Browse Prior Art Database

Telnet Protocols (RFC0318) Disclosure Number: IPCOM000003514D
Original Publication Date: 1972-Apr-01
Included in the Prior Art Database: 2019-Feb-12
Document File: 16 page(s) / 21K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J. Postel: AUTHOR

Related Documents

10.17487/RFC0318: DOI

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 12% of the total text.

Network Working Group Jon Postel Request for Comments: 318 UCLA-NMC NIC: 9348 April 3, 1972 References: RFC 139, 158, and NIC 7104

Telnet Protocol

At the October 1971 Network Working Group Meeting, I promised to promptly produce a document which clearly and succinctly specified and explained the Official Telnet Protocol. This document fails to meet any part of that promise. This document was not produced promptly. This document is neither clear nor succinct. There is NO Official Telnet Protocol.

The following pages present my understanding of the ad hoc Telnet protocol. There are some who have serious questions about this protocol. The proposed changes to the protocol are given in Section IV.

Any comments should be promptly directed to me via the Network Information Center (Ident = JBP) or by phone (213) 825-2368 or by mail.

Jon Postel SPADE Group 3804 Boelter Hall UCLA Los Angeles, California 90024

Postel [Page 1]

RFC 318 Telnet Protocol April 1972


The Network Virtual Terminal (NVT) is a bi-directional character device. The characters are represented by 8 bit codes. The NVT has no timing characteristics. The character codes 0 through 127 are the USASCII codes. (Note all code values are given in decimal.) The codes 128 through 255 are used for special control signals. The NVT is described as having a printer and a keyboard. The printer responds to incoming data and the keyboard produces outgoing data.

The Printer

The NVT printer has an unspecified carriage width (common values are 40, 72, 80, 120, 128, 132). The printer can produce representations of all 95 USASCII graphics (codes 32 through 126). Of the 33 USASCII control codes (0 through 31 and 127) the following 8 have specific meaning to the NVT printer.


NULL (NUL) 0 A no operation.

BELL (BEL) 7 Produces an audible or visible signal.

Back Space (BS) 8 Backspaces the printer one character position.

Horizontal Tab (HT) 9 Moves the printer to next horizontal tab stop.

Line Feed (LF) 10 Moves the printer to next line (keeping the same horizontal position).

Vertical Tab (VT) 11 Moves the printer to the next vertical tab stop.

Form Feed (FF) 12 Moves the printer to the top of the next page.

Carriage Return (CR) 13 Moves the printer to the left margin of the current line.

The remaining USASCII codes (1 through 6, 14 through 31, and 127) do not cause the NVT printer to take any action.

Postel [Page 2]

RFC 318 Telnet Protocol April 1972

The Keyboard

The NVT Keyboard has keys or key combinations or key sequences for generating all of the 128 USASCII codes. Note that although there are codes which have no effect on the NVT printer, the NVT Keyboard is capable of generating these codes.

The End of the Line Convention

The end of a line of text shall be indicated by the character sequence Carriage Return Line Feed (CR, LF). This convention applies to both the sending (Keyboard) and receiving (Printer) (virtual) mechanisms.

Break and Revers...