Comments on Telnet Protocol Changes (RFC0393)
Original Publication Date: 1972-Oct-01
Included in the Prior Art Database: 2019-Feb-12
Internet Society Requests For Comment (RFCs)
Network Working Group Request for Comments: 393 Joel M. Winett NIC 11585 Lincoln Laboratory Categories: TELNET LL-67 References: RFC 109, 139, 158,318, and 328 3 October 1972
Comments on TELNET Protocol Changes
Through this RFC, I am registering my objection to two of the three suggestions for changing the TELNET protocol as described in RFC 328 and am adding my suggestion for the interpretation of the TELNET Reverse Break Control Code.
This code was originally put in the TELNET protocol to give the virtual terminal the ability to simulate a real terminal which has the print suppress capability. If the terminals being used at some installations do not have the ability to disable the printing mechanism, the TELNET being used can either ignore this code or attempt to simulate the function using other means (e. g., blacking out a number of character positions and returning to the first character position). Every attempt should be made to allow a network user of a time-sharing system to have the same facilities as a local user of the time-sharing system. The specification of TELNET protocol should not limit the function of users if a function cannot be supported by all users.
The "Hide-your-input" and "Echo" TELNET control codes provide for the support of two functions available in some time-sharing systems. The "Hide-your-input" function is really a special case of the "Echo" mode of operation where the server tells the user that the server will echo but the server does not. A separate code is used for this func- tion since some servers may support this function but may not support the full "Echo" mode of operation.
] This material has not been reviewed for public release and is [ ] intended only for use with the ARPA network. It should not be [ ] quoted or cited in any publication not related to the ARPA [ ] network. [
The "Hide-your-input" and "Echo" modes of operation are disabled with the "No-echo" control. ASCII control codes could have been chosen for these functions but it was decided that the NVT ASCII control codes should only be specified for commonly used functions.
To indicate the number of characters for which the printing should be suppressed, the "Hide-your-input" TELNET control could be rede- fined to include a byte following the "Hide-your-input" control to indicate the number of characters for which the printing should be concealed. The "No-echo" control would still be sent so that systems with the print suppress feature would not have to count characters.
2. Data Types
The protocol should allow a server to support users with character codes other than ASCII, e. g., EBCDIC. The definition of an alter- nate character code should include the definition of the TELNET control codes. An EBCDIC code has been proposed in RFC # 109 and has been implemented on the Lincoln Laboratory 360/67. If it is desired to allow one to return to the network standard ASCII code, the non-ASCII code should contain a code to...