RFC 857 (rfc857) - Page 1 of 5
Telnet Echo Option
Alternative Format: Original Text Document
Network Working Group J. Postel
Request for Comments: 857 J. Reynolds
ISI
Obsoletes: NIC 15390 May 1983
TELNET ECHO OPTION
This RFC specifies a standard for the ARPA Internet community. Hosts on
the ARPA Internet are expected to adopt and implement this standard.
1. Command Name and Code
ECHO 1
2. Command Meanings
IAC WILL ECHO
The sender of this command REQUESTS to begin, or confirms that it
will now begin, echoing data characters it receives over the
TELNET connection back to the sender of the data characters.
IAC WON'T ECHO
The sender of this command DEMANDS to stop, or refuses to start,
echoing the data characters it receives over the TELNET connection
back to the sender of the data characters.
IAC DO ECHO
The sender of this command REQUESTS that the receiver of this
command begin echoing, or confirms that the receiver of this
command is expected to echo, data characters it receives over the
TELNET connection back to the sender.
IAC DON'T ECHO
The sender of this command DEMANDS the receiver of this command
stop, or not start, echoing data characters it receives over the
TELNET connection.
3. Default
WON'T ECHO
DON'T ECHO
No echoing is done over the TELNET connection.
4. Motivation for the Option
Postel & Reynolds