Telnet and FTP implementation schedule change
A revised schedule for implementing new Telnet and FTP versions.
McKenzie, A.M. and J. Postel, "Telnet and FTP implementation schedule change", RFC 593, DOI 10.17487/RFC0593, November 1973, <https://www.rfc-editor.org/info/rfc593>.
@misc{rfc593,
series = {Request for Comments},
number = 593,
howpublished = {RFC 593},
publisher = {RFC Editor},
doi = {10.17487/RFC0593},
url = {https://www.rfc-editor.org/info/rfc593},
author = {A.M. McKenzie and J. Postel},
title = {{Telnet and FTP implementation schedule change}},
pagetotal = 1,
year = 1973,
month = nov,
} RFC text
Contents
Network Working Group Alex McKenzie
Request for Comments: 593 BBN
Jon Postel
MITRE
Telnet and FTP Implementation Schedule Change
Telnet and FTP Implementation Schedule Change
We have been contacted by several Telnet implementers and concerned
users regarding the scheduled changeover from old to new Telnet.
There is a good deal of concern about accomplishing a coordinated
changeover especially in light of the potential incompatibilities
(RFC 559, NIC18482). Therefore the changeover is reformulated as
follows.
New Telnet implementations are to be ready 1 Jan 74 (as before), but
are to use ICP socket 23 (decimal). That is the server Telnet will
listen on socket 23, and user Telnet programs will connect to socket
23. It will also be useful for the user program to let the user
optionally select the server socket, as many user Telnet programs
currently do. It will also be useful for implementers to consider a
server Telnet program capable of dealing with both protocols as MIT-
DMCG has done (RFC 559). This will provide an opportunity for
testing and debugging the new programs in a way that does not
interfere with normal use.
During January we will survey the technical liaisons to determine the
status of the Telnet implementations. As soon as we determine that
the Telnet implementations have reached a point where the changeover
can be made without disruption of user services the technical
liaisons will be notified.
In light of this change in the Telnet implementation schedule, the
FTP schedule is also modified. New FTP implementations are to be
ready by 1 Feb 74 (as before), but will continue to use ICP socket 21
(decimal) until we can determine that a changeover is appropriate.
References
Telnet Protocol NIC 18639
File Transfer Protocol NIC 17759
[This RFC was put into machine readable form for entry ]
[into the online RFC archives by Mirsad Todorovac 5/98 ]
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§1A Coordinated Telnet Changeover
Several Telnet implementers and users raised concerns about coordinating the move from the old protocol to the new one, including possible incompatibilities described in RFC 559. The authors revised the changeover plan to give implementations a way to be tested without interfering with normal service.
Users and implementers worried that switching Telnet versions together could disrupt service. The RFC changes the plan to provide a separate place for new implementations.
§2New Telnet on ICP Socket 23
New Telnet implementations were still to be ready by January 1, 1974, but servers were to listen on ICP socket 23 and user programs were to connect there. The RFC says it would be useful for clients to let users select the server socket and for servers to handle both protocols, as MIT-DMCG had done, so implementers could test and debug the new version.
During January, technical liaisons would be surveyed. They would be notified when implementations were ready for a changeover that would not disrupt user services.
The new Telnet was assigned socket 23 while sites tested it. Network liaisons would assess readiness before announcing a change that could affect users.
§3FTP Remains on ICP Socket 21
The RFC also changes the FTP schedule in light of the Telnet plan. New FTP implementations were still to be ready by February 1, 1974, but were to continue using ICP socket 21 until the network could determine that changing it was appropriate.
New FTP implementations could be prepared, but they would continue to use socket 21 until the network decided a changeover was suitable.