TERMINAL-SPEED
-
- (Host1 is now free to request status information at any time.)
-
- Host1: IAC SB TERMINAL-SPEED SEND IAC SE
-
- Host2: IAC SB TERMINAL-SPEED IS "1200,1200" IAC SE
-
- (This command is 15 octets.)
-
- 5. Implementation Suggestions
-
- Many systems allow only certain discrete terminal speeds. In such
- cases it is possible that a speed may be received that does not match
- one of the allowed values. We suggest that you pick the nearest
- speed that is allowed, rounding in a "safe" direction. Safety will
- depend upon the use of the speed information. If it is being used
- for padding, it is best to round up, since too much padding is better
- than too little.
-
- Reference
-
- [1] Solomon, M., and Wimmers, E., "Telnet Terminal Type Option",
- RFC 930, January, 1985
-
- [AAuthor's Address:
-
- Charles Hedrick
- Rutgers University
- Center for Computer and Information Services
- Hill Center, Busch Campus
- P.O. Box 879
- Piscataway, NJ 08855-0879
-
- Phone: (201) 932-3088
-
- Email: HEDRICK@ARAMIS.RUTGERS.EDU
-
-
-
-
-
-
-
- Hedrick [Page 3]
-