RFC 593

Telnet and FTP Implementation Schedule Change ✨

Network Working Group 💖 Request for Comments: 593 🦋 Authors: Alex McKenzie (BBN) and Jon Postel (MITRE) 👑

The title block doesn't list a category, date, or anything this RFC obsoletes or updates, so I'm not going to invent any 🙈

okay so bestie, several Telnet implementers and concerned users reached out about the scheduled changeover from old to new Telnet 😭 there's a lot of worry about pulling off a coordinated changeover, especially with the potential incompatibilities (RFC 559, NIC18482). so the changeover got reformulated like this 💅

New Telnet implementations are to be ready 1 Jan 74 (as before) ✨, but they're gonna use ICP socket 23 (decimal). server Telnet listens on socket 23, and user Telnet programs connect to socket 23 🎀 it'll also be useful for the user program to let the user optionally select the server socket, like lots of user Telnet programs already do 💜 and it's useful for implementers to consider a server Telnet program that can deal with both protocols, the way MIT-DMCG did (RFC 559) 🔥 this gives everyone a chance to test and debug the new programs without messing with normal use 🧚

During January we're surveying the technical liaisons to figure out where the Telnet implementations are at 🌈 once we determine the implementations have reached a point where the changeover can happen without disrupting user services, the technical liaisons will be notified 🫶

in light of this change to the Telnet schedule, the FTP schedule is also modified 🍓 New FTP implementations are to be ready by 1 Feb 74 (as before), but they'll keep using 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 ]