telnetd(1M)                                                     telnetd(1M)

NAME
     telnetd, in.telnetd - DARPA TELNET protocol server

SYNOPSIS
     in.telnetd

DESCRIPTION
     telnetd is a server which supports the DARPA standard TELNET virtual
     terminal protocol. telnetd is invoked by the internet server [see
     inetd(1M)], normally for requests to connect to the TELNET port as
     indicated by the /etc/services file [see services(4)].

     telnetd operates by allocating a pseudo-terminal device for a client,
     then creating a login process which has the slave side of the pseudo-
     terminal as its standard input, output, and error. telnetd manipulates
     the master side of the pseudo-terminal, implementing the TELNET proto-
     col and passing characters between the remote client and the login
     process.

     When a TELNET session is started up, telnetd sends TELNET options to
     the client side indicating a willingness to do remote echo of charac-
     ters, to suppress go ahead, and to receive terminal type information
     from the remote client. If the remote client is willing, the remote
     terminal type is propagated in the environment of the created login
     process. The pseudo-terminal allocated to the client is configured to
     operate in "cooked" mode, and with XTABS, ICRNL, and ONLCR enabled
     [see termio(7)].

     telnetd is willing to do: echo, binary, suppress go ahead, and timing
     mark. telnetd is willing to have the remote client do: binary, termi-
     nal type, and suppress go ahead.

NOTES
     Some TELNET commands are only partially implemented.

     The TELNET protocol allows for the exchange of the number of lines and
     columns on the user's terminal, but telnetd doesn't make use of them.

     Binary mode has no common interpretation except between similar
     operating systems.

     The terminal type name received from the remote client is converted to
     lower case.

     The packet interface to the pseudo-terminal should be used for more
     intelligent flushing of input and output queues.

     telnetd never sends TELNET go ahead commands.

     telnetd can only support 64 pseudo-terminals.





Page 1                       Reliant UNIX 5.44                Printed 11/98

telnetd(1M)                                                     telnetd(1M)

SEE ALSO
     telnet(1).

     Postel, Jon, and Joyce Reynolds, Telnet Protocol Specification, RFC
     854, Network Information Center, SRI International, Menlo Park,
     Calif., May 1983.
















































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