[ih] Why FTP uses two ports?

Louis Mamakos louie at transsys.com
Thu Jun 21 06:24:30 PDT 2012


On Jun 21, 2012, at 6:51 AM, John Day wrote:
> 
> 
> BTW, I know that many textbooks and well-known 
> professors describe Telnet as a remote login 
> protocol.  It isn't.  It is a terminal device 
> driver protocol.  This is why this class of 
> protocols use to be called virtual terminal 
> protocols.  Remote log in is one application 
> built using Telnet.  Telnet was also used in FTP, 
> RJE, CCNRJE, and SMTP.
> 
> Take care,
> John

Strictly speaking, at least SMTP did not use the
TELNET protocol, as FTP did for it's control connection.  I
recall implemented IAC escaping when I built my FTP server's
control connection handling. I don't know about RJE,
CONRJE personally.

Louis Mamakos



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