Modifications to the TELNET Specification
A last round of fixes to the new Telnet specification, followed by a freeze on further changes.
McKenzie, A.M., "Modifications to the TELNET Specification", RFC 562, DOI 10.17487/RFC0562, August 1973, <https://www.rfc-editor.org/info/rfc562>.
@misc{rfc562,
series = {Request for Comments},
number = 562,
howpublished = {RFC 562},
publisher = {RFC Editor},
doi = {10.17487/RFC0562},
url = {https://www.rfc-editor.org/info/rfc562},
author = {A.M. McKenzie},
title = {{Modifications to the TELNET Specification}},
pagetotal = 2,
year = 1973,
month = aug,
} RFC text
Network Working Group A. McKenzie Request for Comments: 562 BBN-TENEX NIC: 18638 28 August 1973 Updates: RFC 495 References: RFCs 513, 529 Modifications to the TELNET Specification Almost four months have passed since the new TELNET Protocol specification was published. Since then, only two RFCs have been issued suggesting modifications, and the most recent of these was distributed two months ago. Further, the date from the old TELNET to the new TELNET (1 January 1974) is only four months away. It therefore seems appropriate to officially modify the specification to account for the suggested modifications, and to declare a moratorium on the incorporation of additional suggestions until after the switchover. (Of course, no moratorium on the specification of additional options is required.) The two attached documents represent the revised TELNET Protocol specifications; they replace NIC #15372, TELNET Protocol Specification, and NIC #15373, TELNET Option Specifications. The remainder of this RFC summarizes the changes. Page numbers refer to the earlier documents. Changes to TELNET Protocol Specification Page 8 - The phrase "blocked on input" is removed (see RFC #513). Page 9, 10 - An additional use of IP is mentioned (see RFC #529). Page 10 - The explanation of AO is expanded (see RFC #513). Page 11 - The definition of "'print position' (e.g., an overstrike)" is clarified (see RFC #513). Page 11, 12 - The description of the TELNET Synch Signal is reworked to be in conformance with the ideas of RFC #529 (also see RFC #513). Page 14 - The explanation of the CR-NUL convention is expanded (see RFC #513). Page 16 - An additional command, End of Subnegotiation Parameters (SE) is defined (see RFCs 513, 529). Changes to TELNET Option Specifications Pages 2, 3 - Use of the command SE is explained (see RFCs 513, 529). Page 3 - Doubling of IAC in subnegotiation parameters is required (see RFC #513). [This RFC was put into machine readable form for entry] [into the online RFC archives by Helene Morin, Via Genie 12/99]
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§1Why the Specification Was Revised
The new Telnet Protocol specification had been out for almost four months. In that time only two RFCs had suggested modifications, and the most recent was distributed two months earlier. The date for moving from the old Telnet to the new Telnet, 1 January 1974, was only four months away.
The author therefore proposed to officially modify the specification to account for the suggestions. The RFC references RFCs 513 and 529 as the sources of most of the changes.
Few people had asked for fixes, and the big switch date was getting close, so it was a good time to tidy up the rules.
§2Changes to the Protocol Specification
The RFC lists changes by page of the earlier document. Most are clarifications:
- The phrase "blocked on input" is removed.
- An additional use of IP is mentioned.
- The explanation of AO is expanded.
- The definition of "print position" is clarified.
- The description of the Telnet Synch Signal is reworked to match the ideas of RFC 529.
- The explanation of the CR-NUL convention is expanded.
One change adds something new: a command called End of Subnegotiation Parameters (SE) is defined.
Most fixes just explain confusing parts better. One adds a new signal that says "that is the end of the extra details".
§3Changes to the Option Specifications
Two changes apply to the separate option specifications. The use of the SE command is explained, and doubling of IAC in subnegotiation parameters is now required.
The two attached documents replace the earlier Telnet Protocol Specification (NIC #15372) and Telnet Option Specifications (NIC #15373).
The extra-details part of the rules got a clear ending signal, and one special symbol must be written twice so it is not mistaken for a command.
§4The Moratorium
The RFC declares a moratorium on incorporating additional suggestions until after the switchover. The aim is a stable specification during the changeover.
The moratorium does not apply to options: no moratorium on the specification of additional options is required.
Until the switch was done, no more rule changes were allowed. New add-on features could still be written.