Suggested Telnet Protocol Changes
A proposal to remove three features from the Telnet protocol unless users objected.
Postel, J., "Suggested Telnet Protocol Changes", RFC 328, DOI 10.17487/RFC0328, April 1972, <https://www.rfc-editor.org/info/rfc328>.
@misc{rfc328,
series = {Request for Comments},
number = 328,
howpublished = {RFC 328},
publisher = {RFC Editor},
doi = {10.17487/RFC0328},
url = {https://www.rfc-editor.org/info/rfc328},
author = {J. Postel},
title = {{Suggested Telnet Protocol Changes}},
pagetotal = 2,
year = 1972,
month = apr,
} RFC text
Network Working Group Jon Postel
Request for Comments: 328 Computer Science
UCLA-NMC
NIC 9635 29 April 72
Categories: Telnet
References: RFC 328
Suggested Telnet Protocol Changes
I hereby propose the following changes to the Telnet protocol. If
no substantial negative response is received by 15 May 72 it will be
assumed that these changes are desired and should be incorporated in
any "Official Telnet Protocol".
First I suggest that we drop the idea of a "minimum"
implementation and require a standard implementation which includes all
aspects of the protocol.
Second I suggest that we eliminate the DATA TYPE signals.
Third I suggest that we do away with HIDE YOUR INPUT signal.
Arguments:
Standard Implementation:
The idea of an accepted implementation which does not include
whole protocol is an admission that the parts of the
protocol left out are either not useful or not expected to be
used, and that other mechanisms will be constructed to provide
those functions. Thus there should be no minimum
implementation, but only the standard implementation which
includes the whole protocol.
Data Types:
The DATA TYPE signals are supposed to allow the communicating
processes to switch from ASCII to some other code set. However,
the other code sets suggested do not allow for the Telnet
signals, and thus once the switch is made the Telnet
protocol is no longer applicable. There is no way to specify
how to get back to ASCII or Telnet thus the
conversation is "out of control".
Hide Your Input:
The HIDE YOUR INPUT signal is supposed to tell the user Telnet
process to do whatever it can to hide the user's
subsequent input. One problem with this is determining
how much input is to be hidden. It is very difficult to find a
method of hiding input which works for all combinations of
systems and terminals, but the HIDE YOUR INPUT signal dosen't
help in any real way.
[ This RFC was put into machine readable form for entry ]
[ into the online RFC archives by BBN Corp. under the ]
[ direction of Alex McKenzie. 12/96 ]
ISO Plain Language
On this page
§1Three Suggested Changes
Jon Postel proposes three changes to the Telnet protocol. First, drop the idea of a “minimum” implementation and require a standard implementation that includes all aspects of the protocol. Second, eliminate the DATA TYPE signals. Third, remove the HIDE YOUR INPUT signal.
The memo says that if no substantial negative response arrives by 15 May 1972, the changes will be assumed desired and should be incorporated into any Official Telnet Protocol.
The memo proposes three changes to Telnet and sets a deadline for objections. It does not say what decision was ultimately made.
§1Why Remove the Minimum Implementation
The author argues that accepting an implementation that leaves out part of the protocol implies that the omitted parts are not useful or are not expected to be used. The author also argues that other mechanisms would be built to provide those functions.
On that basis, the memo proposes having one standard implementation that includes the whole protocol rather than defining a minimum subset.
The author says a permitted partial implementation suggests that the excluded features are not needed or will be handled elsewhere. The proposal is to define only a complete standard implementation.
§1Why Remove DATA TYPE and HIDE YOUR INPUT
The DATA TYPE signals are intended to let communicating processes switch from ASCII to another code set. The author argues that the suggested code sets do not allow Telnet signals, so Telnet would no longer apply after the switch and the protocol provides no way to return to ASCII or Telnet.
HIDE YOUR INPUT is intended to tell the user's Telnet process to hide subsequent input. The memo argues that it is difficult to know how much input to hide and to find a method that works for all combinations of systems and terminals. The author concludes that the signal does not help in a useful way.
The author argues that DATA TYPE can switch Telnet into a format with no defined way back. HIDE YOUR INPUT does not say how much input to hide or how every terminal should do it.