Re: TELNET question

[[e-mail]]

  *> 
  *>    The question boils down to this:  Is a TELNET user only a proper implementation
  *>    of TELNET when the server port is 23?         ^^^^
  *> 
  *> You mean "client" where you wrote "user", right?
  *> 

Just to keep the record straight, the Telnet protocol was designed in
the early ARPAnet years when the terms "user" and "server" were in use;
I don't think that the term "client" had been invented yet.  The
preferred terminology is "User Telnet implementation" [RFC-1123],
although if you look back over the past 20 years of email discussion of
Telnet, you will find lots of usage of the more informal but ambiguous
term "Telnet user".

  *> That's really the crux of the matter.  The RFC's document the telnet
  *> *protocol*.  The question is when is the client obligated to follow the
  *> telnet protocol, and when is it not so obligated?
  *> 
  *>    The consequences are as follows:
  *> 
  *>    1.  No - TELNET is TELNET regardless of the server port :
  *>        Then any implementation which defaults to LF as a newline (such as
  *>        unix-based hosts) is not conformant to the TELNET standard.
  *>        (Possible interoperability problems).
  *> 
  *>    2.  Yes - TELNET is only TELNET when the server port is 23:
  *>        Not only did the tester send the wrong character(s), but its testing
  *>        methodology is seriously flawed; the use of the non-standard port
  *>        means that it is not truly testing TELNET, whether it had sent the
  *>        correct newline code or not.
  *> 
  *> Give that the IANA has specified that the port for telnet service is 23,
  *> I would tend towards option 2.  The fair way to test things is on the
  *> original port.
  *> 
  *> I think it is a "local matter" what the telnet client does going to
  *> other ports.  Ideally, there should be a switch that indicates where or
  *> not the client should be initiating the options negotiations.  How that
  *> switch is offered ought to be presented to the user is a UI issue, and
  *> not one that should be addressed in a protocol specification.  (And,
  *> indeed, there is such a switch on the Berkeley reference implementation;
  *> you simply prefix the port number that you specify with a '-'
  *> character.)
  *> 
  *> 						- Ted
  *> 

Both FTP and SMTP both use "telnet streams", with CRLF as end of line.
I would expect that 1. was the right answer, as a question of philosophy.
Of course, reality sometimes intervenes...

Bob Braden